Cleveland Clinic Journal of Medicine

Despite guidelines recommending low-dose oral glucocorticoids over high-dose intravenous (IV) glucocorticoids for inpatient management of acute exacerbations of chronic obstructive pulmonary disease (COPD), we have observed that most patients still receive high-dose IV therapy before being transitioned to low-dose oral therapy at discharge. Clinical inertia undoubtedly plays a significant role in the slow adoption of new recommendations, but in this era of evidence-based practice, the unfortunate lack of data supporting low over high steroid doses for acute exacerbations of COPD also contributes to hesitancy of physicians.

A SIGNIFICANT AND GROWING BURDEN

COPD is one of the most common pulmonary conditions managed by hospitalists today, and by the year 2030, it is predicted to become the third leading cause of death worldwide.¹

COPD is also a significant economic burden, costing $50 billion to manage in the United States, most of that from the cost of lengthy hospital stays.² COPD patients have 1 to 2 exacerbations per year.³ Bacterial and viral infections are responsible for most exacerbations, and 15% to 20% are from air pollution and other environmental causes of airway inflammation.³

CHALLENGES TO CHANGING PRACTICE

Glucocorticoids are the gold standard for treatment of acute exacerbations of COPD. It is well-documented that compared with placebo, glucocorticoids reduce mortality risk, length of hospital stay, and exacerbation recurrence after 1 month.⁴ And while high-dose IV steroid therapy has been the standard approach, oral administration has been found to be noninferior to IV administration with regard to treatment and length of hospital stay.⁵

While adverse effects are more common at higher doses, the optimal dose and duration of systemic glucocorticoid therapy for acute exacerbations of COPD are still largely at the discretion of the physician. The 2019 report of the Global Initiative for Chronic Obstructive Lung Disease (GOLD) recommends low doses (40 mg) for no more than 5 to 7 days for exacerbations, based on reports that showed no worse outcomes with low-dose oral than with high-dose IV therapy.^6,7 (In the 2010 study by Lindenauer et al,⁷ 92% of nearly 80,000 patients received high-dose IV steroids, reflecting standard practice at that time.) However, the GOLD guidelines do not address mortality rates, length of stay, or readmission rates for either approach, as they are devised to direct treatment in patients with stable mild to advanced COPD, not exacerbations.

Mortality rates

Aksoy et al⁸ established that, compared with placebo, low-dose steroids improved mortality rates in a subset of patients with acute exacerbations, specifically those with eosinophilic exacerbations. This study followed the 2013 Reduction in the Use of Corticosteroids in Exacerbated COPD (REDUCE) trial, which showed mortality rates were not lower with 14 days of low-dose prednisone treatment than with 5 days.9

Length of hospital stay

With regard to length of hospital stay, in 2011 Wang et al¹⁰ found no statistically significant difference between high- and low-dose steroid treatment.However, the REDUCE trial found that low-dose steroids shortened the median length of stay by 1 day compared with placebo.⁹

Hospital readmission rates

The REDUCE trial found no statistically significant difference in readmission rates when comparing 5 days of low-dose treatment vs 14 days.⁹ However, Aksoy et al⁸ found that readmission rates were significantly lower with low-dose treatment than with placebo.No study has yet examined readmission rates with high-dose vs low-dose steroid treatment.

What does the evidence tell us?

Low-dose oral glucocorticoid treatment shows definitive benefits in terms of lower mortality rates, shorter hospital length of stay, and lower readmission rates vs placebo in the treatment of acute exacerbations of COPD. Furthermore, a 14-day course is no better than 5 days in terms of mortality rates. And low-dose glucocorticoid treatment shows reduced mortality rates in addition to similar hospital length of stay when compared to high-dose glucocorticoid treatment.

Together, these findings lend credibility to the current GOLD recommendations. However, we have observed that in sharp contrast to the leading clinical guidelines, most patients hospitalized for acute exacerbations of COPD are still treated initially with high-dose IV corticosteroids. Why?

Obstacles that perpetuate the use of high-dose over low-dose treatment include lack of knowledge of glucocorticoid pharmacokinetics among clinicians, use of outdated order sets, and the reflex notion that more of a drug is more efficacious in its desired effect. In addition, administrative obstacles include using high-dose IV steroids to justify an inpatient stay or continued hospitalization.

COUNTERING THE OBSTACLES: THE HOSPITALIST’S ROLE

To counter these obstacles, we propose standardization of inpatient treatment of acute exacerbations of COPD to include initial low-dose steroid treatment in accordance with the most recent GOLD guidelines.⁶ This would benefit the patient by reducing undesirable effects of high-dose steroids, and at the same time reduce the economic burden of managing COPD exacerbations. Considering the large number of hospitalizations for COPD exacerbation each year, hospitalists can play a large role in this effort by routinely incorporating the low-dose steroid recommendation into their clinical practice.

Despite guidelines recommending low-dose oral glucocorticoids over high-dose intravenous (IV) glucocorticoids for inpatient management of acute exacerbations of chronic obstructive pulmonary disease (COPD), we have observed that most patients still receive high-dose IV therapy before being transitioned to low-dose oral therapy at discharge. Clinical inertia undoubtedly plays a significant role in the slow adoption of new recommendations, but in this era of evidence-based practice, the unfortunate lack of data supporting low over high steroid doses for acute exacerbations of COPD also contributes to hesitancy of physicians.

A SIGNIFICANT AND GROWING BURDEN

COPD is one of the most common pulmonary conditions managed by hospitalists today, and by the year 2030, it is predicted to become the third leading cause of death worldwide.¹

COPD is also a significant economic burden, costing $50 billion to manage in the United States, most of that from the cost of lengthy hospital stays.² COPD patients have 1 to 2 exacerbations per year.³ Bacterial and viral infections are responsible for most exacerbations, and 15% to 20% are from air pollution and other environmental causes of airway inflammation.³

CHALLENGES TO CHANGING PRACTICE

Glucocorticoids are the gold standard for treatment of acute exacerbations of COPD. It is well-documented that compared with placebo, glucocorticoids reduce mortality risk, length of hospital stay, and exacerbation recurrence after 1 month.⁴ And while high-dose IV steroid therapy has been the standard approach, oral administration has been found to be noninferior to IV administration with regard to treatment and length of hospital stay.⁵

While adverse effects are more common at higher doses, the optimal dose and duration of systemic glucocorticoid therapy for acute exacerbations of COPD are still largely at the discretion of the physician. The 2019 report of the Global Initiative for Chronic Obstructive Lung Disease (GOLD) recommends low doses (40 mg) for no more than 5 to 7 days for exacerbations, based on reports that showed no worse outcomes with low-dose oral than with high-dose IV therapy.^6,7 (In the 2010 study by Lindenauer et al,⁷ 92% of nearly 80,000 patients received high-dose IV steroids, reflecting standard practice at that time.) However, the GOLD guidelines do not address mortality rates, length of stay, or readmission rates for either approach, as they are devised to direct treatment in patients with stable mild to advanced COPD, not exacerbations.

Mortality rates

Aksoy et al⁸ established that, compared with placebo, low-dose steroids improved mortality rates in a subset of patients with acute exacerbations, specifically those with eosinophilic exacerbations. This study followed the 2013 Reduction in the Use of Corticosteroids in Exacerbated COPD (REDUCE) trial, which showed mortality rates were not lower with 14 days of low-dose prednisone treatment than with 5 days.9

Length of hospital stay

With regard to length of hospital stay, in 2011 Wang et al¹⁰ found no statistically significant difference between high- and low-dose steroid treatment.However, the REDUCE trial found that low-dose steroids shortened the median length of stay by 1 day compared with placebo.⁹

Hospital readmission rates

The REDUCE trial found no statistically significant difference in readmission rates when comparing 5 days of low-dose treatment vs 14 days.⁹ However, Aksoy et al⁸ found that readmission rates were significantly lower with low-dose treatment than with placebo.No study has yet examined readmission rates with high-dose vs low-dose steroid treatment.

What does the evidence tell us?

Low-dose oral glucocorticoid treatment shows definitive benefits in terms of lower mortality rates, shorter hospital length of stay, and lower readmission rates vs placebo in the treatment of acute exacerbations of COPD. Furthermore, a 14-day course is no better than 5 days in terms of mortality rates. And low-dose glucocorticoid treatment shows reduced mortality rates in addition to similar hospital length of stay when compared to high-dose glucocorticoid treatment.

Together, these findings lend credibility to the current GOLD recommendations. However, we have observed that in sharp contrast to the leading clinical guidelines, most patients hospitalized for acute exacerbations of COPD are still treated initially with high-dose IV corticosteroids. Why?

Obstacles that perpetuate the use of high-dose over low-dose treatment include lack of knowledge of glucocorticoid pharmacokinetics among clinicians, use of outdated order sets, and the reflex notion that more of a drug is more efficacious in its desired effect. In addition, administrative obstacles include using high-dose IV steroids to justify an inpatient stay or continued hospitalization.

COUNTERING THE OBSTACLES: THE HOSPITALIST’S ROLE

To counter these obstacles, we propose standardization of inpatient treatment of acute exacerbations of COPD to include initial low-dose steroid treatment in accordance with the most recent GOLD guidelines.⁶ This would benefit the patient by reducing undesirable effects of high-dose steroids, and at the same time reduce the economic burden of managing COPD exacerbations. Considering the large number of hospitalizations for COPD exacerbation each year, hospitalists can play a large role in this effort by routinely incorporating the low-dose steroid recommendation into their clinical practice.

Despite guidelines recommending low-dose oral glucocorticoids over high-dose intravenous (IV) glucocorticoids for inpatient management of acute exacerbations of chronic obstructive pulmonary disease (COPD), we have observed that most patients still receive high-dose IV therapy before being transitioned to low-dose oral therapy at discharge. Clinical inertia undoubtedly plays a significant role in the slow adoption of new recommendations, but in this era of evidence-based practice, the unfortunate lack of data supporting low over high steroid doses for acute exacerbations of COPD also contributes to hesitancy of physicians.

A SIGNIFICANT AND GROWING BURDEN

COPD is one of the most common pulmonary conditions managed by hospitalists today, and by the year 2030, it is predicted to become the third leading cause of death worldwide.¹

COPD is also a significant economic burden, costing $50 billion to manage in the United States, most of that from the cost of lengthy hospital stays.² COPD patients have 1 to 2 exacerbations per year.³ Bacterial and viral infections are responsible for most exacerbations, and 15% to 20% are from air pollution and other environmental causes of airway inflammation.³

CHALLENGES TO CHANGING PRACTICE

Glucocorticoids are the gold standard for treatment of acute exacerbations of COPD. It is well-documented that compared with placebo, glucocorticoids reduce mortality risk, length of hospital stay, and exacerbation recurrence after 1 month.⁴ And while high-dose IV steroid therapy has been the standard approach, oral administration has been found to be noninferior to IV administration with regard to treatment and length of hospital stay.⁵

While adverse effects are more common at higher doses, the optimal dose and duration of systemic glucocorticoid therapy for acute exacerbations of COPD are still largely at the discretion of the physician. The 2019 report of the Global Initiative for Chronic Obstructive Lung Disease (GOLD) recommends low doses (40 mg) for no more than 5 to 7 days for exacerbations, based on reports that showed no worse outcomes with low-dose oral than with high-dose IV therapy.^6,7 (In the 2010 study by Lindenauer et al,⁷ 92% of nearly 80,000 patients received high-dose IV steroids, reflecting standard practice at that time.) However, the GOLD guidelines do not address mortality rates, length of stay, or readmission rates for either approach, as they are devised to direct treatment in patients with stable mild to advanced COPD, not exacerbations.

Mortality rates

Aksoy et al⁸ established that, compared with placebo, low-dose steroids improved mortality rates in a subset of patients with acute exacerbations, specifically those with eosinophilic exacerbations. This study followed the 2013 Reduction in the Use of Corticosteroids in Exacerbated COPD (REDUCE) trial, which showed mortality rates were not lower with 14 days of low-dose prednisone treatment than with 5 days.9

Length of hospital stay

With regard to length of hospital stay, in 2011 Wang et al¹⁰ found no statistically significant difference between high- and low-dose steroid treatment.However, the REDUCE trial found that low-dose steroids shortened the median length of stay by 1 day compared with placebo.⁹

Hospital readmission rates

The REDUCE trial found no statistically significant difference in readmission rates when comparing 5 days of low-dose treatment vs 14 days.⁹ However, Aksoy et al⁸ found that readmission rates were significantly lower with low-dose treatment than with placebo.No study has yet examined readmission rates with high-dose vs low-dose steroid treatment.

What does the evidence tell us?

Low-dose oral glucocorticoid treatment shows definitive benefits in terms of lower mortality rates, shorter hospital length of stay, and lower readmission rates vs placebo in the treatment of acute exacerbations of COPD. Furthermore, a 14-day course is no better than 5 days in terms of mortality rates. And low-dose glucocorticoid treatment shows reduced mortality rates in addition to similar hospital length of stay when compared to high-dose glucocorticoid treatment.

Together, these findings lend credibility to the current GOLD recommendations. However, we have observed that in sharp contrast to the leading clinical guidelines, most patients hospitalized for acute exacerbations of COPD are still treated initially with high-dose IV corticosteroids. Why?

Obstacles that perpetuate the use of high-dose over low-dose treatment include lack of knowledge of glucocorticoid pharmacokinetics among clinicians, use of outdated order sets, and the reflex notion that more of a drug is more efficacious in its desired effect. In addition, administrative obstacles include using high-dose IV steroids to justify an inpatient stay or continued hospitalization.

COUNTERING THE OBSTACLES: THE HOSPITALIST’S ROLE

To counter these obstacles, we propose standardization of inpatient treatment of acute exacerbations of COPD to include initial low-dose steroid treatment in accordance with the most recent GOLD guidelines.⁶ This would benefit the patient by reducing undesirable effects of high-dose steroids, and at the same time reduce the economic burden of managing COPD exacerbations. Considering the large number of hospitalizations for COPD exacerbation each year, hospitalists can play a large role in this effort by routinely incorporating the low-dose steroid recommendation into their clinical practice.

Information was omitted from Table 1 on page 596 of the article, Makin V, Lansang MC. Diabetes management: beyond hemoglobin A_1c (Cleve Clin J Med 2019; 86[9]:595–600, doi:10.3949/ccjm.86a.18031).

The sodium-glucose cotransporter 2 (SGLT2) inhibitors pose a low risk of hypoglyemia, and that should have been noted in the table. The corrected table appears below and online.

Information was omitted from Table 1 on page 596 of the article, Makin V, Lansang MC. Diabetes management: beyond hemoglobin A_1c (Cleve Clin J Med 2019; 86[9]:595–600, doi:10.3949/ccjm.86a.18031).

The sodium-glucose cotransporter 2 (SGLT2) inhibitors pose a low risk of hypoglyemia, and that should have been noted in the table. The corrected table appears below and online.

Information was omitted from Table 1 on page 596 of the article, Makin V, Lansang MC. Diabetes management: beyond hemoglobin A_1c (Cleve Clin J Med 2019; 86[9]:595–600, doi:10.3949/ccjm.86a.18031).

The sodium-glucose cotransporter 2 (SGLT2) inhibitors pose a low risk of hypoglyemia, and that should have been noted in the table. The corrected table appears below and online.

Autoimmune rheumatic diseases increase the risk of cardiovascular disease. In rheumatoid arthritis and systemic lupus erythematosus, the risk is driven primarily by the inflammatory milieu, leading to accelerated coronary and cerebrovascular atherosclerosis independent of traditional atherosclerotic risk factors.^1–3 The extent of cardiovascular involvement in other rheumatologic diseases has been less well characterized but is an area of growing interest.

In this review, we focus on the cardiovascular complications of systemic sclerosis and review recommendations for monitoring these patients in clinical practice.

SYSTEMIC SCLEROSIS, AN AUTOIMMUNE RHEUMATIC DISEASE

Systemic sclerosis is an autoimmune rheumatic disease characterized by excessive extracellular matrix deposition leading to diffuse fibrosis, endothelial dysfunction, and microvascular injury. It is most common in North America, Southern Europe, and Australia,^4,5 and it affects women more than men in ratios ranging from 3:1 to 14:1.⁶ The mean age at diagnosis is around 50. 

The disease can affect the lungs (interstitial lung disease and pulmonary hypertension), the heart, the kidneys, and the gastrointestinal tract.

Systemic sclerosis has 2 main subtypes: limited cutaneous systemic sclerosis, formerly called CREST syndrome) and diffuse cutaneous systemic sclerosis. The limited cutaneous subtype is characterized by tightening of the skin of the distal extremities (below the elbows and knees) and face, while diffuse cutaneous systemic sclerosis can manifest as more extensive skin tightening also involving proximal extremities and the trunk. Both subtypes can have an effect on the cardiovascular system.

Some cardiovascular risk factors such as dyslipidemia, diabetes mellitus, and high body mass index are less common in patients with systemic sclerosis than in patients with rheumatoid arthritis, while the rates of arterial hypertension, smoking, chronic obstructive pulmonary disease, osteoporosis, and neoplasms are similar between the 2 groups.⁷

HEART INVOLVEMENT HAS SERIOUS CONSEQUENCES

Overt cardiac involvement in systemic sclerosis is associated with a mortality rate of up to 70% over 5 years,^8,9 and about one-fourth of deaths in patients with systemic sclerosis are from cardiac causes.^10,11 Studies in Europe^10,12 showed that many patients with systemic sclerosis have cardiac involvement detectable by magnetic resonance imaging even if they do not have clinical disease. Pulmonary arterial hypertension (PAH) is a complication of both subtypes of systemic sclerosis and portends a higher risk of death.⁸

Thus, it is critical for clinicians to understand the potential comorbid conditions associated with systemic sclerosis, particularly the cardiovascular ones, and to work closely with cardiologists to help optimize the evaluation and management.

MECHANISMS OF CARDIAC DISEASE IN SYSTEMIC SCLEROSIS

Abnormal vasoreactivity, a consequence of an imbalance between endothelium-derived vasoconstrictors and vasodilators, defective angiogenesis, and endothelial injury, leads to tissue ischemia and vascular endothelial growth factor expression, which initiates injury and fibrosis in the myocardium and in other organs.^14–17 Fibrosis involves the myocardium, pericardium, and conduction system.^13,18

Myocardial involvement in systemic sclerosis is thought to be due mainly to abnormal vasoreactivity and microvascular abnormalities such as transient coronary artery spasm leading to repeated focal ischemia.^19,20 Abnormal vasoreactivity has been demonstrated during cardiac catheterization²¹: while mean coronary sinus blood flow in systemic sclerosis patients was normal at rest, vasodilator reserve was significantly reduced in patients with diffuse cutaneous systemic sclerosis after maximal vasodilation with dipyridamole. Additionally, endomyocardial biopsy showed fibrosis and concentric intimal hypertrophy with normal epicardial coronary arteries.²¹

More research into other mechanisms of cardiovascular disease in systemic sclerosis is needed to allow for better preventive care for these patients.

Systemic sclerosis can be associated with World Health Organization (WHO) groups 1, 2, 3, and 4 pulmonary hypertension. WHO group 1, called pulmonary arterial hypertension or PAH, is one of the most common cardiac complications of systemic sclerosis, with a reported prevalence as high as 12%.²² Systemic sclerosis-associated PAH carries a high mortality rate, with a mean survival of only 3 years.²³

With advances in treatments for other complications of systemic sclerosis, the percentage of systemic sclerosis patients who die of PAH has increased from 6% to 33%.²⁴

Compared with patients with idiopathic PAH, those with systemic sclerosis get less of a response from therapy and have poorer outcomes despite lower mean pulmonary artery pressures and similar reductions in cardiac index. However, recent studies have suggested that with aggressive treatment, patients with systemic sclerosis-related PAH can achieve outcomes similar to those with idiopathic PAH.²⁵ Thus, recognizing this condition early is imperative.

Pulmonary arterial hypertension defined

PAH is defined as the combination of all of the following²⁶:

• Mean pulmonary artery pressure > 20 mm Hg at rest
• Normal pulmonary capillary wedge pressure (≤ 15 mm Hg)
• Pulmonary vascular resistance ≥ 3 Wood units on right heart catheterization.

Other causes of pulmonary hypertension such as interstitial lung disease, chronic pulmonary thromboembolic disease, and left heart disease must be excluded.^24,27

Remodeling in the pulmonary arteries

The events that lead to PAH in systemic sclerosis remain unclear but are believed to involve initial inflammation or endothelial injury that leads to a dysequilibrium between proliferative mediators and antiproliferative vasodilators. This dysequilibrium, along with endothelial dysfunction, causes an obliterative vasculopathy in the pulmonary artery branches and arterioles. Sympathetic overactivity, hypoxemia, and ischemia-reperfusion injury additionally promote vascular proliferation, fibrosis, and remodeling, leading to increased pulmonary vascular resistance, PAH, and increased right ventricular pressures.^23,27

The subtype of systemic sclerosis is an important factor in the development and progression of PAH. PAH appears to be the major cause of death in limited cutaneous systemic sclerosis, while interstitial lung disease is the major cause of death in diffuse cutaneous systemic sclerosis.²⁸

Pulmonary arterial hypertension is a late complication of systemic sclerosis

Data from the South Australian Scleroderma Registry²⁹ revealed that PAH tends to be a late complication of systemic sclerosis, occurring around 20 years after disease onset. In this study of 608 patients, no patient with diffuse cutaneous systemic sclerosis developed PAH.

Systemic sclerosis-related PAH initially follows an indolent course with few symptoms until right ventricular function deteriorates. Early in the disease, patients may experience nonspecific symptoms of fatigue, lightheadedness, and dyspnea on exertion.²³ As it progresses, they tend to have worsening dyspnea and may experience exertional syncope, palpitations, and chest pain.

Physical findings may suggest elevated right ventricular pressure and right ventricular failure; these include a loud P2, a prominent jugular a wave, a tricuspid regurgitant murmur, jugular venous distention, and lower-extremity edema.²⁷

Screening for pulmonary arterial hypertension in systemic sclerosis

Significant signs and symptoms usually occur late in the disease; thus, it is important to appropriately screen patients who are at risk so that they can begin aggressive treatment.

Doppler echocardiography is recommended by European and American guidelines to screen for PAH in patients who have systemic sclerosis, and most agree that screening is appropriate even if the patient has no symptoms.³⁰ European consensus documents recommend that transthoracic echocardiography be done annually for the first 5 years of disease and be continued every year in patients at high risk, ie, those with anticentromere antibodies, anti-Th/To antibodies, or interstitial lung disease. Patients not at high risk of developing pulmonary hypertension should also have regular transthoracic echocardiography, though the exact timing is not defined.³¹ While American societies have not issued corresponding recommendations, many experts follow the European recommendations.

Worrisome features on echocardiography in asymptomatic patients should be followed up with right heart catheterization to assess mean right ventricular pressure. These include:

• Estimated right ventricular systolic pressure ≥ 40 mm Hg
• Tricuspid regurgitant jet velocity > 2.8 m/s
• Right atrial enlargement > 53 mm
• Right ventricular enlargement (mid-cavity dimension > 35 mm).³²

Although echocardiography is the most common form of screening, it gives only an estimate of right ventricular systolic pressure, which is imprecise. Other noninvasive markers are helpful and necessary to appropriately screen this population.

Diffusion capacity. The Itinerair study³³ found that a diffusing capacity for carbon monoxide (D_^LCO) of 60% or higher has a high specificity in excluding PAH.

Uric acid has been found to be elevated in patients with systemic sclerosis-related PAH, and levels inversely correlate with 6-minute walking distance.³⁴

Other predictors. N-terminal pro-B-type natriuretic peptide (NT-proBNP), left atrial volume, and the right ventricular myocardial performance index have also been shown to be independent predictors of PAH in patients with systemic sclerosis.³⁵

An algorithm. The DETECT study³⁶ enrolled patients at increased risk who had had systemic sclerosis longer than 3 years and a D_^LCO less than 60%. The investigators developed a 2-step algorithm to determine which patients should be referred for right heart catheterization to try to detect PAH earlier while minimizing the number of missed diagnoses and optimizing the use of invasive diagnostic right heart catheterization.

The first step was to assess serum values of anticentromere antibodies, NT-proBNP, and urate, and clinical features (telangiectasias), forced vital capacity, and electrocardiographic changes of right axis deviation to derive a prediction score. The second step was to assess surface echocardiographic features of the right atrial area and tricuspid regurgitation velocity.

This approach led to right heart catheterization in 62% of patients and was associated with a false-negative rate of 4%. Importantly, of the patients with PAH, 1 in 5 had no symptoms, and 33% had tricuspid regurgitation velocity less than 2.8 m/s. No single measurement performed well in isolation in this study.³⁷

Thus, we recommend that, in addition to routine surface echocardiography, a multimodal approach be used that includes laboratory testing, clinical features, and electrocardiographic findings when screening this high-risk patient population.

Although macrovascular disease has not typically been regarded as a significant systemic feature in systemic sclerosis, myocardial infarction and stroke are more common in patients with systemic sclerosis than in controls.^38,39

Coronary artery disease in systemic sclerosis

Man et al³⁸ reported that the incidence of myocardial infarction in patients with systemic sclerosis was 4.4 per 1,000 persons per year, and the incidence of stroke was 4.8 per 1,000 persons per year, compared with 2.5 per 1,000 persons per year for both myocardial infarction and stroke in healthy controls matched for age, sex, and time of entry.

The Australian Scleroderma Cohort Study³⁹ found a 3-fold higher prevalence of coronary artery disease in systemic sclerosis patients than in controls after factoring in traditional risk factors.

Aviña-Zubieta et al,⁴⁰ in a cohort of 1,239 systemic sclerosis patients, estimated a hazard ratio (HR) of 3.49 for myocardial infarction and 2.35 for stroke compared with age- and sex-matched controls. Not all of these events were related to macrovascular atherosclerosis—vasospasm and microvascular ischemia may have played significant roles in the etiology of clinical manifestations.

Studies of coronary atherosclerosis in systemic sclerosis are limited. An autopsy study⁴¹ of 58 patients with systemic sclerosis and 58 controls matched for age, sex, and ethnicity found that the prevalence of atherosclerosis of small coronary arteries and arterioles was significantly higher in systemic sclerosis patients than in controls (17% vs 2%, P < .01). However, the prevalence of medium-vessel coronary atherosclerosis was similar (48% vs 43%).

Why patients with systemic sclerosis develop atherosclerosis has not yet been determined. Traditional risk factors such as hypertension, dyslipidemia, diabetes mellitus, and obesity are typically no more prevalent in systemic sclerosis patients than in controls,^38,42 and thus do not explain the increased risk of atherosclerotic cardiovascular disease. There is some evidence that novel markers of atherosclerotic risk such as homocysteine,⁴³ lipoprotein[a],⁴⁴ and oxidized low-density lipoprotein⁴⁵ are more prevalent in systemic sclerosis, but these results have not been substantiated in more extensive studies.

Peripheral artery disease

It remains unclear whether peripheral artery disease is more prevalent in systemic sclerosis patients than in controls.

Individual studies have shown mixed results in comparing carotid artery stenosis between systemic sclerosis patients and controls using carotid duplex ultrasonography,⁴⁶ the ankle-brachial index,^46–48 carotid intima-media thickness,^49–54 and brachial flow-mediated dilation.^{51,53,55–58} A meta-analysis found that the carotid intima and media are significantly thicker in systemic sclerosis patients than in controls,⁵⁹ and the magnitude of difference is similar to that in other groups at increased cardiovascular risk, such as those with rheumatoid arthritis, diabetes, and familial hypercholesterolemia.^60–63

A meta-analysis of brachial artery findings showed significantly lower flow-mediated dilation in systemic sclerosis patients than in controls.⁶⁴

Overall, given the inconsistency of study results, systemic sclerosis patients should be screened and managed as in other patients with peripheral artery disease, but the clinician should be aware that there may be a higher risk of peripheral artery disease in these patients.

RIGHT AND LEFT VENTRICULAR DYSFUNCTION

Many patients with systemic sclerosis have right ventricular dysfunction as a consequence of PAH.⁶⁵ It is important to detect diastolic dysfunction in this population, as it may be an even stronger predictor of death than pulmonary hypertension on right heart catheterization (HR 3.7 vs 2.0).⁶⁶

Fewer patients have left ventricular dysfunction. In a multicenter study of 570 systemic sclerosis patients, only 1.4% had left ventricular systolic dysfunction on echocardiography, though 22.6% had left ventricular hypertrophy and 17.7% had left ventricular diastolic dysfunction.⁶⁷ In the European League Against Rheumatism (EULAR) database, the prevalence of reduced left ventricular ejection fraction was 5.4%.⁶⁸

Though traditional echocardiographic screening suggests the prevalence of left ventricular dysfunction in systemic sclerosis patients is low, cardiac magnetic resonance imaging (MRI) may be more sensitive than echocardiography for detecting subclinical myocardial involvement. Cardiac MRI has been shown to detect evidence of myocardial pathology (increased T2 signal, left ventricular thinning, pericardial effusion, reduced left ventricular and right ventricular ejection fraction, left ventricular diastolic dysfunction, and delayed myocardial contrast enhancement) in up to 75% of systemic sclerosis cases studied.⁶⁹

Patients with systemic sclerosis should already be undergoing echocardiography every year to screen for PAH, and screening should also include tissue Doppler imaging to detect various forms of left and right ventricular systolic and diastolic dysfunction that may not be clinically apparent.

Though cardiac MRI can provide useful additional information, it is not currently recommended for routine screening in patients with systemic sclerosis.

Patients with systemic sclerosis are prone to arrhythmias due to both conduction system fibrosis and myocardial damage.

Arrhythmias accounted for 6% of the deaths in the EULAR Scleroderma Trials and Research (EUSTAR) database.¹¹

In the Genetics Versus Environment in Scleroderma Outcome Study (GENISOS),⁷⁰  250 patients who had had systemic sclerosis for at least 3 years were studied during a period of approximately 6 years, during which there were 52 deaths, 29 of which were directly attributable to systemic sclerosis. Multivariable Cox modeling showed that 7 variables predicted mortality:

• Body mass index < 18.5 kg/m²
• Age ≥ 65
• Forced vital capacity < 50% predicted
• Systolic blood pressure ≥ 140 or diastolic blood pressure ≥ 90 mm Hg
• Pulmonary fibrosis
• Positive anticentromere antibodies
• Cardiac arrhythmias.

The hazard ratio for death in patients with arrhythmias in this model was 2.18 (95% CI 1.05–4.50, P = .035). Thus, finding arrhythmias in systemic sclerosis patients can provide important prognostic information.

While resting electrocardiography in patients with systemic sclerosis  most commonly shows sinus rhythm, 24-hour electrocardiographic monitoring has revealed nonsustained supraventricular and ventricular arrhythmias in a significant percentage.^71,72 Although difficult to quantify in routine practice, parameters controlled by the autonomic nervous system including heart rate variability and heart rate turbulence have been shown to be impaired in systemic sclerosis, and these measures are associated with an increased risk of malignant arrhythmias and sudden cardiac death.^73,74

Conduction abnormalities

Conduction abnormalities occur in one-fifth to one-third of patients with systemic sclerosis.^75,76 The most common abnormal conduction finding is left bundle branch block, followed by first-degree atrioventricular block. High-degree atrioventricular block is uncommon,⁷⁶ though a few case reports of complete heart block thought to be related to systemic sclerosis have been published.^77–79 An autopsy study showed that the conduction system is relatively spared from myocardial changes seen in systemic sclerosis patients, and thus it is speculated that the conduction disturbances are a consequence of damaged myocardium rather than damage to conduction tissue.⁸⁰

Given the array of electrophysiologic abnormalities that systemic sclerosis patients can have, it is critical to monitor all patients with routine (annual or biannual) electrocardiography; to take possible arrhythmia-related symptoms seriously; and to evaluate them with further workup such as Holter monitoring for 24 hours or even longer, event monitoring, exercise testing, or tilt-table testing.

PERICARDIAL DISEASE

Pericardial disease is clinically apparent in 5% to 16% of patients with systemic sclerosis⁸¹; patients with limited cutaneous systemic sclerosis have more pericardial disease than those with diffuse cutaneous systemic sclerosis (30% vs 16%).⁸² Forty-one percent of systemic sclerosis patients have been shown to have pericardial effusion by echocardiography,⁸¹ but the effusions are typically small and rarely cause tamponade, though tamponade is associated with a poor prognosis.

Large pericardial effusions can develop before skin thickening and diagnosis of systemic sclerosis.^81,83,84 Thus, systemic sclerosis should be considered in patients with pericardial effusions of unknown etiology.

In a small study,⁸⁵ the pericardial fluid in systemic sclerosis was typically exudative, with lactate dehydrogenase greater than 200 U/L, a fluid-serum lactate dehydrogenase ratio greater than 0.6, and a fluid-serum total protein ratio greater than 0.5.

Pericardial effusion can be a sign of impending scleroderma renal crisis,⁸⁶ and thus renal function should be carefully monitored in systemic sclerosis patients with pericardial effusion. Constrictive pericarditis and restrictive cardiomyopathy can rarely occur in systemic sclerosis and may more commonly present with symptoms.

Pericardial disease in systemic sclerosis should be treated in a standard fashion with nonsteroidal anti-inflammatory drugs. Corticosteroids are generally of limited benefit and should be avoided, especially in the setting of scleroderma renal crisis.⁸¹

VALVULAR HEART DISEASE

Based on limited studies, the prevalence of significant valvular heart disease in systemic sclerosis patients does not seem to be higher than that in the general population. While patients with systemic sclerosis and CREST syndrome (calcinosis, Raynaud phenomenon, esophageal dysmotility, sclerodactyly, and telangiectasia) have been shown to have a higher frequency of mitral valve prolapse and mild mitral regurgitation,^87,88 these abnormalities do not often progress in severity, and thus their clinical significance is limited.

It is important for physicians caring for patients with systemic sclerosis to be aware of its most common cardiac manifestations, including left and right ventricular systolic and diastolic dysfunction, pulmonary hypertension, conduction abnormalities, arrhythmias, and cardiomyopathy.

Look for volume overload

On clinical examination, assess for clinical markers of volume overload such as distended neck veins, peripheral edema, or an abnormal blood pressure response to the Valsalva maneuver. These findings should prompt measurement of NT-proBNP,⁸⁹ and may warrant prescription of a diuretic.

Electrocardiography to investigate arrhythmias

Electrocardiography should be done if patients describe symptoms of palpitations, and should also include continuous rhythm monitoring with Holter or event monitoring, depending on the frequency of symptoms. Otherwise, patients should routinely undergo electrocardiography once or twice a year.

Q waves are common in systemic sclerosis patients (especially those with diffuse cutaneous systemic sclerosis), notably in the precordial leads, and can occur without coronary artery disease.⁹⁰ Symptoms such as presyncope should be further investigated with Holter monitoring and tilt-table testing.

Assess, modify traditional risk factors

Subclinical atherosclerosis as detected by carotid intima-media thickness is as common in systemic sclerosis as in rheumatoid arthritis.⁶¹ However, traditional risk indices such as SCORE (Systematic Coronary Risk Evaluation), QRISK2, and the American College of Cardiology/American Heart Association indices may underestimate risk in patients who have systemic sclerosis.

Strict hypertension control should be the goal for all systemic sclerosis patients. Though there are no specific guidelines on which antihypertensive medications are preferred, calcium channel blockers or angiotensin II receptor blockers, which are typically used to treat systemic sclerosis-related Raynaud phenomenon, may be appropriate.

Statins reduce vascular complications and are generally well tolerated in patients with systemic sclerosis.^91,92 

Aspirin is not recommended for routine primary prevention in view of data suggesting that its benefits in diabetic patients are counterbalanced by increased bleeding risk.⁹³

Echocardiography to detect pulmonary arterial hypertension

At this time, guidelines for monitoring for cardiovascular manifestations in systemic sclerosis patients are limited. The only well-defined ones are European consensus guidelines, which suggest annual transthoracic echocardiography for the first 5 years after systemic sclerosis is diagnosed and continued annual screening in patients at risk of developing PAH.³¹

We support this strategy, with annual screening for the first 5 years followed by surveillance echocardiography every 2 to 3 years unless there is a high risk of PAH. Specific attention should be paid to right ventricular diastolic function, right atrial volume, and right ventricular myocardial performance index.

Emerging data suggest that the addition of global longitudinal strain of ventricles to  routine echocardiography can help detect subclinical cardiac risk.⁹⁴ Although further study is needed into the predictive value of global longitudinal strain, it is a low-cost and noninvasive addition to standard echocardiography that can help guide risk stratification, and thus we recommend that it be part of the echocardiographic examination for all systemic sclerosis patients.

Pulmonary function testing. In addition to screening for PAH with echocardiography, we recommend obtaining baseline pulmonary function tests, including D_^LCO, at the time systemic sclerosis is diagnosed, with repeat testing annually.

Magnetic resonance imaging

While echocardiography is the gold standard for monitoring systemic sclerosis patients, cardiovascular MRI may have a role in identifying those at higher risk of dangerous arrhythmias such as ventricular tachycardia and ventricular fibrillation. In addition to assessing ventricular function, MRI can detect myocardial inflammation, ischemia, and fibrosis that may predispose a patient to develop ventricular tachycardia or fibrillation.⁹⁵ Variables such as T1/T2 mapping, extracellular volume fraction, T2 signal ratio, and early vs late gadolinium enhancement can help identify patients who had past ventricular tachycardia or fibrillation.⁹⁶

Finding an increased risk of arrhythmias may prompt a conversation between the patient and the physician about the need for an implantable cardiac defibrillator.

If cardiac MRI is available and is reimbursed by the patient’s insurance carrier, physicians should strongly consider obtaining at least one baseline scan in systemic sclerosis patients to identify those at risk of highly fatal arrhythmias.

Teamwork is needed

Systemic sclerosis has not traditionally been associated with cardiovascular disease to the extent of other rheumatic conditions, but the cardiovascular system can be affected in various ways that can ultimately lead to an early death. These manifestations may be asymptomatic for long periods, and overt clinical disease portends a poorer prognosis.

Primary care physicians managing these patients should be aware of the cardiovascular complications of systemic sclerosis and should implement appropriate screening tests in conjunction with rheumatologists and cardiologists. It is also essential for general and subspecialty cardiologists to understand the broad spectrum of organ system involvement that can affect systemic sclerosis patients and to tailor their investigation and management recommendations accordingly. By designing a multidisciplinary approach to the treatment of systemic sclerosis patients, physicians can help to optimize cardiovascular risk modification in this vulnerable population.

Autoimmune rheumatic diseases increase the risk of cardiovascular disease. In rheumatoid arthritis and systemic lupus erythematosus, the risk is driven primarily by the inflammatory milieu, leading to accelerated coronary and cerebrovascular atherosclerosis independent of traditional atherosclerotic risk factors.^1–3 The extent of cardiovascular involvement in other rheumatologic diseases has been less well characterized but is an area of growing interest.

In this review, we focus on the cardiovascular complications of systemic sclerosis and review recommendations for monitoring these patients in clinical practice.

SYSTEMIC SCLEROSIS, AN AUTOIMMUNE RHEUMATIC DISEASE

Systemic sclerosis is an autoimmune rheumatic disease characterized by excessive extracellular matrix deposition leading to diffuse fibrosis, endothelial dysfunction, and microvascular injury. It is most common in North America, Southern Europe, and Australia,^4,5 and it affects women more than men in ratios ranging from 3:1 to 14:1.⁶ The mean age at diagnosis is around 50. 

The disease can affect the lungs (interstitial lung disease and pulmonary hypertension), the heart, the kidneys, and the gastrointestinal tract.

Systemic sclerosis has 2 main subtypes: limited cutaneous systemic sclerosis, formerly called CREST syndrome) and diffuse cutaneous systemic sclerosis. The limited cutaneous subtype is characterized by tightening of the skin of the distal extremities (below the elbows and knees) and face, while diffuse cutaneous systemic sclerosis can manifest as more extensive skin tightening also involving proximal extremities and the trunk. Both subtypes can have an effect on the cardiovascular system.

Some cardiovascular risk factors such as dyslipidemia, diabetes mellitus, and high body mass index are less common in patients with systemic sclerosis than in patients with rheumatoid arthritis, while the rates of arterial hypertension, smoking, chronic obstructive pulmonary disease, osteoporosis, and neoplasms are similar between the 2 groups.⁷

HEART INVOLVEMENT HAS SERIOUS CONSEQUENCES

Overt cardiac involvement in systemic sclerosis is associated with a mortality rate of up to 70% over 5 years,^8,9 and about one-fourth of deaths in patients with systemic sclerosis are from cardiac causes.^10,11 Studies in Europe^10,12 showed that many patients with systemic sclerosis have cardiac involvement detectable by magnetic resonance imaging even if they do not have clinical disease. Pulmonary arterial hypertension (PAH) is a complication of both subtypes of systemic sclerosis and portends a higher risk of death.⁸

Thus, it is critical for clinicians to understand the potential comorbid conditions associated with systemic sclerosis, particularly the cardiovascular ones, and to work closely with cardiologists to help optimize the evaluation and management.

MECHANISMS OF CARDIAC DISEASE IN SYSTEMIC SCLEROSIS

Abnormal vasoreactivity, a consequence of an imbalance between endothelium-derived vasoconstrictors and vasodilators, defective angiogenesis, and endothelial injury, leads to tissue ischemia and vascular endothelial growth factor expression, which initiates injury and fibrosis in the myocardium and in other organs.^14–17 Fibrosis involves the myocardium, pericardium, and conduction system.^13,18

Myocardial involvement in systemic sclerosis is thought to be due mainly to abnormal vasoreactivity and microvascular abnormalities such as transient coronary artery spasm leading to repeated focal ischemia.^19,20 Abnormal vasoreactivity has been demonstrated during cardiac catheterization²¹: while mean coronary sinus blood flow in systemic sclerosis patients was normal at rest, vasodilator reserve was significantly reduced in patients with diffuse cutaneous systemic sclerosis after maximal vasodilation with dipyridamole. Additionally, endomyocardial biopsy showed fibrosis and concentric intimal hypertrophy with normal epicardial coronary arteries.²¹

More research into other mechanisms of cardiovascular disease in systemic sclerosis is needed to allow for better preventive care for these patients.

Systemic sclerosis can be associated with World Health Organization (WHO) groups 1, 2, 3, and 4 pulmonary hypertension. WHO group 1, called pulmonary arterial hypertension or PAH, is one of the most common cardiac complications of systemic sclerosis, with a reported prevalence as high as 12%.²² Systemic sclerosis-associated PAH carries a high mortality rate, with a mean survival of only 3 years.²³

With advances in treatments for other complications of systemic sclerosis, the percentage of systemic sclerosis patients who die of PAH has increased from 6% to 33%.²⁴

Compared with patients with idiopathic PAH, those with systemic sclerosis get less of a response from therapy and have poorer outcomes despite lower mean pulmonary artery pressures and similar reductions in cardiac index. However, recent studies have suggested that with aggressive treatment, patients with systemic sclerosis-related PAH can achieve outcomes similar to those with idiopathic PAH.²⁵ Thus, recognizing this condition early is imperative.

Pulmonary arterial hypertension defined

PAH is defined as the combination of all of the following²⁶:

• Mean pulmonary artery pressure > 20 mm Hg at rest
• Normal pulmonary capillary wedge pressure (≤ 15 mm Hg)
• Pulmonary vascular resistance ≥ 3 Wood units on right heart catheterization.

Other causes of pulmonary hypertension such as interstitial lung disease, chronic pulmonary thromboembolic disease, and left heart disease must be excluded.^24,27

Remodeling in the pulmonary arteries

The events that lead to PAH in systemic sclerosis remain unclear but are believed to involve initial inflammation or endothelial injury that leads to a dysequilibrium between proliferative mediators and antiproliferative vasodilators. This dysequilibrium, along with endothelial dysfunction, causes an obliterative vasculopathy in the pulmonary artery branches and arterioles. Sympathetic overactivity, hypoxemia, and ischemia-reperfusion injury additionally promote vascular proliferation, fibrosis, and remodeling, leading to increased pulmonary vascular resistance, PAH, and increased right ventricular pressures.^23,27

The subtype of systemic sclerosis is an important factor in the development and progression of PAH. PAH appears to be the major cause of death in limited cutaneous systemic sclerosis, while interstitial lung disease is the major cause of death in diffuse cutaneous systemic sclerosis.²⁸

Pulmonary arterial hypertension is a late complication of systemic sclerosis

Data from the South Australian Scleroderma Registry²⁹ revealed that PAH tends to be a late complication of systemic sclerosis, occurring around 20 years after disease onset. In this study of 608 patients, no patient with diffuse cutaneous systemic sclerosis developed PAH.

Systemic sclerosis-related PAH initially follows an indolent course with few symptoms until right ventricular function deteriorates. Early in the disease, patients may experience nonspecific symptoms of fatigue, lightheadedness, and dyspnea on exertion.²³ As it progresses, they tend to have worsening dyspnea and may experience exertional syncope, palpitations, and chest pain.

Physical findings may suggest elevated right ventricular pressure and right ventricular failure; these include a loud P2, a prominent jugular a wave, a tricuspid regurgitant murmur, jugular venous distention, and lower-extremity edema.²⁷

Screening for pulmonary arterial hypertension in systemic sclerosis

Significant signs and symptoms usually occur late in the disease; thus, it is important to appropriately screen patients who are at risk so that they can begin aggressive treatment.

Doppler echocardiography is recommended by European and American guidelines to screen for PAH in patients who have systemic sclerosis, and most agree that screening is appropriate even if the patient has no symptoms.³⁰ European consensus documents recommend that transthoracic echocardiography be done annually for the first 5 years of disease and be continued every year in patients at high risk, ie, those with anticentromere antibodies, anti-Th/To antibodies, or interstitial lung disease. Patients not at high risk of developing pulmonary hypertension should also have regular transthoracic echocardiography, though the exact timing is not defined.³¹ While American societies have not issued corresponding recommendations, many experts follow the European recommendations.

Worrisome features on echocardiography in asymptomatic patients should be followed up with right heart catheterization to assess mean right ventricular pressure. These include:

• Estimated right ventricular systolic pressure ≥ 40 mm Hg
• Tricuspid regurgitant jet velocity > 2.8 m/s
• Right atrial enlargement > 53 mm
• Right ventricular enlargement (mid-cavity dimension > 35 mm).³²

Although echocardiography is the most common form of screening, it gives only an estimate of right ventricular systolic pressure, which is imprecise. Other noninvasive markers are helpful and necessary to appropriately screen this population.

Diffusion capacity. The Itinerair study³³ found that a diffusing capacity for carbon monoxide (D_^LCO) of 60% or higher has a high specificity in excluding PAH.

Uric acid has been found to be elevated in patients with systemic sclerosis-related PAH, and levels inversely correlate with 6-minute walking distance.³⁴

Other predictors. N-terminal pro-B-type natriuretic peptide (NT-proBNP), left atrial volume, and the right ventricular myocardial performance index have also been shown to be independent predictors of PAH in patients with systemic sclerosis.³⁵

An algorithm. The DETECT study³⁶ enrolled patients at increased risk who had had systemic sclerosis longer than 3 years and a D_^LCO less than 60%. The investigators developed a 2-step algorithm to determine which patients should be referred for right heart catheterization to try to detect PAH earlier while minimizing the number of missed diagnoses and optimizing the use of invasive diagnostic right heart catheterization.

The first step was to assess serum values of anticentromere antibodies, NT-proBNP, and urate, and clinical features (telangiectasias), forced vital capacity, and electrocardiographic changes of right axis deviation to derive a prediction score. The second step was to assess surface echocardiographic features of the right atrial area and tricuspid regurgitation velocity.

This approach led to right heart catheterization in 62% of patients and was associated with a false-negative rate of 4%. Importantly, of the patients with PAH, 1 in 5 had no symptoms, and 33% had tricuspid regurgitation velocity less than 2.8 m/s. No single measurement performed well in isolation in this study.³⁷

Thus, we recommend that, in addition to routine surface echocardiography, a multimodal approach be used that includes laboratory testing, clinical features, and electrocardiographic findings when screening this high-risk patient population.

Although macrovascular disease has not typically been regarded as a significant systemic feature in systemic sclerosis, myocardial infarction and stroke are more common in patients with systemic sclerosis than in controls.^38,39

Coronary artery disease in systemic sclerosis

Man et al³⁸ reported that the incidence of myocardial infarction in patients with systemic sclerosis was 4.4 per 1,000 persons per year, and the incidence of stroke was 4.8 per 1,000 persons per year, compared with 2.5 per 1,000 persons per year for both myocardial infarction and stroke in healthy controls matched for age, sex, and time of entry.

The Australian Scleroderma Cohort Study³⁹ found a 3-fold higher prevalence of coronary artery disease in systemic sclerosis patients than in controls after factoring in traditional risk factors.

Aviña-Zubieta et al,⁴⁰ in a cohort of 1,239 systemic sclerosis patients, estimated a hazard ratio (HR) of 3.49 for myocardial infarction and 2.35 for stroke compared with age- and sex-matched controls. Not all of these events were related to macrovascular atherosclerosis—vasospasm and microvascular ischemia may have played significant roles in the etiology of clinical manifestations.

Studies of coronary atherosclerosis in systemic sclerosis are limited. An autopsy study⁴¹ of 58 patients with systemic sclerosis and 58 controls matched for age, sex, and ethnicity found that the prevalence of atherosclerosis of small coronary arteries and arterioles was significantly higher in systemic sclerosis patients than in controls (17% vs 2%, P < .01). However, the prevalence of medium-vessel coronary atherosclerosis was similar (48% vs 43%).

Why patients with systemic sclerosis develop atherosclerosis has not yet been determined. Traditional risk factors such as hypertension, dyslipidemia, diabetes mellitus, and obesity are typically no more prevalent in systemic sclerosis patients than in controls,^38,42 and thus do not explain the increased risk of atherosclerotic cardiovascular disease. There is some evidence that novel markers of atherosclerotic risk such as homocysteine,⁴³ lipoprotein[a],⁴⁴ and oxidized low-density lipoprotein⁴⁵ are more prevalent in systemic sclerosis, but these results have not been substantiated in more extensive studies.

Peripheral artery disease

It remains unclear whether peripheral artery disease is more prevalent in systemic sclerosis patients than in controls.

Individual studies have shown mixed results in comparing carotid artery stenosis between systemic sclerosis patients and controls using carotid duplex ultrasonography,⁴⁶ the ankle-brachial index,^46–48 carotid intima-media thickness,^49–54 and brachial flow-mediated dilation.^{51,53,55–58} A meta-analysis found that the carotid intima and media are significantly thicker in systemic sclerosis patients than in controls,⁵⁹ and the magnitude of difference is similar to that in other groups at increased cardiovascular risk, such as those with rheumatoid arthritis, diabetes, and familial hypercholesterolemia.^60–63

A meta-analysis of brachial artery findings showed significantly lower flow-mediated dilation in systemic sclerosis patients than in controls.⁶⁴

Overall, given the inconsistency of study results, systemic sclerosis patients should be screened and managed as in other patients with peripheral artery disease, but the clinician should be aware that there may be a higher risk of peripheral artery disease in these patients.

RIGHT AND LEFT VENTRICULAR DYSFUNCTION

Many patients with systemic sclerosis have right ventricular dysfunction as a consequence of PAH.⁶⁵ It is important to detect diastolic dysfunction in this population, as it may be an even stronger predictor of death than pulmonary hypertension on right heart catheterization (HR 3.7 vs 2.0).⁶⁶

Fewer patients have left ventricular dysfunction. In a multicenter study of 570 systemic sclerosis patients, only 1.4% had left ventricular systolic dysfunction on echocardiography, though 22.6% had left ventricular hypertrophy and 17.7% had left ventricular diastolic dysfunction.⁶⁷ In the European League Against Rheumatism (EULAR) database, the prevalence of reduced left ventricular ejection fraction was 5.4%.⁶⁸

Though traditional echocardiographic screening suggests the prevalence of left ventricular dysfunction in systemic sclerosis patients is low, cardiac magnetic resonance imaging (MRI) may be more sensitive than echocardiography for detecting subclinical myocardial involvement. Cardiac MRI has been shown to detect evidence of myocardial pathology (increased T2 signal, left ventricular thinning, pericardial effusion, reduced left ventricular and right ventricular ejection fraction, left ventricular diastolic dysfunction, and delayed myocardial contrast enhancement) in up to 75% of systemic sclerosis cases studied.⁶⁹

Patients with systemic sclerosis should already be undergoing echocardiography every year to screen for PAH, and screening should also include tissue Doppler imaging to detect various forms of left and right ventricular systolic and diastolic dysfunction that may not be clinically apparent.

Though cardiac MRI can provide useful additional information, it is not currently recommended for routine screening in patients with systemic sclerosis.

Patients with systemic sclerosis are prone to arrhythmias due to both conduction system fibrosis and myocardial damage.

Arrhythmias accounted for 6% of the deaths in the EULAR Scleroderma Trials and Research (EUSTAR) database.¹¹

In the Genetics Versus Environment in Scleroderma Outcome Study (GENISOS),⁷⁰  250 patients who had had systemic sclerosis for at least 3 years were studied during a period of approximately 6 years, during which there were 52 deaths, 29 of which were directly attributable to systemic sclerosis. Multivariable Cox modeling showed that 7 variables predicted mortality:

• Body mass index < 18.5 kg/m²
• Age ≥ 65
• Forced vital capacity < 50% predicted
• Systolic blood pressure ≥ 140 or diastolic blood pressure ≥ 90 mm Hg
• Pulmonary fibrosis
• Positive anticentromere antibodies
• Cardiac arrhythmias.

The hazard ratio for death in patients with arrhythmias in this model was 2.18 (95% CI 1.05–4.50, P = .035). Thus, finding arrhythmias in systemic sclerosis patients can provide important prognostic information.

While resting electrocardiography in patients with systemic sclerosis  most commonly shows sinus rhythm, 24-hour electrocardiographic monitoring has revealed nonsustained supraventricular and ventricular arrhythmias in a significant percentage.^71,72 Although difficult to quantify in routine practice, parameters controlled by the autonomic nervous system including heart rate variability and heart rate turbulence have been shown to be impaired in systemic sclerosis, and these measures are associated with an increased risk of malignant arrhythmias and sudden cardiac death.^73,74

Conduction abnormalities

Conduction abnormalities occur in one-fifth to one-third of patients with systemic sclerosis.^75,76 The most common abnormal conduction finding is left bundle branch block, followed by first-degree atrioventricular block. High-degree atrioventricular block is uncommon,⁷⁶ though a few case reports of complete heart block thought to be related to systemic sclerosis have been published.^77–79 An autopsy study showed that the conduction system is relatively spared from myocardial changes seen in systemic sclerosis patients, and thus it is speculated that the conduction disturbances are a consequence of damaged myocardium rather than damage to conduction tissue.⁸⁰

Given the array of electrophysiologic abnormalities that systemic sclerosis patients can have, it is critical to monitor all patients with routine (annual or biannual) electrocardiography; to take possible arrhythmia-related symptoms seriously; and to evaluate them with further workup such as Holter monitoring for 24 hours or even longer, event monitoring, exercise testing, or tilt-table testing.

PERICARDIAL DISEASE

Pericardial disease is clinically apparent in 5% to 16% of patients with systemic sclerosis⁸¹; patients with limited cutaneous systemic sclerosis have more pericardial disease than those with diffuse cutaneous systemic sclerosis (30% vs 16%).⁸² Forty-one percent of systemic sclerosis patients have been shown to have pericardial effusion by echocardiography,⁸¹ but the effusions are typically small and rarely cause tamponade, though tamponade is associated with a poor prognosis.

Large pericardial effusions can develop before skin thickening and diagnosis of systemic sclerosis.^81,83,84 Thus, systemic sclerosis should be considered in patients with pericardial effusions of unknown etiology.

In a small study,⁸⁵ the pericardial fluid in systemic sclerosis was typically exudative, with lactate dehydrogenase greater than 200 U/L, a fluid-serum lactate dehydrogenase ratio greater than 0.6, and a fluid-serum total protein ratio greater than 0.5.

Pericardial effusion can be a sign of impending scleroderma renal crisis,⁸⁶ and thus renal function should be carefully monitored in systemic sclerosis patients with pericardial effusion. Constrictive pericarditis and restrictive cardiomyopathy can rarely occur in systemic sclerosis and may more commonly present with symptoms.

Pericardial disease in systemic sclerosis should be treated in a standard fashion with nonsteroidal anti-inflammatory drugs. Corticosteroids are generally of limited benefit and should be avoided, especially in the setting of scleroderma renal crisis.⁸¹

VALVULAR HEART DISEASE

Based on limited studies, the prevalence of significant valvular heart disease in systemic sclerosis patients does not seem to be higher than that in the general population. While patients with systemic sclerosis and CREST syndrome (calcinosis, Raynaud phenomenon, esophageal dysmotility, sclerodactyly, and telangiectasia) have been shown to have a higher frequency of mitral valve prolapse and mild mitral regurgitation,^87,88 these abnormalities do not often progress in severity, and thus their clinical significance is limited.

It is important for physicians caring for patients with systemic sclerosis to be aware of its most common cardiac manifestations, including left and right ventricular systolic and diastolic dysfunction, pulmonary hypertension, conduction abnormalities, arrhythmias, and cardiomyopathy.

Look for volume overload

On clinical examination, assess for clinical markers of volume overload such as distended neck veins, peripheral edema, or an abnormal blood pressure response to the Valsalva maneuver. These findings should prompt measurement of NT-proBNP,⁸⁹ and may warrant prescription of a diuretic.

Electrocardiography to investigate arrhythmias

Electrocardiography should be done if patients describe symptoms of palpitations, and should also include continuous rhythm monitoring with Holter or event monitoring, depending on the frequency of symptoms. Otherwise, patients should routinely undergo electrocardiography once or twice a year.

Q waves are common in systemic sclerosis patients (especially those with diffuse cutaneous systemic sclerosis), notably in the precordial leads, and can occur without coronary artery disease.⁹⁰ Symptoms such as presyncope should be further investigated with Holter monitoring and tilt-table testing.

Assess, modify traditional risk factors

Subclinical atherosclerosis as detected by carotid intima-media thickness is as common in systemic sclerosis as in rheumatoid arthritis.⁶¹ However, traditional risk indices such as SCORE (Systematic Coronary Risk Evaluation), QRISK2, and the American College of Cardiology/American Heart Association indices may underestimate risk in patients who have systemic sclerosis.

Strict hypertension control should be the goal for all systemic sclerosis patients. Though there are no specific guidelines on which antihypertensive medications are preferred, calcium channel blockers or angiotensin II receptor blockers, which are typically used to treat systemic sclerosis-related Raynaud phenomenon, may be appropriate.

Statins reduce vascular complications and are generally well tolerated in patients with systemic sclerosis.^91,92 

Aspirin is not recommended for routine primary prevention in view of data suggesting that its benefits in diabetic patients are counterbalanced by increased bleeding risk.⁹³

Echocardiography to detect pulmonary arterial hypertension

At this time, guidelines for monitoring for cardiovascular manifestations in systemic sclerosis patients are limited. The only well-defined ones are European consensus guidelines, which suggest annual transthoracic echocardiography for the first 5 years after systemic sclerosis is diagnosed and continued annual screening in patients at risk of developing PAH.³¹

We support this strategy, with annual screening for the first 5 years followed by surveillance echocardiography every 2 to 3 years unless there is a high risk of PAH. Specific attention should be paid to right ventricular diastolic function, right atrial volume, and right ventricular myocardial performance index.

Emerging data suggest that the addition of global longitudinal strain of ventricles to  routine echocardiography can help detect subclinical cardiac risk.⁹⁴ Although further study is needed into the predictive value of global longitudinal strain, it is a low-cost and noninvasive addition to standard echocardiography that can help guide risk stratification, and thus we recommend that it be part of the echocardiographic examination for all systemic sclerosis patients.

Pulmonary function testing. In addition to screening for PAH with echocardiography, we recommend obtaining baseline pulmonary function tests, including D_^LCO, at the time systemic sclerosis is diagnosed, with repeat testing annually.

Magnetic resonance imaging

While echocardiography is the gold standard for monitoring systemic sclerosis patients, cardiovascular MRI may have a role in identifying those at higher risk of dangerous arrhythmias such as ventricular tachycardia and ventricular fibrillation. In addition to assessing ventricular function, MRI can detect myocardial inflammation, ischemia, and fibrosis that may predispose a patient to develop ventricular tachycardia or fibrillation.⁹⁵ Variables such as T1/T2 mapping, extracellular volume fraction, T2 signal ratio, and early vs late gadolinium enhancement can help identify patients who had past ventricular tachycardia or fibrillation.⁹⁶

Finding an increased risk of arrhythmias may prompt a conversation between the patient and the physician about the need for an implantable cardiac defibrillator.

If cardiac MRI is available and is reimbursed by the patient’s insurance carrier, physicians should strongly consider obtaining at least one baseline scan in systemic sclerosis patients to identify those at risk of highly fatal arrhythmias.

Teamwork is needed

Systemic sclerosis has not traditionally been associated with cardiovascular disease to the extent of other rheumatic conditions, but the cardiovascular system can be affected in various ways that can ultimately lead to an early death. These manifestations may be asymptomatic for long periods, and overt clinical disease portends a poorer prognosis.

Primary care physicians managing these patients should be aware of the cardiovascular complications of systemic sclerosis and should implement appropriate screening tests in conjunction with rheumatologists and cardiologists. It is also essential for general and subspecialty cardiologists to understand the broad spectrum of organ system involvement that can affect systemic sclerosis patients and to tailor their investigation and management recommendations accordingly. By designing a multidisciplinary approach to the treatment of systemic sclerosis patients, physicians can help to optimize cardiovascular risk modification in this vulnerable population.

Autoimmune rheumatic diseases increase the risk of cardiovascular disease. In rheumatoid arthritis and systemic lupus erythematosus, the risk is driven primarily by the inflammatory milieu, leading to accelerated coronary and cerebrovascular atherosclerosis independent of traditional atherosclerotic risk factors.^1–3 The extent of cardiovascular involvement in other rheumatologic diseases has been less well characterized but is an area of growing interest.

In this review, we focus on the cardiovascular complications of systemic sclerosis and review recommendations for monitoring these patients in clinical practice.

SYSTEMIC SCLEROSIS, AN AUTOIMMUNE RHEUMATIC DISEASE

Systemic sclerosis is an autoimmune rheumatic disease characterized by excessive extracellular matrix deposition leading to diffuse fibrosis, endothelial dysfunction, and microvascular injury. It is most common in North America, Southern Europe, and Australia,^4,5 and it affects women more than men in ratios ranging from 3:1 to 14:1.⁶ The mean age at diagnosis is around 50. 

The disease can affect the lungs (interstitial lung disease and pulmonary hypertension), the heart, the kidneys, and the gastrointestinal tract.

Systemic sclerosis has 2 main subtypes: limited cutaneous systemic sclerosis, formerly called CREST syndrome) and diffuse cutaneous systemic sclerosis. The limited cutaneous subtype is characterized by tightening of the skin of the distal extremities (below the elbows and knees) and face, while diffuse cutaneous systemic sclerosis can manifest as more extensive skin tightening also involving proximal extremities and the trunk. Both subtypes can have an effect on the cardiovascular system.

Some cardiovascular risk factors such as dyslipidemia, diabetes mellitus, and high body mass index are less common in patients with systemic sclerosis than in patients with rheumatoid arthritis, while the rates of arterial hypertension, smoking, chronic obstructive pulmonary disease, osteoporosis, and neoplasms are similar between the 2 groups.⁷

HEART INVOLVEMENT HAS SERIOUS CONSEQUENCES

Overt cardiac involvement in systemic sclerosis is associated with a mortality rate of up to 70% over 5 years,^8,9 and about one-fourth of deaths in patients with systemic sclerosis are from cardiac causes.^10,11 Studies in Europe^10,12 showed that many patients with systemic sclerosis have cardiac involvement detectable by magnetic resonance imaging even if they do not have clinical disease. Pulmonary arterial hypertension (PAH) is a complication of both subtypes of systemic sclerosis and portends a higher risk of death.⁸

Thus, it is critical for clinicians to understand the potential comorbid conditions associated with systemic sclerosis, particularly the cardiovascular ones, and to work closely with cardiologists to help optimize the evaluation and management.

MECHANISMS OF CARDIAC DISEASE IN SYSTEMIC SCLEROSIS

Abnormal vasoreactivity, a consequence of an imbalance between endothelium-derived vasoconstrictors and vasodilators, defective angiogenesis, and endothelial injury, leads to tissue ischemia and vascular endothelial growth factor expression, which initiates injury and fibrosis in the myocardium and in other organs.^14–17 Fibrosis involves the myocardium, pericardium, and conduction system.^13,18

Myocardial involvement in systemic sclerosis is thought to be due mainly to abnormal vasoreactivity and microvascular abnormalities such as transient coronary artery spasm leading to repeated focal ischemia.^19,20 Abnormal vasoreactivity has been demonstrated during cardiac catheterization²¹: while mean coronary sinus blood flow in systemic sclerosis patients was normal at rest, vasodilator reserve was significantly reduced in patients with diffuse cutaneous systemic sclerosis after maximal vasodilation with dipyridamole. Additionally, endomyocardial biopsy showed fibrosis and concentric intimal hypertrophy with normal epicardial coronary arteries.²¹

More research into other mechanisms of cardiovascular disease in systemic sclerosis is needed to allow for better preventive care for these patients.

Systemic sclerosis can be associated with World Health Organization (WHO) groups 1, 2, 3, and 4 pulmonary hypertension. WHO group 1, called pulmonary arterial hypertension or PAH, is one of the most common cardiac complications of systemic sclerosis, with a reported prevalence as high as 12%.²² Systemic sclerosis-associated PAH carries a high mortality rate, with a mean survival of only 3 years.²³

With advances in treatments for other complications of systemic sclerosis, the percentage of systemic sclerosis patients who die of PAH has increased from 6% to 33%.²⁴

Compared with patients with idiopathic PAH, those with systemic sclerosis get less of a response from therapy and have poorer outcomes despite lower mean pulmonary artery pressures and similar reductions in cardiac index. However, recent studies have suggested that with aggressive treatment, patients with systemic sclerosis-related PAH can achieve outcomes similar to those with idiopathic PAH.²⁵ Thus, recognizing this condition early is imperative.

Pulmonary arterial hypertension defined

PAH is defined as the combination of all of the following²⁶:

• Mean pulmonary artery pressure > 20 mm Hg at rest
• Normal pulmonary capillary wedge pressure (≤ 15 mm Hg)
• Pulmonary vascular resistance ≥ 3 Wood units on right heart catheterization.

Other causes of pulmonary hypertension such as interstitial lung disease, chronic pulmonary thromboembolic disease, and left heart disease must be excluded.^24,27

Remodeling in the pulmonary arteries

The events that lead to PAH in systemic sclerosis remain unclear but are believed to involve initial inflammation or endothelial injury that leads to a dysequilibrium between proliferative mediators and antiproliferative vasodilators. This dysequilibrium, along with endothelial dysfunction, causes an obliterative vasculopathy in the pulmonary artery branches and arterioles. Sympathetic overactivity, hypoxemia, and ischemia-reperfusion injury additionally promote vascular proliferation, fibrosis, and remodeling, leading to increased pulmonary vascular resistance, PAH, and increased right ventricular pressures.^23,27

The subtype of systemic sclerosis is an important factor in the development and progression of PAH. PAH appears to be the major cause of death in limited cutaneous systemic sclerosis, while interstitial lung disease is the major cause of death in diffuse cutaneous systemic sclerosis.²⁸

Pulmonary arterial hypertension is a late complication of systemic sclerosis

Data from the South Australian Scleroderma Registry²⁹ revealed that PAH tends to be a late complication of systemic sclerosis, occurring around 20 years after disease onset. In this study of 608 patients, no patient with diffuse cutaneous systemic sclerosis developed PAH.

Systemic sclerosis-related PAH initially follows an indolent course with few symptoms until right ventricular function deteriorates. Early in the disease, patients may experience nonspecific symptoms of fatigue, lightheadedness, and dyspnea on exertion.²³ As it progresses, they tend to have worsening dyspnea and may experience exertional syncope, palpitations, and chest pain.

Physical findings may suggest elevated right ventricular pressure and right ventricular failure; these include a loud P2, a prominent jugular a wave, a tricuspid regurgitant murmur, jugular venous distention, and lower-extremity edema.²⁷

Screening for pulmonary arterial hypertension in systemic sclerosis

Significant signs and symptoms usually occur late in the disease; thus, it is important to appropriately screen patients who are at risk so that they can begin aggressive treatment.

Doppler echocardiography is recommended by European and American guidelines to screen for PAH in patients who have systemic sclerosis, and most agree that screening is appropriate even if the patient has no symptoms.³⁰ European consensus documents recommend that transthoracic echocardiography be done annually for the first 5 years of disease and be continued every year in patients at high risk, ie, those with anticentromere antibodies, anti-Th/To antibodies, or interstitial lung disease. Patients not at high risk of developing pulmonary hypertension should also have regular transthoracic echocardiography, though the exact timing is not defined.³¹ While American societies have not issued corresponding recommendations, many experts follow the European recommendations.

Worrisome features on echocardiography in asymptomatic patients should be followed up with right heart catheterization to assess mean right ventricular pressure. These include:

• Estimated right ventricular systolic pressure ≥ 40 mm Hg
• Tricuspid regurgitant jet velocity > 2.8 m/s
• Right atrial enlargement > 53 mm
• Right ventricular enlargement (mid-cavity dimension > 35 mm).³²

Although echocardiography is the most common form of screening, it gives only an estimate of right ventricular systolic pressure, which is imprecise. Other noninvasive markers are helpful and necessary to appropriately screen this population.

Diffusion capacity. The Itinerair study³³ found that a diffusing capacity for carbon monoxide (D_^LCO) of 60% or higher has a high specificity in excluding PAH.

Uric acid has been found to be elevated in patients with systemic sclerosis-related PAH, and levels inversely correlate with 6-minute walking distance.³⁴

Other predictors. N-terminal pro-B-type natriuretic peptide (NT-proBNP), left atrial volume, and the right ventricular myocardial performance index have also been shown to be independent predictors of PAH in patients with systemic sclerosis.³⁵

An algorithm. The DETECT study³⁶ enrolled patients at increased risk who had had systemic sclerosis longer than 3 years and a D_^LCO less than 60%. The investigators developed a 2-step algorithm to determine which patients should be referred for right heart catheterization to try to detect PAH earlier while minimizing the number of missed diagnoses and optimizing the use of invasive diagnostic right heart catheterization.

The first step was to assess serum values of anticentromere antibodies, NT-proBNP, and urate, and clinical features (telangiectasias), forced vital capacity, and electrocardiographic changes of right axis deviation to derive a prediction score. The second step was to assess surface echocardiographic features of the right atrial area and tricuspid regurgitation velocity.

This approach led to right heart catheterization in 62% of patients and was associated with a false-negative rate of 4%. Importantly, of the patients with PAH, 1 in 5 had no symptoms, and 33% had tricuspid regurgitation velocity less than 2.8 m/s. No single measurement performed well in isolation in this study.³⁷

Thus, we recommend that, in addition to routine surface echocardiography, a multimodal approach be used that includes laboratory testing, clinical features, and electrocardiographic findings when screening this high-risk patient population.

Although macrovascular disease has not typically been regarded as a significant systemic feature in systemic sclerosis, myocardial infarction and stroke are more common in patients with systemic sclerosis than in controls.^38,39

Coronary artery disease in systemic sclerosis

Man et al³⁸ reported that the incidence of myocardial infarction in patients with systemic sclerosis was 4.4 per 1,000 persons per year, and the incidence of stroke was 4.8 per 1,000 persons per year, compared with 2.5 per 1,000 persons per year for both myocardial infarction and stroke in healthy controls matched for age, sex, and time of entry.

The Australian Scleroderma Cohort Study³⁹ found a 3-fold higher prevalence of coronary artery disease in systemic sclerosis patients than in controls after factoring in traditional risk factors.

Aviña-Zubieta et al,⁴⁰ in a cohort of 1,239 systemic sclerosis patients, estimated a hazard ratio (HR) of 3.49 for myocardial infarction and 2.35 for stroke compared with age- and sex-matched controls. Not all of these events were related to macrovascular atherosclerosis—vasospasm and microvascular ischemia may have played significant roles in the etiology of clinical manifestations.

Studies of coronary atherosclerosis in systemic sclerosis are limited. An autopsy study⁴¹ of 58 patients with systemic sclerosis and 58 controls matched for age, sex, and ethnicity found that the prevalence of atherosclerosis of small coronary arteries and arterioles was significantly higher in systemic sclerosis patients than in controls (17% vs 2%, P < .01). However, the prevalence of medium-vessel coronary atherosclerosis was similar (48% vs 43%).

Why patients with systemic sclerosis develop atherosclerosis has not yet been determined. Traditional risk factors such as hypertension, dyslipidemia, diabetes mellitus, and obesity are typically no more prevalent in systemic sclerosis patients than in controls,^38,42 and thus do not explain the increased risk of atherosclerotic cardiovascular disease. There is some evidence that novel markers of atherosclerotic risk such as homocysteine,⁴³ lipoprotein[a],⁴⁴ and oxidized low-density lipoprotein⁴⁵ are more prevalent in systemic sclerosis, but these results have not been substantiated in more extensive studies.

Peripheral artery disease

It remains unclear whether peripheral artery disease is more prevalent in systemic sclerosis patients than in controls.

Individual studies have shown mixed results in comparing carotid artery stenosis between systemic sclerosis patients and controls using carotid duplex ultrasonography,⁴⁶ the ankle-brachial index,^46–48 carotid intima-media thickness,^49–54 and brachial flow-mediated dilation.^{51,53,55–58} A meta-analysis found that the carotid intima and media are significantly thicker in systemic sclerosis patients than in controls,⁵⁹ and the magnitude of difference is similar to that in other groups at increased cardiovascular risk, such as those with rheumatoid arthritis, diabetes, and familial hypercholesterolemia.^60–63

A meta-analysis of brachial artery findings showed significantly lower flow-mediated dilation in systemic sclerosis patients than in controls.⁶⁴

Overall, given the inconsistency of study results, systemic sclerosis patients should be screened and managed as in other patients with peripheral artery disease, but the clinician should be aware that there may be a higher risk of peripheral artery disease in these patients.

RIGHT AND LEFT VENTRICULAR DYSFUNCTION

Many patients with systemic sclerosis have right ventricular dysfunction as a consequence of PAH.⁶⁵ It is important to detect diastolic dysfunction in this population, as it may be an even stronger predictor of death than pulmonary hypertension on right heart catheterization (HR 3.7 vs 2.0).⁶⁶

Fewer patients have left ventricular dysfunction. In a multicenter study of 570 systemic sclerosis patients, only 1.4% had left ventricular systolic dysfunction on echocardiography, though 22.6% had left ventricular hypertrophy and 17.7% had left ventricular diastolic dysfunction.⁶⁷ In the European League Against Rheumatism (EULAR) database, the prevalence of reduced left ventricular ejection fraction was 5.4%.⁶⁸

Though traditional echocardiographic screening suggests the prevalence of left ventricular dysfunction in systemic sclerosis patients is low, cardiac magnetic resonance imaging (MRI) may be more sensitive than echocardiography for detecting subclinical myocardial involvement. Cardiac MRI has been shown to detect evidence of myocardial pathology (increased T2 signal, left ventricular thinning, pericardial effusion, reduced left ventricular and right ventricular ejection fraction, left ventricular diastolic dysfunction, and delayed myocardial contrast enhancement) in up to 75% of systemic sclerosis cases studied.⁶⁹

Patients with systemic sclerosis should already be undergoing echocardiography every year to screen for PAH, and screening should also include tissue Doppler imaging to detect various forms of left and right ventricular systolic and diastolic dysfunction that may not be clinically apparent.

Though cardiac MRI can provide useful additional information, it is not currently recommended for routine screening in patients with systemic sclerosis.

Patients with systemic sclerosis are prone to arrhythmias due to both conduction system fibrosis and myocardial damage.

Arrhythmias accounted for 6% of the deaths in the EULAR Scleroderma Trials and Research (EUSTAR) database.¹¹

In the Genetics Versus Environment in Scleroderma Outcome Study (GENISOS),⁷⁰  250 patients who had had systemic sclerosis for at least 3 years were studied during a period of approximately 6 years, during which there were 52 deaths, 29 of which were directly attributable to systemic sclerosis. Multivariable Cox modeling showed that 7 variables predicted mortality:

• Body mass index < 18.5 kg/m²
• Age ≥ 65
• Forced vital capacity < 50% predicted
• Systolic blood pressure ≥ 140 or diastolic blood pressure ≥ 90 mm Hg
• Pulmonary fibrosis
• Positive anticentromere antibodies
• Cardiac arrhythmias.

The hazard ratio for death in patients with arrhythmias in this model was 2.18 (95% CI 1.05–4.50, P = .035). Thus, finding arrhythmias in systemic sclerosis patients can provide important prognostic information.

While resting electrocardiography in patients with systemic sclerosis  most commonly shows sinus rhythm, 24-hour electrocardiographic monitoring has revealed nonsustained supraventricular and ventricular arrhythmias in a significant percentage.^71,72 Although difficult to quantify in routine practice, parameters controlled by the autonomic nervous system including heart rate variability and heart rate turbulence have been shown to be impaired in systemic sclerosis, and these measures are associated with an increased risk of malignant arrhythmias and sudden cardiac death.^73,74

Conduction abnormalities

Conduction abnormalities occur in one-fifth to one-third of patients with systemic sclerosis.^75,76 The most common abnormal conduction finding is left bundle branch block, followed by first-degree atrioventricular block. High-degree atrioventricular block is uncommon,⁷⁶ though a few case reports of complete heart block thought to be related to systemic sclerosis have been published.^77–79 An autopsy study showed that the conduction system is relatively spared from myocardial changes seen in systemic sclerosis patients, and thus it is speculated that the conduction disturbances are a consequence of damaged myocardium rather than damage to conduction tissue.⁸⁰

Given the array of electrophysiologic abnormalities that systemic sclerosis patients can have, it is critical to monitor all patients with routine (annual or biannual) electrocardiography; to take possible arrhythmia-related symptoms seriously; and to evaluate them with further workup such as Holter monitoring for 24 hours or even longer, event monitoring, exercise testing, or tilt-table testing.

PERICARDIAL DISEASE

Pericardial disease is clinically apparent in 5% to 16% of patients with systemic sclerosis⁸¹; patients with limited cutaneous systemic sclerosis have more pericardial disease than those with diffuse cutaneous systemic sclerosis (30% vs 16%).⁸² Forty-one percent of systemic sclerosis patients have been shown to have pericardial effusion by echocardiography,⁸¹ but the effusions are typically small and rarely cause tamponade, though tamponade is associated with a poor prognosis.

Large pericardial effusions can develop before skin thickening and diagnosis of systemic sclerosis.^81,83,84 Thus, systemic sclerosis should be considered in patients with pericardial effusions of unknown etiology.

In a small study,⁸⁵ the pericardial fluid in systemic sclerosis was typically exudative, with lactate dehydrogenase greater than 200 U/L, a fluid-serum lactate dehydrogenase ratio greater than 0.6, and a fluid-serum total protein ratio greater than 0.5.

Pericardial effusion can be a sign of impending scleroderma renal crisis,⁸⁶ and thus renal function should be carefully monitored in systemic sclerosis patients with pericardial effusion. Constrictive pericarditis and restrictive cardiomyopathy can rarely occur in systemic sclerosis and may more commonly present with symptoms.

Pericardial disease in systemic sclerosis should be treated in a standard fashion with nonsteroidal anti-inflammatory drugs. Corticosteroids are generally of limited benefit and should be avoided, especially in the setting of scleroderma renal crisis.⁸¹

VALVULAR HEART DISEASE

Based on limited studies, the prevalence of significant valvular heart disease in systemic sclerosis patients does not seem to be higher than that in the general population. While patients with systemic sclerosis and CREST syndrome (calcinosis, Raynaud phenomenon, esophageal dysmotility, sclerodactyly, and telangiectasia) have been shown to have a higher frequency of mitral valve prolapse and mild mitral regurgitation,^87,88 these abnormalities do not often progress in severity, and thus their clinical significance is limited.

It is important for physicians caring for patients with systemic sclerosis to be aware of its most common cardiac manifestations, including left and right ventricular systolic and diastolic dysfunction, pulmonary hypertension, conduction abnormalities, arrhythmias, and cardiomyopathy.

Look for volume overload

On clinical examination, assess for clinical markers of volume overload such as distended neck veins, peripheral edema, or an abnormal blood pressure response to the Valsalva maneuver. These findings should prompt measurement of NT-proBNP,⁸⁹ and may warrant prescription of a diuretic.

Electrocardiography to investigate arrhythmias

Electrocardiography should be done if patients describe symptoms of palpitations, and should also include continuous rhythm monitoring with Holter or event monitoring, depending on the frequency of symptoms. Otherwise, patients should routinely undergo electrocardiography once or twice a year.

Q waves are common in systemic sclerosis patients (especially those with diffuse cutaneous systemic sclerosis), notably in the precordial leads, and can occur without coronary artery disease.⁹⁰ Symptoms such as presyncope should be further investigated with Holter monitoring and tilt-table testing.

Assess, modify traditional risk factors

Subclinical atherosclerosis as detected by carotid intima-media thickness is as common in systemic sclerosis as in rheumatoid arthritis.⁶¹ However, traditional risk indices such as SCORE (Systematic Coronary Risk Evaluation), QRISK2, and the American College of Cardiology/American Heart Association indices may underestimate risk in patients who have systemic sclerosis.

Strict hypertension control should be the goal for all systemic sclerosis patients. Though there are no specific guidelines on which antihypertensive medications are preferred, calcium channel blockers or angiotensin II receptor blockers, which are typically used to treat systemic sclerosis-related Raynaud phenomenon, may be appropriate.

Statins reduce vascular complications and are generally well tolerated in patients with systemic sclerosis.^91,92 

Aspirin is not recommended for routine primary prevention in view of data suggesting that its benefits in diabetic patients are counterbalanced by increased bleeding risk.⁹³

Echocardiography to detect pulmonary arterial hypertension

At this time, guidelines for monitoring for cardiovascular manifestations in systemic sclerosis patients are limited. The only well-defined ones are European consensus guidelines, which suggest annual transthoracic echocardiography for the first 5 years after systemic sclerosis is diagnosed and continued annual screening in patients at risk of developing PAH.³¹

We support this strategy, with annual screening for the first 5 years followed by surveillance echocardiography every 2 to 3 years unless there is a high risk of PAH. Specific attention should be paid to right ventricular diastolic function, right atrial volume, and right ventricular myocardial performance index.

Emerging data suggest that the addition of global longitudinal strain of ventricles to  routine echocardiography can help detect subclinical cardiac risk.⁹⁴ Although further study is needed into the predictive value of global longitudinal strain, it is a low-cost and noninvasive addition to standard echocardiography that can help guide risk stratification, and thus we recommend that it be part of the echocardiographic examination for all systemic sclerosis patients.

Pulmonary function testing. In addition to screening for PAH with echocardiography, we recommend obtaining baseline pulmonary function tests, including D_^LCO, at the time systemic sclerosis is diagnosed, with repeat testing annually.

Magnetic resonance imaging

While echocardiography is the gold standard for monitoring systemic sclerosis patients, cardiovascular MRI may have a role in identifying those at higher risk of dangerous arrhythmias such as ventricular tachycardia and ventricular fibrillation. In addition to assessing ventricular function, MRI can detect myocardial inflammation, ischemia, and fibrosis that may predispose a patient to develop ventricular tachycardia or fibrillation.⁹⁵ Variables such as T1/T2 mapping, extracellular volume fraction, T2 signal ratio, and early vs late gadolinium enhancement can help identify patients who had past ventricular tachycardia or fibrillation.⁹⁶

Finding an increased risk of arrhythmias may prompt a conversation between the patient and the physician about the need for an implantable cardiac defibrillator.

If cardiac MRI is available and is reimbursed by the patient’s insurance carrier, physicians should strongly consider obtaining at least one baseline scan in systemic sclerosis patients to identify those at risk of highly fatal arrhythmias.

Teamwork is needed

Systemic sclerosis has not traditionally been associated with cardiovascular disease to the extent of other rheumatic conditions, but the cardiovascular system can be affected in various ways that can ultimately lead to an early death. These manifestations may be asymptomatic for long periods, and overt clinical disease portends a poorer prognosis.

Primary care physicians managing these patients should be aware of the cardiovascular complications of systemic sclerosis and should implement appropriate screening tests in conjunction with rheumatologists and cardiologists. It is also essential for general and subspecialty cardiologists to understand the broad spectrum of organ system involvement that can affect systemic sclerosis patients and to tailor their investigation and management recommendations accordingly. By designing a multidisciplinary approach to the treatment of systemic sclerosis patients, physicians can help to optimize cardiovascular risk modification in this vulnerable population.

Perioperative medicine is an evolving field with a rapidly growing body of literature, particularly in cardiology.

In this update, we review 6 articles to answer questions related to preoperative cardiac risk assessment, perioperative medication management, and postoperative cardiac complications. We surveyed perioperative literature from February 2018 through January 2019 and chose the final articles by consensus, based on relevance to clinicians who provide preoperative evaluations and postoperative care to surgical patients.

These summaries are derived from “Updates in Perioperative Medicine” presented at the 14th Annual Perioperative Medicine Summit (Orlando, FL, February 13–16, 2019) and the 2019 Society of Hospital Medicine Annual Meeting (National Harbor, MD, March 24–27, 2019).

PREOPERATIVE CARDIAC EVALUATION

How well do measures of functional capacity predict perioperative complications and mortality in noncardiac surgical patients?

Functional capacity is commonly assessed in preoperative evaluations to estimate patients’ risks of perioperative complications and death. The American College of Cardiology/American Heart Association¹ and the European Society of Cardiology² guidelines both include estimation of cardiopulmonary fitness as a step in preoperative assessment before major noncardiac surgery.

“Subjective assessment” is one way to estimate functional capacity. Simply put, clinicians try to form a rough idea about the fitness of patients by asking questions about routine activities such as walking or climbing stairs. Although commonly used, subjective assessment of functional capacity lacks strong evidence that it predicts adverse perioperative events.

Cardiopulmonary exercise testing is a third option. It measures peak oxygen consumption and anaerobic threshold during exercise. It is probably the best objective measurement of functional capacity, but not necessarily for predicting postoperative cardiac complications, and it is performed relatively infrequently.

[Wijeysundera DN, Pearse RM, Sulman MA, et al. Assessment of functional capacity before major non-cardiac surgery: an international, prospective cohort study. Lancet 2018; 391(10140):2631–2640. doi:10.1016/S0140-6736(18)31131-0]

In a multicenter, prospective cohort study, Wijeysundera et al⁴ compared subjective functional capacity assessment, the Duke Activity Status Index, cardiopulmonary exercise testing, and the preoperative N-terminal pro-B-type natriuretic peptide (NT-proBNP) level in their ability to predict complications and death in 1,401 noncardiac surgery patients older than 40 with at least 1 cardiovascular risk factor. After surgery, patients had daily electrocardiograms and troponin measurements until postoperative day 3 or discharge.

The primary outcome was the 30-day incidence of death or myocardial infarction (MI). Additional outcomes included the 30-day incidence of death or myocardial injury after noncardiac surgery (MINS), the 1-year mortality rate, and moderate to severe in-hospital perioperative complications.

Findings. Two percent of patients died or had an MI within 30 days of surgery.⁴

Subjective assessment had only a 19.2% sensitivity (95% confidence interval [CI] 14.2–25) but a 94.7% specificity (95% CI 93.2–95.9) for predicting inability to attain 4 metabolic equivalents during exercise.⁴

A lower Duke Activity Status Index predicted the primary outcome of death or MI within 30 days (adjusted odds ratio [OR] 0.96, 95% CI 0.83–0.99, P = .03), and it was the only measure that did so. Additionally, the Duke index and NT-proBNP level predicted the risk of death or MINS within 30 days.⁴

Only elevated NT-proBNP was associated with death at 1 year.⁴

On exercise testing, low peak oxygen consumption was significantly associated with perioperative complications.

Limitations. The number of primary outcome events (death and MI) was low, potentially affecting the statistical power of the study.

Conclusions. Subjective assessment of functional capacity misclassifies too many patients as being at low risk of perioperative complications and should not be used for preoperative risk stratification. Other tools, such as the Duke Activity Status Index and NT-proBNP levels, are better predictors of adverse perioperative cardiovascular outcomes and should be considered for use in preoperative cardiac risk assessment.

Although the Duke Activity Status Index is a better predictor of adverse outcomes than subjective functional capacity assessment, a specific perioperative threshold for risk classification has not been established. Its correlate for metabolic equivalents should be considered for use in clinical practice at this point.

Is perioperative aspirin beneficial in patients undergoing vascular surgery?

The Perioperative Ischemic Evaluation 2 (POISE-2) trial,⁵ a 2-by-2 factorial randomized controlled trial in which patients received perioperative aspirin, clonidine, both, or neither, demonstrated that perioperative aspirin did not reduce cardiovascular events and increased major bleeding. Patients with recently placed coronary stents and those undergoing carotid endarterectomy were excluded because aspirin is known to have a beneficial effect in these patients.

A subsequent substudy⁶ found perioperative aspirin to be beneficial in patients with coronary stents placed more than a year before noncardiac surgery. Whether perioperative aspirin is beneficial in other subgroups was unknown.

[Biccard BM, Sigamani A, Chan MTV, et al. Effect of aspirin in vascular surgery in patients from a randomized clinical trial (POISE-2). Br J Surg 2018; 105(12):1591–1597. doi:10.1002/bjs.10925]

Biccard et al⁷ investigated the effect of perioperative aspirin in the subgroup of patients from the POISE-2 trial who underwent vascular surgery. The primary outcome was death or MI within 30 days. Secondary outcomes in this substudy included vascular occlusive complications (amputation and peripheral arterial thrombosis) and major or life-threatening bleeding.

Limitations. There were few adverse events, and this substudy was underpowered for the primary and secondary outcomes.

Conclusion. Starting or continuing aspirin did not improve outcomes, and withdrawing it did not increase cardiovascular or occlusive complications.

Do ACE inhibitors affect risk in noncardiac nonvascular surgery?

Angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs) are some of the most commonly used medications for treating hypertension. But whether patients should continue receiving them on the day of surgery or whether they should be held remains unclear.

Although current recommendations are inconsistent, the most recent American College of Cardiology/American Heart Association¹ perioperative practice guidelines say that continuing ACE inhibitors or ARBs is reasonable perioperatively. This recommendation, however, acknowledges that published evidence is limited. There is general agreement that preoperative exposure to ACE inhibitors and ARBs is associated with intraoperative hypotension, but whether this increases the risk of adverse clinical outcomes remains unclear. Needed was a study to determine the effect on perioperative morbidity and mortality of continuing vs withholding ACE inhibitors and ARBs before surgery.

[Shiffermiller JF, Monson BJ, Vokoun CW, et al. Prospective randomized evaluation of preoperative angiotensin-converting enzyme inhibition (PREOP-ACEI). J Hosp Med 2018; 13(10):661–667. doi:10.12788/jhm.3036]

Shiffermiller et al⁸ performed a randomized controlled trial comparing the effect of 2 preoperative ACE inhibitor management protocols in patients undergoing noncardiac nonvascular surgery. Patients were randomized to either receive or not receive their final preoperative ACE inhibitor dose, whether scheduled on the morning of surgery or the night before.

Exclusion criteria included hypotension or hypertension at their preoperative clinic appointment (defined as systolic blood pressure < 90 or ≥ 160 mm Hg, and diastolic blood pressure < 60 or ≥ 95 mm Hg), moderate to severe heart failure, and end-stage renal disease requiring dialysis. Excluded surgery types were cardiac, vascular, organ transplant, oncologic, and all outpatient procedures. Patients taking ARBs were also excluded.

The primary outcome was intraoperative hypotension defined as any systolic blood pressure less than 80 mm Hg from the time of anesthesia induction until transfer to the postanesthesia care unit. Secondary outcomes were measured until hospital discharge and included postoperative acute kidney injury, postoperative hypotension (systolic pressure < 90 mm Hg) and hypertension (systolic pressure > 180 mm Hg), major cardiac events (composite of acute coronary syndrome, acute heart failure, or new-onset arrhythmia), and death.

Findings. A total of 453 patients were screened for eligibility, and of these, 291 were included for randomization. Their average age was 64, 48% were men, and 87% were white. About 50% underwent general anesthesia, 25% spinal, and 25% regional. Over half of the surgeries were orthopedic, and 20% were spine surgeries.

The primary outcome of intraoperative hypotension occurred significantly less often in patients randomized to ACE inhibitor omission than in the continuation group (55% vs 69%, relative risk [RR] 0.81, 95% CI 0.67–0.97, P = .03). This translates to 1 case of intraoperative hypotension for every 7.5 patients continuing an ACE inhibitor perioperatively (number needed to harm 7.5). Intraoperative hypotension associated with vasopressor administration also occurred significantly less frequently in the ACE inhibitor omission group.

Patients in the ACE inhibitor omission group were also less likely to experience postoperative hypotension, but on the other hand, they were more likely to experience severe postoperative hypertension (defined as any systolic blood pressure > 180 mm Hg). The two groups fared the same in terms of rates of acute kidney injury and major adverse cardiac events (MACE) and hospital length of stay, and no patients died in either group.

Limitations. Several factors limit the generalizability of this single-center study, including the many exclusion criteria, the predominance of orthopedic and spine surgeries, and the low-risk patient population (the average Revised Cardiac Risk Index score was 0, range 0–3). Other limitations include not controlling for the specific ACE inhibitor used and not including the precise timing of the final dose in relation to surgery. Lastly, this study lacked power to measure postoperative outcomes.

Conclusions. Continuing ACE inhibitor treatment before noncardiac nonvascular surgery is associated with a greater frequency and duration of intraoperative hypotension, but it did not increase the incidences of acute kidney injury, MACE, or death nor the hospital length of stay.

[Hollmann C, Fernandes NL, Biccard BM. A systematic review of outcomes associated with withholding or continuing angiotensin-converting enzyme inhibitors and angiotensin receptor blockers before noncardiac surgery. Anesth Analg 2018; 127(3):678–687. doi:10.1213/ANE.0000000000002837]

Hollmann et al⁹ performed a meta-analysis to determine whether it is better to continue or withhold ACE inhibitors and ARBs before surgery. The patients were adults undergoing noncardiac surgery and receiving an ACE inhibitor or ARB, which was either withheld or continued on the morning of surgery.

Primary outcomes were all-cause mortality and MACE, while secondary outcomes included the incidence of acute kidney injury, heart failure, stroke, intraoperative and postoperative hypotension, and length of hospital stay. Randomized controlled trials and observational studies were included, while case reports and case-control studies were excluded.

Findings. This meta-analysis included 5 randomized controlled trials and 4 cohort studies, with a total of 6,022 patients; 1,816 had their ACE inhibitor or ARB withheld before surgery, while 4,206 continued therapy. It found no difference between the 2 groups in the incidence of death or MACE, and there were not enough data to determine a difference in heart failure, stroke, acute kidney injury, or hospital length of stay.

Seven studies, with 5,414 patients, examined intraoperative hypotension. The overall incidence was 30%, but was significantly lower if the ACE inhibitor or ARB was withheld (OR 0.63, 95% CI 0.47–0.85, ^P = .002). Findings were similar in an analysis of only the randomized controlled trials. No difference was observed in postoperative hypotension.

Limitations. There was no standard definition of the morbidity outcomes, including hypotension and MACE. The assessment of MACE included data only for MI and not MINS. The specific duration of hypotension was not reported, and this meta-analysis did not take into account different anesthetic techniques. The duration of follow-up varied widely among studies, ranging from the day of hospital discharge to 30 days after surgery. And the randomized controlled trial performed by Shiffermiller et al⁸ was not included.

Conclusions. While continuing ACE inhibitors or ARBs before noncardiac surgery was associated with intraoperative hypotension, it did not seem to affect other outcomes, including death and MACE. The authors propose that a large randomized controlled trial is needed to determine whether continuing or withholding ACE inhibitor or ARB therapy before surgery is safer.

How should we treat MINS?

MINS is associated with an increased risk of cardiovascular events and death in both the short term and long term. MINS is defined as an elevated postoperative troponin level related to an ischemic etiology. However, whether to routinely measure troponin after surgery is unclear, as most patients do not present with ischemic symptoms, and there is no standard of care for treatment of this entity. Limited observational data suggest that starting or intensifying cardiac medications, particularly aspirin and statins, may be beneficial in terms of reducing 30-day mortality rates in patients with MI or cardiac events at 1 year in vascular surgery patients with MINS.

The Management of Myocardial Injury After Noncardiac Surgery (MANAGE) trial was designed to evaluate the potential of the anticoagulant dabigatran to prevent major vascular complications in patients with MINS.

[Devereaux PJ, Duceppe E, Guyatt G, et al. Dabigatran in patients with myocardial injury after non-cardiac surgery (MANAGE): an international, randomised, placebo-controlled trial. Lancet 2018; 391(10137):2325–2334. doi:10.1016/S0140-6736(18)30832-8]

Devereaux et al¹⁰ randomized patients who were at least 45 years old and had developed MINS within the previous 35 days to receive dabigatran 110 mg orally twice daily or placebo for up to 2 years. Patients not already taking a proton pump inhibitor were also randomized to take either omeprazole 20 mg once daily or placebo.

The primary efficacy outcome initially was major vascular complications, which included vascular mortality, nonfatal MI, nonhemorrhagic stroke, and peripheral arterial thrombosis. However, amputation and symptomatic venous thromboembolism were subsequently added during the study.

The primary safety outcome was a composite of life-threatening, major, and critical organ bleeding. Major bleeding required a decrease in hemoglobin of at least 4 g/dL, transfusion of at least 3 units of red blood cells within a 24-hour period, or a procedure to stop the bleeding.

Findings. The original goal was to recruit 3,200 patients, but due to slow enrollment and loss of funding, the sample was reduced to 1,754 patients (877 in each group). Approximately 45% of each group stopped taking the study drug prematurely.

The primary efficacy outcome occurred in significantly fewer patients receiving dabigatran (97, 11%) than placebo (133, 15%, HR 0.72, 95% CI 0.55–0.93, P = .0115). The incidence of the primary safety outcome was similar in both groups: 3% with dabigatran and 4% with placebo (HR 0.92, 95% CI 0.55–1.53, P = .76). The only individual efficacy outcome meeting statistical significance was a lower rate of nonhemorrhagic stroke in the dabigatran group. Subgroup analyses showed a trend benefiting patients randomized within 5 days of MINS or with a diagnosis of MI, although it was not statistically significant.

Limitations. The efficacy outcomes were expanded to include venous thromboembolism and others not directly related to MINS, raising questions about the conclusions. Further, as defined by the protocol, bleeding had to be fairly severe to be deemed major. The high number of patients who discontinued the study drug is another limitation of this study.

Conclusion. Dabigatran lowered the risk of major vascular complications with no significant increase in major bleeding in patients with MINS.

What is the risk of thromboembolism in postoperative atrial fibrillation, and what are the benefits of anticoagulation?

Although nonvalvular atrial fibrillation is associated with increased risks of ischemic stroke and systemic embolic events in nonsurgical patients, the association of new-onset postoperative atrial fibrillation with long-term thromboembolic events in the noncardiac surgical population is not well established.

[Butt JH, Olesen JB, Havers-Borgersen E, et al. Risk of thromboembolism associated with atrial fibrillation following noncardiac surgery. J Am Coll Cardiol 2018; 72(17):2027–2036. doi:10.1016/j.jacc.2018.07.088]

In this retrospective cohort study using a nationwide registry in Denmark, Butt et al¹¹ assessed the long-term risk of thromboembolic events in noncardiac surgical patients with new postoperative atrial fibrillation. Patients were identified who had no previous history of atrial fibrillation and developed it after noncardiac, nonobstetric surgeries, and were matched in a 1:4 ratio with patients who developed nonvalvular atrial fibrillation during nonsurgical hospitalizations. Matching was based on age, sex, heart failure, hypertension, diabetes, known history of thromboembolic events, ischemic heart disease, and the year patients presented with new atrial fibrillation.

Patients were excluded if they received antiarrhythmic drugs or oral anticoagulants before hospitalization or surgery, had cancer in the year prior, or died in the hospital.

The primary outcome of the study was thromboembolic events—a composite of ischemic stroke, transient cerebral ischemia, and peripheral arterial thrombosis or embolism. Secondary outcomes included rehospitalization for atrial fibrillation and all-cause mortality.

Findings. Overall, 0.4% of patients developed new postoperative atrial fibrillation, of whom 3,380 were matched with 15,320 patients with nonvalvular atrial fibrillation. Over a median follow-up of 3.2 years, the risk of thromboembolic events was similar in both groups (31.7 and 29.9 per 1,000 person-years, HR 0.95, 95% CI 0.85–1.07). The groups did not differ in their CHA₂DS₂-VASc risk scores, HAS-BLED risk scores, or year in which patients were diagnosed.

Anticoagulation lowered the risk of thromboembolic events to a similar extent in both groups compared with no anticoagulation:

• In postoperative atrial fibrillation—HR 0.57, 95% CI 0.40–0.67
• In nonvalvular atrial fibrillation—HR 0.56, 95% CI 0.51–0.62.

Despite the similar reduction in thromboembolic events, only 24.4% of the postoperative atrial fibrillation patients were started on anticoagulation therapy within 30 days of discharge, compared with 41.5% of those with nonvalvular atrial fibrillation.

Limitations. Although this was a large study with excellent follow-up data, it was observational. It may have underestimated the number of patients who developed postoperative atrial fibrillation because episodes that were judged not to be clinically significant may not have been charted. Many patients are not monitored with continuous telemetry postoperatively, which also may have led to underestimation of the number of atrial fibrillation events.

The study also did not examine the number of atrial fibrillation episodes per patient, the heart rhythm at discharge or long-term, or indication for and duration of anticoagulation. There were no data regarding international normalized ratio levels.

Conclusions. Postoperative atrial fibrillation is associated with outcomes similar to those of nonsurgical nonvalvular atrial fibrillation. Anticoagulation decreases the risks of stroke and death. However, substantially fewer patients with postoperative atrial fibrillation receive anticoagulation. Anticoagulation should be considered in these patients, while noting bleeding risk.

Perioperative medicine is an evolving field with a rapidly growing body of literature, particularly in cardiology.

In this update, we review 6 articles to answer questions related to preoperative cardiac risk assessment, perioperative medication management, and postoperative cardiac complications. We surveyed perioperative literature from February 2018 through January 2019 and chose the final articles by consensus, based on relevance to clinicians who provide preoperative evaluations and postoperative care to surgical patients.

These summaries are derived from “Updates in Perioperative Medicine” presented at the 14th Annual Perioperative Medicine Summit (Orlando, FL, February 13–16, 2019) and the 2019 Society of Hospital Medicine Annual Meeting (National Harbor, MD, March 24–27, 2019).

PREOPERATIVE CARDIAC EVALUATION

How well do measures of functional capacity predict perioperative complications and mortality in noncardiac surgical patients?

Functional capacity is commonly assessed in preoperative evaluations to estimate patients’ risks of perioperative complications and death. The American College of Cardiology/American Heart Association¹ and the European Society of Cardiology² guidelines both include estimation of cardiopulmonary fitness as a step in preoperative assessment before major noncardiac surgery.

“Subjective assessment” is one way to estimate functional capacity. Simply put, clinicians try to form a rough idea about the fitness of patients by asking questions about routine activities such as walking or climbing stairs. Although commonly used, subjective assessment of functional capacity lacks strong evidence that it predicts adverse perioperative events.

Cardiopulmonary exercise testing is a third option. It measures peak oxygen consumption and anaerobic threshold during exercise. It is probably the best objective measurement of functional capacity, but not necessarily for predicting postoperative cardiac complications, and it is performed relatively infrequently.

[Wijeysundera DN, Pearse RM, Sulman MA, et al. Assessment of functional capacity before major non-cardiac surgery: an international, prospective cohort study. Lancet 2018; 391(10140):2631–2640. doi:10.1016/S0140-6736(18)31131-0]

In a multicenter, prospective cohort study, Wijeysundera et al⁴ compared subjective functional capacity assessment, the Duke Activity Status Index, cardiopulmonary exercise testing, and the preoperative N-terminal pro-B-type natriuretic peptide (NT-proBNP) level in their ability to predict complications and death in 1,401 noncardiac surgery patients older than 40 with at least 1 cardiovascular risk factor. After surgery, patients had daily electrocardiograms and troponin measurements until postoperative day 3 or discharge.

The primary outcome was the 30-day incidence of death or myocardial infarction (MI). Additional outcomes included the 30-day incidence of death or myocardial injury after noncardiac surgery (MINS), the 1-year mortality rate, and moderate to severe in-hospital perioperative complications.

Findings. Two percent of patients died or had an MI within 30 days of surgery.⁴

Subjective assessment had only a 19.2% sensitivity (95% confidence interval [CI] 14.2–25) but a 94.7% specificity (95% CI 93.2–95.9) for predicting inability to attain 4 metabolic equivalents during exercise.⁴

A lower Duke Activity Status Index predicted the primary outcome of death or MI within 30 days (adjusted odds ratio [OR] 0.96, 95% CI 0.83–0.99, P = .03), and it was the only measure that did so. Additionally, the Duke index and NT-proBNP level predicted the risk of death or MINS within 30 days.⁴

Only elevated NT-proBNP was associated with death at 1 year.⁴

On exercise testing, low peak oxygen consumption was significantly associated with perioperative complications.

Limitations. The number of primary outcome events (death and MI) was low, potentially affecting the statistical power of the study.

Conclusions. Subjective assessment of functional capacity misclassifies too many patients as being at low risk of perioperative complications and should not be used for preoperative risk stratification. Other tools, such as the Duke Activity Status Index and NT-proBNP levels, are better predictors of adverse perioperative cardiovascular outcomes and should be considered for use in preoperative cardiac risk assessment.

Although the Duke Activity Status Index is a better predictor of adverse outcomes than subjective functional capacity assessment, a specific perioperative threshold for risk classification has not been established. Its correlate for metabolic equivalents should be considered for use in clinical practice at this point.

Is perioperative aspirin beneficial in patients undergoing vascular surgery?

The Perioperative Ischemic Evaluation 2 (POISE-2) trial,⁵ a 2-by-2 factorial randomized controlled trial in which patients received perioperative aspirin, clonidine, both, or neither, demonstrated that perioperative aspirin did not reduce cardiovascular events and increased major bleeding. Patients with recently placed coronary stents and those undergoing carotid endarterectomy were excluded because aspirin is known to have a beneficial effect in these patients.

A subsequent substudy⁶ found perioperative aspirin to be beneficial in patients with coronary stents placed more than a year before noncardiac surgery. Whether perioperative aspirin is beneficial in other subgroups was unknown.

[Biccard BM, Sigamani A, Chan MTV, et al. Effect of aspirin in vascular surgery in patients from a randomized clinical trial (POISE-2). Br J Surg 2018; 105(12):1591–1597. doi:10.1002/bjs.10925]

Biccard et al⁷ investigated the effect of perioperative aspirin in the subgroup of patients from the POISE-2 trial who underwent vascular surgery. The primary outcome was death or MI within 30 days. Secondary outcomes in this substudy included vascular occlusive complications (amputation and peripheral arterial thrombosis) and major or life-threatening bleeding.

Limitations. There were few adverse events, and this substudy was underpowered for the primary and secondary outcomes.

Conclusion. Starting or continuing aspirin did not improve outcomes, and withdrawing it did not increase cardiovascular or occlusive complications.

Do ACE inhibitors affect risk in noncardiac nonvascular surgery?

Angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs) are some of the most commonly used medications for treating hypertension. But whether patients should continue receiving them on the day of surgery or whether they should be held remains unclear.

Although current recommendations are inconsistent, the most recent American College of Cardiology/American Heart Association¹ perioperative practice guidelines say that continuing ACE inhibitors or ARBs is reasonable perioperatively. This recommendation, however, acknowledges that published evidence is limited. There is general agreement that preoperative exposure to ACE inhibitors and ARBs is associated with intraoperative hypotension, but whether this increases the risk of adverse clinical outcomes remains unclear. Needed was a study to determine the effect on perioperative morbidity and mortality of continuing vs withholding ACE inhibitors and ARBs before surgery.

[Shiffermiller JF, Monson BJ, Vokoun CW, et al. Prospective randomized evaluation of preoperative angiotensin-converting enzyme inhibition (PREOP-ACEI). J Hosp Med 2018; 13(10):661–667. doi:10.12788/jhm.3036]

Shiffermiller et al⁸ performed a randomized controlled trial comparing the effect of 2 preoperative ACE inhibitor management protocols in patients undergoing noncardiac nonvascular surgery. Patients were randomized to either receive or not receive their final preoperative ACE inhibitor dose, whether scheduled on the morning of surgery or the night before.

Exclusion criteria included hypotension or hypertension at their preoperative clinic appointment (defined as systolic blood pressure < 90 or ≥ 160 mm Hg, and diastolic blood pressure < 60 or ≥ 95 mm Hg), moderate to severe heart failure, and end-stage renal disease requiring dialysis. Excluded surgery types were cardiac, vascular, organ transplant, oncologic, and all outpatient procedures. Patients taking ARBs were also excluded.

The primary outcome was intraoperative hypotension defined as any systolic blood pressure less than 80 mm Hg from the time of anesthesia induction until transfer to the postanesthesia care unit. Secondary outcomes were measured until hospital discharge and included postoperative acute kidney injury, postoperative hypotension (systolic pressure < 90 mm Hg) and hypertension (systolic pressure > 180 mm Hg), major cardiac events (composite of acute coronary syndrome, acute heart failure, or new-onset arrhythmia), and death.

Findings. A total of 453 patients were screened for eligibility, and of these, 291 were included for randomization. Their average age was 64, 48% were men, and 87% were white. About 50% underwent general anesthesia, 25% spinal, and 25% regional. Over half of the surgeries were orthopedic, and 20% were spine surgeries.

The primary outcome of intraoperative hypotension occurred significantly less often in patients randomized to ACE inhibitor omission than in the continuation group (55% vs 69%, relative risk [RR] 0.81, 95% CI 0.67–0.97, P = .03). This translates to 1 case of intraoperative hypotension for every 7.5 patients continuing an ACE inhibitor perioperatively (number needed to harm 7.5). Intraoperative hypotension associated with vasopressor administration also occurred significantly less frequently in the ACE inhibitor omission group.

Patients in the ACE inhibitor omission group were also less likely to experience postoperative hypotension, but on the other hand, they were more likely to experience severe postoperative hypertension (defined as any systolic blood pressure > 180 mm Hg). The two groups fared the same in terms of rates of acute kidney injury and major adverse cardiac events (MACE) and hospital length of stay, and no patients died in either group.

Limitations. Several factors limit the generalizability of this single-center study, including the many exclusion criteria, the predominance of orthopedic and spine surgeries, and the low-risk patient population (the average Revised Cardiac Risk Index score was 0, range 0–3). Other limitations include not controlling for the specific ACE inhibitor used and not including the precise timing of the final dose in relation to surgery. Lastly, this study lacked power to measure postoperative outcomes.

Conclusions. Continuing ACE inhibitor treatment before noncardiac nonvascular surgery is associated with a greater frequency and duration of intraoperative hypotension, but it did not increase the incidences of acute kidney injury, MACE, or death nor the hospital length of stay.

[Hollmann C, Fernandes NL, Biccard BM. A systematic review of outcomes associated with withholding or continuing angiotensin-converting enzyme inhibitors and angiotensin receptor blockers before noncardiac surgery. Anesth Analg 2018; 127(3):678–687. doi:10.1213/ANE.0000000000002837]

Hollmann et al⁹ performed a meta-analysis to determine whether it is better to continue or withhold ACE inhibitors and ARBs before surgery. The patients were adults undergoing noncardiac surgery and receiving an ACE inhibitor or ARB, which was either withheld or continued on the morning of surgery.

Primary outcomes were all-cause mortality and MACE, while secondary outcomes included the incidence of acute kidney injury, heart failure, stroke, intraoperative and postoperative hypotension, and length of hospital stay. Randomized controlled trials and observational studies were included, while case reports and case-control studies were excluded.

Findings. This meta-analysis included 5 randomized controlled trials and 4 cohort studies, with a total of 6,022 patients; 1,816 had their ACE inhibitor or ARB withheld before surgery, while 4,206 continued therapy. It found no difference between the 2 groups in the incidence of death or MACE, and there were not enough data to determine a difference in heart failure, stroke, acute kidney injury, or hospital length of stay.

Seven studies, with 5,414 patients, examined intraoperative hypotension. The overall incidence was 30%, but was significantly lower if the ACE inhibitor or ARB was withheld (OR 0.63, 95% CI 0.47–0.85, ^P = .002). Findings were similar in an analysis of only the randomized controlled trials. No difference was observed in postoperative hypotension.

Limitations. There was no standard definition of the morbidity outcomes, including hypotension and MACE. The assessment of MACE included data only for MI and not MINS. The specific duration of hypotension was not reported, and this meta-analysis did not take into account different anesthetic techniques. The duration of follow-up varied widely among studies, ranging from the day of hospital discharge to 30 days after surgery. And the randomized controlled trial performed by Shiffermiller et al⁸ was not included.

Conclusions. While continuing ACE inhibitors or ARBs before noncardiac surgery was associated with intraoperative hypotension, it did not seem to affect other outcomes, including death and MACE. The authors propose that a large randomized controlled trial is needed to determine whether continuing or withholding ACE inhibitor or ARB therapy before surgery is safer.

How should we treat MINS?

MINS is associated with an increased risk of cardiovascular events and death in both the short term and long term. MINS is defined as an elevated postoperative troponin level related to an ischemic etiology. However, whether to routinely measure troponin after surgery is unclear, as most patients do not present with ischemic symptoms, and there is no standard of care for treatment of this entity. Limited observational data suggest that starting or intensifying cardiac medications, particularly aspirin and statins, may be beneficial in terms of reducing 30-day mortality rates in patients with MI or cardiac events at 1 year in vascular surgery patients with MINS.

The Management of Myocardial Injury After Noncardiac Surgery (MANAGE) trial was designed to evaluate the potential of the anticoagulant dabigatran to prevent major vascular complications in patients with MINS.

[Devereaux PJ, Duceppe E, Guyatt G, et al. Dabigatran in patients with myocardial injury after non-cardiac surgery (MANAGE): an international, randomised, placebo-controlled trial. Lancet 2018; 391(10137):2325–2334. doi:10.1016/S0140-6736(18)30832-8]

Devereaux et al¹⁰ randomized patients who were at least 45 years old and had developed MINS within the previous 35 days to receive dabigatran 110 mg orally twice daily or placebo for up to 2 years. Patients not already taking a proton pump inhibitor were also randomized to take either omeprazole 20 mg once daily or placebo.

The primary efficacy outcome initially was major vascular complications, which included vascular mortality, nonfatal MI, nonhemorrhagic stroke, and peripheral arterial thrombosis. However, amputation and symptomatic venous thromboembolism were subsequently added during the study.

The primary safety outcome was a composite of life-threatening, major, and critical organ bleeding. Major bleeding required a decrease in hemoglobin of at least 4 g/dL, transfusion of at least 3 units of red blood cells within a 24-hour period, or a procedure to stop the bleeding.

Findings. The original goal was to recruit 3,200 patients, but due to slow enrollment and loss of funding, the sample was reduced to 1,754 patients (877 in each group). Approximately 45% of each group stopped taking the study drug prematurely.

The primary efficacy outcome occurred in significantly fewer patients receiving dabigatran (97, 11%) than placebo (133, 15%, HR 0.72, 95% CI 0.55–0.93, P = .0115). The incidence of the primary safety outcome was similar in both groups: 3% with dabigatran and 4% with placebo (HR 0.92, 95% CI 0.55–1.53, P = .76). The only individual efficacy outcome meeting statistical significance was a lower rate of nonhemorrhagic stroke in the dabigatran group. Subgroup analyses showed a trend benefiting patients randomized within 5 days of MINS or with a diagnosis of MI, although it was not statistically significant.

Limitations. The efficacy outcomes were expanded to include venous thromboembolism and others not directly related to MINS, raising questions about the conclusions. Further, as defined by the protocol, bleeding had to be fairly severe to be deemed major. The high number of patients who discontinued the study drug is another limitation of this study.

Conclusion. Dabigatran lowered the risk of major vascular complications with no significant increase in major bleeding in patients with MINS.

What is the risk of thromboembolism in postoperative atrial fibrillation, and what are the benefits of anticoagulation?

Although nonvalvular atrial fibrillation is associated with increased risks of ischemic stroke and systemic embolic events in nonsurgical patients, the association of new-onset postoperative atrial fibrillation with long-term thromboembolic events in the noncardiac surgical population is not well established.

[Butt JH, Olesen JB, Havers-Borgersen E, et al. Risk of thromboembolism associated with atrial fibrillation following noncardiac surgery. J Am Coll Cardiol 2018; 72(17):2027–2036. doi:10.1016/j.jacc.2018.07.088]

In this retrospective cohort study using a nationwide registry in Denmark, Butt et al¹¹ assessed the long-term risk of thromboembolic events in noncardiac surgical patients with new postoperative atrial fibrillation. Patients were identified who had no previous history of atrial fibrillation and developed it after noncardiac, nonobstetric surgeries, and were matched in a 1:4 ratio with patients who developed nonvalvular atrial fibrillation during nonsurgical hospitalizations. Matching was based on age, sex, heart failure, hypertension, diabetes, known history of thromboembolic events, ischemic heart disease, and the year patients presented with new atrial fibrillation.

Patients were excluded if they received antiarrhythmic drugs or oral anticoagulants before hospitalization or surgery, had cancer in the year prior, or died in the hospital.

The primary outcome of the study was thromboembolic events—a composite of ischemic stroke, transient cerebral ischemia, and peripheral arterial thrombosis or embolism. Secondary outcomes included rehospitalization for atrial fibrillation and all-cause mortality.

Findings. Overall, 0.4% of patients developed new postoperative atrial fibrillation, of whom 3,380 were matched with 15,320 patients with nonvalvular atrial fibrillation. Over a median follow-up of 3.2 years, the risk of thromboembolic events was similar in both groups (31.7 and 29.9 per 1,000 person-years, HR 0.95, 95% CI 0.85–1.07). The groups did not differ in their CHA₂DS₂-VASc risk scores, HAS-BLED risk scores, or year in which patients were diagnosed.

Anticoagulation lowered the risk of thromboembolic events to a similar extent in both groups compared with no anticoagulation:

• In postoperative atrial fibrillation—HR 0.57, 95% CI 0.40–0.67
• In nonvalvular atrial fibrillation—HR 0.56, 95% CI 0.51–0.62.

Despite the similar reduction in thromboembolic events, only 24.4% of the postoperative atrial fibrillation patients were started on anticoagulation therapy within 30 days of discharge, compared with 41.5% of those with nonvalvular atrial fibrillation.

Limitations. Although this was a large study with excellent follow-up data, it was observational. It may have underestimated the number of patients who developed postoperative atrial fibrillation because episodes that were judged not to be clinically significant may not have been charted. Many patients are not monitored with continuous telemetry postoperatively, which also may have led to underestimation of the number of atrial fibrillation events.

The study also did not examine the number of atrial fibrillation episodes per patient, the heart rhythm at discharge or long-term, or indication for and duration of anticoagulation. There were no data regarding international normalized ratio levels.

Conclusions. Postoperative atrial fibrillation is associated with outcomes similar to those of nonsurgical nonvalvular atrial fibrillation. Anticoagulation decreases the risks of stroke and death. However, substantially fewer patients with postoperative atrial fibrillation receive anticoagulation. Anticoagulation should be considered in these patients, while noting bleeding risk.

Perioperative medicine is an evolving field with a rapidly growing body of literature, particularly in cardiology.

In this update, we review 6 articles to answer questions related to preoperative cardiac risk assessment, perioperative medication management, and postoperative cardiac complications. We surveyed perioperative literature from February 2018 through January 2019 and chose the final articles by consensus, based on relevance to clinicians who provide preoperative evaluations and postoperative care to surgical patients.

These summaries are derived from “Updates in Perioperative Medicine” presented at the 14th Annual Perioperative Medicine Summit (Orlando, FL, February 13–16, 2019) and the 2019 Society of Hospital Medicine Annual Meeting (National Harbor, MD, March 24–27, 2019).

PREOPERATIVE CARDIAC EVALUATION

How well do measures of functional capacity predict perioperative complications and mortality in noncardiac surgical patients?

Functional capacity is commonly assessed in preoperative evaluations to estimate patients’ risks of perioperative complications and death. The American College of Cardiology/American Heart Association¹ and the European Society of Cardiology² guidelines both include estimation of cardiopulmonary fitness as a step in preoperative assessment before major noncardiac surgery.

“Subjective assessment” is one way to estimate functional capacity. Simply put, clinicians try to form a rough idea about the fitness of patients by asking questions about routine activities such as walking or climbing stairs. Although commonly used, subjective assessment of functional capacity lacks strong evidence that it predicts adverse perioperative events.

Cardiopulmonary exercise testing is a third option. It measures peak oxygen consumption and anaerobic threshold during exercise. It is probably the best objective measurement of functional capacity, but not necessarily for predicting postoperative cardiac complications, and it is performed relatively infrequently.

[Wijeysundera DN, Pearse RM, Sulman MA, et al. Assessment of functional capacity before major non-cardiac surgery: an international, prospective cohort study. Lancet 2018; 391(10140):2631–2640. doi:10.1016/S0140-6736(18)31131-0]

In a multicenter, prospective cohort study, Wijeysundera et al⁴ compared subjective functional capacity assessment, the Duke Activity Status Index, cardiopulmonary exercise testing, and the preoperative N-terminal pro-B-type natriuretic peptide (NT-proBNP) level in their ability to predict complications and death in 1,401 noncardiac surgery patients older than 40 with at least 1 cardiovascular risk factor. After surgery, patients had daily electrocardiograms and troponin measurements until postoperative day 3 or discharge.

The primary outcome was the 30-day incidence of death or myocardial infarction (MI). Additional outcomes included the 30-day incidence of death or myocardial injury after noncardiac surgery (MINS), the 1-year mortality rate, and moderate to severe in-hospital perioperative complications.

Findings. Two percent of patients died or had an MI within 30 days of surgery.⁴

Subjective assessment had only a 19.2% sensitivity (95% confidence interval [CI] 14.2–25) but a 94.7% specificity (95% CI 93.2–95.9) for predicting inability to attain 4 metabolic equivalents during exercise.⁴

A lower Duke Activity Status Index predicted the primary outcome of death or MI within 30 days (adjusted odds ratio [OR] 0.96, 95% CI 0.83–0.99, P = .03), and it was the only measure that did so. Additionally, the Duke index and NT-proBNP level predicted the risk of death or MINS within 30 days.⁴

Only elevated NT-proBNP was associated with death at 1 year.⁴

On exercise testing, low peak oxygen consumption was significantly associated with perioperative complications.

Limitations. The number of primary outcome events (death and MI) was low, potentially affecting the statistical power of the study.

Conclusions. Subjective assessment of functional capacity misclassifies too many patients as being at low risk of perioperative complications and should not be used for preoperative risk stratification. Other tools, such as the Duke Activity Status Index and NT-proBNP levels, are better predictors of adverse perioperative cardiovascular outcomes and should be considered for use in preoperative cardiac risk assessment.

Although the Duke Activity Status Index is a better predictor of adverse outcomes than subjective functional capacity assessment, a specific perioperative threshold for risk classification has not been established. Its correlate for metabolic equivalents should be considered for use in clinical practice at this point.

Is perioperative aspirin beneficial in patients undergoing vascular surgery?

The Perioperative Ischemic Evaluation 2 (POISE-2) trial,⁵ a 2-by-2 factorial randomized controlled trial in which patients received perioperative aspirin, clonidine, both, or neither, demonstrated that perioperative aspirin did not reduce cardiovascular events and increased major bleeding. Patients with recently placed coronary stents and those undergoing carotid endarterectomy were excluded because aspirin is known to have a beneficial effect in these patients.

A subsequent substudy⁶ found perioperative aspirin to be beneficial in patients with coronary stents placed more than a year before noncardiac surgery. Whether perioperative aspirin is beneficial in other subgroups was unknown.

[Biccard BM, Sigamani A, Chan MTV, et al. Effect of aspirin in vascular surgery in patients from a randomized clinical trial (POISE-2). Br J Surg 2018; 105(12):1591–1597. doi:10.1002/bjs.10925]

Biccard et al⁷ investigated the effect of perioperative aspirin in the subgroup of patients from the POISE-2 trial who underwent vascular surgery. The primary outcome was death or MI within 30 days. Secondary outcomes in this substudy included vascular occlusive complications (amputation and peripheral arterial thrombosis) and major or life-threatening bleeding.

Limitations. There were few adverse events, and this substudy was underpowered for the primary and secondary outcomes.

Conclusion. Starting or continuing aspirin did not improve outcomes, and withdrawing it did not increase cardiovascular or occlusive complications.

Do ACE inhibitors affect risk in noncardiac nonvascular surgery?

Angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs) are some of the most commonly used medications for treating hypertension. But whether patients should continue receiving them on the day of surgery or whether they should be held remains unclear.

Although current recommendations are inconsistent, the most recent American College of Cardiology/American Heart Association¹ perioperative practice guidelines say that continuing ACE inhibitors or ARBs is reasonable perioperatively. This recommendation, however, acknowledges that published evidence is limited. There is general agreement that preoperative exposure to ACE inhibitors and ARBs is associated with intraoperative hypotension, but whether this increases the risk of adverse clinical outcomes remains unclear. Needed was a study to determine the effect on perioperative morbidity and mortality of continuing vs withholding ACE inhibitors and ARBs before surgery.

[Shiffermiller JF, Monson BJ, Vokoun CW, et al. Prospective randomized evaluation of preoperative angiotensin-converting enzyme inhibition (PREOP-ACEI). J Hosp Med 2018; 13(10):661–667. doi:10.12788/jhm.3036]

Shiffermiller et al⁸ performed a randomized controlled trial comparing the effect of 2 preoperative ACE inhibitor management protocols in patients undergoing noncardiac nonvascular surgery. Patients were randomized to either receive or not receive their final preoperative ACE inhibitor dose, whether scheduled on the morning of surgery or the night before.

Exclusion criteria included hypotension or hypertension at their preoperative clinic appointment (defined as systolic blood pressure < 90 or ≥ 160 mm Hg, and diastolic blood pressure < 60 or ≥ 95 mm Hg), moderate to severe heart failure, and end-stage renal disease requiring dialysis. Excluded surgery types were cardiac, vascular, organ transplant, oncologic, and all outpatient procedures. Patients taking ARBs were also excluded.

The primary outcome was intraoperative hypotension defined as any systolic blood pressure less than 80 mm Hg from the time of anesthesia induction until transfer to the postanesthesia care unit. Secondary outcomes were measured until hospital discharge and included postoperative acute kidney injury, postoperative hypotension (systolic pressure < 90 mm Hg) and hypertension (systolic pressure > 180 mm Hg), major cardiac events (composite of acute coronary syndrome, acute heart failure, or new-onset arrhythmia), and death.

Findings. A total of 453 patients were screened for eligibility, and of these, 291 were included for randomization. Their average age was 64, 48% were men, and 87% were white. About 50% underwent general anesthesia, 25% spinal, and 25% regional. Over half of the surgeries were orthopedic, and 20% were spine surgeries.

The primary outcome of intraoperative hypotension occurred significantly less often in patients randomized to ACE inhibitor omission than in the continuation group (55% vs 69%, relative risk [RR] 0.81, 95% CI 0.67–0.97, P = .03). This translates to 1 case of intraoperative hypotension for every 7.5 patients continuing an ACE inhibitor perioperatively (number needed to harm 7.5). Intraoperative hypotension associated with vasopressor administration also occurred significantly less frequently in the ACE inhibitor omission group.

Patients in the ACE inhibitor omission group were also less likely to experience postoperative hypotension, but on the other hand, they were more likely to experience severe postoperative hypertension (defined as any systolic blood pressure > 180 mm Hg). The two groups fared the same in terms of rates of acute kidney injury and major adverse cardiac events (MACE) and hospital length of stay, and no patients died in either group.

Limitations. Several factors limit the generalizability of this single-center study, including the many exclusion criteria, the predominance of orthopedic and spine surgeries, and the low-risk patient population (the average Revised Cardiac Risk Index score was 0, range 0–3). Other limitations include not controlling for the specific ACE inhibitor used and not including the precise timing of the final dose in relation to surgery. Lastly, this study lacked power to measure postoperative outcomes.

Conclusions. Continuing ACE inhibitor treatment before noncardiac nonvascular surgery is associated with a greater frequency and duration of intraoperative hypotension, but it did not increase the incidences of acute kidney injury, MACE, or death nor the hospital length of stay.

[Hollmann C, Fernandes NL, Biccard BM. A systematic review of outcomes associated with withholding or continuing angiotensin-converting enzyme inhibitors and angiotensin receptor blockers before noncardiac surgery. Anesth Analg 2018; 127(3):678–687. doi:10.1213/ANE.0000000000002837]

Hollmann et al⁹ performed a meta-analysis to determine whether it is better to continue or withhold ACE inhibitors and ARBs before surgery. The patients were adults undergoing noncardiac surgery and receiving an ACE inhibitor or ARB, which was either withheld or continued on the morning of surgery.

Primary outcomes were all-cause mortality and MACE, while secondary outcomes included the incidence of acute kidney injury, heart failure, stroke, intraoperative and postoperative hypotension, and length of hospital stay. Randomized controlled trials and observational studies were included, while case reports and case-control studies were excluded.

Findings. This meta-analysis included 5 randomized controlled trials and 4 cohort studies, with a total of 6,022 patients; 1,816 had their ACE inhibitor or ARB withheld before surgery, while 4,206 continued therapy. It found no difference between the 2 groups in the incidence of death or MACE, and there were not enough data to determine a difference in heart failure, stroke, acute kidney injury, or hospital length of stay.

Seven studies, with 5,414 patients, examined intraoperative hypotension. The overall incidence was 30%, but was significantly lower if the ACE inhibitor or ARB was withheld (OR 0.63, 95% CI 0.47–0.85, ^P = .002). Findings were similar in an analysis of only the randomized controlled trials. No difference was observed in postoperative hypotension.

Limitations. There was no standard definition of the morbidity outcomes, including hypotension and MACE. The assessment of MACE included data only for MI and not MINS. The specific duration of hypotension was not reported, and this meta-analysis did not take into account different anesthetic techniques. The duration of follow-up varied widely among studies, ranging from the day of hospital discharge to 30 days after surgery. And the randomized controlled trial performed by Shiffermiller et al⁸ was not included.

Conclusions. While continuing ACE inhibitors or ARBs before noncardiac surgery was associated with intraoperative hypotension, it did not seem to affect other outcomes, including death and MACE. The authors propose that a large randomized controlled trial is needed to determine whether continuing or withholding ACE inhibitor or ARB therapy before surgery is safer.

How should we treat MINS?

MINS is associated with an increased risk of cardiovascular events and death in both the short term and long term. MINS is defined as an elevated postoperative troponin level related to an ischemic etiology. However, whether to routinely measure troponin after surgery is unclear, as most patients do not present with ischemic symptoms, and there is no standard of care for treatment of this entity. Limited observational data suggest that starting or intensifying cardiac medications, particularly aspirin and statins, may be beneficial in terms of reducing 30-day mortality rates in patients with MI or cardiac events at 1 year in vascular surgery patients with MINS.

The Management of Myocardial Injury After Noncardiac Surgery (MANAGE) trial was designed to evaluate the potential of the anticoagulant dabigatran to prevent major vascular complications in patients with MINS.

[Devereaux PJ, Duceppe E, Guyatt G, et al. Dabigatran in patients with myocardial injury after non-cardiac surgery (MANAGE): an international, randomised, placebo-controlled trial. Lancet 2018; 391(10137):2325–2334. doi:10.1016/S0140-6736(18)30832-8]

Devereaux et al¹⁰ randomized patients who were at least 45 years old and had developed MINS within the previous 35 days to receive dabigatran 110 mg orally twice daily or placebo for up to 2 years. Patients not already taking a proton pump inhibitor were also randomized to take either omeprazole 20 mg once daily or placebo.

The primary efficacy outcome initially was major vascular complications, which included vascular mortality, nonfatal MI, nonhemorrhagic stroke, and peripheral arterial thrombosis. However, amputation and symptomatic venous thromboembolism were subsequently added during the study.

The primary safety outcome was a composite of life-threatening, major, and critical organ bleeding. Major bleeding required a decrease in hemoglobin of at least 4 g/dL, transfusion of at least 3 units of red blood cells within a 24-hour period, or a procedure to stop the bleeding.

Findings. The original goal was to recruit 3,200 patients, but due to slow enrollment and loss of funding, the sample was reduced to 1,754 patients (877 in each group). Approximately 45% of each group stopped taking the study drug prematurely.

The primary efficacy outcome occurred in significantly fewer patients receiving dabigatran (97, 11%) than placebo (133, 15%, HR 0.72, 95% CI 0.55–0.93, P = .0115). The incidence of the primary safety outcome was similar in both groups: 3% with dabigatran and 4% with placebo (HR 0.92, 95% CI 0.55–1.53, P = .76). The only individual efficacy outcome meeting statistical significance was a lower rate of nonhemorrhagic stroke in the dabigatran group. Subgroup analyses showed a trend benefiting patients randomized within 5 days of MINS or with a diagnosis of MI, although it was not statistically significant.

Limitations. The efficacy outcomes were expanded to include venous thromboembolism and others not directly related to MINS, raising questions about the conclusions. Further, as defined by the protocol, bleeding had to be fairly severe to be deemed major. The high number of patients who discontinued the study drug is another limitation of this study.

Conclusion. Dabigatran lowered the risk of major vascular complications with no significant increase in major bleeding in patients with MINS.

What is the risk of thromboembolism in postoperative atrial fibrillation, and what are the benefits of anticoagulation?

Although nonvalvular atrial fibrillation is associated with increased risks of ischemic stroke and systemic embolic events in nonsurgical patients, the association of new-onset postoperative atrial fibrillation with long-term thromboembolic events in the noncardiac surgical population is not well established.

[Butt JH, Olesen JB, Havers-Borgersen E, et al. Risk of thromboembolism associated with atrial fibrillation following noncardiac surgery. J Am Coll Cardiol 2018; 72(17):2027–2036. doi:10.1016/j.jacc.2018.07.088]

In this retrospective cohort study using a nationwide registry in Denmark, Butt et al¹¹ assessed the long-term risk of thromboembolic events in noncardiac surgical patients with new postoperative atrial fibrillation. Patients were identified who had no previous history of atrial fibrillation and developed it after noncardiac, nonobstetric surgeries, and were matched in a 1:4 ratio with patients who developed nonvalvular atrial fibrillation during nonsurgical hospitalizations. Matching was based on age, sex, heart failure, hypertension, diabetes, known history of thromboembolic events, ischemic heart disease, and the year patients presented with new atrial fibrillation.

Patients were excluded if they received antiarrhythmic drugs or oral anticoagulants before hospitalization or surgery, had cancer in the year prior, or died in the hospital.

The primary outcome of the study was thromboembolic events—a composite of ischemic stroke, transient cerebral ischemia, and peripheral arterial thrombosis or embolism. Secondary outcomes included rehospitalization for atrial fibrillation and all-cause mortality.

Findings. Overall, 0.4% of patients developed new postoperative atrial fibrillation, of whom 3,380 were matched with 15,320 patients with nonvalvular atrial fibrillation. Over a median follow-up of 3.2 years, the risk of thromboembolic events was similar in both groups (31.7 and 29.9 per 1,000 person-years, HR 0.95, 95% CI 0.85–1.07). The groups did not differ in their CHA₂DS₂-VASc risk scores, HAS-BLED risk scores, or year in which patients were diagnosed.

Anticoagulation lowered the risk of thromboembolic events to a similar extent in both groups compared with no anticoagulation:

• In postoperative atrial fibrillation—HR 0.57, 95% CI 0.40–0.67
• In nonvalvular atrial fibrillation—HR 0.56, 95% CI 0.51–0.62.

Despite the similar reduction in thromboembolic events, only 24.4% of the postoperative atrial fibrillation patients were started on anticoagulation therapy within 30 days of discharge, compared with 41.5% of those with nonvalvular atrial fibrillation.

Limitations. Although this was a large study with excellent follow-up data, it was observational. It may have underestimated the number of patients who developed postoperative atrial fibrillation because episodes that were judged not to be clinically significant may not have been charted. Many patients are not monitored with continuous telemetry postoperatively, which also may have led to underestimation of the number of atrial fibrillation events.

The study also did not examine the number of atrial fibrillation episodes per patient, the heart rhythm at discharge or long-term, or indication for and duration of anticoagulation. There were no data regarding international normalized ratio levels.

Conclusions. Postoperative atrial fibrillation is associated with outcomes similar to those of nonsurgical nonvalvular atrial fibrillation. Anticoagulation decreases the risks of stroke and death. However, substantially fewer patients with postoperative atrial fibrillation receive anticoagulation. Anticoagulation should be considered in these patients, while noting bleeding risk.

Over the last 3 decades, the endoscope has become a highly valued visualization tool in neurosurgery, applicable to a broad range of neurosurgical procedures. Following the pace of technological innovations, the quality of the instrumentation has greatly improved along with the status of endoscopy in the neurosurgical field. The use of the endoscope in interdisciplinary extended transnasal approaches revolutionized skull-base surgery.¹ Transcranial neurosurgery took advantage of the endoscope for inspection, endoscope-assisted, and endoscope-controlled procedures, although the main visualization tool during these interventions remains the operating microscope.

At present, endoscopy has applications in a variety of neurosurgical procedures including transnasal approaches for pituitary and other skull-base tumors, third ventriculostomy, and resection of intraventricular tumors. The range of application is expanding to include extracranial procedures such as peripheral nerve and spine surgery.

From Li KW, Nelson C, Suk I, Jallo GI. Neuroendoscopy: past, present, and future. Neurosurg Focus 2005; 19(6):E1. Figure used with permission.

CURRENT CONCEPTS

Hopf and Perneczky² defined the terminology regarding endoscopic procedures and divided them into 3 categories:

Pure endoscopic neurosurgery, ie, procedures performed through working channels under complete endoscopic visualization and with endoscopic instrumentation (Figure 1).³

Endoscope-controlled microsurgery, ie, operations performed with standard microsurgical instruments under endoscopic visualization—the microscope is not used (Figure 2).

Endoscope-assisted neurosurgery, ie, the use of both microscope and endoscope during the same intervention. In endoscopic inspection the endoscope is solely used as an adjunctive tool for visualization and not for surgical manipulations.

Enhanced area and surgical dissection

Technical innovations are probably the major reason for the growing role of endoscopy in neurosurgery over the last 3 decades.⁴ High-definition imaging, neuronavigation, new instruments, an interdisciplinary approach mostly with ear, nose, and throat (ENT) surgeons, and detailed anatomic studies led to the breakthrough of endoscopic endonasal extended approaches in skull-base surgery.⁵

These endoscopic techniques allow the neurosurgeon to optimize tumor resection, increasing the area of surgical dissection without increasing the size of the surgical approach, thereby limiting perioperative morbidity due to surgical manipulation of eloquent brain structures. Endoscopy offers direct illumination of the operative field, magnification, and the ability to look around corners with angled optics.

However, while angled endoscopic optics provide various visual perspectives, the surgical issue is not only to see but also to work on and around remote structures. Microsurgical endoscope-assisted manipulations require optimal working angles that are guaranteed only by a sufficiently large craniotomy. As an example, a dissection study by Chaynes et al⁶ highlights that a craniotomy that is too narrow often hinders a sufficient exploration of the entire cerebellopontine angle. Most neuro­surgeons are familiar with the operating microscope. The microscopic field of inspection is 3-dimensional (3D) and of high quality. However, the light stream is straight and thus limited in the narrow and angled corridor of the cerebellopontine angle or in the perimesencephalic cisterns. In these situations, the angled optic of the endoscope offers the advantage of being able to look around the corner with the appropriate amount of direct illumination.⁷

Minimally invasive endoscopic approaches are also being used in peripheral nerve surgery, especially carpal tunnel decompression. The first carpal tunnel release treated endoscopically was performed by Okutsu et al in the late 1980s.⁸ Since that time, endoscopic carpal tunnel decompression has become very common and is the preferred method for many surgeons, using either single-portal or dual-portal techniques. Although the superiority of endoscopic over conventional minimally invasive microsurgical peripheral nerve surgeries has not been proven, large series of endoscopic carpal tunnel decompressions have reported low complication rates and excellent success rates with high patient satisfaction scores.^8,9

Visualization of the spinal canal

Expanding the use of the endoscope to spine surgery, endoscopic explorations of the interlaminar spaces after having completed open surgical laminectomies have been reported since the early 1980s,¹⁰ while endoscope-assisted interlaminar procedures started in the late 1990s.^11–13 The development of fully endoscopic transforaminal or interlaminar approaches for lumbar stenosis or lumbar disk herniation has been ongoing in the last 2 decades. The rationale for direct endoscopic visualization of the spinal canal is to reduce scarring of the epidural space, which might affect the outcome of possible revision surgeries (recurrent disk herniation), and to reduce injury to the paraspinal muscles, which may reduce postoperative incisional pain and length of hospital stay. Major limiting factors for fully endoscopic spine surgeries such as the narrow working channels (which are limited by the osseous perimeter of the neuroforamina, as well as the pelvis and abdominal structures) and the learning curve for the surgeons are, however, still matters of debate and restrict the use of endoscopy to very carefully selected cases.^14,15

Pediatric craniosynostosis

Recently, the use of the endoscope has extended to treatment of craniosynostosis in pediatric patients, historically treated with large and occasionally staged craniotomic approaches. A meta-analysis of the literature showed statistically significant reductions in blood loss and rates of perioperative complications, reoperation, and transfusion compared with open approaches.¹⁶

Technical limitations

While neurosurgeons increasingly advocate the use of the endoscope in their practice, the development of instruments for endoscopic surgery does not always follow the same pace. There are technical problems with current rigid endoscopes and ergonomic limitations of the endoscope-assisted techniques in trans­cranial neurosurgery. The endoscope itself occupies space in an already limited surgical corridor like the posterior fossa, the parasellar space, or the intraventricular region. The ideal endoscope is thin and sturdy, does not generate heat, and provides high-resolution images. In addition, a self-irrigating feature could minimize the need to remove and reinsert the endoscope for cleaning. Finally, most intracranial surgery is extremely delicate and requires bimanual dissection. The ideal endoscope should also be easily integrated with a holder that allows the surgeon to easily transition between static and dynamic endoscope movements.

Newer flexible fiberscopes with even smaller diameters are likely to be launched on the market in the near future. When working in a surgical corridor less than 10 mm wide, this difference could be substantial.

In addition, surgical instruments specifically designed for endoscopic endonasal procedures are needed for microdissection in these regions, which were previously only visible but not reachable endoscopically. These include tools such as malleable suctions and curettes, rotatable back-biting microscissors, and malleable bipolar instruments (Figure 3).

IMPACT OF NEUROENDOSCOPY IN CURRENT CLINICAL PRACTICE

The introduction of endoscopy in neurosurgery changed many treatment paradigms and had an important impact on morbidity and outcomes. In this section, we discuss the specific indications, contraindications, and expected benefit of endoscopic vs open surgical approaches applied to neurosurgical pathology at the present time.

Skull-base tumors and CSF leaks

The use of the endoscope in skull-base surgery was originally applied to purely midline intrasellar tumors without suprasellar or lateral extension beyond the carotid cave. Ideal cases were intrasellar pituitary microadenomas not responding to medical treatment or Rathke cleft cysts.

These pathologies were traditionally addressed via microscopic craniotomic approaches and later through sublabial or transnasal transsphenoidal approaches. Traditional transsphenoidal approaches were highly invasive for the oral mucosa, causing delayed healing, oral dysesthesia, and, in some cases, loss of the superior dental arch (sublabial) or limited visualization and surgical maneuverability (microscopic endonasal).

The endoscope offered better visualization and surgical freedom, thus allowing higher resection rates to be achieved. Resection of purely intrasellar pathology with preservation of the diaphragma sellae as a barrier to the subarachnoid cysterns and third ventricle guaranteed a lower incidence of cerebrospinal fluid (CSF) leaks.

New endoscope optics with varied angles, together with dedicated long surgical instruments with low steric volume, offered a large variety of new endonasal surgical corridors, so-called expanded endonasal approaches on the sagittal and coronal planes, as discussed in detail by Kassam et al.^17–19 These allowed endoscopic treatment of invasive tumors extending on the coronary plane into the suprasellar region or invading the cavernous sinuses (pituitary macroadenomas, craniopharyngiomas).

Highly specialized centers with expertise in endoscopic skull-base surgery can now also offer pure endoscopic treatment for some selected cases of lesions located far laterally to the cavernous sinus, such as trigeminal schwannomas, or along the sagittal plane like olfactory groove or tuberculum sellae meningiomas and clival lesions (chordomas, chondrosarcomas).

As one might expect, the increase in surgical complexity corresponded to an increase in complication rates. For example, the incidence of CSF leaks varied from 5% for standard midline transsphenoidal approaches to 11% for expanded endonasal approaches.^20,21 The consolidation of the use of the endoscope and the cooperation with ENT surgeons led to the development of surgical strategies to prevent and reduce the incidence of CSF leaks, such as the use of “rescue flaps,” nasoseptal flaps, or temporoparietal fascia flaps.^21–23

The development of such techniques allowed endoscopic endonasal approaches to be used in treatment of other pathologies, such as spontaneous CSF leaks, treated in the past with large transcranial repairs that carried high morbidity rates due to the surgical frontal lobe retraction and injury to the olfactory mucosa.^24,25 Progress in the field of neuroendoscopy therefore led to the creation of specialized endoscopic skull-base surgery centers, including neurosurgery, ENT, ophthalmology, and endocrinology services.

In clinical practice, when evaluating a patient with intracranial skull-base pathology amenable to endoscopic resection, one should consider referring the patient not only to a neurosurgeon, but also to an ENT surgeon for preoperative assessment of the sinonasal cavities. The same concept applies to postsurgical follow-up, which is mostly performed by the ENT physician to assess nasal mucosa healing and nasal hygiene.

The introduction of endoscopic third ventriculostomy created the opportunity to offer a more physiologic treatment in selected patients with obstructive hydrocephalus by creating an internal CSF diversion through the basal cisterns. Two advantages of this procedure are that it does not create dependence on a CSF shunt, and it eliminates the related risks of shunt infection and malfunction. Its drawback is the recurrence rate of hydrocephalus (around 58% at 2 years of follow-up) due to formation of scarring in the perforated Lilie­quist membrane, which may require repeat surgery or conversion to CSF shunting.^26,27

Neuroendoscopic approaches are also used in cases of purely intraventricular pathology such as colloid cyst or choroid plexus papillomas. The concept behind neuroendoscopy is to achieve maximal resection in a minimally invasive way, using the natural cavity of the cerebral ventricles and reducing the need for brain retraction and, in particular, the risk of injury of the fornix (therefore causing memory deficits) of open transventricular approaches and of the corpus callosum necessary in inter­hemispheric approaches. Large tumor size and inability to tolerate a longer surgical procedure can be relative contraindications to a pure endoscopic approach to these lesions.

Degenerative spine disease

In recent years there has been a growing interest in the use of endoscopy for selected cases of degenerative lumbar spondylosis (generally, lateral disk herniation above the L5-S1 level or spinal canal stenosis). This approach has been shown to reduce postoperative incisional pain, scarring of the epidural space affecting the outcome of possible revision surgeries (recurrent disc herniation), and length of hospital stay.^14,15 Information on surgical nuances should be provided when consulting on selected patients with lumbar degenerative disease resistant to conservative treatment.

Carpal tunnel syndrome

Although endoscopic carpal tunnel release is controversial, its supporters report smaller incision size and lower recurrence rates due to better visualization of the entire carpal ligament compared with open surgery, with high patient satisfaction scores.^8,9,28

Craniosynostosis

Increasing data from specialized centers show that early endoscopic suturectomy is an effective treatment option alone or when combined with open surgeries for patients with syndromic and nonsyndromic craniosynostosis. The aesthetic advantage of small incisions (which can also be achieved with some open techniques) is accompanied by significant reductions in blood loss (median 162.4 mL), operative time (median 112.38 minutes), length of stay (median 2.56 days), and rates of perioperative complications (odds ratio 0.58), reoperation (odds ratio 0.37), and transfusion (odds ratio 0.09) compared with open approaches.¹⁶

SURGICAL TRAINING

Today’s patients expect high-quality healthcare, and they approach their surgeons with an enormous amount of information collected through unlimited Web-based access or peer-group blogs. In this respect, the pressure on young surgeons to achieve excellent results is high and growing from the very beginning of their careers.

Residency training programs differ in each country, and surgical standards usually focus on open microscopic procedures rather than newly developed endoscopic techniques. Endoscopic pituitary adenoma surgery, the most frequent neuroendoscopic procedure, is still performed mostly by experienced neurosurgeons, not trainees. Moreover, many training institutions might not offer pediatric neurosurgery care, limiting exposure to endoscopic third ventriculostomy procedures. The European Union of Medical Specialists, responsible for harmonizing and improving the quality of training of medical specialists in Europe, set low neuroendoscopic surgical requirements for trainees to complete their residency programs (minimum of 0 to optimum of 5 total transcranial or transsphenoidal pituitary adenoma resections as first operator, 10 procedures as assistant, and a minimum of 2 to an optimum of 4 endoscopic third ventriculostomies as first operator).²⁹

The need to develop training programs in neuroendoscopy is especially urgent because endoscopic surgery has a steeper learning curve than conventional microneurosurgery. In particular, endoscopy requires a good deal of dexterity and hand-eye coordination, which surgeons consider the main pitfall of neuroendoscopy. For such reasons, many accredited clinical fellowship programs have been developed inside and outside North America that offer intensive training in endoscopic skull-base surgery and pediatric neurosurgery after residency.

Some clinical studies have shown that the complication rate of neuroendoscopy is 15% to 18%.^27,30 In view of this statistic, it is ethically questionable to perform a randomized study to prospectively compare microscopic and endoscopic procedures. Surgeons specialize in one technique or the other, experience their own learning curve, and do not randomly decide which tool to use. Furthermore, every intracranial surgical exploration is unique and somewhat difficult to compare with each other without the risk of bias.

Multivariable rigid endoscopes like the EndoCAMeleon (Karl Storz, Tuttlingen, Germany) or the EndActive (Karl Storz, Tuttlingen, Germany) for cerebellopontine angle surgery represent a starting point to overcome some of the aforementioned limitations.^31,32 They are inserted in the surgical field with a direct 0° angulation view into the operative site beyond neurovascular structures that need to be preserved and that obstruct the microscopic view. Once the final position is reached, the field of view is directed toward the region of interest without moving the endoscope tip.

The EndoCAMeleon is a rigid rod-lens endoscope, steerable in one plane from –10° to +120° by a fine optomechanical mechanism. Anatomic laboratory testing found it to be superior in terms of usability and visualization compared with rigid fixed-angle endoscopes.^₃₁ The first clinical experiences have been promising; however, ergonomics and the limited perspective of a single plane of rotation leave room for improvement.

The EndActive endoscope might overcome such limitations.³³ This device is a rigid videoendoscope connected to a laptop (video data) and USB port (control and power supply); thus, it weighs less and can be held in one hand like a microsurgical instrument. The endoscopic imaging system allows the operator to simultaneously see a 160° wide-angle view of the site and an inset of a specific region of interest. The surgeon can hold the device like a microsurgical instrument in one hand and control movements precisely due to its reduced weight and ergonomic shape.

The multiplanar variable-view rigid endoscope has proven to be useful for working on diverse anatomic structures such as intracranial vessels and cranial nerves. The device is effective in narrow working spaces where even small movements can jeopardize the delicate surrounding structures. The multiplanar variable-viewing mechanism in a compact device offers advantages in terms of safety and ergonomics. Improving the usability will probably optimize the applicability of those endoscopic devices in neurosurgery. A major drawback of the current prototype is poor image resolution, which will probably soon be overcome with the ongoing progress in electronic microchip technology.

The addition of laser technology to endoscopic techniques offers a huge potential to neurosurgery but has achieved little acceptance to date. The reasons include concern regarding heat production, uncontrollable and distant penetration, and tissue interaction. Experiences with a 2-micron continuous­- wave laser (RevoLix Jr, LISA Laser Products, Katlenburg-Lindau, Germany) for neuroendoscopic intraventricular procedures proved this laser to be a valuable and useful tool with safe applicability for endoscopic intracranial procedures in patients of all ages.³⁴

Parallel to the launch of video screens for other uses with higher image definition, the image quality on the 2D endoscope cameras has been constantly improving over the last years. At the same time, the introduction of modern 3D endoscopic monitors is promising. However, 3D endoscopes have some disadvantages compared with the 2D endoscopes. First, the smallest 3D endoscopes are 4 mm in diameter, compared with 2.7 mm for 2D endoscopes. Moreover, the field of view with the 3D endoscope is less than half of that with conventional 2D endoscopes.³⁴ When working in and around a region with critical neurovascular structures in close proximity, this loss of field of view can result in an increase in iatrogenic injury from the endoscope. In addition, 3D endoscopes require special glasses, generating a potential obstacle to the seamless integration of visual information from the microscope and endoscope. Finally, some surgeons experience vertigo when looking at the 3D picture through the glasses, which limits its universal applicability.

CONCLUSIONS

Using the endoscope and microscope as complementary and not competing tools allows surgeons to benefit from both technologies at the same time.^35,36 The intraoperative combination of these 2 powerful visualization tools expands the effectiveness of microsurgical procedures and has the potential to further improve surgical results and reduce surgical risks. With endoscope-assisted microsurgery, visualization is often far superior to surgical maneuverability.

Endoscopic neurosurgery will likely be influenced by further innovations in optical physics, electronics, and robotics. Specific implementations in endoscopic systems are likely to pave the way for remarkable progress in minimally invasive surgery, such as robotic surgical technology, further miniaturization of devices, improvements in 3D endoscopy, multiport endoscopy, and new designs for surgical instruments. Future progress in flexible endoscopes and wireless capsule or camera technology may reduce our dependence on rigid rod lens systems. Rigid variable-view endoscopes will bring endoscopes closer to ideal attributes utilizing newer instrumentation that is tailored to specific indications and techniques.^37,38 Extension of the visual field by the feature of a movable optic lens may allow the neurosurgeon to use tailored keyhole approaches to treat pathologies in smaller surgical corridors with less trauma and greater efficacy.