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Navigating the obstacle course of diagnosing, managing pediatric hypertension

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Mitchel L. Zoler, PhD

The clinical context of high blood pressure shifts abruptly when a person comes of age.

In adults 18 years old and up it’s fairly simple. Blood pressure above 140/90 mm Hg is generally a clear problem, less than 130/85 is probably okay for now, and in between is something to monitor. When pressure stays above 140/90 mm Hg despite lifestyle interventions it’s time to start treatment with any of several antihypertensive drug options that mostly have well-documented safety and efficacy track records in adults and widely agreed-on benefits that outweigh risks.

For pediatric practice, children and adolescents 3-17 years old, dealing with high blood pressure is much more an obstacle course of complex diagnostic criteria, challenges in pressure measurement, and seemingly inconsistent recommendations. Pediatric hypertension also often brings clinicians up against the child and adolescent obesity epidemic, which has made pediatric hypertension more common than ever.

Against this backdrop, a panel assembled by the American Academy of Pediatrics is revising the 2004 The Fourth Report on the Diagnosis, Evaluation, and Treatment of High Blood Pressure in Children and Adolescents, the reigning standard for pediatric blood pressure assessment and hypertension management and now more than a decade old. With new guidance from the AAP expected in the second half of 2017, best-practice approaches to pediatric hypertension are in flux and need updating just when the disorder is more prevalent than it’s ever been.

Diagnosing pediatric hypertension falls short

This shifting landscape and increasing burden of pediatric hypertension comes at a time when primary-care pediatricians and family practice physicians are failing to perform fully comprehensive blood pressure monitoring of their pediatric patients. Current practice recommendations from the National Heart Lung and Blood Institute (in the form of the 2004 Fourth Report), and from American Heart Association (most recently reiterated in a scientific statement in August 2016) call measuring blood pressure levels at every patient encounter starting at 3 years old, the approach also endorsed by the American Academy of Pediatrics.

But that’s often not done. “Results from plenty of studies show that we are not doing a great job” identifying children and adolescents with hypertension, said Tammy M. Brady, MD, a pediatric nephrologist at Johns Hopkins Medical Center in Baltimore.

One piece of evidence she cited was a study of more than 93,000 U.S. ambulatory pediatric visits during 2000-2009 in data collected by the National Ambulatory Medical Care Survey and the National Hospital Ambulatory Medical Care Survey, and sampling that represented an average 142 million ambulatory visits each year by 3-18 year olds. The data showed blood pressure screening occurred during 35% of ambulatory visits, 67% of preventive visits, and during 84% of preventive visits for a child or adolescent who was overweight or obese (Pediatrics. 2012 October;130[4]:604-10).

While the numbers showed good practice with a reasonably high level of routine blood pressure measurement in overweight and obese patients, they also suggest that perhaps a third of all U.S. children and adolescents don’t have their blood pressure checked at least once a year. Statistical analyses from this study showed that blood pressure measurement was about twice as likely in children diagnosed as overweight or obese than normal-weight patients, and that blood pressure measurement was 2.6-fold more common in adolescents 13-18 years old compared with children 3-7 years old.

In a second, recent study of 29,000 2-17 years old seen at Children’s Hospital of Chicago, 3% had at least three elevated blood pressure measurements in their hospital record, but in this subset of patients at high risk of having hypertension 21% were actually identified in their medical record as having high blood pressure.

Dr. Brady pointed out that while many of the children and adolescents in this study with three or more high blood pressure readings may not actually have hypertension, defined as a sustained elevation of blood pressure, they are all at risk for development of hypertension and should be targeted for prevention.

“We do a bad job identifying when blood pressure is high,” Dr. Brady said in an interview. She cited a study she recently ran that examined the impact that EMR alerts could have on this diagnostic challenge. She reviewed records for 1,305 patient encounters done before or after institution of a EMR alert that warmed clinicians when a patient’s blood pressure measurement fell above the normal range. The results showed that for these patients, 3-21 years old, the rate of recognition of a high pressure measurement increased from 13% before the alert system started to 42% with the alert system in place (Clin Ped. 2015 June;54[7]:667-75). “That meant more than half the patients with high blood pressure measurements were still going unrecognized”, even with an EMR alert, Dr. Brady said.

“The U.S. clinical community falls way short” of adequately following blood pressure levels in children and adolescents, agreed Julia Steinberger, MD, professor and director of pediatric cardiology at the University of Minnesota in Minneapolis. She chalks this up to several factors: time-pressured clinicians who may let blood pressure slide when other aspects of a visit require more attention and the index of suspicion for elevated blood pressure is low, insufficient education to the primary-care community on how to proceed once an elevated blood pressure reading is made, the difficulty of measuring blood pressure in young or uncooperative patients, and lack of size-appropriate equipment.

Once a single high pressure is recorded, ideal follow-up means measuring and finding elevated blood pressures again on at least two subsequent visits, followed by even more confirmation with home monitoring or 24-hour ambulatory blood pressure monitoring (ABPM), now considered the gold standard for both diagnosing and following pediatric patients with hypertension, especially if they receive antihypertensive medications. In 2014, a scientific statement from the American Heart Association said routine APBM was indicated to confirm the diagnosis of hypertension in a patient with high casual blood pressure measurements. Not many primary-care physicians have ready access to or experience using and interpreting ABPM.

Other reasons for low diagnostic rates include therapeutic inertia, and the sheer complexity and time of identifying what is a high blood pressure reading, at least until automated calculation of high levels by EMRs became possible. “With a paper analysis you need to look at two different charts” and factor in the patient’s sex, age, and height to determine if a pressure reading is high or not for a particular patient. “Diagnosis has been a problem, especially in busy practice,” noted Dr. Brady. “I think we are addressing that with the EMR and pop-up alerts.”

Streamlining the diagnostic process

“We have a complex way to diagnose hypertension in kids,” admitted Bonita Falkner, MD, who chaired the Fourth Report panel that produced the complicated diagnostic process still used today. “It’s complex and tedious to calculate. There have been a number of reports of missed hypertension because of the complexity of the tables,” said Dr. Falkner, professor and director of hypertension and obesity research at Thomas Jefferson University in Philadelphia. “Because it’s so burdensome to diagnose the detection rate of hypertension is not as accurate as it should be. Hopefully this will be improved with the new guidelines. We plan to make them simpler, easier to use and more streamlined,” she said in an interview.

“One of the challenges is how to make high blood pressure identification simpler and more straightforward. Without question there are children and adolescents with persistently high blood pressures who fall through the cracks,” said Stephen R. Daniels, MD, professor and chairman of pediatrics at the University of Colorado in Aurora. “Recognizing hypertension in adults is much simpler, with a single set of values. The AAP is in the process of developing new guidelines and one goal is to make blood pressure measurement and recognition of hypertension as simple as possible. There is a tension between simplicity and precision. Finding the right balance will be the trick.”

Dr. Falkner highlighted two other new aspects the revised pediatric hypertension recommendations will address. The panel appears to be on track to recalculate the reference blood pressure tables to eliminate the contribution of overweight and obese children and adolescents. Because high blood pressure is defined statistically--pressures at or above the 95th percentile for a child’s sex, age and height--inclusion of overweight and obese children and adolescents in the databases that produced the original tables skewed the 95th percentile thresholds higher than they would be for those who are at normal-weights. “It will make the reference numbers somewhat lower, but not dramatically lower,” Dr. Falkner said.

When the 2004 Fourth Report was written and the calculation tables created “it was early in the obesity epidemic and we were not as tuned into it as a problem” for hypertension,” said Dr. Daniels, also a member of the Fourth Report panel.

Another new aspect will likely be highlighting the role of overweight in addition to obesity as a hypertension risk factor. “In 2004, obesity was a concern but overweight was considered just a risk factor for obesity. Now if a child is overweight we know they are also at increased risk for having high blood pressure,” said Dr. Falkner. “We’ve been trying to get an update of the Fourth Report going for some time; a lot has happened since 2004.”

The Preventive Services Task Force effect

One notable recent development in the field of pediatric hypertension was the 2013 statement by the U.S. Preventive Services Task Force that reinforced a similar conclusion the group had reached a decade before, in 2003. In 2013, the USPSTF said that following a review of the evidence “the USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of screening for primary hypertension in asymptomatic children and adolescents to prevent subsequent cardiovascular disease in childhood or adulthood. (I statement)” (Pediatrics. 2013 Nov;132[5]:907-14).

The USPSTF’s 2013 reassertion of this position triggered several strong reactions from pediatric hypertension specialists, who critiqued the Task Force’s analysis as being overly restrictive. Among those weighing with comments that highlighted the flaws in the Task Force’s reasoning were Dr. Falkner, Dr. Brady, and Dr. Steinberger. Earlier in 2013, before the Task Force statement, Dr. Daniels wrote a commentary with similar arguments in favor of routine blood pressure measurements in response to a published assessment of pediatric blood pressure screening that largely presaged what the USPSTF said.

In brief, the USPSTF analysis “was flawed by an overly-narrow selection of evidence,” Dr. Steinberger said recently. “Short-term and observational studies were not considered. We think that in the absence of perfect data the practitioner must use common sense when superior evidence does not exist. The question of whether hypertension in adults can be prevented or modified by early intervention will never be answered unless we continue to measure blood pressure in children.”

“One of the problems with the USPSTF statement was the questions they addressed: Is blood pressure in children and adolescents clearly associated with hard cardiovascular disease outcomes in adults? That is a very tough question to answer. It would need studies that are 30, 40 years in duration, and is almost unanswerable,” said Dr. Daniels in an interview. “I think the USPSTF paid less attention to the fact that clearly a certain percentage of children and adolescents with hypertension already have developed left ventricular hypertrophy, increased carotid intimal-medial thickness and vascular stiffness. This shows that higher blood pressure in the short term is having several adverse effects on the cardiovascular system. If you insist on seeing a connection between pediatric blood pressure and adult outcomes there will always be insufficient evidence.”

Although, as Dr. Steinberger pointed out, the International Childhood Cardiovascular Cohort Consortium has been putting together long-term follow-up data from seven observational cohorts established in several different world regions. Collectively these seven cohorts include more than 340,000 people who have now been followed for about 40 years. This analysis may soon yield more definitive insight into the long-term consequences of childhood hypertension, Dr. Steinberger said.

Another relevant issue is that prevention of adult cardiovascular disease “is not why children are screened for hypertension, or at least not the primary reason,” Dr. Falkner said. “They are screened to find high blood pressure with an underlying cause, like coarctation of the aorta, which is only picked up by first noting a high blood pressure. Several other cardiovascular and renal disorders that can exist in childhood can also cause high blood pressure and measuring blood pressure is the only way to find them. It would be a tragedy to miss coarctation of the aorta by not measuring blood pressure.”

The family practice position

Despite rejection of the USPSTF analysis by many pediatric hypertension specialists, the USPSTF position has been officially embraced by the family practice community. The American Academy of Family Practice has adopted the USPSTF position as its own, although family practice physicians are also quick to point out that the USPSTF conclusion does not say that pediatric blood pressures should not be measured.

“An I level from the USPSTF doesn’t mean that screening is harmful or shouldn’t be done, just that more research is needed to fully evaluate if blood pressure screening in childhood has long-term health impacts,” said Margaret A. Riley, MD, a family practice physician at the University of Michigan in Ann Arbor with an interest in pediatric hypertension.

“I think the I rating has had little impact on practice. Measuring blood pressure is a routine and standard part of office practice. If the USPSTF had given blood pressure screening a D rating, causing more harm than good, that would be different. In my practice I screen blood pressure at every visit or at least once a year,” Dr. Riley said in an interview.

That’s the same approach taken by Wanda D. Filer, MD, a family practice physician in York, Pa. and president of the American Academy of Family Physicians. “This does not mean you don’t screen blood pressure, and it doesn’t mean you should screen. It says that data are not there either way. In my office we check everyone age 3 and up, and I think a lot of family practice physicians do that routinely.

“Most of us screen blood pressure, but the AAFP approach is to always look at the evidence. The AAFP stand is not opposite to other organizations [that have endorsed routine blood pressure measurements]. They take a stronger position in favor of screening than we do, but we don’t say do not screen. Other societies have relied on less direct evidence or expert opinion. Our approach is to see proof of benefit,” Dr. Filer said in an interview.

“I imagine most family practice physicians measure blood pressure in children aged 3 or older,” she added. “I work in a Federally-qualified health center, and we have a very diverse population. We routinely measure blood pressures because the patients are so diverse. Other family practice practices may come to a different decision. You need to look at your practice and your work flow and decide whether it is an appropriate use of time.

“I do it because I’m convinced there is a possibility of benefit from screening,” Dr. Filer said. “I am also convinced that the evidence is not there [to prove benefits]. But I won’t wait for the evidence to do this in my practice. For the mix of patients I see it is important to screen blood pressures, but I am comfortable if a family practice physician with a different patient population says that high blood pressure yields are not there; they never see them.”

Overweight and obesity raise a red flag

If there is one subgroup of the pediatric population that most everyone agrees needs close attention to blood pressure it’s the overweight or obese child or teenager. “Primary hypertension in children and adolescents is largely associated with obesity,” said Dr. Falkner. Study findings also suggest that obese children and teens with hypertension are much more likely to have or develop left ventricular hypertrophy than normal-weight patients with elevated blood pressures.

The consequences are two fold: First, it suggests that even if the entire pediatric population fails to get their blood pressures checked regularly diligent attention to blood pressure is a must for overweight and obese children and adolescents, many experts agree. “A child who is overweight as well as obese requires attention to their blood pressure. That is emerging as a guideline,” Dr. Falkner said.

Second, a growing number of U.S. clinical programs are geared to addressing hypertension in the overweight or obese pediatric patient using an aggressive and multidisciplinary treatment approach.

For example, a clinic devoted to the overweight or obese child or teen with hypertension, the ReNEW (Reversing the Negative Cardiovascular Effects of Weight) program, opened at Johns Hopkins Medical Center in February 2015.

“We were seeing a lot of obesity-related hypertension without an underlying secondary cause. And in a study we ran the only thing that could predict left ventricular hypertrophy in children with hypertension was body mass index,” said Dr. Brady, medical director for ReNEW. “This motivated me to try to find a better way to treat obesity and hypertension; the only real treatment for hypertension in obese patients is to treat the obesity.”

During its first year, the ReNEW program enrolled 35 patients 5-22 years old. “We assess them for any secondary cause of hypertension,” Dr. Brady said. “We do an echocardiography examination and assess left ventricular hypertrophy and the need for blood pressure reducing medications. We do interventions for weight loss, diet, exercise, a musculoskeletal assessment, psychiatric assessment and other comorbidity interventions such as for sleep apnea. We start blood pressure reducing drugs when appropriate.”

The average body mass index among the first 35 patients was 38 kg/m2, with an average 31 kg/m2 in kids 5-10 years old and 43 kg/m2 in those 18-21 years old. Fifty percent had obstructive sleep apnea, 33% had anxiety or depression, and about 25%-33% had diabetes. “These kids are at a really great risk for a cardiac event in early adulthood. They are probably one of the most vulnerable populations we see,” she said.

A major lesson she’s learned from the ReNEW experience so far is the spectrum of comorbidities that can affect these patients and the importance of behavioral change for the entire family to produce favorable changes in the patient. “Depression and anxiety are big factors that can affect a family’s success with weight loss. Many kids also have underlying orthopedic issues. There remains a lot of confusion about diet. We try to offer families a one-stop shop, a multidisciplinary clinic that can thoroughly address the patient’s full range of cardiovascular-disease risk factors.

“I’ve been how shocked by how complex these patients are. When there is a significant overweight or obesity problem the only way to succeed is to involve the whole family. And don’t forget about the role of mental health. That is a significant part of overweight and obesity,” Many of the psychiatric disorders that overweight and obese children and teenagers show results from learned family behaviors, Dr. Brady said.

Another U.S. clinic specifically targeted at obese children and adolescents also sees many patients with hypertension at the University of Minnesota, a program begun in about 2010 that now has treated more than 1,000 patients including “hundreds” with comorbid hypertension, as well as similar numbers with comorbid hyperlipidemia and comorbid diabetes , said Dr. Steinberger.

“There are very few of these programs in the U.S.; it is not widely available. The cardiovascular health promotion effort should include this approach because for the primary care physician there is insufficient time or expertise to do these evaluations and treatments. You need a group of clinicians with the needed expertise,” she said. “Our multidisciplinary approach to treating comorbidities like hypertension, dyslipidemia and elevated glucose uses specialists for each of these areas as well as dieticians, social workers, and other specialists.

“In general, when the primary care physician does not have the resources to further evaluate and treat overweight or obesity they should be able to refer the patient to a program like this. It is never too soon to refer and treat. To treat overweight you need to involve the whole family. Most children do not ‘grow out’ of overweight or obesity. The overweight or obese child will generally grow up to be the overweight or obese adult,” Dr. Steinberger said.

Targeting the greatest hypertension risk

The growing trend to focus multidisciplinary resources on hypertension in the overweight or obese pediatric patient may exemplify part of a new era of targeted attention for pediatric blood pressure screening.

“We have a hard time measuring blood pressure in kids, we know the importance of obesity [in causing hypertension] and we also know that first-line management for most hypertensive patients is non-drug, lifestyle interventions. Therefore, is it possible that a greater good can be achieved by addressing lifestyle and all the health issues that would reduce the risk for hypertension, such as making sure all children engage in more movement and exercise and get off devices rather than medicalizing the problem” with frequent blood pressure measurement, wondered Howard Trachtman, MD, a pediatric nephrologist at New York University.

“Routinely screening blood pressure in every child and adolescent is very burdensome and carries the potential cost of inconvenience and mislabeling errors. Could clinicians focus on the children and adolescents who really are at risk of high blood pressure? Can we use the EMR and alerts to make sure that repeated measures of blood pressure are done only when needed, after we identify who is at greatest risk?

“We need to become more precise in defining who is it in the age range of 8-17 years old who needs to be regularly screened for high blood pressure so we can focus our resources on these people and better avoid mislabeling and causing anxiety” for the many children and adolescents who have a very low risk for having hypertension, said Dr. Trachtman. He said that he is currently collaborating on a study that is examining whether data contained in a patient’s EMR can help in improving blood pressure assessment.

“We need to keep an open mind about who might have hypertension, but there are good data that it tracks with waist circumference, hypertriglyceridemia, and insulin resistance. The more of these you have the greater your risk. This is the kind of productive research I’m talking about, to determine whether you can be more thoughtful in identifying who is at risk of high blood pressure and who needs more systematic screening. Targeting blood pressure screening to overweight or obese kids is a step toward trying to be more methodical. The USPSTF statement should be a spur to pediatric nephrologists to make our case for blood pressure screening more cogently and to collect better data so that when we speak about this it is not based on speculation or extrapolation but on data,” Dr. Trachtman said.

“There are no arguments against optimizing health and reducing risk factors in all children, but that is not an acceptable rationale for not measuring blood pressure and attending to elevated levels in children,” responded Dr. Falkner. Dr Trachtman’s proposal to reduce health risks in all children “is a public health issue whereas the issue of detecting and managing hypertension in childhood is a clinical issue” faced by physicians as they see individual patients, she said.

Many pediatric hypertension specialists may not warm to a screening proposition that retreats from the notion that every child and teen 3 years old and up should have their blood pressure checked at least annually. But many of those specialists also realize that what’s now done has a lot of problems and that a more user-friendly approach is needed. As an expert panel works to produce a revision to the Fourth Report next year (which will not be the Fifth Report as the update is now outside the NHLBI purview), changes in how pediatric hypertension will be approached in the future seem likely.

Dr. Brady, Dr. Steinberger, Dr. Falkner, Dr. Daniels, Dr. Riley, Dr. Filer, and Dr. Trachtman had no disclosures.

[email protected]

On Twitter @mitchelzoler

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