A large multicenter study provides further evidence supporting the rationale for multidisciplinary teams for cardiogenic shock, one of the most lethal diseases in cardiovascular medicine.
The analysis of 24 critical care ICUs in the Critical Care Cardiology Trials Network showed that the presence of a shock team was independently associated with a 28% lower risk for CICU mortality (23% vs. 29%; odds ratio, 0.72; P = .016).
Patients treated by a shock team also had significantly shorter CICU stays and less need for mechanical ventilation or renal replacement therapy, as reported in the Journal of the American College of Cardiology.
“It’s observational, but the association that we’re seeing here, just because of our sample size, is the strongest that’s been published yet,” lead author Alexander Papolos, MD, MedStar Washington Hospital Center, said in an interview.
Although a causal relationship cannot be drawn, the authors suggest several factors that could explain the findings, including a shock team’s ability to rapidly diagnose and treat cardiogenic shock before multiorgan dysfunction occurs.
Centers with shock teams also used significantly more pulmonary artery catheters (60% vs. 49%; adjusted OR, 1.86; P < .001) and placed them earlier (0.3 vs. 0.66 days; P = .019).
Pulmonary artery catheter (PAC) use has declined after earlier trials like ESCAPE showed little or no benefit in other acutely ill patient groups, but positive results have been reported recently in cardiogenic shock, where a PAC is needed to determine the severity of the lesion and the phenotype, Dr. Papolos observed.
A 2018 study showed PAC use was tied to increased survival among patients with acute myocardial infarction cardiogenic shock (AMI-CS) supported with the Impella (Abiomed) device. Additionally, a 2021 study by the Cardiogenic Shock Working Group demonstrated a dose-dependent survival response based on the completeness of hemodynamic assessment by PAC prior to initiating mechanical circulatory support (MCS).
A third factor might be that a structured, team-based evaluation can facilitate timely and optimal MCS device selection, deployment, and management, suggested Dr. Papolos.
Centers with shock teams used more advanced types of MCS – defined as Impella, TandemHeart (LivaNova), extracorporeal membrane oxygenation, and temporary or durable surgical ventricular assist devices – than those without a shock team (53% vs. 43%; adjusted OR, 1.73; P = .005) and did so more often as the initial device (42% vs. 28%; P = .002).
Overall MCS use was lower at shock team centers (35% vs. 43%), driven by less frequent use of intra-aortic balloon pumps (58% vs. 72%).
“The standard, basic MCS has always been the balloon pump because it’s something that’s easy to put in at the cath lab or at the bedside,” Dr. Papolos said. “So, if you take away having all of the information and having the right people at the table to discuss what the best level of support is, then you’re going to end up with balloon pumps, and that’s what we saw here.”
The study involved 6,872 consecutive medical admissions at 24 level 1 CICU centers during an annual 2-month period from 2017 to 2019. Of these, 1,242 admissions were for cardiogenic shock and 546 (44%) were treated at one of 10 centers with a shock team.
Shock team centers had higher-acuity patients than centers without a shock team (Sequential Organ Failure Assessment score, 4 vs. 3) but a similar proportion of patients with AMI-CS (27% vs. 28%).
Among all admissions, CICU mortality was not significantly different between centers with and without a shock team.
For cardiogenic shock patients treated at centers with and without a shock team, the median CICU stay was 4.0 and 5.1 days, respectively, mechanical ventilation was used in 41% and 52%, respectively, and new renal replacement therapy in 11% and 19%, respectively (P < .001 for all).
Shock team centers used significantly more PACs for AMI-CS and non–AMI-CS admissions; advanced MCS therapy was also greater in the AMI-CS subgroup.
Lower CICU mortality at shock team centers persisted among patients with non-AMI-CS (adjusted OR, 0.67; P = .017) and AMI-CS (adjusted OR, 0.79; P = .344).
“This analysis supports that all AHA level 1 cardiac ICUs should strongly consider having a shock team,” Dr. Papolos said.
Evidence from single centers and the National Cardiogenic Shock Initiative has shown improved survival with a cardiogenic shock algorithm, but this is the first report specifically comparing no shock teams with shock teams, Perwaiz Meraj, MD, Northwell Health, Manhansett, N.Y., told this news organization.
“People may say that it’s just another paper that’s saying, ‘shock teams, shock teams, rah, rah, rah,’ but it’s important for all of us to really take a close look under the covers and see how are we best managing these patients, what teams are we putting together, and to create systems of care, where if you’re at a center that really doesn’t have the capabilities of doing this, then you should partner up with a center that does,” he said.
Notably, the 10 shock teams were present only in medium or large urban, academic medical centers with more than 500 beds. Although they followed individual protocols, survey results show service-line representation, structure, and operations were similar across centers.
They all had a centralized way to activate the shock team, the service was 24/7, and members came from areas such as critical care cardiology (100%), cardiac surgery (100%), interventional cardiology (90%), advanced heart failure (80%), and extracorporeal membrane oxygenation service (70%).
Limitations of the study include the possibility of residual confounding, the fact that the registry did not capture patients with cardiogenic shock managed outside the CICU or the time of onset of cardiogenic shock, and data were limited on inotropic strategies, sedation practices, and ventilator management, the authors wrote.
“Although many critics will continue to discuss the lack of randomized controlled trials in cardiogenic shock, this paper supports the process previously outlined of a multidisciplinary team-based approach improving survival,” Dr. Meraj and William W. O’Neill, MD, director of the Center for Structural Heart Disease and Henry Ford Health System, Detroit, and the force behind the National Cardiogenic Shock Initiative, wrote in an accompanying editorial.
They point out that the report doesn’t address the escalation of care based on invasive hemodynamics in the CICU and the protocols to prevent acute vascular/limb complications (ALI) that can arise from the use of MCS.
“Many procedural techniques and novel CICU models exist to mitigate the risk of ALI in CS patients with MCS,” they wrote. “Finally, escalation of care and support is vital to the continued success of any shock team and center.”
One coauthor has served as a consultant to Abbott. Another has served as a consultant to the Abiomed critical care advisory board. All other authors reported having no relevant financial relationships. Dr. Meraj has received research and grant funding from Abiomed, Medtronic, CSI, and Boston Scientific. Dr. O’Neill has received consulting/speaker honoraria from Abiomed, Boston Scientific, and Abbott.
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