Cardiogenic Shock Teams May Lower Mortality in Cardiac ICUs

Centers with multidisciplinary teams created to rapidly respond to cardiogenic shock are more likely to use invasive hemodynamic monitoring and advanced mechanical circulatory support (MCS), but less likely to use MCS more broadly, potentially translating into better patient outcomes, according to data from a network of North American cardiac ICUs.

Patients with cardiogenic shock were less likely to die in the cardiac ICU at centers with versus without shock teams (23% vs 29%; adjusted OR 0.72; 95% CI 0.55-0.94), Alexander Papolos, MD (MedStar Washington Hospital Center, Washington, DC), and colleagues report in a study published in the September 28, 2021, issue of the Journal of the American College of Cardiology.

Because of the observational nature of the study, no conclusions can be drawn in terms of causality, but Papolos speculated about what could explain the observed difference in outcomes, which was consistent in patients with and without shock related to acute MI.

“We think this is a multifactorial thing—places with shock teams are going to have more awareness of rapidly identifying shock and streamlining the identification and classification of the severity of shock [and then] come up with a plan to provide sufficient but not excessive support as fast as possible,” he told TCTMD. “And I think that’s the real difference here between the centers.”

Further research—including a randomized trial—is needed to delve into how shock teams might be influencing management and outcomes, Papolos said, noting that having a shock team is resource intensive. However, “the shock team centers not only had lower cardiogenic shock mortality, but they also had lower ICU resource utilization, which I think is a big point,” he added.

While awaiting further studies, he said, “our data really suggest that all AHA [American Heart Association] level 1 cardiac ICU centers should consider starting a shock team if they don’t already have one.”

Perwaiz Meraj, MD (Northwell Health, Manhasset, NY), who wrote an accompanying editorial with William O’Neill, MD (Henry Ford Health System, Detroit, MI), said he would take that conclusion a bit further and apply it to any center that cares for shock patients and has cardiac intensivists, interventional cardiologists, heart failure specialists, and cardiac surgeons available. “If you have those four groups together, then I think you should definitely be developing a shock team at your center,” he told TCTMD.

The team approach is critical, Meraj stressed. “Historically it’s been about what device we can put in, and I don’t think that’s the way to approach shock,” he said. “I think the more-important focus is for shock as a whole. And I think this changes the mindset of all of us for how we approach a patient in cardiogenic shock.”

Streamlining Shock Care

Some centers have started creating shock teams bringing together multiple specialties, including critical care cardiology, advanced heart failure and transplant cardiology, interventional cardiology, and cardiac surgery. The aim is to “facilitate early shock recognition and expedite multidisciplinary discussions regarding evaluation and management, including the need for timely [MCS] and appropriate device selection when indicated,” Papolos et al write. Results of single-center experiences have suggested the team approach improves survival.

The current study expands that assessment to multiple centers—specifically, 24 AHA level 1 cardiac ICUs in the United States and Canada participating in the Critical Care Cardiology Trials Network. Of those centers, 10 had multidisciplinary shock teams with similar compositions and operations. They were all centrally activated, were available around-the-clock, and heavily relied on invasive hemodynamics, Papolos noted.

The analysis included 6,872 cardiac ICU admissions for any reason, including 1,242 for cardiogenic shock, between 2017 and 2019.

Centers with shock teams accounted for 44% of the cardiogenic shock admissions. These centers were more likely to use pulmonary artery catheters (60% vs 49%; adjusted OR 1.86; 95% CI 1.47-2.35) and less likely to use MCS overall (35% vs 43%; adjusted OR 0.74; 95% CI 0.59-0.95) compared with those without shock teams. When MCS was used, however, cardiac ICUs with shock teams were more likely to select advanced technologies like the Impella devices (Abiomed), TandemHeart (LivaNova), venoarterial and extracorporeal membrane oxygenation, or temporary/durable surgical ventricular assist devices rather than intra-aortic balloon pumps (53% vs 43% of all MCS; adjusted OR 1.73; 95% CI 1.19-2.51).

In terms of resource use, the presence of a shock team appeared to be beneficial overall, since it was associated with a lower number of inotropic agents per patient (median 1 vs 2); a shorter median cardiac ICU stay (4.0 vs 5.1 days); and lower rates of mechanical ventilation (41% vs 52%) and new renal replacement therapy (11% vs 19%)—these were all significant differences.

Papolos said the difference in clinical outcomes between centers with versus without a shock team could be related to broader differences between hospitals, although he noted that overall cardiac ICU mortality—incorporating patients with and without cardiogenic shock—was similar irrespective of the presence of a team (9.8% vs 8.8%; P = 0.15).

Open Questions

More research, including RCTs, is needed to determine whether shock teams are actually improving clinical outcomes. If they are, Papolos said, there are remaining questions to answer, such as the necessary aspects of a shock team and whether it needs to be available 24/7, who should be a part of it, the importance of early invasive hemodynamic monitoring, and which interventions have the highest healthcare value.

In addition, he and his co-authors write, “Further efforts are needed to identify and overcome impediments to implementation of cardiogenic shock teams in diverse communities and establish criteria for prioritizing them over other hospital initiatives.”

In their editorial, Meraj and O’Neill note that the current study doesn’t address two other areas, including “escalation of care based on the invasive hemodynamics in the cardiac ICU and the protocols to prevent acute vascular/limb complications (ALI) that can arise from the use of MCS, especially in this population of patients.”

Even so, and despite the lack of RCTs in this area, “this paper supports the process previously outlined of a multidisciplinary team-based approach improving survival,” they say. “Establishing shock teams and cardiac ICUs that are based in centers dedicated to cardiogenic shock is the path to improved survival. Post-MCS care is of the utmost importance to escalate appropriately if patients are not improving and avoid ALI, which are typically fatal in these extremely ill patients.

“The continued support for shock teams,” they conclude, “is vital to the improvement in care models and survival while the randomized data on MCS use in cardiogenic shock continues to be developed.”