A team-based protocol for treating cardiogenic shock helped one center boost its 30-day survival rates for those patients by nearly 20 percentage points over a two-year period, researchers reported in the Journal of the American College of Cardiology.
In-hospital mortality rates for cardiogenic shock (CS) after acute myocardial infarction have exceeded 50% for nearly two decades, noted lead author Behnam N. Tehrani, MD, and colleagues with Inova Heart and Vascular Institute in Falls Church, Virginia.
“Despite the growing body of evidence supporting timely recognition of CS, hemodynamic monitoring, tailored escalation to MCS (mechanical circulatory support), and centralized care, variations in practice patterns in CS management endure and may contribute to persistently high mortality rates,” they wrote. “We hypothesized that the deployment of a multidisciplinary ‘shock team’ providing timely diagnosis and utilizing standardized protocols would reduce practice variations and improve clinical outcomes.”
To test this theory, a task force at the hospital developed a new algorithm for diagnosing and treating patients with cardiogenic shock. It emphasized five clinical goals, according to the authors: rapid identification of the shock state, mandatory invasive hemodynamics, minimizing use of vasopressors and inotropes, early mechanical ventricular support and cardiac recovery.
When a patient was suspected to be in CS a multidisciplinary shock team was activated through a single-call line. This would prompt on-call physicians from interventional cardiology, cardiovascular surgery, advanced heart failure and critical care to gather to discuss treatment options.
This setup and standardized algorithm was drafted and formalized in the second half of 2016 and put in place by January 2017.
Before the program’s implementation, cardiogenic shock patients at the hospital survived to 30 days post-discharge 47% of the time. But those rates swiftly increased to 57.9% and 76.6% in 2017 and 2018, respectively.
A total of 204 patients with CS were treated in the 18 months after the program was initiated, including those who experienced shock following acute MI and following acute decompensated heart failure. Few previous studies of cardiogenic shock management included patients in both groups, according to Tehrani and colleagues.
“Our observational study suggests that the implementation of a shock team predicated on a multidisciplinary standardized team-based approach emphasizing timely diagnosis, mandatory invasive hemodynamics, and appropriate use of MCS is not only feasible but may result in improved survival in all-comer patients with CS,” the researchers wrote. “In addition, a validated score that uses demographic, laboratory, and hemodynamic markers can help to stratify risk and guide clinical decision-making in patients with all phenotypes of CS.”
That risk score included seven variables which were found to be predictive of mortality in the study—age of 71 or older, lactate levels of at least 3.0 mg/dl, cardiac power output below 0.6 W, diabetes, need for dialysis, pulmonary arterial pulsatility index below 1.0 at 24 hours after diagnosis, and treatment with vasopressors for more than 36 hours.
The researchers said their small sample size, single-center design and short follow-up durations were limitations of the study. Nevertheless, they were encouraged by the results.
One notable aspect of the study was that 52% of patients were transferred in from outside institutions, yet still appeared to benefit from the protocol. The authors distributed their management algorithm to relevant physicians at regional, “spoke” facilities and encouraged them to use the CS call line to initiate the shock team at the “hub” hospital. There was no significant increase in mortality for patients transferred from another facility.
“Although different hypothetical models have been proposed to develop CS hub-and-spoke systems, we believe it is critically important to implement coordinated regionalized systems of care to reduce practice variation and centralize the care of the patient with CS to high-volume tertiary medical centers able to offer early escalation of therapy and full-spectrum, multidisciplinary care,” Tehrani et al. wrote.