Early vs. Delayed Mechanical Circulatory Support in Patients with Acute Myocardial Infarction and Cardiogenic Shock

Abstract

Background: Despite increased temporary mechanical circulatory support (tMCS) utilization for acute myocardial infarction complicated by cardiogenic shock (AMI-CS), data regarding efficacy and optimal timing for tMCS support are limited. This study aimed to describe outcomes based on tMCS timing in AMI-CS and to identify predictors of 30-day mortality and readmission.

Methods: Patients with AMI-CS identified in the National Readmissions Database were grouped according to the use of tMCS and early (<24 hours) vs. delayed (≥24 hours) tMCS. The correlation between tMCS timing and inpatient outcomes was evaluated using linear regression. Multivariate logistic regression was used to identify variables associated with 30-day mortality and readmission.

Results: Of 294,839 patients with AMI-CS, 109,148 patients were supported with tMCS (8,067 veno-arterial extracorporeal membrane oxygenation, 33,577 Impella, and 79,161 intra-aortic balloon pump). Of patients requiring tMCS, patients who received early tMCS (n = 79,906) had shorter lengths of stay (7 days vs. 15 days, p < 0.001) and lower rates of ischemic and bleeding complications than those with delayed tMCS (n = 32,241). Patients requiring tMCS had higher in-hospital mortality (OR [95% CI]) (1.7 [1.7-1.8], p < 0.001). Among patients requiring tMCS, early support was associated with fewer complications, lower mortality (0.90 [0.85-0.94], p < 0.001), and fewer 30-day readmissions (0.91 [0.85-0.97], p = 0.005) compared to patients with delayed tMCS.

Conclusion: Among patients receiving tMCS for AMI-CS, early tMCS was associated with fewer complications, shorter lengths of stay, lower hospital costs, and fewer deaths and readmissions at 30 days.

Keywords: Acute myocardial infarction; cardiogenic shock; mechanical circulatory support.