Early vs. delayed mechanical circulatory support in patients with acute myocardial infarction and cardiogenic shock

Aims 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 and results Patients with AMI-CS identified in the National Readmissions Database were grouped according to the use of tMCS and early (<24 h) vs. delayed (≥24 h) 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. Of 294 839 patients with AMI-CS, 109 148 patients were supported with tMCS (8067 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 vs. 15 days, P < 0.001) and lower rates of ischaemic and bleeding complications than those with delayed tMCS (n = 32 241). Patients requiring tMCS had higher in-hospital mortality [odds ratio (95% confidence interval)] [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 with 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.