Survival Benefit of Extracorporeal Life Support in Patients with Acute Myocardial Infarction-Induced Cardiogenic Shock: A Propensity Score Matched Study

Objectives: Extracorporeal membrane oxygenation (ECMO) is frequently used for emergency support in patients with profound cardiogenic shock (CS) of all etiologies. However, no controlled clinical studies investigating ECMO in myocardial infarction–induced CS are available.

Methods: A total of 476 patients with acute myocardial infarction (AMI)-induced CS (ICD codes: R57: CS; I21.9) were investigated. One hundred and twenty-seven patients (26.7%) received emergency venoarterial ECMO support, and 349 patients did not receive mechanical circulatory support.

Patients were propensity score matched based on relevant clinical factors at admission such as age, gender, and the IABP shock II score at admission in the cath lab. Propensity score matching revealed 127 matched pairs.

Results: Mean age of patients was 65.1 ± 12.9 years and mean Syntax score was 27.5 ± 13.9 in the full unmatched patient population. Survival at 1, 3, and 5 years after CS was 45.6, 43.5, and 41.3% in the ECMO group and 11.0, 10.1, and 9.0% in the full unmatched control group (log-rank: p < 0.001). After propensity score matching, 1-, 3-, and 5-year survivals were 14.6, 13.6, and 11.3% in the matched control group (p < 0.001). Survival was significantly higher in patients with low and intermediate IABP II shock scores compared with high IABP II shock scores (p < 0.001) and higher in patients with completeness of revascularization (log-rank: p < 0.001).

Conclusions: Extracorporeal life support by ECMO significantly increased survival in patients with AMI-induced CS. ECMO insertion increased survival probability 3.1-fold and should be considered as first-line treatment in patients with AMI-induced CS followed by optimal left ventricular distension management and completeness of revascularization.