Long-term clinical outcomes in patients with acute myocardial infarction complicated by cardiogenic shock according to the application and initiation time of extracorporeal membrane oxygenation in South Korea

BACKGROUND: Limited data are available regarding the proper application time and long-term outcomes of extracorporeal membrane oxygenation (ECMO) in patients with cardiogenic shock. This cohort study appraised the clinical outcomes according to ECMO application without or before cardiopulmonary resuscitation (CPR) in patients with acute myocardial infarction (AMI) combined with cardiogenic shock. METHODS: Between 2011 and 2015, a total of 13,104 patients with AMI were enrolled in a nationwide AMI registry. Eligible patients with cardiogenic shock, who underwent percutaneous coronary intervention, with a 3-year clinical follow-up, were analyzed. The 949 included patients were divided into two groups: no ECMO (n = 845) and ECMO application (n = 104). The ECMO group was further divided into ECMO without or before CPR (n = 11) and ECMO after CPR (n = 93). RESULTS: Significant differences were noted in major adverse cardiac events (MACEs) between the no ECMO and ECMO application groups during the 3-year follow-up (41.5% vs. 80.8%; p < 0.001). However, the ECMO without or before CPR group showed similar outcomes to the no ECMO group in 3-year MACEs (63.6% vs. 41.5%; p = 0.055). MACEs during 3 years of follow-up were significantly lower in the ECMO without or before CPR group than in the ECMO after CPR group (63.6% vs. 82.8%; p = 0.005). CONCLUSIONS: A significantly lower risk of major cardiac events in ECMO without or before CPR suggests that early application of ECMO can be a reasonable strategy to improve outcomes in patients with AMI complicated by cardiogenic shock.