Completeness of Revascularisation Increases Survival and Weaning Success in Patients with Myocardial Infarction-Induced Cardiogenic Shock Requiring Extracorporeal Membrane Oxygenation Support

Abstract

Objectives: Aim of this study was to investigate the prognostic outcome of patients with AMI and profound CS in patients receiving emergency veno-arterial extracorporeal membrane oxygenation (va-ECMO). Methods: A consecutive series of 81 patients with AMI and severe CS receiving emergency va-ECMO from 1997 to 2015 in was investigated. Outcome evaluation regarding in-hospital mortality, “bridge to recovery” and long-term outcome in patients with successful weaning from va-ECMO was performed. Kaplan Meier survival analysis was performed to identify relevant prognostic parameters predicting weaning from va-ECMO and patient survival. Permission to perform this study was obtained from the local IRB. Results: Mean patient age was 58.8 ± 10.0 years and 77.8% were male gender. Out-of-hospital mechanical cardiopulmonary resuscitation (CPR) was performed in 7 patients (8.9%), within the cath-laboratory in 18 patients (24.1%) and during surgical insertion of va-ECMO in 20 patients (25.3%). Initial installation of intra-aortic-balloon counter-pulsation (IABP) was sustained in 33 patients (41.8%). De novo MI was responsible for 43 (53.1%) of cases, acute stent thrombosis in 13 (16.0%), and complications resulting from PCI were responsible for MI in 30.9%. Mean duration of va-ECMO support was 5.9 ± 5.4 days. Mean time from onset of MCI to reperfusion was 5.4 ± 3.9 hours. Mean “door-to-reperfusion-time” was 1.35 ± 1.2 hours. Actuarial 30-day survival was 52.6%, 43.8% at 1 year and 36.4% at 5 years. Restoration of spontaneous circulation enabling bridge to recovery and weaning from va-ECMO was possible in 33 patients (46.8%) and was significantly higher in patients with complete revascularisation (p = 0.026). Bridge to recovery was significantly higher in patients with va-ECMO and consecutive coronary artery bypass grafting (CABG) versus patients with culprit lesion PCI (p = 0.011). In patients successfully weaned from ECMO, CABG patients demonstrated significantly higher long term survival than PCI patients (log-rank: p = 0.04). Conclusion: AMI complicated by cardiogenic shock is associated with a high in-hospital mortality even in patients undergoing emergency va-ECMO. Complete revascularisation significantly improves weaning success from va-ECMO and long term survival. Complete revascularisation seems to be better provided by CABG rather than PCI only - therefore weaning and long term prognosis is significantly improved by consecutive CABG rather than PCI or consecutive conservative management.