Risk Scores in ST-Segment Elevation Myocardial Infarction Patients with Refractory Cardiogenic Shock and Veno-Arterial Extracorporeal Membrane Oxygenation

Although many risk models have been tested in patients implanted by veno-arterial extracorporeal membrane oxygenation (VA-ECMO), few scores assessed patients' prognosis in the setting of ST-segment elevation myocardial infarction (STEMI) with refractory cardiogenic shock. We aimed at assessing the performance of risk scores, notably the prEdictioN of Cardiogenic shock OUtcome foR AMI patients salvaGed by VA-ECMO (ENCOURAGE) score, for predicting mortality in this particular population. This retrospective observational study included patients admitted to Tours University Hospital for STEMI with cardiogenic shock and requiring hemodynamic support by VA-ECMO. Among the fifty-one patients, the 30-day and 6-month survival rates were 63% and 56% respectively. Thirty days after VA-ECMO therapy, probabilities of mortality were 12, 17, 33, 66, 80% according to the ENCOURAGE score classes 0-12, 13-18, 19-22, 23-27, and ≥28, respectively. The ENCOURAGE score (AUC of the Receiving Operating Characteristic curve = 0.83) was significantly better compared to other risk scores. The hazard ratio for survival at 30 days for each point of the ENCOURAGE score was 1.10 (CI 95% (1.06, 1.15); p < 0.001). Decision curve analysis indicated that the ENCOURAGE score had the best clinical usefulness of the tested risk scores and the Hosmer-Lemeshow test suggested an accurate calibration. Our data suggest that the ENCOURAGE score is valid and the most relevant score to predict 30-day mortality after VA-ECMO therapy in STEMI patients with refractory cardiogenic shock. It may help decision-making teams to better select STEMI patients with shock for VA-ECMO therapy.