The ENCOURAGE mortality risk score and analysis of long-term outcomes after VA-ECMO for acute myocardial infarction with cardiogenic shock

Purpose: This study was designed to identify factors associated with in-intensive care unit (ICU) death and develop a practical mortality risk score for venoarterial-extracorporeal membrane oxygenation (VA-ECMO)-treated acute myocardial infarction (AMI) patients. Long-term survivors' health-related quality of life (HRQOL), anxiety, depression, and post-traumatic stress disorder (PTSD) frequencies were also assessed.

Methods: Data from 138 ECMO-treated AMI patients admitted to two French ICUs (2008-2013) were analyzed. ICU survivors contacted >6 months post-ICU discharge were assessed for HRQOL, psychological and PTSD status.

Results: Sixty-five patients (47%) survived to ICU discharge. On the basis of multivariable logistic regression analyses, the ENCOURAGE score was constructed with seven pre-ECMO parameters: age >60, female sex, body mass index >25 kg/m(2), Glasgow coma score <6, creatinine >150 μmol/L, lactate (<2, 2-8, or >8 mmol/L), and prothrombin activity <50%. Six months after ECMO, probabilities of survival were 80, 58, 25, 20, and 7% for ENCOURAGE score classes 0-12, 13-18, 19-22, 23-27, and ≥28, respectively. The ENCOURAGE score ROC AUC [0.84 (95% CI 0.77-0.91)] was significantly better than those of the SAVE, SAPS II, and SOFA scores. Survivors' HRQOL evaluated after median follow-up of 32 months revealed satisfactory mental health but persistent physical and emotional-related difficulties, with 34% (95% CI 20-49%) anxiety, 20% (95% CI 8-32%) depression, and 5% (95% CI 0-12%) PTSD symptoms reported.

Conclusions: The ENCOURAGE score might be a useful tool to predict mortality of severe cardiogenic shock AMI patients who received VA-ECMO. However, it now needs prospective validation on other populations of AMI patients.