Introduction: There are limited data to develop a risk prediction model of in-hospital mortality for acute myocardial infarction (AMI) patients treated with venoarterial-extracorporeal membrane oxygenation (VA-ECMO).
Objectives: We aimed to develop a risk prediction model for in-hospital mortality in patients with AMI who were treated with VA-ECMO.
Methods: A total of 145 patients with AMI who underwent VA-ECMO between May 2004 and April 2016 were included from the Samsung Medical Center ECMO registry. The primary outcome was in-hospital mortality. To develop a new predictive scoring system, named the AMI-ECMO score, backward stepwise elimination and β coefficient-based scoring were used based on logistic regression analyses. Leave-one-out cross-validation (LOOCV) method was performed for internal validation.
Results: In-hospital mortality occurred in 69 patients (47.6%). In multivariable logistic regression analysis, the AMI-ECMO score comprised seven pre- and post-ECMO or angiographic parameters: age >65 years, body mass index >25 kg/m2, Glasgow Coma Score <6, lactic acid >8 mmol/L, anterior wall infarction, no attempted or failed revascularization, and gastro-intestinal bleeding complication. The AMI-ECMO score had a higher C-index value (0.895, 95% confidence interval [CI] 0.837-0.953) for predicting in-hospital mortality than the ENCOURAGE (C-index 0.756, 95% CI 0.673-0.840, p = 0.003 for AMI ECMO score vs. ENCOURAGE) and SAVE (C-index 0.647, 95% CI 0.550-0.743, p < 0.001 for AMI-ECMO score vs. SAVE) scores. A LOOCV analysis for internal validation confirmed the low misclassification rate of the AMI-ECMO score compared to ENCOURAGE and SAVE (12% vs. 26% and 38%, respectively).
Conclusions: The AMI-ECMO score can help predict early prognosis in AMI patients who undergo VA-ECMO.