Predictors of in-hospital mortality and midterm outcomes of patients successfully weaned from venoarterial extracorporeal membrane oxygenation

Abstract

Objectives: There is limited evidence to guide the decision to proceed with weaning from venoarterial extracorporeal membrane oxygenation, and approximately 30% of patients weaned "successfully" do not survive to hospital discharge. We evaluated predictors of in-hospital mortality and midterm outcomes of patients successfully weaned from venoarterial extracorporeal membrane oxygenation after support for cardiogenic shock, surviving more than 24 hours after weaning, with the aim of improving patient selection for durable weaning.

Methods: We performed a retrospective analysis of 92 patients supported on venoarterial extracorporeal membrane oxygenation and successfully weaned between January 2013 and February 2018. Survival was estimated by the Kaplan-Meier method. Predictors of in-hospital mortality were identified using a Cox proportional hazards model and an Akaike information criterion-selected multivariate model.

Results: Overall survival at hospital discharge was 64.2%; survival was 54.6% 1 year after support and 51.4% 3 years after support. A history of diabetes, previous myocardial infarction, prolonged extracorporeal membrane oxygenation support, and hypoxemia at extracorporeal membrane oxygenation weaning were independent predictors of in-hospital mortality. At midterm follow-up, New York Heart Association class I heart function was observed in 53% of patients, class II in 19%, class III in 16%, and class IV in 12%. Average left ventricular ejection fraction was 46.5% ± 18.2%, and 50% of the patients had been readmitted to the hospital because of heart failure.

Conclusions: Durable extracorporeal membrane oxygenation weaning with acceptable midterm functional status is obtainable in well-selected patients. Previous myocardial infarction, diabetes, prolonged extracorporeal membrane oxygenation support, and pulmonary dysfunction strongly predicted in-hospital mortality after venoarterial extracorporeal membrane oxygenation weaning. In this high-risk situation, other heart replacement therapies should be considered.

Keywords: cardiogenic shock; extracorporeal membrane oxygenation; in-hospital mortality.