Venoarterial extracorporeal membrane oxygenation for postcardiotomy shock: Risk factors for mortality

Abstract

Objectives: Refractory postcardiotomy cardiogenic shock is associated with a high mortality, and venoarterial extracorporeal membrane oxygenation can offer acute cardiopulmonary life support. The aim of this study was to identify pre-venoarterial extracorporeal membrane oxygenation risk factors of 90-day mortality.

Methods: We retrospectively analyzed 105 consecutive patients supported with venoarterial extracorporeal membrane oxygenation due to refractory postcardiotomy cardiogenic shock. The association between preimplant variables and all-cause mortality at 90 days was analyzed with univariable and multivariable logistic regression.

Results: Main surgical subgroups were single noncoronary artery bypass grafting (29%), isolated coronary artery bypass grafting (20%), and 2 and 3 concomitant surgical procedures (31% and 20%, respectively). The median age of patients was 62 years (interquartile range, 52-68 years), and 76% were men. Cardiopulmonary resuscitation was performed in 30% of patients before venoarterial extracorporeal membrane oxygenation initiation. The median duration of venoarterial extracorporeal membrane oxygenation was 7 days (interquartile range, 3-14). The 90-day overall mortality was 57%, and in-hospital mortality was 56%. Forty-seven percent of patients died on venoarterial extracorporeal membrane oxygenation, 51% of patients were successfully weaned, 1% of patients were bridged to heart transplantation, and 1% of patients were bridged to left ventricular assist device. Multivariable logistic regression analysis identified arterial lactate (odds ratio per unit, 1.22; 95% confidence interval, 1.07-14.0; P = .004) and ischemic heart disease (odds ratio, 7.87; 95% confidence interval, 2.55-24.3; P < .001) as independent risk factors of 90-day mortality.

Conclusions: In patients with postcardiotomy cardiogenic shock, ischemic heart disease and level of arterial lactate before venoarterial extracorporeal membrane oxygenation initiation were identified as independent pre-venoarterial extracorporeal membrane oxygenation risk factors of 90-day mortality. These risk factors are easily available for pre-venoarterial extracorporeal membrane oxygenation risk prediction and may improve patient selection for this resource-intensive therapy.

Keywords: extracorporeal life support; extracorporeal membrane oxygenation; ischemic heart disease; lactate; postcardiotomy cardiogenic shock.