Mortality in patients with normal left ventricular function requiring emergency VA-ECMO for postcardiotomy cardiogenic shock due to coronary malperfusion.

Objectives: To analyze outcomes in patients with normal preoperative left ventricular ejection fraction (LVEF) undergoing venoarterial extracorporeal membrane oxygenation (VA-ECMO) therapy due to postcardiotomy cardiogenic shock (PCCS) related to coronary malperfusion.

Methods: Retrospective single-center analysis in patients with normal preoperative LVEF treated with VA-ECMO for coronary malperfusion-related PCCS between May 1998 and May 2018. The primary outcome was 30-day mortality, which was compared using the Kaplan-Meier method and the log-rank test. Multivariable logistic regression was performed to identify predictors of mortality.

Results: During the study period, a total of 62,125 patients underwent cardiac surgery at our institution. Amongst them, 59 patients (0.1%) with normal preoperative LVEF required VA-ECMO support due to coronary malperfusion-related PCCS. The mean duration of VA-ECMO support was 6 days (interquartile range 4-7 days). The 30-day mortality was 50.8%. Under VA-ECMO therapy, a complication composite outcome of bleeding, re-exploration for bleeding, acute renal failure, acute liver failure, and sepsis occurred in 51 (86.4%) patients. Independent predictors of 30-day mortality were lactate levels > 9.9 mmol/l before VA-ECMO implantation (odds ratio [OR]: 3.3; 95% confidence interval [CI] 1.5-7.0; p = 0.002), delay until revascularization > 278 minutes (OR: 2.9; 95% CI 1.3-6.4; p = 0.008) and peripheral arterial artery disease (OR: 3.3; 95% 1.6-7.5; p = 0.001).

Conclusions: Mortality rates are high in patients with normal preoperative LVEF who develop PCCS due to coronary malperfusion. The early implantation of VA-ECMO before the development of profound tissue hypoxia and early coronary revascularization increases the likelihood of survival. Lactate levels are useful to define optimal timing for the VA-ECMO initiation.