30-Day perioperative mortality following venoarterial extracorporeal membrane oxygenation for postcardiotomy cardiogenic shock in patients with normal preoperative ejection fraction

Abstract

Objectives: Assessment of early outcomes in patients with normal preoperative left ventricular ejection fraction (LVEF) in whom venoarterial extracorporeal membrane oxygenation (VA-ECMO) was implanted for postcardiotomy cardiogenic shock (PCCS) during the first postoperative 48 h.

Methods: Retrospective single-centre analysis in adult patients with normal LVEF, who received VA-ECMO support for PCCS from May 1998 to May 2018. The primary outcome was 30-day perioperative mortality during the index hospitalization.

Results: A total of 62 125 adult patients underwent cardiac surgery at our institution during the study period. Among them, 173 patients (0.3%) with normal preoperative LVEF required VA-ECMO for PCCS. Among them, 71 (41.1%) patients presented PCCS due to coronary malperfusion and in 102 (58.9%) patients, no evident cause was found for PCCS. Median duration of VA-ECMO support was 5 days (interquartile range 2-8 days). A total of 135 (78.0%) patients presented VA-ECMO-related complications and the overall 30-day perioperative mortality was 57.8%. Independent predictors of mortality were: lactate level just before VA-ECMO implantation [odds ratio (OR) 1.27; P < 0.001], major bleeding during VA-ECMO (OR 3.76; P = 0.001), prolonged cardiopulmonary bypass time (OR 1.01; P < 0.001) and female gender (OR 4.87; P < 0.001).

Conclusions: Mortality rates of VA-ECMO in PCCS patients are high, even in those with preoperative normal LVEF. Coronary problems are an important cause of PCCS; however, the aetiology remains unknown in the vast majority of the cases. The implantation of VA-ECMO before development of tissue hypoperfusion and the control of VA-ECMO-associated complications are the most important prognostic factors in PCCS patients. Lactate levels may help guide timing of VA-ECMO implantation and define the extent of therapeutic effort.

Keywords: Extracorporeal life support; Extracorporeal membrane oxygenation; Postcardiotomy cardiogenic shock.