On-Support and Postweaning Mortality in Postcardiotomy Extracorporeal Membrane Oxygenation

Post-cardiotomy veno-arterial extracorporeal membrane oxygenation (V-A ECMO) is characterized by discrepancies between weaning and survival-to-discharge rates. This study analyzes the differences between post-cardiotomy V-A ECMO patients who survived, died on ECMO, or died after ECMO weaning. Causes of death and variables associated with mortality at different time points are investigated. The retrospective, multicenter, observational Post-cardiotomy Extracorporeal Life Support Study includes adults requiring post-cardiotomy V-A ECMO between 2000 and 2020. Variables associated with on-ECMO mortality and post-weaning mortality were modeled using mixed-Cox proportional hazards including random effects for center. In 2058 patients [males:59%; median age:65 (IQR:55-72 years)], weaning rate was 62.7%, while survival-to-discharge was 39.6%. Deceased patients (n=1244) included 754 on-ECMO deaths [(36.6%; median support time:79 (IQR:24-192 hours)], and 476 post-weaning deaths [(23.1%; median support time:146 (IQR:96-235.5 hours)]. Multi-organ (n=431/1158, 37.2%) and persistent heart failure (n=423/1158, 36.5%) were the main causes of death, followed by bleeding (n=56/754, 7.4%) for on-ECMO mortality and sepsis (n=61/401, 15.4%) for post-weaning mortality. On-ECMO death was associated with emergency surgery, preoperative cardiac arrest, cardiogenic shock, right ventricular failure, cardiopulmonary bypass time, ECMO implantation timing. Diabetes, post-operative bleeding, cardiac arrest, bowel ischemia, acute kidney injury, and septic shock were associated with post-weaning mortality. A discrepancy exists between weaning and discharge rate in post-cardiotomy ECMO. Deaths occurred during ECMO support in 36.6% of patients, mostly associated with unstable pre-operative hemodynamics. Another 23.1% of patients died after weaning in association with severe complications. This underscores the importance of post-weaning care for post-cardiotomy V-A ECMO patients.