On-Support and Post-Weaning Mortality in Post-Cardiotomy Extracorporeal Membrane Oxygenation.

Background: 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. Methods: 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. Results: 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. Conclusions: 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.