Risk Stratification for Patients Bridged to Heart Transplantation on Venoarterial Extracorporeal Membrane Oxygenation Support.

BACKGROUND

The 2018 heart allocation policy led to increased use of venoarterial extracorporeal membrane oxygenation (VA-ECMO) as a bridge to heart transplantation (HT). Despite known poorer outcomes with ECMO bridging, no established risk stratification tool exists to guide candidate selection. This study analyzed risk factors for 1-year mortality after VA-ECMO bridged to HT to provide a risk stratification guide for decision-making.

METHODS

The United Network for Organ Sharing registry was used to identify all adults bridged to HT with VA-ECMO from January 2000 to June 2024. Recipient and donor characteristics were analyzed. Univariable and multivariable Cox regression analyses were performed to identify recipient and donor variables associated with increased 1-year post-HT mortality. Kaplan-Meier analysis was used to compare survival stratified by the number of risk factors.

RESULTS

Among 1235 VA-ECMO-bridged HT patients, unadjusted survival at 30 days, 90 days, 1 year, and 5 years was 93.09%, 89.28%, 84.29%, and 72.71%, respectively. Risk factors for increased 1-year mortality included age ≥61 years (P = .024), creatinine ≥1.4 (P < .001), ventilator-dependence prior to HT (P < .001), total bilirubin ≥3.4 (P < .001), ischemic cardiomyopathy (P = .006), and patients undergoing retransplantation (P < .001). Donor variables associated with increased risk of 1-year mortality were female-to-male donor-recipient sex mismatch (P = .003) and ischemic times ≥3.9 hours (P = .035). One-year survival in patients with 0, 1, 2, and ≥3 risk factors were 95.36%, 91.12%, 86.10%, and 60.95%, respectively.

CONCLUSIONS

Patients bridged to transplant with VA-ECMO face elevated posttransplant mortality. Identifying key risk factors enables more informed patient selection. Patients with ≥2 risk factors had <87% 1-year survival, warranting cautious consideration for transplant.