Survival after heart transplants from circulatory-dead versus brain-dead donors: Meta-analysis of reconstructed time-to-event data

Background

Heart transplantation (HTx) using donors after circulatory death (DCD) has the potential to significantly boost overall transplant rates. This study aims to reconstruct data from individual studies comparing survival between HTx from DCD recipients and donation after brain (DBD) recipients.

Methods

MEDLINE, Embase, Scopus, were searched up to August 2024. We included studies that reported a Kaplan-Meier summary of survival comparing DCD and DBD HTx. Digitization of the Kaplan-Meier curves and reconstruction of individual patient data followed by survival analysis that was conducted using R software.

Results

Six studies including a total of 3240 patients (2242 DBD and 998 DCD) were included in the final analysis. There was no significant difference in the overall survival rates between DCD and DBD patients (Hazard Ratio (HR): 1.01, 95 % CI [0.81–1.25], P = 0.91). However, the proportional hazard assumption was violated, deeming such results inconclusive. Time-varying flexible parametric model revealed a significantly declining survival in DCD recipients 3 years after surgery. Landmark analyses further suggest this declining trend in the DCD group at the two-year landmark (HR: 1.67, p = 0.021) and the four-year mark (HR: 2.78, p = 0.002). However, data beyond 6 years is limited. Evidence comparing direct procurement and normothermic regional perfusion is scarce, with no significant survival differences observed.

Conclusion

This meta-analysis shows that, despite similar early survival outcomes, DCD heart transplants showed a trend towards a lower long-term survival, with the difference becoming evident around three years post-transplantation. These findings highlight the need for enhanced monitoring and optimized post-transplant care in DCD recipients. Further studies with strict and long-term follow-up are warranted to confirm these results.