Influence of donor brain death duration on outcomes following heart transplantation: A United Network for Organ Sharing Registry analysis

Abstract

Objectives: We hypothesized that an increased duration of donor brain death may worsen survival following orthotopic heart transplantation.

Methods: The United Network for Organ Sharing Registry was queried for first-time, adult recipients of heart transplant from 2006 to 2018. Cox proportional hazards with penalized smooth splines was used to stratify patients based on donor brain death interval: shorter (<22 hours), reference (22-42 hours), and longer (>42 hours). Overall survival was estimated using Kaplan-Meier and Cox proportional hazards models.

Results: A total of 22,960 patients met study criteria (9.2% shorter, 55.0% reference, and 35.8% longer). Longer brain death duration recipients were more likely to have a later year of transplant and have a mechanical bridge to transplant, whereas longer duration donors were more likely to be black and die of anoxia compared with shorter duration and reference donors. Compared with reference, neither shorter (hazard ratio, 1.02; 95% confidence interval, 0.94-1.12) nor longer donor brain death interval (hazard ratio, 1.01; 95% CI, 0.94-1.08) was associated with posttransplant survival in either unadjusted or multivariable analyses (both P values >0.6).

Conclusions: Longer duration of brain death was not associated with worse survival following heart transplantation. Donors with prolonged interval of brain death should not necessarily be excluded based on brain death period alone.

Keywords: brain death duration; donor brain death; heart transplant.

Figure 1.

Distribution of heart transplant donor brain death duration

Figure 2.

Cox Proportional Hazard analysis of donor brain death duration with penalized smooth splines. 95% confidence interval depicted by gold lines. Approximate inflection points identified with vertical dotted lines used to separate population into three cohorts for subsequent analyses.

Figure 3.

Kaplan-Meier analysis of recipient survival stratified by donor brain death duration. No survival difference observed between cohorts (p=0.9).

Figure 4.

Kaplan-Meier analysis of recipient survival, restricted to donors with brain death duration <5^th percentile or >95^th percentile, stratified by donor brain death duration. No survival difference observed between cohorts (p=0.67).