Stroke in young donors tied to higher recipient mortality, allograft failure

Stroke, a common cause of donor brain death, exhibits a substantially different effect on recipient and allograft survival depending on the age of the donor, suggests a recent study. Among younger donors, stroke contributes to increased recipient mortality and allograft failure than other causes of brain death.

“The strength of this association decreased with increasing donor age such that the increased hazard was no longer present in donors older than approximately 40 years,” the authors said.

To examine the effect of the cause of donor brain death on recipients, the authors compared long-term mortality and allograft failure in individuals who underwent heart transplantation in the US from 2005 through 2018 between allograft recipients from donors with stroke as the cause of brain death (n=3,761) and nonstroke causes (n=14,677) using the United Network for Organ Sharing registry.

The authors used inverse probability weighting for risk adjustment and examined associations between the cause of brain death and other conventional donor risk factors for recipient mortality.

Donor age was significantly associated with the cause of brain death (p_interaction=0.008). When allografts were obtained from donors aged 40 years or younger, stroke as the cause of brain death resulted in a higher risk of mortality (23 percent vs 19 percent at 5 years; hazard ratio [HR], 1.17, 95 percent confidence interval [CI], 1.02‒1.35) and allograft failure (HR, 1.30, 95 percent CI, 1.04‒1.63).

However, when donors were older than 40 years, the cause of brain death did not correlate with these outcomes, according to the authors.