Donor diabetes status impacts long-term survival in diabetic heart transplant recipients

Survival for heart transplant recipients with type 2 diabetes mellitus is reduced; however, the effect of donor diabetes in this cohort is unknown. We examined the impact of donor diabetes status on long-term outcomes among diabetic heart transplant recipients.

The United Network for Organ Sharing database was queried to identify adult diabetic recipients undergoing single-organ heart transplantation between 2005 and 2025. The primary outcome was 10-year all-cause mortality, assessed after propensity score matching on 26 variables in a Cox proportional hazards model. Secondary outcomes included 30-day mortality, dialysis requirement, stroke, permanent pacemaker implantation, and length of stay. Median follow-up time was 7.05 years (95% CI 7.00-7.18).

Of 13,091 heart transplant recipients identified, 540 (4%) received a diabetic donor heart and 12,551 (96%) received a non-diabetic donor heart. Recipients in the diabetic donor group were older (60.0 years [IQR 54.0-65.0] vs 59.0 [52.0-64.0], p < 0.001) and had shorter waitlist times (44.5 days [IQR 14.0-185.5] vs 60.0 [17.0-213.0], p = 0.02). Donors with diabetes were older (41.0 years [IQR 34.0-48.0] vs 32.0 [23.0-41.0], p < 0.001), had a higher prevalence of hypertension (55.9% vs 15.2%, p < 0.001), and were more likely to have donor-recipient sex mismatch (26.9% vs 21.5%, p = 0.003). Propensity score matching produced 539 pairs. In the matched cohort, 10-year survival was lower among recipients of diabetic donor hearts compared with non-diabetic donor hearts (48.5% vs 57.0%, adjusted HR: 1.26, 95% CI: 1.00-1.59, p = 0.04). Secondary outcomes were similar between groups.

Diabetic heart transplant recipients experience worse long-term survival when a diabetic donor heart is utilized.