Association of recipient age and causes of heart transplant mortality: Implications for personalization of post-transplant management-An analysis of the International Society for Heart and Lung Transplantation Registry

Background: Survival beyond 1 year after heart transplantation has remained without significant improvement for the last 2 decades. A more individualized approach to post-transplant care could result in a reduction of long-term mortality. Although recipient age has been associated with an increased incidence of certain post-transplant morbidities, its effect on cause-specific mortality has not been established.

Methods: We analyzed overall and cause-specific mortality of heart transplant recipients registered in the International Society for Heart and Lung Transplantation Registry between 1995 and 2011. Patients were grouped by recipient age: 18 to 29, 30 to 39, 40 to 49, 50 to 59, 60 to 69, and ≥ 70 years. Multivariable regression models were used to examine the association between recipient age and leading causes of post-transplant mortality. We also compared immunosuppression (IS) use among the different recipient age groups.

Results: There were 52,995 recipients (78% male; median age [5th, 95th percentile]: 54 [27, 66] years). Survival through 10 years after transplant was lower in heart transplant recipients in the 2 more advanced age groups: 49% for 60 to 69 years and 36% for ≥ 70 years (p < 0.01 for pairwise comparisons with remaining groups). The risk of death caused by acute rejection (hazard ratio [HR], 4.11; p < 0.01), cardiac allograft vasculopathy (HR, 2.85; p < 0.01), and graft failure (HR, 2.29; p < 0.01) was highest in the youngest recipients (18-29 years) compared with the reference group (50-59 years). However, the risk of death caused by infection (HR, 2.10; p < 0.01) and malignancy (HR, 2.23; p < 0.01) was highest in older recipients (≥ 70 years). Similarly, the risk of death caused by renal failure was lower in younger recipients than in the reference group (HR, 0.53; p < 0.01 for 18-49 years vs 50-59 years). The use of induction IS was similar among the different recipient age groups, and differences in maintenance IS were not clinically important.

Conclusions: Causes of death in this large cohort of heart transplant recipients varied significantly with recipient age at the time of transplant, with cause-specific mortality profiles suggesting a possible effect of inadequate IS in younger recipients and over-IS in older recipients. Thus, a more personalized approach, possibly including different IS strategies according to recipient age, might result in improved post-transplant survival.