Log in to MyACC
Donor Brain Death Due to Stroke and Prognosis After Heart Transplant
Quick Takes
- Stroke as the cause of donor brain death compared to all other causes of brain death was not associated with increased mortality or allograft failure in heart transplant recipients.
- However, when stratifying by donor age, there was an association between younger donors (aged ≤40 years) who died from stroke and worse post-heart transplant prognosis. The reasons for this are unclear.
Study Questions:
Does the cause of donor brain death impact outcomes after heart transplantation?
Methods:
This was a retrospective cohort study using the United Network for Organ Sharing (UNOS) registry from January 2005–April 2018. Patients were included if they received an isolated heart transplant from donation after brain death. Causes of brain death included stroke, traumatic brain injury, anoxia, and brain tumor. Patients were excluded for recipient age <18 years, donor age <15 years, and re-transplant. The primary outcome was all-cause mortality. The secondary outcome was allograft failure (causes included primary graft failure, acute rejection, and chronic rejection).
Results:
There were 18,438 transplant recipients that met inclusion and exclusion criteria. Of these, 3,761 (20.4%) patients received an organ from a donor with stroke as the cause of brain death (stroke group). The remaining 14,677 patients received organs from donors with other causes of brain death (nonstroke group). Median follow-up was 4.0 years (interquartile range 2.0-5.0 years).
With respect to the primary outcome, there was no difference in overall mortality post-transplant when comparing the stroke versus nonstroke donor groups after risk adjustment (adjusted hazard ratio [HR], 1.07; 95% confidence interval [CI], 0.96-1.19). However, a significant interaction between the primary outcome and donor age was noted (p for interaction = 0.008). When assessing donors aged ≤40 years, patients receiving organs from the stroke group had worse overall mortality compared to the nonstroke group (23% vs. 19% at 5 years; adjusted HR, 1.17; 95% CI, 1.02-1.35). This was also noted to be the case with the secondary outcome of allograft failure (adjusted HR, 1.30; 95% CI, 1.04-1.63). No difference in mortality was noted for donors over the age of 40 years (adjusted HR, 0.95; 95% CI, 0.80-1.12). Further analysis revealed that the age-dependent effects on mortality were mostly seen within the first 60 days after transplant and predominantly in recipients with high pulmonary vascular resistance.
Conclusions:
When considering all adult heart transplant recipients, stroke as the cause of donor brain death did not impact post-transplant mortality compared to nonstroke causes of donor brain death. However, in a subgroup with donor age of ≤40 years, the stroke group had higher rates of mortality and allograft failure compared to the nonstroke group.
Perspective:
Many donor and recipient factors are known to impact post-transplant mortality and graft survival. Their factors are closely considered when selecting potential transplant candidates for listing and when accepting donor organs for transplant. While stroke as a cause of brain death is not generally thought of as a limiting factor for organ utilization, studies have been lacking. The authors looked to explore this issue further and noted that there was not a statistical difference between the stroke and nonstroke donor groups. However, when broken down by donor age, younger donors with stroke had worse post-transplant outcomes compared to donors without stroke. The authors postulate that this interesting finding could be related to the higher rates and possible deleterious effects of intracranial hemorrhage in younger individuals, possible underlying vasculopathy in the absence of traditional cardiovascular risk factors, or prolonged brain death evaluations. While the results of this study will not likely change current utilization of organs from donors with stroke, especially in the context of a global organ shortage and high transplant waitlist mortality, it does invite further research into why this association exists and what strategies can be implemented to mitigate this risk.
Clinical Topics: Cardiac Surgery, Cardiovascular Care Team, Heart Failure and Cardiomyopathies, Invasive Cardiovascular Angiography and Intervention, Cardiac Surgery and Heart Failure, Acute Heart Failure, Heart Transplant
Keywords: Hypoxia, Allografts, Brain Death, Brain Injuries, Traumatic, Brain Neoplasms, Graft Survival, Heart Disease Risk Factors, Heart Failure, Heart Transplantation, Hypoxia, Brain, Intracranial Hemorrhages, Risk Adjustment, Risk Factors, Stroke, Tissue and Organ Procurement, Tissue Donors, Transplant Recipients, Vascular Diseases, Vascular Resistance
< Back to Listings
