Severe primary graft failure: Are there lasting impacts? Analysis from the PHTS Database

Area of Science:

• Cardiovascular Surgery
• Transplantation Immunology
• Pediatric Cardiology

Background:

• Primary graft failure (PGF) is a major cause of early morbidity and mortality following heart transplantation (HTx).
• PGF arises from graft ischemia and subsequent ischemia-reperfusion injuries to the donor heart's cardiomyocytes and vasculature.
• Longer-term outcomes for patients experiencing PGF after HTx remain understudied.

Purpose of the Study:

• To investigate the long-term outcomes and survival rates of patients who experience primary graft failure (PGF) after heart transplantation (HTx).
• To identify predictors of PGF and its impact on graft survival, rejection, and coronary allograft vasculopathy (CAV).

Main Methods:

• Retrospective analysis of 4,982 patients undergoing primary HTx between January 1, 2010, and June 30, 2022, using the Pediatric Heart Transplant Society registry.
• PGF defined as death, retransplantation, or need for mechanical circulatory support within 72 hours of HTx.
• Kaplan-Meier analysis and Cox proportional hazard modeling were employed to assess survival and risk factors.

Main Results:

• 5.4% of patients (n=269) experienced PGF, characterized by younger age, higher prevalence of congenital heart disease, longer bypass and ischemic times, and increased pre-transplant support.
• PGF was associated with significantly lower overall survival at 1 year (54% vs. 94%) and predicted early graft loss and conditional survival up to 90 days.
• No significant differences in freedom from rejection or coronary allograft vasculopathy (CAV) were observed between PGF and non-PGF groups beyond 90 days.

Conclusions:

• Severe PGF independently predicts early mortality post-HTx but does not adversely affect long-term survival, rejection rates, or CAV.
• Further investigation into the impact of milder forms of PGF on patient outcomes is warranted.
• Developing strategies to mitigate PGF risk, such as improved preservation techniques, may reduce early post-HTx mortality.