Right Ventricular Mass Oversizing Is Associated With Improved Post-transplant Survival in Heart Transplant Recipients With Elevated Transpulmonary Gradient

Background: This study evaluates the effects of pre-transplant transpulmonary gradient (TPG) and donor right ventricular mass (RVM) on outcomes following heart transplantation.

Methods: UNOS registry was queried to analyze adult recipients who underwent primary isolated heart transplantation from 1/1/2010 to 12/31/2018. The recipients were dichotomized into 2 groups based on their TPG at the time of transplantation, < 12 and ≥ 12 mmHg. The outcomes included 5-year survival and post-transplant complications. Propensity score-matching was performed. Subanalysis was performed to evaluate the effects of donor-recipient RVM matching, where a ratio < 0.85 was classified as undersized, 0.85-1.15 as size-matched, and > 1.15 as oversized.

Results: We analyzed 17,898 isolated heart transplant recipients, and 5129 (28.7%) recipients had TPG ≥ 12 mmHg at the time of transplantation. The recipients with TPG ≥ 12 mmHg experienced significantly lower 5-year survival rates (78.4% vs 81.2%; P < 0.001) compared to the recipients with TPG < 12 mmHg, and this finding persisted in the propensity score-matched comparison. The recipients with TPG ≥ 12 mmHg experienced a higher rate of post-transplant dialysis and a longer duration of hospitalization. Oversizing the donor RVM considerably improved the 5-year survival among the recipients with TPG ≥ 12 mmHg, comparable to those with TPG < 12 mmHg.

Conclusion: Elevated pre-transplant TPG is associated with significantly reduced post-transplant survival. However, oversizing the donor RVM is associated with improved survival rates in recipients with elevated TPG, resulting in improved survival that is comparable to that of recipients with normal TPG. Therefore, careful risk stratification and donor matching among recipients with elevated TPG is essential to improve outcomes in this vulnerable population.