(172) Right Ventricular Oversizing Mitigates Post-Transplant Mortality in Recipients with Pulmonary Hypertension

• Published in: The Journal of heart and lung transplantation Vol. 42; no. 4; pp. S85 - S86
• Main Authors: Hess, N., Hong, Y., Ziegler, L., Keebler, M., Huston, J., Mathier, M., Hickey, G., Kaczorowski, D.
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.04.2023
• ISSN: 1053-2498; 1557-3117
• DOI: 10.1016/j.healun.2023.02.188

The purpose of this study is to analyze the relationships of right ventricular (RV) donor-recipient sizing and recipient pulmonary hypertension on post-heart transplant survival. The UNOS database was queried to identify all adult isolated heart transplant recipients from 6/30/2007 to 6/30/217 with 5-year follow-up . Recipients were stratified into four categories based on their trans-pulmonary gradient (TPG) at time of transplantation (Group 1, <5 mmHg; Group 2, 5-10; Group 3, 10-15; Group 4, >15). Recipients were also stratified based on donor:recipient predicted right ventricular mass (pRVM) ratios. A ratio <0.85 was considered undersized, 0.85-1.15 size-matched, and a ratio >1.15 was considered oversized. Five-year post-transplant survival was compared among cohorts. Multivariable modeling was performed to measure the risk-adjusted hazards of donor-recipient RV sizing on 5-year mortality. A total of 19,515 recipients were included in this analysis (Group 1, n=2,256; Group 2, n=8,896; Group 3, n=4,626; Group 4, n=3,737). Five-year survival was lowest among recipients with TPG >15, and highest among recipients with TPG <5 (HR 1.35; 95% CI 1.20 to 1.52; P<0.001) (Figure A). For TPG groups 1, 2, and 3, neither pRVM undersizing or oversizing was found to have significant impacts on 5-year post-transplant mortality in univariate analysis. In Group 4 (TPG >15), five-year post-transplant survival was highest in those with an oversized donor RV and lowest in those with an undersized RV (Figure B). After adjustment for known risk factors of post-transplant mortality, pRVM oversizing was associated with a 20% reduction in mortality hazards (HR 0.81, 95% CI 0.70 to 0.93; P=0.004) among recipients with TPG >15. Pre-existing pulmonary hypertension appears to negatively impact post-transplant survival in recipients undergoing isolated heart transplant. However, RV oversizing based on pRVM measurements can reduce this risk.