PREDICTED HEART MASS BASED SIZE MATCHING AMONG RECIPIENTS WITH MODERATE PULMONARY HYPERTENSION: OUTCOMES AND GENDER EFFECT

Abstract Background There is a lack of evidence to guide appropriate donor sizing in recipients with moderate pulmonary hypertension (mod-pHTN) awaiting heart transplantation (HTx). It is common practice to oversize hearts for such recipients to prevent post-operative right ventricular failure. Therefore, our objective was to determine if oversizing in pre-transplant mod-pHTN provides a survival advantage. Methods The United Network for Organ Sharing database was analyzed to include HTx recipients from years 1994 to 2016. Recipients were considered as having mod-pHTN if the pulmonary vascular resistance (PVR) was 2.5-5 WU or transpulmonary gradient (TPG) was 10-18 mmHg. Heart size mismatch was determined using the predicted heart mass (pHM) equations. A size mismatch of ≥15% in either direction was considered undersized, and oversized, respectively. Ninety-day and 1-year survival were analyzed based on size-matching via univariate and Cox-regression analysis. Propensity matching was performed to specifically evaluate the effect of donor sex among male transplant recipients. Results Among 29,441 HTx recipients, 10,666 had moderate pHTN by PVR criteria and 12,624 HTx patients had moderate pHTN according to TPG criteria. Among patients with a PVR of 2.5 to 5 WU, oversizing was not associated with lower mortality compared to matched hearts at 90 days (7.6% vs. 7.4%; p=0.75) and 1-year (12.1% vs. 11.3%; p=0.26). Conversely, undersizing the donor was associated with a higher 90-day (10.6% vs. 7.6% vs. 7.4%; p Conclusion In this registry based analysis, there was no benefit to oversizing donors for cardiac transplant recipients with mod-pHTN. Elimination of this restriction could increase the donor pool and reduce wait times for such recipients.