Background: Pulmonary vascular resistance (PVR) is used as a surrogate of pulmonary vascular remodeling and risk-predictor of post-transplant outcomes when selecting heart transplant (HT) candidates. Recent pulmonary hypertension (PH) guidelines propose use of diastolic pulmonary gradient (DPG) to further categorize patients with post-capillary PH. However, predictive value of these newer PH categories among HT recipients have not been studied. We evaluate the association of pre-HT PH categories using DPG and PVR and post-HT outcomes.
Methods: Using the United Network for Organ Sharing database, we identified 27,775 adult patients who underwent HT between 1988-2016 and had pre-HT hemodynamic data. We classified patients into no PH (mean pulmonary artery pressure, mPAP<25 mmHg, N=10325), post-capillary PH (mPAP>25 and pulmonary capillary wedge pressure, pCWP>15, N=16424) and pre-capillary PH (mPAP>25 and pCWP<=15, N=1026) groups. Post-capillary PH were further divided into three categories: post-capillary PH with normal PVR, (PVR<=3) and normal DPG (DPG <7) (N=10361), post-capillary PH with elevation of either PVR or DPG (N=4664) and post-capillary PH with elevated both PVR and DPG (N=1399). Multi-variable cox-proportional and Kaplan-Meier survival analyses were performed to estimate the association of PH categories and post-HT mortality.
Results: One year post-HT mortality based on pre-HT PH classification are presented in Figure 1 and Table 1. These associations were homogenous across pre-HT LVADs, and inotropes subgroups.
Conclusions: Among HT recipients with post-capillary PH, those with elevation of both PVR and DPG had worst one year mortality. Post-capillary PH with elevation of either PVR or DPG and post-capillary PH with normal PVR and DPG had similar outcomes. Incorporating DPG in risk stratification of HT candidates may identify a large group of patients who can be reclassified as lower risk compared to PVR based risk assessment alone.