Elevated left ventricular filling pressure (measured as mean pulmonary capillary wedge pressure, PCWPm) at rest or with exercise is diagnostic of heart failure with preserved ejection fraction (HFpEF). However, the capacity of the right ventricle to compensate for a high PCWPm and thus maintain an appropriate transpulmonary gradient (TPG) and perfusion of the pulmonary capillaries is likely an important contributor to gas exchange efficiency and exercise capacity. Therefore, this study aimed to determine whether a higher TPG at peak exercise is associated with superior exercise capacity and gas exchange. Gas exchange data from dyspneic patients referred for exercise right heart catheterization were retrospectively analyzed and patients were split into two groups based on TPG. Patients with a higher TPG at peak exercise had a higher peak VO (1025±227 vs.823±276, p=0.038), end-tidal partial pressure of CO (PETCO; 42.2±7.9 vs. 38.0±4.7, p=0.044), and gas exchange estimates of pulmonary vascular capacitance (GX; 408±90 vs. 268±108, p=0.001). A higher TPG at peak exercise correlated with a higher peak VO, O pulse, and stroke volume (R=0.42, 0.44 and 0.42, respectively, all p<0.05). These findings indicate that a greater TPG with exercise might be important for improving exercise capacity in HFpEF.
Copyright © 2020. Published by Elsevier Inc.