Association between right heart size and right ventricular output reserve in patients with pulmonary arterial hypertension.

Objectives: Right ventricular (RV) output reserve, defined as increase of cardiac output during exercise, is reduced in patients with pulmonary arterial hypertension (PAH). Aim of this study was to evaluate the association of right heart size measured by echocardiography and invasively measured RV function at rest and during exercise in PAH patients.
Methods: Adult PAH-patients who received routine haemodynamic assessment at rest and during exercise by right heart catheterisation and echocardiographic measurement of right heart size (right atrial (RA) and RV area) were included in this study. Clinical, echocardiographic, laboratory, exercise and invasive haemodynamic parameters were retrospectively analysed. The primary endpoint was to assess the association between right heart size and right ventricular function.
Results: Data from 215 PAH patients (age 58.9 ± 15.9 years, 63.3% female, 62.2% double or triple combination treatment) were analysed in this cross-sectional study. Cardiac index was significantly lower for patients with enlarged RA-area > 18 cm ² at rest, and at 25 and 50 W (all p < 0.001) and for patients with enlarged RV area > 20 cm ² at rest, 25, 50 and 75 W (all p < 0.001). Furthermore, pulmonary vascular resistance and mPAP/CO slope (all p < 0.001) were significantly higher and pulmonary arterial compliance (all p < 0.05) was significantly lower in patients with enlarged RA or RV area. RA and RV area correlated with TAPSE/sPAP (both p < 0.001, R - 0.570 and - 0.530).
Conclusion: This study could underline that an enlargement of RA- and RV-area is associated with an impaired RV function at rest and during exercise in patients with PAH.
Competing Interests: Declaration of competing interest BE: received travel fees, consulting fees, speaking fees, and/or honoraria from Janssen, MSD, Bayer and OMT, outside the submitted work. KFW, AMM: nothing to declare. CAE: received speaking fees from MSD outside the submitted work. SH: received honoraria for lectures, consultancy, or both from Actelion, AOP, Bayer/MSD, GSK, Novartis, OMT, Pfizer, and United Therapeutics out-side the submitted work. EG: has received grants and personal fees from Actelion, Bayer AG, and MSD; grants from GSK, Novartis, and United Therapeutics and personal fees from SCOPE, OrPha Swiss GmbH, and Zurich Heart House, outside the submitted work. PX: has received personal fees from MSD and OMT outside the submitted work. NB: received speaker fees from University Hospital Zurich and AOP.
(Copyright © 2024. Published by Elsevier B.V.)