Exercise Right Atrial Stiffness From Pressure-Volume Loops and Prognosis in Pulmonary Hypertension
Year: 2026
Type: article
Study design: Observational Study
Abstract: BACKGROUND: In pulmonary hypertension (PH), risk assessment focuses on right ventricular function and may overlook exercise-related right atrial (RA) functional limitation. We investigated whether RA stiffness during exercise reflects impaired right-heart filling reserve and is associated with prognosis beyond conventional measures. METHODS: We prospectively enrolled 68 participants in this observational study, including 42 with precapillary PH. Participants who had PH ruled out and patients with postcapillary PH formed reference groups. Participants underwent 3-dimensional echocardiography, right heart catheterization, and invasive RA pressure-volume loop analysis at rest and during standardized semisupine exercise. RA filling stiffness was derived from the reservoir phase. Patients with precapillary PH were stratified by median exercise RA filling stiffness. RESULTS: At rest, high- and low-stiffness groups had comparable right ventricular function, afterload, and cardiac index, but the high-stiffness group exhibited impaired phasic RA strain and venous congestion (median [interquartile range] liver stiffness, 7.1 [6.0–8.8] versus 5.2 [4.8–5.8] kPa; P =0.021). During exercise, mean RA pressure increased similarly, but the high-stiffness group had impaired peak cardiac index (3.3±1.0 versus 4.1±0.9 L/min per m 2 ; P =0.015) and RA strain. Unlike resting RA stiffness, high exercise RA stiffness was independently associated with mortality (adjusted hazard ratio, 4.37 [95% CI, 1.20–15.96]). A model including RA conduit strain and right ventricular functional reserve discriminated high RA stiffness (area under the receiver operating characteristic curve, 0.90). CONCLUSIONS: RA stiffness during exercise integrates resting congestion with limited cardiac reserve and unmasks mortality risk missed by resting metrics. RA conduit strain and right ventricular functional reserve noninvasively identify the high-stiffness subgroup.
Source: Circulation Heart Failure
Institutions: Justus-Liebig-Universität Gießen, German Center for Lung Research, Universities of Giessen and Marburg Lung Center, Medical University of Graz, Catharina Ziekenhuis, Erasmus MC, Institut für Chirurgische Forschung, Ludwig-Maximilians-Universität München, Kerckhoff Klinik, Imperial College London, Sigmund Freud Privatuniversität Wien, Ludwig Boltzmann Institute for Lung Vascular Research, Charité – Universitätsmedizin Berlin, Mayo Clinic
Language: English
Subfield: Pulmonary and Respiratory Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W7225094497