Sex-based differences and determinants of right ventricular function and right ventricular-pulmonary arterial...

Compared with left ventricular (LV) remodeling in cardiac aging, right ventricular (RV) adaptations to pulmonary arterial (PA) changes are less well characterized. We evaluated CMR-derived indices of RV function and a volume-based surrogate of RV-PA coupling in community-dwelling older adults without cardiovascular disease. Participants underwent cardiac magnetic resonance with assessment of RV volumes (EDV, ESV), function (RVEF, RV global longitudinal strain [RVGLS]), and RV-PA coupling (LV stroke volume/RVESV). An RV-PA ratio >1.5 indicated effective adaptation. We studied 255 participants (54.5% females, 70.8 ± 9.1 yr) with normal biventricular function (mean: LVEF = 65.1 ± 7.5%, RVEF = 64.3 ± 7.0%). RV-PA <1.5 was associated with lower RVEF (56.6% vs. 67.5%, P < 0.001), less negative RVGLS (-28.1% vs. -32.8%, P = 0.007) and higher-indexed RVEDV (73.2 vs. 63.3 mL/m², P < 0.001). Female sex independently predicted more favorable RV indices (better RVGLS and smaller RVESV), whereas higher BMI and older age were associated with larger RVESV. Compared with men, women had higher RVEF and more negative RVGLS, but lower RV stroke volume and peak V̇o₂, and higher RV-PA ratios (2.1 vs. 1.8, P < 0.001). Female sex remained independently associated with higher RV-PA ratio. In healthy, community-dwelling older adults, CMR-derived measures characterize RV function and a surrogate of RV-PA interaction, with women demonstrating more favorable right heart phenotype and higher RV-PA ratios than men within this cohort. These findings highlight sex-related differences in RV adaptation to aging not captured by LV-focused assessment. As a cross-sectional study, they should be interpreted as physiological reference data rather than prognostic.NEW & NOTEWORTHY Our study used cardiovascular magnetic resonance to examine sex-based differences in right ventricular function and right ventricular-pulmonary arterial (RV-PA) coupling in 255 healthy older adults. Women had smaller right ventricular volumes but demonstrated higher ejection fraction, superior myocardial strain, and stronger RV-PA coupling compared with men. These findings highlight distinct hemodynamic adaptations of the aging right heart, suggesting that sex-specific reference values may be needed to differentiate physiological variation from early pathological changes.