Right Ventricular–Pulmonary Artery Coupling by 3-Dimensional Echocardiography Predicts Outcomes in Heart Failure with Preserved Ejection Fraction

BACKGROUND In advanced heart failure with preserved ejection fraction (HFpEF), right ventricular (RV) dysfunction and impaired RV-pulmonary artery (PA) coupling are increasingly recognized as contributors to prognosis. While conventional echocardiography mainly assesses longitudinal RV function, three-dimensional (3D) imaging enables more comprehensive evaluation. We investigated the prognostic value of 3D-derived RV function and RV-PA coupling in patients with HFpEF. METHODS Of 311 prospectively enrolled patients with HFpEF between 2022 and 2023, 229 (age 74.1 ± 10.3 years; 41.5% male) were analyzed. 3D RV ejection fraction (RVEF), pulmonary artery systolic pressure (PASP), tricuspid annular plane systolic excursion (TAPSE), RV free-wall longitudinal strain (RVFWS), and coupling indices (3D RVEF/PASP, TAPSE/PASP, and RVFWS/PASP) were assessed. The primary endpoint was a composite of cardiovascular death or heart failure hospitalization. RESULTS During a median follow-up of 23.5 months, 34 patients (14.8%) experienced the primary endpoint. Reduced 3D RVEF and impaired 3D RVEF/PASP were associated with higher event rates. On time-dependent ROC analysis, 3D RVEF/PASP showed higher discriminatory ability than TAPSE/PASP at 6, 12, and 18 months (P = .009, .032, and .021, respectively). In multivariable Cox analysis, 3D RVEF/PASP remained independently associated with adverse outcomes (adjusted HR 0.86, 95% CI 0.77-0.96; P = .007). The prognostic value of 3D RVEF/PASP persisted in patients with moderate-to-severe TR. CONCLUSIONS 3D RVEF/PASP independently predicted cardiovascular outcomes and showed higher prognostic discrimination than TAPSE/PASP in HFpEF. 3D RV-PA coupling may provide complementary information for noninvasive risk stratification.