Right Ventricular-Pulmonary Artery Coupling by 3D 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.