Right Ventricular Dimension for Heart Failure With Preserved Ejection Fraction Involving Right Ventricular-Vascular Uncoupling

Background: Right ventricular (RV) to pulmonary artery (PA) uncoupling is known to be important for the prognosis of not only heart failure (HF) with reduced ejection fraction but also HF with preserved ejection fraction (HFpEF). We further investigated key factors in the poor prognosis for HFpEF patients with RV-PA uncoupling. Methods: We studied 817 patients with HFpEF who were discharged alive in a multicentred cohort using post hoc analyses, with a primary endpoint of cardiac mortality or HF readmission. A total of 288 RV-PA uncoupled patients were observed, namely those with a tricuspid annular plane systolic excursion (TAPSE)/PA systolic pressure (PASP) ratio < 0.46 mm/mm Hg. Results: Among the RV-PA uncoupled patients, 101 adverse outcomes occurred over a median of 340 days. Echocardiographic RV dimension (RVD) was significantly important for prognosis in both univariable and multivariable Cox regression testing (hazard ratio 1.044, 95% confidence interval 1.014-1.074, P = 0.0042, and hazard ratio 1.036, 95% confidence interval 1.001-1.072, P = 0.0438, respectively) considered with the covariates of age, atrial fibrillation, renal function, N-terminal pro-brain natriuretic peptide, and other echocardiographic parameters. We further divided the patients into 4 groups, first into 2 groups with a TAPSE/PASP either ≥ or < 0.46 mm/mm Hg, and then into 4 groups by RVD medians of 31.9 mm and 33.3 mm, respectively. Kaplan-Meier curve analysis showed that outcomes were worst in patients with a low TAPSE/PASP ratio and larger RVD (log-rank P < 0.0001). Conclusions: This multicentre observational study highlighted the further prognostic importance of larger RVD among HFpEF patients with RV-PA uncoupling.