Impaired Right Ventricular–Pulmonary Arterial Coupling and Effect of Sildenafil in Heart Failure With Preserved Ejection Fraction

Background—Right ventricular (RV) dysfunction (RVD) is a poor prognostic factor in heart failure with preserved ejection fraction (HFpEF). The physiological perturbations associated with RVD or RV function indexed to load (RV–pulmonary arterial [PA] coupling) in HFpEF have not been defined. HFpEF patients with marked impairment in RV–PA coupling may be uniquely sensitive to sildenafil. Methods and Results—In a subset of HFpEF patients enrolled in the Phosphodiesteas-5 Inhibition to Improve Clinical Status And Exercise Capacity in Diastolic Heart Failure (RELAX) trial, physiological variables and therapeutic effect of sildenafil were examined relative to the severity of RVD (tricuspid annular plane systolic excursion [TAPSE]) and according to impairment in RV–PA coupling (TAPSE/pulmonary artery systolic pressure) ratio. The prevalence of atrial fibrillation and diuretic use, n-terminal probrain natriuretic peptide levels, renal dysfunction, neurohumoral activation, myocardial necrosis and fibrosis biomarke...