Implications of tricuspid regurgitation and right ventricular volume overload in patients with heart failure with preserved ejection fraction

Aims The aim of this study was to assess the pathophysiological implications of severe tricuspid regurgitation (TR) in patients with heart failure with preserved ejection fraction (HFpEF) by using tricuspid transcatheter edge-to-edge repair (T-TEER) as a model of right ventricular (RV) volume overload relief. Methods and results This prospective interventional single arm trial (NCT04782908) included patients with invasively diagnosed HFpEF. The following parameters were prospectively assessed before and after T-TEER: left ventricular (LV) diastolic properties by invasive pressure-volume loop recordings; biventricular time-volume curves and function as well as septal curvature by cardiac magnetic resonance imaging; strain analyses for timing of septal motion. Overall, 20 patients (median age 78, interquartile range [IQR] 72-83 years, 65% female) were included. T-TEER reduced TR by a median of 2 (of 5) grades (IQR 2-1). T-TEER increased LV stroke volume and LV end-diastolic volume (LVEDV) (p < 0.001), without increasing LV end-diastolic pressure (LVEDP) (p = 0.094), consequently diastolic function improved with a reduction in LVEDP/LVEDV (p = 0.001) and a rightward shift of the end-diastolic pressure-volume relationship. The increase in LVEDV correlated with a decrease in RV end-diastolic volume (p < 0.001) and LV transmural pressure increased (p = 0.028). Secondary to a decrease in early RV filling, improvements in early LV filling were observed, correlating with an alleviation of leftwards bowing of the septum (p < 0.01, respectively). Conclusion Diastolic LV properties in patients with HFpEF and severe TR are importantly determined by ventricular interaction in the setting of RV volume overload. T-TEER reduces RV volume overload and improves biventricular interaction and physiology.