Prognostic Impact of Right Ventricular Strain in Isolated Severe Tricuspid Regurgitation

Abstract

Right ventricular (RV) systolic function is an established marker of outcomes in patients with severe tricuspid regurgitation (TR). Timely detection of RV dysfunction using conventional two-dimensional echocardiography is challenging. RV strain has emerged as an accurate and sensitive tool for the evaluation of RV function, with the capability to detect subclinical RV dysfunction. The aim of this study was to evaluate the prognostic value of RV strain parameters in early stages of severe TR. Consecutive patients with at least severe TR (severe, massive, or torrential) and the absence of a formal indication for tricuspid valve intervention in secondary TR evaluated in the Heart Valve Clinic were prospectively included. RV systolic function was measured using conventional echocardiographic indices (RV fractional area change, tricuspid annular plane systolic excursion, and Doppler tissue imaging S wave [S']) and speckle-tracking echocardiography-derived automatic peak global longitudinal strain and free wall longitudinal strain (FWLS) using an automated two-dimensional strain analytic software. A combined end point of hospital admission due to heart failure or all-cause mortality was defined. A total of 266 patients were enrolled in the study, and 151 were ultimately included. Strain parameters detected a higher percentage of abnormal RV values compared with conventional indices. During a median follow-up period of 26months (interquartile range, 13-42months), 35% of the patients reached the combined end point. Cumulative event-free survival was significantly worse in patients with impaired RV global longitudinal strain and RV FWLS. Conventional indices of RV systolic function were not associated with outcomes (P>.05 for all). On multivariate analysis, RV FWLS was independently associated with mortality and heart failure (adjusted hazard ratio for abnormal RV FWLS, 5.90; 95% CI, 3.17-10.99; P<.001). In early stages of severe TR, RV FWLS is more frequently impaired compared with conventional indices of RV function. Among all parameters, RV FWLS is the strongest predictor of mortality and heart failure, independent of additional prognostic markers.