Prognostic Impact of Right Ventricular Strain in Isolated Severe Tricuspid Regurgitation

Background Right ventricular (RV) systolic function is an established marker of outcomes in patients with severe tricuspid regurgitation (TR). Timely detection of RV dysfunction with conventional 2D echocardiography is challenging. RV strain has emerged as an accurate and sensitive tool for evaluation of RV function with the capability of detecting subclinical RV dysfunction. This study aimed to evaluate the prognostic value of RV strain parameters in early stages of severe TR. Methods Consecutive patients with at least (≥) severe TR (severe, massive or torrential TR) and 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 with conventional echocardiographic indices (RV fractional area change [FAC], tricuspid annular plane systolic excursion [TAPSE], DTI S wave [`S]) and with Speckle-tracking echocardiography (STE) derived automatic peak global and free wall longitudinal strain (RV-GLS and RV-FWLS respectively) using an automated 2D strain analytical software. A combined endpoint of hospital admission due to heart failure (HF) or all-cause mortality was defined. Results A total of 266 patients were enrolled in the study and 151 were finally included. Strain parameters detected a higher percentage of abnormal RV values compared to conventional indices. During a median follow up of 26 months (IQR: 13-42 months), 35% of the patients reached the combined endpoint. Cumulative event-free survival was significantly worse in patients with impaired RV-GLS and RV-FWLS. Conventional indices of RV systolic function were not associated with outcomes (p>0.05 for all). On multivariate analysis, RV-FWLS was independently associated with mortality and HF (adjusted HR for abnormal RV-FWLS: 5.90 (3.17-10.99), <0.001). Conclusion In early stages of severe TR, RV-FWLS is more frequently impaired compared to conventional indices of RV function. Among all parameters, RV-FWLS is the strongest predictor of mortality and HF independently of additional prognostic markers.