Right heart function in isolated severe tricuspid regurgitation. a new stratification approach by Speckle tracking echocardiography

Abstract

Abstract Background Optimal management of severe tricuspid regurgitation (TR) remains controversial. While right ventricular (RV) systolic function is an established prognostic marker of outcomes, the potential role of right atrial (RA) function is unknown. Purpose to evaluate the clinical utility of combining RV and RA strain by Speckle-tracking echocardiography to assess RV and RA function for prediction of cardiovascular outcomes. Methods Consecutive patients with at least severe TR (severe, massive or torrential TR) evaluated in the Heart Valve Clinic were prospectively included following a comprehensive clinical protocol. Consecutive control subjects and patients with permanent atrial fibrillation were included for comparison. An independent cohort of patients was included for external validation. RA and RV mechanics analysis was performed using a novel, automated 2D strain analytical software. A combined endpoint of hospital admission due to heart failure (HF) or all-cause mortality was defined. Results 176 patients with at least severe TR, 20 AF patients and 20 control subjects were included in this study. Patients with TR showed lower RA reservoir strain (RASr) and RV-free wall longitudinal strain (RV-FWLS) compared to controls and to AF patients (p<0,001). After a median follow-up of 2,2 years (IQR: 12-41 months), 38% reached the combined endpoint. Reservoir RA strain (RASr) and RV-FWLS were predictors of outcomes independently of TR severity and RV dimensions in a multivariate Cox analysis (table, model 1). RA strain showed incremental value to RV strain. Conventional parameters of RV function were not predictive of events. RV-FWLS>-20% and RASr <10% identified patients with a higher event rate (p<0,001). The combination of abnormal values of RA and RV strain (STREI stratification) stratified 4 different groups of risk independently of TR severity, RV dimensions and clinical status (adj HR per stratum 1,89 (1,4-2,34), p<0,001) (table-model 2 and figure). Pre-defined cut-off values achieved similar prognostic performance in the validation cohort (n=50). Conclusion Clinical outcomes demonstrate that strain parameters are superior to conventional indices of RV function in patients with at least severe TR. The combination of RA and RV strain stratify better patients’ risk, reflecting a broader effect of TR on right heart chambers.STREI STRATIFICATION.Cox regression analysis