Concomitant mitral regurgitation is associated with worse outcomes after T-TEER: insights from the EuroTR registry

Abstract Background Tricuspid valve regurgitation (TR) is often caused by left heart disease (LHD) and thus regularly accompanied by significant mitral valve regurgitation (MR). Treatment of the underlying LHD often leads to reduction of TR severity, however the impact of persistent MR on outcome after tricuspid valve edge-to-edge repair (T-TEER) remains unclear. Purpose This study evaluates the impact of concomitant MR on functional outcomes and survival in T-TEER patients. Methods Patients from the European Registry of Transcatheter Repair for Tricuspid Regurgitation (EuroTR) registry were stratified according to concomitant MR severity at the timepoint of T-TEER. Impact of MR severity on New York Heart Association (NYHA) functional class at follow-up and 2-year all-cause mortality was assessed using Kaplan-Meier and Cox regression analysis. Results 2,067 patients (median age 80 IQR: 76-86 years, 53.4% female) were stratified into 3 groups according to concomitant MR grade before the T-TEER procedure: trace/mild (0/1+; n=1,502), moderate (2+; n=508) and moderate-to-severe/severe (3+/4+; n=57). While preinterventional TR grades did not differ between the three groups, suboptimal procedural TR results (residual TR grade ≥2+) were more prevalent in patients with increasing MR severity (53.8% in MR 0/1+ vs. 60.8% in 2+ vs. 69.2% in 3+/4­+; p=0.004). Higher MR grades were associated with more severe symptoms at follow-up (NYHA class III or IV: 37.0% vs. 47.1% vs. 60.0%; p0.001) and higher 2-year all-cause mortality rates (61.9% vs. 65.9% vs. 71.9%; p=0.005). Severity of MR was independently associated with higher 2-year mortality following T-TEER (MR 2+ adjusted hazard ratio (adj. HR): 1.48; 95%-CI 1.04 – 2.09, p=0.029; MR grades 3+/4+ adj. HR: 2.16; 95%-CI 0.99 – 4.71, p=0.052). Conclusions Concomitant mitral regurgitation is associated with worse long-term prognosis in patients undergoing T-TEER. Even moderate MR is linked to higher 2-year mortality after T-TEER. Thus, timely treatment of MR should be considered in these patients.