Right ventricular dysfunction predicts outcome after transcatheter mitral valve repair for primary mitral valve regurgitation.

AIMS: Right ventricular dysfunction (RVD), as expressed by right ventricular to pulmonary artery coupling, has recently been identified as a strong outcome predictor in patients undergoing mitral valve edge-to-edge repair (M-TEER) for secondary mitral regurgitation (MR). The aim of this study was to define RVD in patients undergoing M-TEER for primary MR (PMR) and to evaluate its impact on procedural MR reduction, symptomatic development and 2-year all-cause mortality.

METHODS AND RESULTS: This multicentre study included patients undergoing M-TEER for symptomatic PMR at nine international centres. The study cohort was divided into a derivation (DC) and validation cohort (VC) for calculation and validation of the best discriminatory value for RVD. A total of 648 PMR patients were included in the study. DC and VC were comparable regarding procedural success and outcomes at follow-up. Sensitivity analysis identified RVD as an independent predictor for 2-year mortality in the DC (hazard ratio [HR] 2.37, 95% confidence interval [CI] 1.47-3.81, p < 0.001), which was confirmed in the VC (HR 2.06, 95% CI 1.36-3.13, p < 0.001). Procedural success (MR ≤2+) and symptomatic improvement at follow-up (New York Heart Association [NYHA] class ≤II) were lower in PMR patients with RVD (MR ≤2+: 82% vs. 93%, p = 0.002; NYHA class ≤II: 57.3% vs. 66.5%, p = 0.09 for with vs. without RVD). In all PMR patients, the presence of RVD significantly impaired 2-year survival after M-TEER (HR 2.23, 95% CI 1.63-3.05, p < 0.001).

CONCLUSIONS: Mitral valve edge-to-edge repair is an effective treatment option for PMR patients. The presence of RVD is associated with less MR reduction, less symptomatic improvement and increased 2-year mortality. Accordingly, RVD might be included into pre-procedural prognostic considerations.