Prognostic impact of transcatheter mitral valve repair in patients with exercise-induced secondary mitral regurgitation

AIMS: Although exercise-induced secondary mitral regurgitation (MR) is known to have a poor prognosis, the therapeutic strategy towards this condition remains to be investigated. In the present study, we aimed to investigate the prognostic impact of transcatheter mitral valve repair (TMVr) using the MitraClip in patients with exercise-induced secondary MR. METHODS AND RESULTS: Of the 200 consecutive patients with secondary MR who underwent exercise stress echocardiography, 46 (23%) that presented with exercise-induced secondary MR [i.e. increase in effective regurgitant orifice area (EROA) of ≥ 0.13 cm2] were enrolled in the present investigation. The composite endpoints of all-cause mortality and hospitalization for heart failure were evaluated. Of the 46 patients included in the current cohort, 19 (41%) underwent TMVr and 27 (59%) were medically managed (control group). Although the TMVr group tended to present with a greater EROA at rest (0.26 ± 0.10 vs. 0.20 ± 0.08 cm2, P = 0.047), there were no differences in the EROA changes during exercise between the two groups (0.18 ± 0.10 vs. 0.18 ± 0.04 cm2, P = 0.940). While the TMVr group reported a higher event-free survival rate after the 13-month follow-up period (log-rank P = 0.017), the Cox proportional-hazard analysis suggested the TMVr to be associated with clinical outcomes (hazard ratio: 0.419, P = 0.044). CONCLUSION: As opposed to the medical management, TMVr treatment was associated with a lower risk of composite endpoints in patients with exercise-induced secondary MR. Exercise stress echocardiography is considered to have played an important role in decision-making for secondary MR.