P4726Functional mitral regurgitation treated with percutaneous repair: a relative survival analysis of a national Swiss cohort

Abstract Introduction Percutaneous treatment of functional mitral regurgitation (FMR) with MitraClip (MC) has led to discordant results in recent randomized clinical trials. We aimed at estimating excess mortality (EM) and to evaluate its predictors in a large Swiss FMR population treated with MC. Methods FMR patients enrolled in the MitraSwiss Registry (479 pts) with a mean age of 74.7±9.42 years were evaluated. We computed and plotted EM up to 5 years after implant using the Swiss 2008–20013 mortality tables, stratified by age and sex. A Poisson regression was used to model EM as a function of age, sex, pre-implant RV/RA gradient, calendar period (2011–2013; 2014–2015,2016–2017), ischemic vs non ischemic aetiology, acute procedural success and residual MR. Results Patient's survival at 1,2,3,4 and 5 years were respectively 0.84, 0.72, 0.59, 0.53 and 0.48. FMR patients treated with MC showed excess mortality of +13% (95% CI,10%-18%), +22% (95% CI,17%-28%), +34% (95% CI,27%-41%), +37% (95% CI,28%-46%) and +39% (95% CI,28%-50%) at each time point as compared to the Swiss population, with not differences over the entire follow up (p=0.481). Age group, sex, RV/RA gradient calendar period, ischemic vs non ischemic and residual MR were not associated with excess mortality while a clear association was recognized with acute procedural success (p=0.011). Conclusions In FMR patients treated with MC a persistent EM was observed at a 5 years follow up. Acute procedural success is the only determinant of EM with a 65% lower EM as compared to procedural failures.