AIMS - The Italian Society of Interventional Cardiology (GIse) Registry Of Transcatheter Treatment of Mitral Valve RegurgitaTiOn (GIOTTO) was conceived in order to assess the safety and efficacy of the MitraClip therapy in Italy. Aim of the study was to assess the procedural, the mid-term outcomes and their predictors after MitraClip therapy, stratifying the results according to diagnosis of functional and degenerative mitral regurgitation (FMR vs. DMR).

METHODS AND RESULTS -  Between January 2016 and March 2020, 1659 patients were prospectively included in the GIOTTO registry (FMR 59.4% vs. DMR 40.6%). Acute Mitral Valve Academic Research Consortium (MVARC) technical success was achieved in 97.2% of patients, without differences between FMR and DMR and with sustained results at 30-day. In the available population, the rate of all-cause death was of 4.0% at 30 days, 17.5% at one-year and 34.6% at two-year. Cardiovascular death was the most frequent cause of mortality. Overall hospitalization rate was 6.3% at 30 days, 23.4% at one-year and 31.7% at two-year. The most frequent cause of hospitalization was heart failure, specifically in the early 30-day. FMR, MVARC structural and functional failures were strongly associated with one-year mortality. Residual MR 1 + (rMR) was independently related to a reduced risk of one-year mortality (HR 0.62; p = 0.005). Coherently, at two-year follow up, FMR was associated with worse outcomes than DMR, and Kaplan-Meier all-cause mortality was related to rMR.

CONCLUSIONS -  FMR etiology affects one-year mortality after MitraClip, and differences in mortality and hospitalizations can be observed between FMR and DMR within two-year. Optimal rMR 1+ was correlated to a most favorable mid-term outcome, especially in FMR.