Impact of aetiology of mitral regurgitation on outcome after Mitraclip: lessons learned from MitraSwiss Registry.

AIMS: The Swiss national registry on percutaneous mitral valve interventions was established in 2011 to monitor safety and efficacy of percutaneous mitral valve repair (PMVR) with MitraClip devices. We report in-hospital, short and mid-term outcomes of all patients prospectively enrolled. METHODS AND RESULTS: Since 2011, MitraSwiss enrolled 1212 patients with moderate-to-severe or severe MR of functional (FMR) or degenerative (DMR) etiology treated with PMVR in 10 centers. Pre-specified endpoints included clinical, echocardiographic and functional parameters with follow up planned up to 5 years. Outcomes are compared according to MR etiology. Acute procedural success was achieved in 91.5% of cases, with no differences between FMR and DMR and sustained good mid-term results. NYHA class and pulmonary pressure improved significantly in both cohorts. Cumulative probability of death at 5 years was 54% (95%CI 45-63) in FMR and 45% (95%CI 37-54) in the DMR (HR=1.15, p=0.009). Age, anemia, impaired renal function and reduced left ventricular ejection fraction resulted as independent predictors of death at 5 years. CONCLUSIONS: In a large contemporary cohort of non-surgical patients with severe MR, PMVR confirms its safety and effectiveness. At a mid-term follow up mortality and MACE are lower in DMR patients, though MR aetiology is not directly and independently associated with outcome.