Predictors for efficacy of percutaneous mitral valve repair using the MitraClip system: the results of the MitraSwiss registry.

Background: Percutaneous mitral valve repair (MVR) using the MitraClip system has become a valid alternative for patients with severe mitral regurgitation (MR) and high operative risk.
Objective: To identify clinical and periprocedural factors that may have an impact on clinical outcome.
Design: Multi-centre longitudinal cohort study.
Setting: Tertiary referral centres.
Patients: Here we report on the first 100 consecutive patients treated with percutaneous MVR in Switzerland between March 2009 and April 2011. All of them had moderate-severe (3+) or severe (4+) MR, and 62% had functional MR. 82% of the patients were in New York Heart Association (NYHA) class III/IV, mean left ventricular ejection fraction was 48% and the median European System for Cardiac Operative Risk Evaluation was 16.9%.
Interventions: MitraClip implantation performed under echocardiographic and fluoroscopic guidance in general anaesthesia.
Main Outcome Measures: Clinical, echocardiographic and procedural data were prospectively collected.
Results: Acute procedural success (APS, defined as successful clip implantation with residual MR grade ≤2+) was achieved in 85% of patients. Overall survival at 6 and 12 months was 89.9% (95% CI 81.8 to 94.6) and 84.6% (95% CI 74.7 to 91.0), respectively. Univariate Cox regression analysis identified APS (p=0.0069) and discharge MR grade (p=0.03) as significant predictors of survival.
Conclusions: In our consecutive cohort of patients, APS was achieved in 85%. APS and residual discharge MR grade are important predictors of mid-term survival after percutaneous MVR.