Concept of the central clip: when to use one or two MitraClips®

Aims: Percutaneous edge-to-edge mitral valve repair with the MitraClip (R) was shown to be a safe and feasible alternative compared to conventional surgical mitral valve repair. We analyse the concept of the central clip and the predictors for the need of more than one MitraClip in our high-risk surgical population with severe mitral regurgitation (MR). Methods and results: Patients with severe MR (3 or 4+) and high operative risk (as defined by logistic EuroSCORE) refused for conventional mitral valve repair were considered for MitraClip. The procedure was performed under general anaesthesia with transoesophageal echocardiographic (TOE) guidance. Device success was defined as placement of one or more MitraClip (R) with a reduction of MR to <= 2+. Patients were followed up clinically and with TOE at one month and one year. From September 2009 to March 2012,43 patients with severe MR with a mean age of 74.8 +/- 10.7 years (30 males, 13 females; mean logistic EuroSCORE 24.1 +/- 11, mean LVEF 47.5 +/- 18.5%; mean +/- SD) were treated. Median follow-up was 385 days (104-630; Q1-Q3). Device implantation success was 93%. All patients were treated following the central clip concept: 52.5% of MR was degenerative in aetiology and 47.5% was functional. The degree of MR was reduced from 3.6 +/- 0.4 to 1.4 +/- 0.6 (p<0.001); NYHA Class improved from 3.1 +/- 0.4 to 1.8 +/- 0.7 (p<0.001). Nineteen patients (47.5%) received two or more clips. Vena contracta (p<0.001) and the presence of two broad jets (p<0.001) were correlated with the need for a second clip. The presence of a restricted posterior mitral valve leaflet (PML) was inversely correlated with the need for more than one clip (p=0.02). A cut-off value of >= 7.5 mm for vena contracta predicted the need for a second clip (sensitivity 83%, specificity 90%, p=0.01). Conclusions: The central MitraClip (R) concept achieved a significant reduction in the degree of mitral regurgitation in the majority of patients treated. The presence of a broad jet (quantified by a vena contracta greater than 7.5 mm) significantly predicted the need for more than one clip.