A meta-analysis of mitraclip system versus surgery for treatment of severe mitral regurgitation

The purpose of this meta–analysis is to compare the safety, clinical efficacy, and survival outcomes of MitraClip implantation with surgical correction of severe MR. Despite a higher risk profile in the MitraClip patients compared to surgical intervention, the clinical outcomes were similar although surgery was more effective in reducing MR in the early post procedure period. The authors conclude the non–inferiority of the MitraClip as a treatment option for severe, symptomatic MR in comparison to conventional valvular surgery.

Methods

Six electronic databases were searched for original published studies from January 2000 to August 2013.
Two reviewers independently appraised studies, using a standard form, and extracted data on methodology, quality criteria, and outcome measures.
All data were extracted and tabulated from the relevant articles’ texts, tables, and figures and checked by another reviewer.
Overall 435 publications were identified.
Results

After applying selection criteria and removing serial publications with accumulating number of patients or increased length of follow-up, four publications with the most complete dataset were included for quality appraisal and data extraction.
There was one randomized controlled trial (RCT) and three prospective observational studies.
At baseline, patients in the MitraClip group were significantly older (P=0.01), had significantly lower LVEF (P=0.03) and significantly higher EuroSCORE (P<0.0001).
The number of patients with post-procedure residual MR severity >2 was significantly higher in the MitraClip group compared to the surgical group (17.2% vs. 0.4%; P<0.0001).
30-day mortality was not statistically significant (1.7% vs. 3.5%; P=0.54), nor were neurological events (0.85% vs. 1.74%; P=0.43), reoperations for failed MV procedures (2% vs. 1%; P=0.56), NYHA Class III/IV (5.7% vs. 11.3; P=0.42) and mortality at 12 months (7.4% vs. 7.3%; P=0.66).