Survival Advantage of MitraClip® Over Medical Treatment in Patients with Mitral Regurgitation: A Meta-Analysis.

Background: The MitraClip® system is a percutaneous treatment for mitral regurgitation (MR) that has shown promising results in patients who are inoperable or at high risk for mitral surgery. Data on the efficacy of the system over optimal medical therapy, above all in patients with functional MR, are scarce. The study aim was to assess the effect of MitraClip on the survival of patients with moderate/severe or severe MR compared to medical therapy, using meta-analytical techniques.

Methods: Independently, reviewers searched electronically for relevant articles based on predefined criteria and end-points. Only articles with a comparison between MitraClip and conservative therapy were included. Standard meta-analysis techniques were used. The primary outcomes were 30-day and one-year mortalities.

Results: Five observational reports were included that enrolled a total of 1,271 patients: 720 patients underwent percutaneous mitral valve repair (PMVR) with the MitraClip device, and 551 were managed conservatively. A total of 49 all-cause mortality events was reported at 30 days: 3.05% (22/720) in the PMVR arm, and 4.90% (27/510) in the conservative group, with no significant differences in all-cause mortality (OR 0.64; 95% CI 0.36-1.14). A total of 269 all-cause mortality events at one year was reported: 15.14% (109/720) in the PMVR arm, and 29.04% (160/551) in the conservative group. A significant difference favoring PMVR with the MitraClip system over medical therapy alone was observed (OR 0.44; 95% CI 0.30-0.64, p <0.0001). Neither significance between study heterogeneity (p = 0.18) nor publication bias was detected (p = 0.3).

Conclusions: PMVR with the MitraClip system may be associated with an improvement in one-year survival compared to stand-alone medical management.