MitraClip for Severe Symptomatic Mitral Regurgitation in Patients at High Surgical Risk: A Comprehensive Systematic Review

Background: The optimal treatment of patients with severe mitral regurgitation (MR) at high surgical risk (HSR) is unknown. Recently, the EVEREST II (Endovascular Valve Edge-to-Edge Repair) High Risk Study suggested MitraClip (MC) was a safe and effective treatment option. Methods: We performed a search strategy for MC or mitral valve surgery (MVS) in patients at HSR for surgical mortality (logistic EuroSCORE > 18 or STS score > 10) using Medline databases, proceedings of international meetings, and the STS database. We identified 21 studies utilizing MC (n=3,198) and MVS (n=3,265, > 90% from the STS database) from 2003 to 2013. Information about patient characteristics, surgical risk, and 30-day and 1-year outcomes were extracted. Results: Patients who underwent MC or MVS had a mean age of 74610 years with no differences in surgical risk, NYHA class, or MR grade (P=0.46). Technical success was achieved in 96% of patients undergoing MC versus 98% in the MVS group (P=0.45). Patients undergoing MC were treated with one or two MC in 90% (n=2,878) with only a few requiring repeat MC (0.4%, n=13) or mitral surgery (0.3%, n=52) at 30 days. The pooled event rates for mortality was 3.2% (95% CI [2.5-4.2]), stroke was 1.1% (95% CI [0.7-0.2]) at 30 days. At 31 days to 1 year, the pooled event rate for mortality was 13.0% [95% CI (9-18.3)], stroke was 1.6% [95% CI (0.8-3.2)], and repeat MVS was 1.3% [95% CI (0.7-2.6)] with the majority of patients in the mild/moderate MR grade and NYHA class after MC. The 30-day event rates for mortality and stroke were 16.8% (95% CI [14-19]) and 4.5% (95% CI [3.9-5.3]) after MVS, respectively. Conclusion: Based on high risk MC studies and high risk MVS data predominantly from STS database, patients with severe MR who are at HSR can be effectively treated with MC or MVS. MC can be safely implanted in high risk patients with relatively low mortality and stroke risk. (C) 2014 Wiley Periodicals, Inc.