Percutaneous Treatment of Functional Mitral Regurgitation
What are the acute feasibility results for a transcatheter device for direct mitral annular plication (Mitralign system; Mitralign; Tewksbury, MA) in the treatment of functional mitral regurgitation (MR)?
In a prospective, multicenter, single-arm feasibility study, a cohort of 71 patients with at least moderate functional MR and left ventricular ejection fraction (LVEF) ≥20% were treated with a transcatheter (transfemoral access) device that allows plication of the mitral annulus. Mean patient age was 67.7 ± 11.3 years, with LVEF 34.0 ± 8.3%. Safety was assessed with the endpoint of 30-day composite incidence of death, stroke, myocardial infarction, or emergency surgical intervention. Performance was assessed using need for mitral valve surgical intervention, device and/or procedure-related death, and echocardiographic parameters of LV reverse remodeling during 6-month follow-up. The delivery system was modified after treatment of the first 20 patients.
The procedure was successful in 50 of 71 patients (70%), with no intraprocedural deaths. Cardiac tamponade occurred in four patients (9%) who completed the procedure. Respective rates for all-cause mortality, stroke, and myocardial infarction were 4.4%, 4.4%, and 0.0% at 30 days (n = 45); and 12.2%, 4.9%, and 0.0% at 6 months (n = 41). Echocardiography at 6 months revealed a reduction in MR grade in 50% of treated patients (mean reduction 1.3 grades); decrease in anterior-posterior (–0.3 ± 0.4 cm) and septal-lateral annular dimensions (–0.2 ± 0.3 cm), decrease in mitral valve tenting area (–0.6 ± 1.1 cm2), increase in mitral valve coaptation length (0.1 ± 0.2 cm); and decreases in LV end-diastolic diameter (–0.2 ± 0.4 mm) and volume (–22 ± 39 ml). Among treated patients, there were increases in 6-minute walk distances (57 ± 92 m) and prevalence of New York Heart Association class III/IV symptoms (from 53% to 23%) at 6 months.
The authors concluded that percutaneous direct annuloplasty using this device is feasible and safe among high-risk patients with functional MR, and associated with LV reverse remodeling and clinical improvement after 6 months.
Percutaneous edge-to-edge ‘repair’ of the mitral valve using the MitraClip system (Abbott Vascular; Santa Clara, CA) has been shown to be noninferior to open mitral repair in the treatment of selected patients with predominantly degenerative MR. However, the effectiveness and durability of the MitraClip among patients with functional MR is probably limited. This is an early clinical look at one of a handful of transcatheter therapies under development that are intended to directly alter the size and shape of the mitral annulus for the percutaneous treatment of functional MR. These early data suggest that there may be some promise, but additional experience and data will be required.
< Back to Listings