Clinical outcomes through 12 months in patients with degenerative mitral regurgitation treated with the MitraClip® device in the ACCESS-EUrope Phase I trial

Abstract

Objectives: Percutaneous treatment with the MitraClip device represents an alternative option for selected patients with degenerative mitral regurgitation (DMR) considered ineligible for surgery due to contraindications or high surgical risk by an inter-disciplinary heart team. We describe 12-month outcomes following treatment with the MitraClip device in DMR patients.

Methods: The MitraClip Therapy Economic and Clinical Outcomes Study Europe (ACCESS-EU) Study has completed the enrolment of 567 patients as of April 2011, 117 of whom were DMR. Baseline demographics, procedural and acute safety results at 30 days and survival at 12 months were evaluated in the DMR subset. Effectiveness results, defined by a reduction in MR, and improvement in clinical outcomes based on changes in New York Heart Association (NYHA) functional Class, 6-min walk test (6MWT) and quality-of-life data were also assessed. Furthermore, DMR patients were stratified into high- and low-risk subgroups (logistic European System of Cardiac Operative Risk Evaluation I (logEuroSCORE I ≥20% or <20%, respectively) and differentially evaluated.

Results: One hundred and seventeen DMR patients underwent the MitraClip procedure with a 94.9% rate (111 of 117) of successful clip implantation. Baseline characteristics and comorbidities included NYHA Class III/IV (74%), left ventricular ejection fraction (LVEF) <40% (9%), prior cardiac surgery (24%) and prior myocardial infarction (MI) (22%). Mean logEuroSCORE I was 15.5 ± 13.3%. Mortalities at 30 days and 12 months were 6.0 and 17.1%, respectively. At 12 months, 74.6% (53 of 71) of patients in follow-up achieved MR ≤grade 2+ and 80.8% (63 of 78) were in NYHA functional class I/II. Both Minnesota Living with Heart Failure questionnaire (MLHFQ) scores and 6MWT distance improved significantly at 12 months compared with baseline (P = 0.03 and P < 0.0001, respectively).

Conclusions: The MitraClip procedure resulted in significant reductions in MR and improvements in clinical outcomes at 12 months in selected patients with severe DMR. MitraClip therapy may serve as a complementary non-surgical therapeutic option for DMR patients who are considered at high risk or ineligible for surgery by an inter-disciplinary dedicated heart team. Interventional treatment should be indicated following the discussion of patients in an inter-disciplinary conference of cardiologists and cardiac surgeons as suggested by current international guidelines.

Keywords: Degenerative mitral regurgitation; MitraClip; Percutaneous.