P5098Percutaneous repair of functional mitral regurgitation in heart failure patients: a meta-analysis of 23 studies on mitraclip implantation

Background: A gap of evidence on the clinical performance of MitraClip (MC) in functional mitral regurgitation (MR) and on the prognostic predictors of outcome still remains in daily practice. Purpose: To investigate short- and long-term survival, clinical status and echocardiographic findings of heart failure patients with severe functional MR undergoing MC treatment and to explore the prognostic impact of their baseline characteristics on clinical and functional outcome. Methods: Randomized and observational studies including patients with functional MR undergoing MC were collected in a meta-analysis finalized to evaluate the overall survival in-hospital and at 1, 6, 12 and 24 months, the New York Heart Association (NYHA) class and the echocardiographic changes after MC treatment. The baseline features associated to overall mortality and to the echocardiographic changes at follow-up were also investigated in order to identify predictors of outcome. Results: After a comprehensive MEDLINE, COCHRANE, ISI Web of Sciences, and SCOPUS search, 23 studies enrolling 3253 patients were included in the analysis. The overall death rate was 2.31 (95% CI: 0.14–4.48) in-hospital, 5.37 (95% CI: 2.90–7.84) at 1 month, 11.87 at 6 months (95% CI: 8.60–15.30), 18.47 (95% CI: 15.59–21.35) at 1 year and 31.08 (95% CI: 24.59–37.57) at two years. MR grade 1+ or 2+ was observed in 92.76% (95% CI: 90.46–95.07) at discharge and in 83.36% (95% CI: 79.22–87.50) at a mean follow up of 11.7±3.5 months. The 76.63% (95% CI: 71.57–81.69) of patients were in NYHA class I or II at mean follow-up of 11.5±5.0 months. A significant reduction of left ventricular (LV) volumes (end-diastolic: -21.96±4.94 mL, p<0.0001; end-systolic: -15.32±7.44 mL, p=0.0395) and systolic pulmonary arterial pressures (7.85±1.10 mmHg, p<0.0001) associated to a significant increase of LV ejection fraction (+2.40±1.12, p=0.0315) were observed at a median follow-up of 12.4±4.8 months. Meta-regression analysis showed a statistically significant negative effect of atrial fibrillation (AF) on 1-year survival (β:0.18±0.06, p=0.0047) (see Figure) and on the reduction of LV end-diastolic (β:-1.05±0.47, p=0.0248) and end-systolic volumes (β:-2.60±0.53, p=0.0024) was observed.