Aims:To identify predictors of clinical outcomes in patients undergoing mitral valve edge-to-edge repair for significant mitral regurgitation (MR) utilizing advanced echocardiographic analysis.
Methods: We prospectively analyzed 56 patients with significant MR, successfully implanted with MitraClip device, between October 2014 and June 2020 at a single center. The analysis included clinical and echocardiography evaluation including global longitudinal strain (GLS) and noninvasive pressure-volume analysis. The primary end point was 2-years mortality.
Results: The mean patient age was 77 ± 9 years and 32% were females. The average left ventricle ejection fraction was 38% ± 14%, 31 patients (55%) had functional mechanism of MR and the average surgical risk calculated by EUROSCORE II was 13% ± 12%. Mitral regurgitation reduction was significant after the procedure (3.7 ± 0.5 vs 1.4 ± 0.6, p>0.01). NYHA class (3.2 ± 0.4 to 2.5 ± 0.5 p<0.01), Minnesota questionnaire grades (49 ± 24 to 41 ± 22, p=0.03) and left ventricle end-diastolic volume (LVEDV) (168 ± 71 mL vs. 154 ± 66, p=0.02) significantly improved at 1-year follow-up.
Within mean follow up of 24 months, 16 patients (29%) died. 18 patients (32%) were hospitalized due to heart failure in the first year. In Cox-regression analysis, baseline LVEDV (HR 1.008 [CI 1.002-1.014], p = 0.007), GLS (HR1.147 [CI 1.034 – 1.273], p=0.01), ventricular-arterial coupling (HR1.271 [CI1.032-1.564], p=0.024), myocardial efficiency (HR 0.011 [CI 0.000-0.449], p=0.017) and right ventricle GLS (HR 1.094, [CI 1.005-1.190], p=0.038) were associated with increased risk of mortality. Baseline, strain derived, global work index and global work efficiency were not related to prognosis.
Conclusion: MitraClip implantation for mitral valve repair is associated with clinical improvement. Baseline LV volume, LV and RV function and ventricular-arterial coupling are predictors of mortality. These results may improve current risk stratification in patients considered for MitraClip therapy.