Analysis of changes in “mitral valve reserve” after coronary artery bypass grafts in patients with functional mitral regurgitation

INTRODUCTION: The treatment of moderate functionalmitral regurgitation (FMR) during coronary artery bypass grafting (CABG) is still debated. Our primary end point was to assess the improvement of “mitral valve reserve” (MVR) after CABG alone as a clinical demonstration of left ventricular (LV) recovery. MATERIALS AND METHODS: Between June 2019 and June 2021, we prospectively enrolled 104 consecutive patients undergoing CABG with moderate FMR. Inclusion criteria were inferior-posterior-lateral wall hypokinesia and revascularization of the circumflex or right coronary artery. MVR was calculated as the ratio between anterior and posterior leaflets’ straight length. All patients were followed for 1 year. The improvement of MVR has been considered as a reduction of the ratio between anterior and posterior leaflets straight length. RESULTS: Compared to baseline, mean MVR was significantly reduced both at 6 (2.24 ± 0.95 vs. 1,91 ± 0.6; p = 0,047) and 12 months follow-up (2.24 ± 0.95 vs. 1,69 ± 0.49; p = 0,006). Left ventricular (LV) reverse remodeling, meant as improvement of LV ejection fraction and reduction of LV end-systolic volume index and mitral anulus diameter were evaluated at 6 months and 1 year. Mitral regurgitation grade were also significantly reduced at 6 months (p < .001). CONCLUSION: The benefits of myocardial revascularization in term of improvement of mitral regurgitation’s degree can be explained by the changes of MVR. The patients with FMR, who could have more advantages from CABG alone, should be the ones who have LVESVi just moderately increased.