TRANSESOPHAGEAL ECHOCARDIOGRAPHIC EVALUATION OF MITRAL VALVE DEFORMATION DURING CORONARY ARTERY BYPASS GRAFTING

Introduction: Ischemic Mitral Regurgitation (iMR) is a result of functional imbalance between mitral valve leaflets tethering and closing forces caused by left ventricular remodeling following myocardial infarction. 41% of the patients undergoing coronary artery bypass grafting (CABG) may have associated iMR. Uncorrected iMR even a milder one poses an increased risk for death and heart-failure hospitalization. In-hospital mortality rates for isolated CABG is 3% and 7- 20% for CABG and concomitant mitral procedure. This makes preoperative evaluation of ischemic MR and its determinants a necessity. In present study aimed at evaluating the mitral valve deformation in different grades of ischemic MR using transesophageal echocardiography in subjects posted electively for CABG ± Mitral valve procedure. Objective: To determine values of echo indices of mitral valve tenting in different grades of ischemic MR in subjects undergoing elective coronary artery bypass grafting (CABG) ± mitral valve repair/replacement procedure using transesophageal echocardiography. Materials And Methods: 196 subjects undergoing elective coronary artery bypass grafting (CABG) ± mitral valve procedure were prospectively enrolled in this observational study. Subjects were evaluated for presence of ischemic MR (iMR) and extent of mitral valve deformation using transesophageal echocardiography. iMR was quantified into either “No” or “Mild,” “Moderate” and “Severe” ischemic mitral regurgitation (iMR) grades based on current guidelines of iMR quantification. The echo indices of mitral valve tenting were analyzed in different grades of iMR. Results: Mean MV systolic tenting area (TA) (1.87±0.42, 2.15±0.46 & 3.65± 0.26 vs. 1.34±0.44) (cm2) (p<0.0001), height (Th) (1.19±0.25 , 1.33±0.27 & 2.13±0.19 vs. 0.88±0.27) (cm) (p<0.0001) , posterior mitral leaflet angle (PMLAβ) (50.96±8.85, 53.74±8.53 & 62.66±8.76 vs. 35.52 ±6.82) (0) (p<0.0001), and mitral annular height to commissural width ratio (MAhCwR) (0.33±0.07,0.36±0.07,0.54±0.07 vs.0.25±0.07)(p<0.01) were significantly higher in mild, moderate & severe iMR groups vs. no iMR group respectively. The increased iMR grade exhibited higher degree of MV deformation in a linear manner. Conclusion: Increased Mitral valve deformation was seen with increasing grade of ischemic MR severity. Both systolic and diastolic indices of MV deformation predicted ischemic MR severity in a linear manner in subjects undergoing coronary artery bypass grafting surgery ± mitral valve procedure.