Risk of Ischemic Mitral Regurgitation Recurrence after Combined Valvular and Subvalvular Repair

Abstract Background Mitral valve repair combined with papillary muscle approximation (MVr+PMA) may improve repair durability in severe ischemic mitral regurgitation (MR), when compared with MVr alone. We sought to identify preoperative transthoracic echocardiographic markers associated with MR recurrence after MVr+PMA. Methods A post-hoc analysis was performed on patients with severe ischemic MR who underwent coronary artery bypass grafting with MVr+PMA, in the Papillary Muscle Approximation Randomized Trial. PMA was performed utilizing a 4-mm polytetrafluouroethylene graft placed around the papillary muscles. Linear regression analyses and receiver operating characteristic curves were used to identify echocardiographic variables and diagnostic models associated with recurrent MR. Results There were 48 patients with a mean age of 63 ± 7 years, a left ventricular (LV) ejection fraction of 35 ± 5%, and an LV end-diastolic diameter of 63 ± 3 mm. Of these, 37 had baseline and 5-year follow-up echocardiograms, with moderate-to-severe MR recurring in 27%. Linear regression analyses revealed associations between preoperative pulmonary artery systolic pressure (standardized beta coefficient, β=0.49/mmHg, p=0.002), MV tenting area (β=0.47/cm 2 , p=0.004), a symmetric MV tethering pattern (β=0.44, p=0.007), and LV end-diastolic diameter (β=0.37/mm, p=0.02), with follow-up MR grade. The presence of both an MV tenting area ≥ 3.1 cm2 (AUC=0.822) and LV end-diastolic diameter ≥ 64 mm (AUC=0.801) was the most robust discriminative model for moderate-to-severe MR recurrence (specificity=92%, sensitivity=69%, AUC=0.804, p=0.003). Conclusions In patients undergoing coronary artery bypass grafting with MVr+PMA, the extent of baseline MV apparatus and LV geometric remodeling identifies patients at increased risk for MR recurrence.