Abstract 2289: Is Revascularization Alone Truly Sufficient in Patients With Mild Mitral Regurgitation?: Echocardiographic Follow-up of Mild Ischemic Mitral Regurgitation After Isolated Coronary Artery Bypass Grafting
Although it is generally believed that mild mitral regurgitation (MR) can be left alone at the time of coronary artery bypass grafting (CABG), there are few follow-up studies focusing on the fate of untreated mild MR after CABG. We sought to determine the impact of CABG alone on preoperative mild ischemic MR and to analyze the relationship between postoperative MR and left ventricular (LV) geometry and function. From 2002 to 2007, 1965 patients with 1+/2+ MR, on a scale of 0 to 4+, underwent CABG at Cleveland Clinic. Patients with structural valvular disease and previous heart operations were excluded, leaving 150 patients (116 male, age 65±10 years) with ejection fraction <45% who met inclusion criteria and who had an ECHO obtained more than 1 month after CABG. They all had functional ischemic MR of a mild degree, which was defined as Doppler jet area/left atrial area ratio <20%. LV volume was calculated using the Simpson’s method. Postoperative ECHO was obtained a median of 23 months after CABG.
Results: After isolated CABG, MR disappeared in 40 (27%), remained in a mild degree in 89 (59%), and deteriorated to a moderate to severe degree in 21 (14%) patients. In patients with no and mild MR after CABG, LV end-systolic volume index (ESVI) was significantly decreased after CABG (−16±10 and −8±9 mL/m2, respectively). However, ESVI of patients with moderate to severe MR after CABG, was significantly increased (12±12 mL/m2). In patients with moderate to severe MR after CABG, the proportion of patients (n=14, 67%) who revealed LV remodeling, defined as an increase in ESVI >15%, was significantly larger than in other groups (n=2, 2%; P<0.001). In the majority of patients, preoperative mild ischemic MR was diminished or remained in a mild degree after isolated CABG during follow-up. However, 14% of patients revealed worsening of MR to a moderate to severe degree, which was highly associated with ongoing LV remodeling despite revascularization.