The impact of unrepaired versus repaired mitral regurgitation on functional status of patients with ischemic cardiomyopathy at one year after coronary artery bypass grafting.

BACKGROUND AND AIM OF THE STUDY: The issues regarding the appropriate management of patients with ischemic mitral regurgitation (MR) and advanced left ventricular (LV) dysfunction are controversial and limited. The present study was undertaken to evaluate the mid-term dynamics of MR, LV dimensions, function and NYHA functional class in patients with ischemic cardiomyopathy (ICM) and MR who underwent coronary artery bypass grafting (CABG) either alone or combined with mitral valve (MV) repair. METHODS: A total of 199 patients with LV ejection fraction (LVEF) <35% were included in the study. Of these patients, 73 had MR grade 2+ (group 1), 66 had 0 or 1+ MR (group 2) and underwent isolated CABG, and 60 had MR > 2+ and underwent CABG with MV repair (group 3). RESULTS: At one year after surgery, the severity of MR was unchanged from preoperative grade in group 1 (2.1 +/- 0.5 vs. 1.97 +/- 0.8), and increased in group (0.76 +/- 0.43 vs. 1.44 +/- 0.77; p < 0.05), but was significantly lower in group (2.8 +/- 0.5 vs. 1.6 +/- 0.7; p <0.05). In group 1, the LV end-systolic volume index (LVESVI) tended to increase, the LV end-diastolic volume index (LVEDVI) increased from 69.6 +/- 22.6 to 79.6 +/- 23.2 ml/m2 with an increase in LVEF (from 27.9 +/- 5.9 to 31.3 +/- 9.4%), and pulmonary artery pressure (PAP) increased from 31.9 +/- 7.0 to 39.5 +/- 17.4 mmHg. In group 2, the LV volumes tended to increase, LVEF increased from 30. 3 +/- 4.1 to 34.9 +/- 9.1%, and PAP remained unchanged. In group 3, the LVESVI decreased from 55.4 +/- 16.9 to 47.1 +/- 21.7 ml/m2, LVED-VI tended to decrease, LVEF increased from 31.4 +/- 8.6 to 36.5 +/- 11.3%, and PAP decreased from 35.5 +/- 6.0 to 32.8 +/- 8.3 mmHg. CONCLUSION: Isolated CABG in patients with ICM had no favorable effect on MR reduction, and did not prevent its development. MR grade 2+ in patients with ICM at one year after isolated CABG had a deleterious effect on LV functional status, with progression of LV dilatation and increased PAP. A significant reduction or elimination of MR after combined surgery had a marked positive impact on reverse LV remodeling, including regression of LV dilatation, an increased LVEF, and decreased PAP.