Management of Moderate Ischemic Mitral Regurgitation in Patients Undergoing Surgical Revascularization
Authors: Hawary Khaled M , Elghanam Mohamed A , Al-saiegh Mohamed T , Desokey Ahmed S , ElAasey Said M , Abdallah Alaa A , Al-saiegh Tarek M 
Published: August 2023

Abstract

Background
Chronic ischemic mitral regurgitation (IMR) is not uncommonly seen in association with patients diagnosed with coronary artery disease and represents a late sequel of chronic myocardial ischemia and infarction. It adversely affects cardiovascular mortality and morbidity especially in patients undergoing coronary artery bypass grafting (CABG) surgery. We aim to identify the optimal management of moderate IMR in patients undergoing coronary artery bypass grafts surgery (CABG), whether to address this pathology during revascularization surgery or not.

Methods
100 patients diagnosed with Ischemic Heart Disease (IHD) associated with moderate IMR undergoing Coronary Artery Bypass Grafting (CABG). Patients were divided into two equal groups according to their Mitral valve intervention: Group A; 50 Patients with IMR planned for complete revascularization only and Group B; 50 patients planed for revascularization combined with mitral valve surgery. The two groups were compared demographically, for intraoperative and post-operative events. The primary end point was hospital mortality, secondary end points included post-operative improvement in the NYHA functional class, improvement of EF % and reduction of LV dimensions in post-operative echocardiography and finally, the incidence of neurological dysfunction in both groups.

Results
All the patients in both groups underwent CABG surgery using cardiopulmonary bypass machine. Patients in group B underwent combined Mitral valve surgery in the form of; Mitral valve replacement using a mechanical valve in 7 patients, Mitral valve repair with downsizing annuloplasty surgery using complete semi-rigid ring in 43 patients, of which 13 patients required additional chordal repair with artificial chordea.
Group (A) patients were found to have statistically significant shorter total bypass time 72.2± 17.6 vs 113.5± 14.3 (p &lt; 0.001), ischemic time 47.4 min ± 12.1 vs 79.7 min ± 12.3 (p &lt; 0.001), mechanical ventilation duration 10.9 hours ±14.9 vs 14.9 hours ±12.1 (p &lt; 0.001), total period of ICU stay was 46.1 hours ±21.2 vs 63.7 hours ±22.2 and ward stay 5.7 days ±2.3 vs 6.8 days ±2.9 vs (p &lt; 0.001) in group A vs group B respectively. Hospital mortality was insignificant between the 2 groups [(5 patients in group A (10%) vs 4 patients in group B (8%) P = 0.84)]. One month post-surgery, all survivors showed improvement of their ejection fraction and reduction in left ventricular and left atrial dimensions in Transthoracic echo however, there were no statistical significant improvement when comparing patients in both groups. Both groups showed similar improvement in Dyspnea score at one month follow up. Neurological insults were comparable in both groups (none vs one patient in group A vs B simultaneously.

Conclusion
Addition of mitral-valve surgery to CABG in patients with moderate degree of Ischemic Mitral regurgitation did not show significant benefit on survival, post-operative NYHA class of the patients, the echocardiographic findings or stroke incidence during the short term follow up. On the contrary, it resulted in longer durations of cardiopulmonary bypass, aortic cross-clamp time and longer ICU stay. Longer term follow-up is required to identify its potential benefit.