Repair of chronic moderate functional ischemic mitral regurge during coronary bypass surgery versus no repair: experience and early results

ABSTRACT

An increased attention is nowadays being focused on the surgical management of chronic functional mitral valve regurgitation coexisting with ischemic heart disease [IHD]. The optimum approach as to its management is still under debate as different techniques have been proposed to correct tethering-induced regurgitation caused by derangement in the mitral valve apparatus. This study was carried out to assess the results of surgical repair of isolated chronic moderate functional ischemic mitral regurgitation [IMR] as regards the technique and postoperative left ventricular functions for the first year postoperatively. This comparative prospective-retrospective study was carried out between April 1999 and May 2008 in the Department of Cardiothoracic Surgery of Cairo University as well as the private practice after obtaining the approval of the local ethical committees in these places. The study population included 100 patients who were all diagnosed to have coronary heart disease complicated by moderate degree of ischemic functional mitral regurge. Patients were equally divided to two groups of equal number. Patients of the two groups were chosen to match as close as possible for sex, mean age, and preoperative risk factors. Group A patients contained 50 patients were submitted for mitral valve repair in addition to coronary artery bypass graft [CABG]; whereas group B patients contained another 50 patients were submitted for CABG alone without mitral repair. Perioperative patient evaluation included clinical examination; transthoracic [TTE]; and or transoesophageal [TEE] echocardiography. The surgical times [total operative time, total cardiopulmonary bypass time, and the cross-clamping time] were longer in group A patients [with statistical significance]. The mean number of bypass grafts done in group A was 3.4 +/- 0.4 [range 3-5 grafts]; versus 3.2 +/- 0.6 for group B patients [range 2-5] [pNS]. Intraoperative IABCP was needed in 5 [10%] of group A patients; versus 14 [28%] of group B patients [p<0.03]. Before going out of the OR, TEE examination revealed trivial or no MR in all of group A patients together with no valve-related complications. The overall mortality was 13 [13%] 4 [8%] in group A and 9 [18%] in group B [p < 0.05]. Intraoperatively 2 of group A [4%]; versus 2 [4%] of group B died for refractory cardiac muscle failure; while in-hospital mortality occurred in 6 [12%] of group B patients versus 1 [2%] of group A patients within the first 15 days postoperatively, mortality after 6 months was 1 in group A versus 1 in group B. Morbidity occurred in 11 [22%] of group A patients; versus 4 [8%] group B [p <0.04]. In group A, 4 patients [8%] needed prolonged mechanical ventilation with inotropic support; 4 patients [8%] were reoperated for hemostasis; 2 patients [8%] had transient hepato-renal insufficiency and superficial wound infection; while 1 patient [2%] newly-developed transient episode of atrial fibrillation that was medically-controlled. In group B, 3 patients [6%] needed prolonged mechanical ventilation with inotropic support; while another 3 patients [6%] developed prolonged non-fatal low cardiac output symptoms that became controlled on prolonged inotropic support. In both groups, all morbidity were adequately-controlled without fatal consequences. NYHA class has showed a significant improvement in survivors of group A than B with lower percent of patients with NYHA III/IV in group A [7/46] versus [14/41] in group B [p value 0.04]. The group A had a higher LVEF at 6 months 62 +/- 6 than group B 46 +/- 0.9 [p value 0.0001] despite matching of the preoperative LVEF of both groups. Combined CABG and repair of moderate degree of ischemic functional mitral regurge was associated with higher incidence of intraoperative and in-hospital non-fatal morbidity. Performing CABG with no mitral repair was associated with progressive deteroration of the left ventricular dimensions and functions especially in the patient subset with dilated preoperative LV diameters [LA and LVEDD] and compromised functional parameters [LVEF% and FS]. We advocate combining CABG with repair of moderate IMR in specific patient groups for augmenting postoperative LV performance and maximizing surgical results: