Surgical Repair of Moderate Ischemic Mitral Regurgitation—A Systematic Review and Meta-analysis

Abstract

Moderate mitral regurgitation (MR) of ischemic etiology has been associated with worse outcomes after coronary artery bypass grafting (CABG). Studies comparing concomitant mitral valve replacement/repair (MVR/Re) with CABG and standalone CABG have reported conflicting results. We performed a systematic review and meta-analysis of the published literature. We searched using PubMed, Cochrane, EMBASE, CINAHL, and Google scholar databases from January 1960 to June 2016 for clinical trials comparing CABG to CABG + MVR/Re for moderate MR. Pooled risk ratio or mean difference (MD) with 95% confidence intervals (CI) for individual outcomes were calculated using random effects model and heterogeneity was assessed using Cochrane's Q-statistic. A total of 11 studies were included. Mean follow-up was 35.3 months. All-cause mortality (Mantel-Haenszel [MH] risk ratio [RR]: 0.96, 95% CI: 0.75-1.24, = 0.775), early mortality (MH RR: 0.65, 95% CI: 0.39-1.07, = 0.092), and stroke rates (MH RR 0.65, 95% CI: 0.21-2.03, = 0.464) were similar between CABG and CABG + MVR/Re groups. Adverse event at follow-up was lower with CABG (MH RR: 0.90, 95% CI: 0.61-1.32, = 0.584). MD of change from baseline in left ventricular (LV) end-systolic dimension (MD: - 2.50, 95% CI: - 5.21 to - 0.21, = 0.071) and LV ejection fraction (MD: 0.48, 95% CI: - 2.48 to 3.44, = 0.750) were not significantly different between the groups. Incidence of moderate MR (MH RR: 3.24, 95% CI: 1.79-5.89, < 0.001) was higher in the CABG only group. Addition of MVR/Re to CABG in patients with moderate ischemic MR did not result in improvement in early or overall mortality, stroke risk, or intermediate markers of LV function when compared with CABG alone.

Temporary mechanical circulatory support & enhancing recovery after cardiac surgery

“…Since the Coronary Artery Surgery Study [10,11] demonstrated the value of coronary artery bypass (CAB), patient risk profiles and complexity have escalated [12][13][14][15] and the Surgical Treatment for Ischemic Heart Failure Trial (STICH) [16][17][18] bolstered recommendations for CAB in patients with impaired left ventricular function, despite the increased short-term risks and a 5.1% 30-day mortality [19]. Innovation in the evaluation and treatment of ischemic cardiomyopathy advances [20,21] along with the volume of patients burdened with ischemic cardiomyopathy (to include mitral regurgitation where mitral valve repair or replacement may complement CAB [22][23][24][25][26] and less commonly aortic regurgitation).…”

The Prognostic Role of SYNTAX Score in Moderate Ischemic Mitral Regurgitation Puzzle

“…I have read the article entitled "Surgical Repair of Moderate Ischemic Mitral Regurgitation-A Systematic Review and Metaanalysis" by Anantha Narayanan et al, 1 recently published in this journal, with great interest. The investigators reported that concomitant mitral valve surgery for moderate ischemic mitral regurgitation (MR) at the time of surgical revascularization does not support the addition of mitral valve replacement/repair to standard coronary artery bypass grafting (CABG) surgery.…”

“…Further research should focus on identifying subgroups of patients with moderate ischemic MR who may benefit from mitral surgery with CABG, such as those with large areas of infarct without viable myocardium who would theoretically not be expected to benefit from revascularization alone. 1 Secondary MR is caused by progressive left ventricular remodeling and dilatation after myocardial injury and has been estimated to affect 1.6 to 2.8 million people in the United States. 2 Synergy between Percutaneous Coronary Intervention with TAXUS and Cardiac Surgery (SYNTAX) score is an angiographic scoring system and is widely used to evaluate the severity and complexity of coronary artery disease (CAD).…”