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

Introduction 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. Patients and Methods 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. Results 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, p = 0.775), early mortality (MH RR: 0.65, 95% CI: 0.39-1.07, p = 0.092), and stroke rates (MH RR 0.65, 95% CI: 0.21-2.03, p = 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, p = 0.584). MD of change from baseline in left ventricular (LV) end-systolic dimension (MD: - 2.50, 95% CI: - 5.21 to - 0.21, p = 0.071) and LV ejection fraction (MD: 0.48, 95% CI: - 2.48 to 3.44, p = 0.750) were not significantly different between the groups. Incidence of moderate MR (MH RR: 3.24, 95% CI: 1.79-5.89, p < 0.001) was higher in the CABG only group. Conclusion 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.

Anantha Narayanan M ，Aggarwal S ，Reddy YNV ，Alla VM ，Baskaran J ，Kanmanthareddy A ，Suri RM ... -  《-》

Effect of systematic downsizing rigid ring annuloplasty in patients with moderate ischemic mitral regurgitation.

Functional ischemic mitral regurgitation (FIMR) increases mortality independently of the baseline characteristics and ventricular function. The effect of treating FIMR with annuloplasty is unclear when mitral regurgitation is moderate. Myocardial revascularization alone has been shown to improve mitral valve function. We randomized 31 patients with moderate (grade 2-4) FIMR to receive either coronary artery bypass grafting (CABG) alone or CABG plus downsizing mitral ring annuloplasty. The patients were followed up for clinical outcomes and echocardiographic assessment of mitral valve function and left ventricular dimensions at 3 and 12 months. Clinical improvement was assessed using the Minnesota quality-of-life questionnaire, 6-minute walk test, and brain natriuretic peptide levels. The clinical course was similar in the 2 groups of patients during the study period. FIMR was perfectly corrected intraoperatively in the ring group. Echocardiographic follow-up at 3 months showed no difference in the FIMR grade between the 2 groups (66% less than grade 2 in the CABG alone and 86% in the CABG plus ring group; P = .316). The improvement in the CABG alone group was even more marked at 12 months (85% less than grade 2 in the CABG group and 85% in the CABG plus ring group). The left ventricular ejection fraction was significantly better at 3 months in the CABG alone group, although at 12 months, the left ventricular ejection fraction in the 2 groups had improved similarly. Although initially effective at reducing moderate FIMR, the addition of a ring did not change the clinical course after CABG surgery. At 12 months, no echocardiographic difference was found in terms of residual mitral regurgitation, left ventricular dimensions and function, or clinical outcomes.

Bouchard D ，Jensen H ，Carrier M ，Demers P ，Pellerin M ，Perrault LP ，Lambert J ... -  《-》

Coronary revascularization alone or with mitral valve repair: outcomes in patients with moderate ischemic mitral regurgitation.

Goland S ，Czer LS ，Siegel RJ ，DeRobertis MA ，Mirocha J ，Zivari K ，Kass RM ，Raissi S ，Fontana G ，Cheng W ，Trento A ... -  《-》

Should the mitral valve be repaired for moderate ischemic mitral regurgitation at the time of revascularization surgery?

Ischemic mitral regurgitation (IMR) is associated with increased mortality and recurrent congestive heart failure following coronary artery bypass graft (CABG) surgery. While mitral surgery should be undertaken for severe MR during CABG, the treatment of moderate IMR remains controversial. We conducted a meta-analysis to determine the outcomes of CABG alone and combine with mitral valve repair (MVr) in moderate IMR. A literature search was conducted by Pubmed, Ovid, and Embase, which included 643 articles. Eleven studies (seven observational studies and four randomized controlled trials) with a total of 1406 patients were included (CABG alone = 864 and CABG plus MVr = 542). There was no difference in operative mortality (odds ratio 1.56, 95% confidence interval [CI] 0.92-2.71) or long-term survival at 1 or 5 years (hazard ratio 0.98, 95%CI 0.71-1.35, P = 0.49) between the two groups, and little evidence of heterogeneity was found in the studies (I2  = 0.0, P = 0.562). There was significantly greater improvement in MR grade (weighted mean difference [WMD] -1.15, 95%CI -1.67 to -0.064, P = < 0.001) and left ventricular systolic diameter (WMD -3.02, 95%CI -4.85 to -1.18, P = 0.001) following CABG and MVr compared to CABG alone. No difference in postoperative functional class or ejection fraction was found. Our results show that in the presence of moderate IMR, adding MVr to revascularization reduces MR grade on follow-up echocardiography and promotes ventricular remodeling, with no improvement in long-term survival or functional class.

Salmasi MY ，Harky A ，Chowdhury MF ，Abdelnour A ，Benjafield A ，Suker F ，Hubbard S ，Vohra HA ... -  《-》

Mitral valve surgery and coronary artery bypass grafting for moderate-to-severe ischemic mitral regurgitation: Meta-analysis of clinical and echocardiographic outcomes.

This meta-analysis was conducted to compare clinical and echocardiographic outcomes following isolated coronary artery bypass grafting (CABG) versus CABG and mitral valve (MV) surgery in patients with moderate-to-severe ischemic mitral regurgitation (IMR). Seven databases were systematically searched to identify relevant studies. For eligibility, studies were required to report on the primary endpoint of perioperative or late mortality. Data were analyzed according to predefined clinical endpoints. Four randomized controlled trials (RCTs) (n = 505) and 15 observational studies (OS) (n = 3785) met the criteria for inclusion. Compared with isolated CABG, concomitant CABG and MV surgery was not associated with increased perioperative mortality (RCTs: relative risk [RR] 0.89, 95% confidence interval [CI], 0.26-3.02; OS: RR 1.40, 95% CI, 0.88-2.23). CABG and MV surgery was associated with significantly lower incidence of moderate-to-severe MR at follow-up (RCTs: RR 0.16, 95% CI, 0.04-0.75; OS: RR 0.20, 95% CI, 0.09-0.48). Late mortality was similar between the surgical approaches in RCTs (hazard ratio [HR] 1.20, 95% CI, 0.57-2.53) and OS (HR 0.99, 95% CI, 0.81-1.21). There were no significant differences in echocardiographic outcomes. These results remained consistent in subgroup analyses restricted to patients with strictly moderate IMR. In patients with moderate-to-severe IMR, the addition of MV surgery to CABG was not associated with increased perioperative mortality. Although concomitant MV surgery reduced recurrence of moderate-to-severe MR at follow-up, this was not associated with a reduction in late mortality. Larger trials with longer follow-up duration are required to further assess long-term survival and freedom from reintervention.

Virk SA ，Tian DH ，Sriravindrarajah A ，Dunn D ，Wolfenden HD ，Suri RM ，Munkholm-Larsen S ，Cao C ... -  《-》