Early hazards of mitral ring annuloplasty in patients with moderate to severe ischemic mitral regurgitation undergoing coronary revascularization: the importance of preoperative myocardial viability.

Le Polain De Waroux, Jean-Benoît [UCL] Pouleur, Anne-Catherine [UCL] Vancraeynest, David [UCL] Pasquet, Agnes [UCL] Gerber, Bernhard [UCL] El Khoury, Gebrine [UCL] Noirhomme, Philippe [UCL] Robert, Annie [UCL] Vanoverschelde, Jean-Louis [UCL]

BACKGROUND AND AIM OF THE STUDY: The impact of adding mitral ring annuloplasty (MRA) to coronary bypass grafting (CABG) in patients with ischemic mitral regurgitation (iMR) is unclear. The study aim was to compare the 30-day and four-year survival of patients with moderate to severe iMR undergoing CABG or CABG+MRA, and to investigate the role of contractile reserve (CR) in the prognostic response to MRA. METHODS: A total of 76 coronary patients (61 men, 15 women; mean age 62 +/- 9 years) with poor left ventricular ejection fraction (LVEF) of 33 +/- 11% and grade > or =2 iMR underwent low-dose dobutamine echocardiography to identify their CR before CABG. The survival of 34 patients undergoing CABG+MRA was compared to that of 42 patients who underwent CABG alone. The groups were further substratified according to their preoperative CR. RESULTS: During follow up, 24 patients died from cardiac causes, and two others required heart transplantation. At one year, the residual iMR and NYHA functional class were lower in patients undergoing MRA than in those that did not. The 30-day and four-year survivals were lower in patients undergoing MRA in the absence of CR than in the other patients (71 +/- 11% versus 95 +/- 3% at 30 days, p = 0.002; 35 +/- 11% versus 69 +/- 6% at four years, p = 0.008). Cox's proportional hazard analysis identified CR (HR = 0.14, 95% CI 0.05-0.38, p < 0.001), MRA (HR = 3.54, 95% CI 1.48-8.50, p = 0.004), additive EuroSCORE (HR = 1.29, 95% CI 1.08-1.55, p = 0.006) and LVEF (HR = 0.93, 95% CI 0.59-0.98, p = 0.001) as independent predictors of long-term outcome in this population. CONCLUSION: In patients with moderate to severe iMR, survival after CABG is mainly influenced by the presence of CR. By contrast, adding MRA to CABG does not affect long-term survival, except in patients without CR, in whom it increases early mortality.