Improved functional mitral regurgitation after off-pump revascularization in acute coronary syndrome.

Abstract

We evaluated the effect of isolated off-pump coronary artery bypass grafting on functional ischemic mitral regurgitation (IMR) associated with acute coronary syndrome. Of 1,419 acute coronary syndrome patients who underwent coronary revascularization between 2000 and 2010 (1,324 off-pump and 95 on-pump), 59 OPCAB patients had greater than mild degree functional IMR preoperatively (31 mild to moderate, 23 moderate, 5 severe). Clinical outcomes and results from echocardiography, angiography, and myocardial single-photon emission computed tomography performed early and 1 year postoperatively were analyzed. Operative mortality was 5.1% (3 of 59). All survivors underwent early postoperative echocardiograms, which showed 0 patients with worsened IMR; 41 with less than or equal to mild degree residual IMR (NMR group); and 15 with greater than mild degree IMR (RMR group). Myocardial single-photon emission computed tomography revealed that RMR patients had more reversible ischemic myocardial segments preoperatively than NMR patients (p=0.009). Successful right coronary revascularization with proven graft patency was a predictor of early improvement of IMR (p=0.024). There were no differences in postoperative morbidities between the 2 groups. One-year follow-up echocardiograms demonstrated further improvement in 10 of 13 RMR patients. No patients experienced mitral valve-related events during follow-up. Overall survival and major adverse cardiac event-free survival rates at 5 years were 84.6% and 78.1%, respectively, with no intergroup differences. Most functional IMR associated with acute coronary syndrome, including severe degree IMR, improved during the first postoperative year after off-pump coronary artery bypass grafting.