Coronary artery bypass grafting in the presence of valvular disease.

Compared with isolated coronary artery bypass grafting (CABG), the combination of valve replacement or repair with coronary revascularization generally increases operative risk. However, complete revascularization is superior to no revascularization in patients with valvular and coronary artery disease (CAD). Patients who undergo aortic valve replacement and CABG have two unrelated disease processes; these patients only infrequently have ischemic cardiomyopathy, and the operative mortality is slightly increased to 4-7% for the combined procedure versus isolated aortic valve replacement. Patients who are operated on for mitral valve disease and CAD fall into two groups: 1) where CAD and mitral valve disease are not etiologically related, and 2) where mitral valve dysfunction is the result of ischemic changes. In the latter group, operative mortality significantly exceeds that for isolated mitral valve surgery, and surgical priority increases that difference (operative mortality 7-20%). Thus, the operative risk for a mitral valve procedure plus CABG exceeds that for isolated coronary revascularization or isolated valve replacement. In the combined procedure, risk increases if valve dysfunction is caused by CAD, if severe left ventricular function is present, if the patient has been assigned to Class IV, or if emergency operation is required.