An unsuspected cause for recurrent angina: subclavian artery stenosis.

The advantages of internal mammary artery (IMA) grafts over saphenous vein grafts (SVG) for coronary artery bypass grafting have been extensively recorded in the literature. Operative results and postoperative mortality in patients with IMA versus SVG are comparable. The relative risks of thrombosis, however, of an SVG are four to five times greater than an IMA graft, and the probability of recurrent angina or need for reoperation is significantly less in IMA grafted patients. Coltharp et al. also showed that the risks of reoperation for recurrent angina were decreased by a previously constructed IMA graft.