Clinical trials of revascularization therapy in diabetics

Diabetic patients are a high-risk group for cardiovascular morbidity and mo rtality, with poorer long-term outcomes, with or without revascularization, than non-diabetic patients. Results from the Bypass Angioplasty Revascular ization Investigation (BARI) trial, the largest randomized study of coronar y revascularization strategies, showed that diabetic patients with multives sel coronary disease who were undergoing an initial revascularization proce dure had a significant long-term survival advantage with coronary artery by pass graft surgery (CABG) compared with percutaneous transluminal coronary angioplasty (PTCA). The 8-year follow-up data from the Emery Angioplasty Ve rsus Surgery Trial (EAST) study, the other major US trial of CABG versus PT CA, and results of other clinical trials that enrolled similar patients are consistent with an advantage for CABG in diabetic patients but not for non diabetic patients. This benefit is entirely a result of improved cardiac mo rtality. It is limited to patients receiving an internal mammary artery (IM A) graft and is apparent earlier in insulin-treated patients. The benefit o f CABG in diabetic patients may be significantly related to a protective ef fect on mortality after myocardial infarction, because CABG greatly reduced the risk of death after spontaneous Q-wave myocardial infarction in BARI-e ligible diabetic patients (relative risk 0.09, P < 0.001), an effect not se en in non-diabetic patients. (C) 2000 Lippincott Williams & Wilkins, Inc.