Cardiac prognosis of patients with carotid stenosis and no history of coronary artery disease. Veterans Affairs Cooperative Study Group 167

Abstract

Background and purpose: Patients with carotid stenosis have a high frequency of asymptomatic coronary artery disease (CAD). The purpose of this study of patients with asymptomatic carotid stenosis was to test the hypothesis that patients without a history of CAD have the same cardiac prognosis as patients with a history of CAD.

Methods: Men enrolled in the Department of Veterans Affairs study on the efficacy of carotid endarterectomy for asymptomatic carotid stenosis underwent a baseline cardiac evaluation (history, physical examination, and electrocardiogram) to document previous angina or myocardial infarction. Patients were randomized to medical therapy alone or medical therapy and carotid endarterectomy. Medical therapy consisted of aspirin 650 mg twice daily and treatment of risk factors. All episodes of angina, myocardial infarction, or sudden death during follow-up (average of 47.9 months) were recorded.

Results: Of 444 men enrolled in the study, 200 (45%) had a history of CAD. During the study 86 (43%) of 200 patients with CAD and 81 (33%) of 244 patients without a history of CAD had cardiac ischemic events (P = .03). In patients without a history of CAD, the first cardiac event was myocardial infarction or sudden death in 45 patients (56%). Factors that were independently associated with cardiac events in patients without a history of CAD were diabetes (odds ratio [OR], 2.14; 95% confidence interval [CI], 1.15 to 3.97), intracranial occlusive disease (OR, 2.13; 95% CI, 1.13 to 4.02), and peripheral vascular disease (OR, 2.04; 95% CI, 1.14 to 3.66). Forty-two percent of patients with two of these factors and 69% of patients with all three factors had cardiac events.

Conclusions: Men with carotid stenosis and no history of CAD have a lower rate of cardiac events than men with carotid stenosis who have a history of CAD. However, a subgroup of patients with carotid stenosis and no history of CAD who have coexistent intracranial occlusive disease, diabetes, or peripheral vascular disease have a risk of cardiac events similar to that of patients with a history of CAD.