Frequency and prognostic significance of silent coronary artery disease in patients with cerebral ischemia undergoing carotid endarterectomy

To evaluate the prevalence and prognostic role of silent coronary artery disease (CAD) in patients with symptomatic high-grade carotid stenosis (70 to 99%) undergoing carotid endarterectomy, and with neither history nor symptoms of CAD, 106 patients (76 men, 30 women, mean age 58.7 years [range 42 to 71]) with recent cerebral ischemia were prospectively studied. Patients were stratified as to the presence (n = 27, 25%) or absence (n = 79, 75%) of silent CAD defined by concordant abnormal exercise electrocardiographic testing and thallium-201 myocardial scintigraphy. The male sex, the severity of the symptomatic carotid lesion (>90%), and the coexistence of contralateral carotid disease identified patients with higher probability of coexisting CAD. The 106 patients underwent 121 operations (bilateral in 15). In the perioperative period, no deaths or cardiac events occurred, 1 patient suffered a recurrent stroke and 3 had a transient ischemic attack. During a mean follow-up period of 5.4 years, 9 patients died (1.7%/year): fatal myocardial infarction occurred in 5 (all in the silent CAD group), cancer in 3 and vertebrobasilar stroke in 1. Nonfatal events occurred in 9 patients: myocardial infarction in 1 (without silent CAD), unstable angina in 3 (with silent CAD), and cerebral ischemic attacks in 5. After 7 years, the Kaplan-Meier estimated survival free from coronary events was 51% in patients with silent CAD, and 98% in patients without CAD (p < 0.01). In conclusion, among patients with symptomatic high-grade carotid stenosis undergoing carotid endarterectomy, even in absence of history or symptoms of CAD, a silent CAD is detectable in one fourth of the patients. Silent CAD did not affect the perioperative outcome, but strongly influenced the long-term prognosis. These results suggest the need for routine screening of silent CAD in patients with severe carotid stenosis to identify those at high long-term risk of cardiac events, for whom a more aggressive management should be warranted.