Risk of Stroke and Cardiac Events in Medically Treated Asymptomatic Carotid Stenosis

Abstract

The risk of stroke in patients with 50% or more asymptomatic carotid stenosis (ACS) on intensive medical treatment is low. Hence, the optimal treatment of ACS remains controversial at this point of time. We assessed the risk of stroke/transient ischemic attack (TIA) and cardiac events in patients with 50% or more ACS on intensive medical treatment. All patients with TIA/minor stroke (National Institutes of Health Stroke Scale score ≤5) who had undergone vessel imaging as part of their evaluation and patients with coronary artery disease who had undergone vessel imaging before cardiac intervention were screened for the presence of asymptomatic carotid stenosis. The risk of TIA/stroke, cardiac events, and vascular deaths were evaluated. Of 1,800 patients, 92 patients (.05%) had ACS having 50% to 99% stenosis; 63 had TIA/minor stroke, and 29 had coronary artery disease, of whom 7 patients had bilateral ACS, thus constituting 99 study units of ACS. The mean follow-up was 34.7 months (range 3-120 months). Two patients developed ischemic events on the side ipsilateral to the ACS and 9 patients developed cardiac events during the follow-up. The average annual event rate for cerebral ischemic events was .93% (95% confidence interval [CI], .11-3.37), 4.21% (95% CI, 1.92-7.98) for cardiac events, and 3.27% (95% CI, 1.31-6.74) for death. Although the risk of stroke in patients with ACS is low, acute coronary events and vascular deaths were significant. This highlights the importance of intensive risk factor modification to reduce adverse cardiovascular events in ACS rather than revascularization of the carotid stenosis.