Annual stroke rate for asymptomatic severe carotid stenosis without surgical intervention is 0.9%

Reference

Chang RW, Tucker LY, Rothenberg KA, et al. Incidence of ischemic stroke in patients with asymptomatic severe carotid stenosis without surgical intervention. JAMA 2022;327(20):1974-1982.

Synopsis

Using data from the Kaiser Permanente health-care system in Northern California, these investigators identified 3737 patients with severe carotid stenosis (defined as 70% to 99% stenosis due to atherosclerotic lesions) during a 4-year period ending in 2012. Patients with a stroke or transient ischemic attack in the 6 months prior to the study or those with any previous carotid interventions were excluded. Patients were followed up through 2019, or until death or surgical intervention. The cohort had a mean age of 74 years and 58% were men. Of the group, 60% did not have an intervention by the end of the study period. These patients were more likely to be older and female and have a higher comorbidity burden. Overall, 4230 asymptomatic stenotic arteries were identified in the 3737 patients (3244 with 1 stenotic artery, 493 with 2 stenotic arteries). The primary outcome of ipsilateral stroke prior to any surgical intervention occurred 133 times in 129 patients over a mean follow-up of 4.1 years. The mean annual rate of stroke was calculated as 0.9% and the cumulative risk of stroke at 5 years was 4.7%.