Key points Ask What is the stroke rate in patients with asymptomatic severe carotid stenosis without surgical intervention? Findings This retrospective cohort study included 3737 participants with asymptomatic 70% to 99% carotid stenosis identified between 2008 and 2012 and followed up through 2019 who did not undergo surgical intervention. The estimated rate of ipsilateral carotid-related acute ischemic stroke was 4.7% over 5 years. Meaning These findings may inform treatment decisions for patients with asymptomatic severe carotid stenosis. |
Importance
The optimal treatment of patients with asymptomatic severe carotid stenosis is uncertain due to advances in medical care and the lack of contemporary data comparing medical and surgical treatment.
Aim
To estimate stroke outcomes among patients with medically treated asymptomatic severe carotid stenosis who did not undergo surgical intervention.
Design, environment and participants
Retrospective cohort study including 3737 adult participants with asymptomatic severe carotid stenosis (70%-99%) diagnosed between 2008 and 2012 and without prior intervention or ipsilateral neurological event in the previous 6 months.
Participants were followed through 2019 and were all members of an integrated U.S. regional health system serving 4.5 million members.
Exhibitions
Imaging diagnosis of asymptomatic 70% to 99% carotid stenosis.
Main results and measures
Occurrence of ipsilateral carotid-related acute ischemic stroke. Censoring occurred upon death, disaffiliation, or ipsilateral intervention.
Results
Among 94,822 patients with eligible imaging studies, 4,230 arteries in 3,737 (mean age, 73.8 [SD 9.5 years]; 57.4% men) met selection criteria, including 2,539 arteries in 2,314 patients who had never received intervention.
The mean follow-up in this cohort was 4.1 years (SD 3.6 years).
Before any intervention, there were 133 ipsilateral strokes with a mean annual stroke rate of 0.9% (95% confidence interval [CI], 0.7%-1.2%).
The Kaplan-Meier estimate of ipsilateral stroke at 5 years was 4.7% (95% CI, 3.9%-5.7%).
Conclusions and relevance
In a community-based cohort of patients with asymptomatic severe carotid stenosis who did not undergo surgical intervention, the estimated rate of ipsilateral carotid-related acute ischemic stroke was 4.7% over 5 years.
These findings may inform decision making regarding surgical and medical treatment for patients with asymptomatic severe carotid artery stenosis.
