Incidence of Ischemic Stroke in Patients With Asymptomatic Severe Carotid Stenosis Without Surgical Intervention

• Published in: JAMA : the journal of the American Medical Association 2022-05, Vol.327 (20), p.1974-1982
• Main Authors: Chang, Robert W, Tucker, Lue-Yen, Rothenberg, Kara A, Lancaster, Elizabeth, Faruqi, Rishad M, Kuang, Hui C, Flint, Alexander C, Avins, Andrew L, Nguyen-Huynh, Mai N
• Format: Article
• Language: English
• Subjects: Adult; Aged; Arteries; Asymptomatic; Carotid artery; Carotid Stenosis - complications; Carotid Stenosis - diagnostic imaging; Carotid Stenosis - surgery; Confidence intervals; Decision making; Endarterectomy, Carotid - adverse effects; Female; Health services; Humans; Incidence; Intervention; Ischemia; Ischemic Stroke; Male; Medical imaging; Medical treatment; Original Investigation; Patients; Retrospective Studies; Risk Factors; Stenosis; Stents; Stroke; Stroke - epidemiology; Stroke - etiology
• ISSN: 0098-7484; 1538-3598
• DOI: 10.1001/jama.2022.4835

IMPORTANCE: Optimal management of patients with asymptomatic severe carotid stenosis is uncertain, due to advances in medical care and a lack of contemporary data comparing medical and surgical treatment. OBJECTIVE: To estimate stroke outcomes among patients with medically treated asymptomatic severe carotid stenosis who did not undergo surgical intervention. DESIGN, SETTING, AND PARTICIPANTS: Retrospective cohort study that included 3737 adult participants with asymptomatic severe (70%-99%) carotid stenosis diagnosed between 2008 and 2012 and no prior intervention or ipsilateral neurologic event in the prior 6 months. Participants received follow-up through 2019, and all were members of an integrated US regional health system serving 4.5 million members. EXPOSURES: Imaging diagnosis of asymptomatic carotid stenosis of 70% to 99%. MAIN OUTCOMES AND MEASURES: Occurrence of ipsilateral carotid-related acute ischemic stroke. Censoring occurred with death, disenrollment, or ipsilateral intervention. RESULTS: Among 94 822 patients with qualifying imaging studies, 4230 arteries in 3737 (mean age, 73.8 [SD 9.5 years]; 57.4% male) patients met selection criteria including 2539 arteries in 2314 patients who never received intervention. The mean follow-up in this cohort was 4.1 years (SD 3.6 years). Prior to 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 by 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.