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What’s the risk of stroke with untreated asymptomatic severe carotid stenosis?

Reuters Health - 24/05/2022 - For patients with asymptomatic severe carotid stenosis who opt out of surgery, the risk of stroke hovers around 5% over five years, a new study suggests.

How best to manage patients with asymptomatic severe carotid stenosis remains "uncertain, due to advances in medical care and a lack of contemporary data comparing medical and surgical treatment," Dr. Robert Chang of Kaiser Permanente Northern California (KPNC), in Oakland, and colleagues note in JAMA.

They retrospectively evaluated stroke outcomes among patients with medically treated asymptomatic severe carotid stenosis who did not have surgery.

The cohort included 3,737patients (4,230 unique arteries) with 70% to 99% asymptomatic carotid stenosis identified between 2008 and 2012 and followed up through 2019 as part of KPNC.

Prior to any intervention, there were 133 ipsilateral strokes with an average annual stroke rate of 0.9% (95% CI, 0.7% to 1.2%). Over five years, the estimated rate of ipsilateral carotid-related acute ischemic stroke was 4.7% (95% CI, 3.9% to 5.7%).

"Proportional hazards modeling showed that a high-grade lesion at baseline or progression of a severe lesion to high-grade stenosis or occlusion was associated with an increased risk for stroke," Dr. Chang and colleagues report.

In this analysis, they say "liberal methods for estimating stroke rates were used, including unknown and likely lacunar strokes in the numerator when calculating ipsilateral stroke rates as there can be uncertainty about etiology."

"This category included patients without brain imaging or when two or more etiologies were clinically possible (eg, cardiac arrhythmia and carotid stenosis). Thus, the true stroke rate due to carotid disease may be lower than the presented estimates," they say.

"The broad representation of the study cohort and the KPNC population in general implies that these results may be generalizable to insured patients in a similar geographic region in the U.S.," they add.

These findings help clinicians and patients make informed decisions regarding management of asymptomatic severe carotid stenosis, Dr. Chang and colleagues say.

SOURCE: https://bit.ly/3NzU7pg JAMA, online May 24, 2022.

By Reuters Staff

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