By Matthew E. Fink, MD
Louis and Gertrude Feil Professor and Chair, Department of Neurology, Associate Dean for Clinical Affairs, New York Presbyterian/Weill Cornell Medical College
Dr. Fink reports no financial relationships relevant to this field of study.
SOURCE: Keyhani S, Cheng EM, Hoggatt KJ, et. al. Comparative effectiveness of carotid endarterectomy vs initial medical therapy in patients with asymptomatic carotid stenosis. JAMA Neurology 2020;77:1110-1121.
It has been more than 25 years since patients who had asymptomatic carotid artery stenosis were studied and followed. Since the pivotal trials demonstrating the benefit of endarterectomy vs. medical therapy many years ago,1,2 there has been significant improvement in the risk factors for atherosclerosis, including better treatment of blood pressure and diabetes, as well as improved antiplatelet medication regimens and high-potency statins.
In this real-world comparative effectiveness study, data were mined from several large databases of prospectively collected information on patients followed by the Department of Veterans Affairs (VA). This included both VA records data as well as Medicare data. This study was conducted from 2018-2020, and the data were analyzed of those veterans aged 65 years or older who had carotid imaging between Jan. 1, 2005, and Dec. 31, 2009.
Patients who had carotid stenosis of 50% or greater and were treated with medical therapy or carotid endarterectomy were followed for five years. Survival curves were computed to estimate the risk of fatal and nonfatal strokes in each cohort, and outcomes were calculated for each group and compared. The sample then was restricted to patients who would meet criteria for a randomized controlled trial and compared once again.
Of 5,221 patients, 51.9% underwent carotid endarterectomy (mean age 73.6 years, 98.8% were men) and 48.1% received initial medical therapy (mean age 73.6 years, 98.8% men). In the group that underwent carotid endarterectomy, the 30-day, perioperative rate of stroke or death was 2.5%. Overall, the five-year risk of fatal and nonfatal strokes was lower in the patients randomized to carotid endarterectomy compared with patients randomized to medical therapy (5.6% vs. 7.8%). However, when incorporating the risk of death, the risk difference between the two cohorts after five years was not significantly different, primarily because of the upfront risk of perioperative stroke and death in the group that underwent carotid endarterectomy. The absolute risk reduction of endarterectomy was less than half of what was reported in studies from the 1990s — 0.46% per year, with number needed to treat of 43 to reduce one stroke over five years. This lack of difference is attributed to improved medical therapy.
At the present time, the benefit of carotid endarterectomy in asymptomatic patients with carotid artery stenosis ≥ 50% is questionable, and most patients will benefit from medical treatment.
- Hobson RW 2nd, Weiss DG, Fields WS, et al. Efficacy of carotid endarterectomy for asymptomatic carotid stenosis. The Veterans Affairs Cooperative Study Group. N Engl J Med 1993;328:221-227.
- Halliday A, Mansfield A, Marro J, et al. Prevention of disabling and fatal strokes by successful carotid endarterectomy in patients without recent neurological symptoms: Randomised controlled trial. Lancet 2004;363:1491-1502.