By Matthew E. Fink, MD
Louis and Gertrude Feil Professor in Clinical Neurology and Chairman, Department of Neurology, Weill Cornell Medical College; Neurologist-in-Chief, New York Presbyterian Hospital
Dr. Fink reports no financial relationships relevant to this field of study.
SOURCE: Yang C, et al. Risk of stroke at the time of carotid occlusion. JAMA Neurol 2015; doi:10.1001/jamaneurol.2015.1843.
In recent years, there is increasing evidence that modern intensive medical therapy in most patients with asymptomatic carotid stenosis is effective in stroke prevention, and few patients seem to benefit from carotid endarterectomy or carotid stenting.
However, in the United States, 90% of carotid interventions are for asymptomatic stenosis, compared to Denmark, where the rate is 0%. The investigators conducted a retrospective analysis of data collected from patients at the stroke prevention clinic of Victoria Hospital, Ontario, Canada, from 1990 until 1995 using annual surveillance carotid ultrasound, and then compared them to a similar group followed from 1995 through 2014.
Among 3681 patients followed with annual ultrasound, 316 (8.6%) were asymptomatic before a carotid occlusion occurred during the observation period. Most of the new occlusions (80%) occurred before 2002, when medical therapy was less intensive and the frequency of occlusion decreased in subsequent years. Only a single patient (0.3%) had a stroke at the time of carotid occlusion, and only three patients (0.9%) had ipsilateral stroke during follow-up.
In reviewing survival analyses, neither severity of stenosis nor the presence of contralateral occlusion predicted the risk of stroke or TIA, fatal stroke, or death from other causes in > 3 years of follow-up from carotid occlusion. From this study, it appears that the risk of progression to carotid occlusion is well below the risk of carotid stenting or carotid endarterectomy, and intensive medical therapy appears to be preferred for the vast majority of patients with asymptomatic carotid artery stenosis.
However, the CREST-2 trial, which is now underway and designed as a prospective, randomized trial, will be able to answer this question definitively.