The fate of asymptomatic severe carotid stenosis in the era of best medical therapy

Background: Medical therapy for asymptomatic carotid artery stenosis (ACAS) may obviate the carotid revascularization, according to recent literature reports, but many studies also considered moderate carotid artery stenosis (50-69% NASCET). This study reviews the most recent series of ACAS focusing on ipsilateral transient ischemic attack (TIA) stroke and annual risk of stroke in patients with ACAS ≥70%, thereby also evaluating the adherence to best medical therapy (BMT).

Methods: A systematic review consisting of all the series of patients with ACAS being treated medically was performed, which was published after 2005. The annual pooled risk of ipsilateral TIA-stroke and stroke in patients with ACAS ≥70% was calculated. A subgroup of studies with BMT defined as ≥90% of the patients in antiplatelet and statin therapy was performed.

Results: Eleven studies, with the enrolling period from 1996 to 2009, were reviewed. Overall, 2185 patients were considered, with a follow-up from 2 to 13 years, for a total of 6834 patients/year. The pooled risk was 3.4%/year for ipsilateral TIA-stroke and 1.6%/year for stroke. Five studies, published from 2014, had BMT adherence, for a total of 1665 patients/year. The pooled risk was 3.5%/year for ipsilateral TIA-stroke and for stroke.

Conclusion: The most recent series of ACAS ≥70% and BMT had an overall stroke rate which is relatively low; however, the risk of developing symptoms is still relevant (3.4%/year).