Real-world use of medical therapy in moderate asymptomatic carotid stenosis

Despite level 1 evidence demonstrating the benefit of carotid endarterectomy for the prevention of stroke in patients with severe asymptomatic carotid stenosis (ACS), there has been a trend toward recommending optimal medical therapy (OMT) alone. This recommendation has been promulgated based on the observation that modern advances in OMT reduce the overall stroke risk in the general population, but the success of this treatment strategy is dependent on patient and provider adherence. In current practice, patients with moderate ACS are nearly all treated with OMT alone. The objective of this study was to evaluate adherence to OMT in a cohort of patients with moderate ACS undergoing treatment with OMT alone.

Consecutive carotid duplex ultrasound examinations were reviewed for the years 2019 and 2020. Those with moderate (50%-69%) ACS based on Society for Vascular Surgery guidelines were included in the study. Patients were assessed for OMT at the time of the index duplex, the first follow-up visit, and at each subsequent follow-up visit until the end of the study. OMT was defined as abstinence from smoking, aspirin or other antiplatelet use, and statin or other lipid-lowering therapy. Patients were stratified based on their ability to achieve OMT, and each component was evaluated to identify shortfalls in therapy.

A total of 323 duplex ultrasound examinations with moderate ACS in 255 patients were identified. Of the 255 patients, 143 (56.1%) were on OMT at the time of the first duplex; that number increased to 163 (63.9%) by the first follow-up visit and 175 (68.6%) by the completion of the study. There were 112 (43.9%) patients who were not on OMT at the time of the index duplex, 43 (38.4%) of whom achieved OMT over a median follow-up time of 2.7 years. By the end of follow-up, 86 (76.8%) were taking aspirin or another antiplatelet medication, 93 (83.0%) were on statin or other lipid-lowering therapy, and 74 (66.1%) were abstinent from smoking. Pre-duplex smoking was independently associated with failure to achieve OMT (hazard ratio: 0.452, P = .017).

Among patients with moderate ACS who were not previously on OMT, the rate of OMT achievement is poor. Although advances in lipid management through statin therapy have been praised for their role in improving the effectiveness of OMT, smoking cessation represents an important target for improving uptake and as a result effectiveness of OMT.