Brain lesions that appear on diffusion-weighted imaging (DWI) after carotid artery stenting (CAS) may be a sign of stroke to come. A study in the Feb. 17 issue of the Journal of the American College of Cardiology found patients with lesions on post-intervention magnetic resonance imaging were more than twice as likely to have a stroke or transit ischemic attack (TIA) in the five years that followed.

These findings came from another look at the International Carotid Artery Stenting Study (ICSS). ICSS reviewed the short- and long-term outcomes of patients who underwent CAS against carotid endarterectomy. Henrik Gensicke, MD, from the University Hospital Basel in Switzerland, and colleagues focused on the data on the 124 patients who underwent CAS over the course of the parent study.

They found new ischemic lesions through DWI in 62 patients. Over  almost five years, patients positive for lesions on DWI were more likely to have recurrent strokes or TIA (hazard ratio 2.85). The probability of having a stroke or TIA at one year for patients with lesions was 15.1 percent, as opposed to 3.2 percent for those without. The highest risk of stroke or TIA occurred within the first six months following treatment. There was no difference between those with or without lesions in mortality rate.

Similarly, little difference was seen between patients with or without lesions when the study’s population of carotid endarterectomy was examined for stroke outcomes.

Gensicke et al suggested extended dual antiplatelet therapy (DAPT) to counteract potential stroke risks following CAS or carotid endarterectomy. However, an editorial written by William A. Gray, MD, of the Center for Interventional Vascular Therapy at Columbia University Medical Center in New York City, didn’t find this course advisable, citing the small size of the study.

“Given the lack of differentiation between hard endpoints between the 2 therapies in the present study, along with the small but real increase in bleeding, extended DAPT does not seem justified or advisable,” Gray wrote.

The findings of Gensicke et al, however, offer a glimpse at a larger picture. They  wrote that larger studies would help clarify whether lesions found on DWI after CAS or endarterectomy could pose a greater stroke risk over time.