Cerebral Ischemic Events Ipsilateral to Carotid Artery Stenosis. The Carotid Asymptomatic Stenosis (CARAS) Observational Study: First Year Preliminary Results

Abstract

To report the characteristics of the prospective observational cohort study "Carotid Asymptomatic Stenosis (CARAS)", including patients with asymptomatic carotid stenosis under medical treatment and their first year of follow-up, in order to estimate the risk of cerebral ischemic events. This is a prospective observational cohort study of CARAS>60% (Nascet criteria) patients, identified in a single duplex-ultrasonography (DUS) vascular laboratory (trail registration N: NCT04825080). Patient's enrollment started in January 2019 and ended in March 2020 with the follow-up conclusion scheduled in December 2025. The aimed sample size was calculated at 300 patients for a 5-year follow-up. The primary outcome were the incidence of ipsilateral neurologic ischemic events (stokes and transient ischemic attacks [TIA]), plaque progression rate, and survival. The follow-up was scheduled at six-month intervals for clinical visit and annually for DUS examination. a total of 307 patients completed the first follow-up year. The mean age was 81±4 years, 55% were male. Contralateral stenosis >60% was present in 90 (29%) patients. Antiplatelet therapy and statins adherence was 80% and 88%, respectively. During the first year, 3 ispilateral strokes (1%) and 4 TIAs (1.3%) occurred, for a total of 2.3% ipsilateral ischemic events. During the first year, 43 (14%) plaques had a stenosis progression, which was correlated with the occurrence of neurological events (9.3% vs. 1.1%, P=.001, OR: 8.9; 95%CI: 1.9-41); 6 deaths (2%) occurred in the same period. the preliminary one-year results of this prospective study suggest that the overall rate of any ipsilateral ischemic event, and specifically ipsilateral strokes, correlates with plaque progression.