One-year progression of moderate asymptomatic carotid stenosis predicts the risk of vascular events.

BACKGROUND AND PURPOSE This study aimed at evaluating whether ultrasound monitoring of moderate asymptomatic carotid stenosis may help in identifying subjects at high risk for vascular events. METHODS We included 523 subjects with unilateral asymptomatic carotid stenosis of 50% to 69%. Follow-up carotid ultrasound was performed within 12 months from inclusion to detect the frequency and degree of stenosis progression. Subjects were prospectively evaluated for a median period of 42 months (interquartile range, 38-45) after a second ultrasound evaluation. Outcome measures were any stroke and transient ischemic attack, myocardial infarction, and death. RESULTS Carotid stenosis progression was associated with the occurrence of vascular events (hazard ratio, 21.57; 95% confidence interval, 11.81-39.39; P<0.001). During follow-up, 96.7% of subjects without progressive carotid stenosis remained free from vascular events. Among patients with progressive stenosis, 53.7% experienced a vascular event and 27.1% experienced an ipsilateral stroke. CONCLUSIONS One-year moderate asymptomatic carotid stenosis progression is related to higher risk of vascular events, including ipsilateral stroke.