Long-term prognosis and the effect of carotid endarterectomy in patients with recurrent ipsilateral ischemic events. North American Symptomatic Carotid Endarterectomy Trial Group.

Abstract

The present study examines how the prognosis of patients who present with an ischemic event (TIA or nondisabling stroke) referable to a 70 to 99% carotid artery stenosis is modified by the pattern of their ischemic history. We also examined the benefits of performing carotid endarterectomy on the recently symptomatic artery. A total of 608 patients was divided into two groups. The recent group (N = 444) consisted of patients who became newly symptomatic within the previous 6 months of their presenting event. Prior to this, they were asymptomatic. The recurrent group (N = 164) consisted of patients who had one or more ischemic events within the previous 6 months of their presenting event, as well as one or more within the previous 7 to 12 months. All events were ipsilateral to the presenting event. Kaplan-Meier risk estimates of ipsilateral stroke at 2 years for medically treated patients were 18.6 +/- 3.3% in the recent group and 41.2 +/- 6.9% in the recurrent group (p = 0.0002, logrank test). For patients who underwent carotid endarterectomy, the risks were 7.8 +/- 2.0% and 10.8 +/- 3.4% (p = 0.36, logrank test). Multivariate analyses did not identify any baseline patients characteristics as confounders nor any statistical interactions. There is a need for urgency in considering carotid endarterectomy for patients with 70 to 99% carotid artery stenosis who have had recurrent ipsilateral ischemic events extending back more than 6 months. These patients are at more than twice the risk of stroke as those who are newly symptomatic.