Long-term prognosis and the effect of carotid endarterectomy in patients with recurrent ipsilateral ischemic events

Background and purpose: 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. Methods: 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. Results: 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 patient characteristics as confounders nor any statistical interactions. Conclusions: 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.