Recurrent stroke risk is high after a single cerebrovascular event in patients with symptomatic 50-99% carotid stenosis: a cohort study

Abstract

Background: Recurrent TIAs are thought to signal a high stroke risk. The aim of this study is to examine if repeated ischemic events increase the risk of recurrent ipsilateral stroke among patients with symptomatic 50-99% carotid stenosis.

Methods: This is a secondary analysis of the ANSYSCAP study, where we analyzed recurrent ipsilateral ischemic stroke before carotid endarterectomy in 230 consecutive patients with symptomatic 50-99% carotid stenosis. Here, we further analyzed the patients according to if they were clinically stable, unstable or highly unstable - respectively defined as having 0, 1 or ≥2 additional ipsilateral events within 7 days before and/or after the ischemic cerebrovascular event for which the patient sought health care (the presenting event).

Results: Of the 230 included patients, 155 (67%) were clinically stable, 47 (20%) were clinically unstable and 28 (12%) were clinically highly unstable. Eighteen patients suffered a stroke within 7 days; of these patients, 12 (67%) were clinically stable. The risk of recurrent ipsilateral ischemic stroke within 7 days was equally high for clinically stable (8%), unstable (9%) and highly unstable (7%) patients. Fourteen patients had 3-11 additional ipsilateral events; of these patients, only one suffered a recurrent ipsilateral ischemic stroke.

Conclusions: The seemingly clinical stable symptomatic 50-99% carotid stenosis patients without additional ipsilateral events have a high risk of recurrent stroke. Patients without additional events should undergo preoperative evaluation and carotid endarterectomy in the same expedient manner as patients with additional events.

Figure 1

Prevalence of additional ipsilateral events. Numbers inside bars denotes number of patients. PE = presenting event; RAO = retinal artery occlusion; Afx = amaurosis fugax; LAA = large artery atherosclerosis

Figure 2

Kaplan Meier analysis of the risk of recurrent ipsilateral stroke after the presenting event with patients divided by number of events within 7 days before and/or after the presenting event: Clinically stable (0 events), clinically unstable (1 event), and clinically highly unstable (≥2 events). CEA was used a censor.

Figure 3

Kaplan Meier analysis of the risk of recurrent ipsilateral stroke after the presenting event with patients divided by number of additional events within 7 days before the presenting event. CEA was used a censor.

Figure 4

Kaplan Meier analysis of the risk of recurrent ipsilateral stroke after the presenting event with patients divided by number of additional events within 7 days after the presenting event. CEA was used a censor.

Figure 5

Type of presenting event among the patients with recurrent ipsilateral ischemic stroke within 7 days divided between clinically stable, unstable and highly unstable. Numbers inside bars denotes number of patients.