Background: Although previous reports of carotid stenting with embolic protection (CAS) have focused on clinical outcomes of death, stroke and myocardial infarction, there are few data available characterizing the strokes that occur during CAS, thus limiting understanding of potential mechanisms. This report examines the timing, location, severity, and type of strokes occurring with CAS in the Carotid ACCULINK/ACCUNET Post Approval Trial to Uncover Unanticipated or Rare Events (CAPTURE) study.
Methods: The CAPTURE is a prospective, multicenter registry conducted to assess outcomes of CAS in the postapproval setting after device approval. A neurologist examined the patients before the procedure, at 24 hours and 30 days post-procedure. The primary end point was a composite of death, any stroke, or myocardial infarction within 30 days post-procedure. Strokes and all neurologic events suspected to be strokes were adjudicated by an independent Clinical Events Adjudication Committee using prespecified definitions. Source documents of all patients with strokes in this cohort were reviewed.
Results: The 30-day results were available for 3500 patients. The 30-day primary end point event rate of death, stroke, and myocardial infarction was 6.3% (95% confidence interval: 5.5%-7.1%), and the rate of major stroke and death was 2.9% (95% confidence interval: 2.4 to 3.5). 4.8% of patients experienced a stroke (3.9% ipsilateral and 0.9% nonipsilateral, 2% major). A majority of stroke symptoms (57.7%) were noted post-procedure and pre-discharge, whereas 22.3% were noted during the procedure and 20% postdischarge. A similar timing distribution regardless of preprocedural symptomatic status was found.Overall, 41% (69 of 170) of all strokes were major. The incidence of major strokes was statistically significantly greater among symptomatic compared with asymptomatic patients, 4.6% (22 of 482) and 1.6% (47 of 3018), respectively. There were more minor than major strokes in asymptomatic patients (63% vs. 37%; P=0.10), whereas stroke severity was equally distributed in symptomatic patients. Among the ipsilateral strokes, almost half (44%) were major, whereas only one-quarter (26%) of the nonipsilateral strokes were major.Overall, 23% of the major strokes were hemorrhagic and 94% of these strokes were noted on the ipsilateral side. There was a tendency toward more major hemorrhagic strokes in symptomatic than in asymptomatic patients (36% vs. 17%; P=0.07). Fifty-four percent of the strokes post-procedure and pre-discharge were major, whereas 27% of the strokes postdischarge were major. Furthermore, 65% of hemorrhagic strokes were noted post-procedure and pre-discharge, 30% postdischarge.
Conclusions: Strokes related to CAS seem to become clinically apparent after the procedure but before discharge in the majority of events. Nevertheless, a significant minority of stroke symptoms follows discharge from the hospital, typically after 24 hours. Timing of stroke after CAS seems to be similar to timing of stroke after carotid endarterectomy. Moreover, nearly 1 in 5 strokes occur in a nonipsilateral distribution, with the exception of intraprocedural events, which were all ipsilateral to the stent being implanted. Hemorrhagic stroke seemed to be more prevalent in the strokes occurring in the post-procedure period. These descriptors of stroke severity, location, and timing may provide insight in to the mechanistic causes of adverse neurologic outcomes in CAS.