Risk factors associated with major cerebrovascular complications after intracranial stenting

BACKGROUND:: There are limited data on the relationship between patient and site characteristics and clinical outcomes after intracranial stenting. METHODS:: We performed a multivariable analysis that correlated patient and site characteristics with the occurrence of the primary endpoint (any stroke or death within 30 days of stenting or stroke in the territory of the stented artery beyond 30 days) in 160 patients enrolled in this stenting registry. All patients presented with an ischemic stroke, TIA, or other cerebral ischemic event (e.g., vertebrobasilar insufficiency) in the territory of a suspected 50-99% stenosis of a major intracranial artery while on antithrombotic therapy. RESULTS:: Cerebral angiography confirmed that 99% (158/160) of patients had a 50-99% stenosis. In multivariable analysis, the primary endpoint was associated with posterior circulation stenosis (vs anterior circulation) (hazard ratio [HR] 3.4, 95% confidence interval [CI] 1.2-9.3, p ≤ 0.018), stenting at low enrollment sites (<10 patients each) (vs high enrollment site) (HR 2.8, 95% CI 1.1-7.6, p ≤ 0.038), <10 days from qualifying event to stenting (vs ≥10 days) (HR 2.7, 95% CI 1.0-7.8, p ≤ 0.058), and stroke as a qualifying event (vs TIA/other) (HR 3.2, 95% CI 0.9-11.2, p ≤ 0.064). There was no significant difference in the primary endpoint based on age, gender, race, or percent stenosis (50-69% vs 70-99%). CONCLUSIONS:: Major cerebrovascular complications after intracranial stenting may be associated with posterior circulation stenosis, low volume sites, stenting soon after a qualifying event, and stroke as the qualifying event. These factors will need to be monitored in future trials of intracranial stenting.