Background
Recent evidence suggested an association between artery-to-artery embolism (AAE) and CBZ infarcts in patients with symptomatic intracranial atherosclerotic stenosis (sICAS).
Methods
In this cohort study, we recruited patients with 50-99% anterior-circulation sICAS. Stroke mechanisms were categorized as parent artery atherosclerosis occluding penetrating artery (PAO), AAE, hypoperfusion, and mixed mechanisms, using two classification systems. In Classification I, the probable stroke mechanisms of IBZ and CBZ infarcts were both hypoperfusion, which were respectively hypoperfusion and AAE in Classification II. Other classification criteria were the same in the two systems. We compared the predictive values of the two systems in predicting recurrent ischemic stroke in the same territory (SIT) within 90 days and 1 year.
Results
Among 145 patients, 101 (69.7%) were males. The numbers of patients with PAO, AAE, hypoperfusion and mixed mechanisms were respectively 28 (19.3%), 18 (12.4%), 52 (35.9%), and 47 (32.4%) in Classification I, and respectively 28 (19.3%), 43 (29.7%), 30 (20.8%), and 44 (30.3%) in Classification II. Overall, 11 (7.6%) and 19 (13.1%) patients respectively had 90-day or 1-year recurrent SIT. Compared with Classification I, Classification II better predicted the risk of 90-day recurrent SIT, when patients were divided into 4 groups according to baseline stroke mechanisms (p=0.029), or by the presence of hypoperfusion (p<0.001). The two classification systems had comparable predictive values for 1-year recurrent SIT.
Conclusions
In sICAS patients, considering AAE rather than hypoperfusion as the stroke mechanism for CBZ infarcts had higher predictive value for early recurrent SITs under current medical treatment regimen.