Hemodynamic evaluation of symptomatic and asymptomatic intracranial atherosclerotic stenosis using cerebral angiographic images: an exploratory study

BACKGROUND: Previous studies suggest that it may be inappropriate to determine treatment strategies solely based on the degree of stenosis for patients with intracranial atherosclerotic stenosis (ICAS). In order to better risk stratify patients with ICAS, we developed a novel non-invasive fractional flow (FF) calculation technique based on intracranial angiography (Angio-FF) to assess the hemodynamics for patients with ICAS. This study aims to investigate the difference in FF between symptomatic and asymptomatic patients with ICAS and its potential optimal threshold. METHODS: A total of 124 patients with ICAS with severe intracranial stenosis who had undergone cerebral angiography were recruited. According to the time of onset, the patients were divided into a symptomatic ICAS group (n=78) and an asymptomatic ICAS group (n=46). The Angio-FF of each group was collected and compared. Receiver-operating characteristic curve (ROC) analysis was performed to assess the discriminative ability of Angio-FF to predict hemodynamics for ICAS. RESULTS: Compared with the asymptomatic ICAS group, the symptomatic ICAS group had a significantly lower Angio-FF (0.75 (0.66-0.85) vs 0.85 (0.77-0.89), P<0.001). The optimal cut-off value of Angio-FF for distinguishing symptomatic ICAS from asymptomatic ICAS was 0.785 (sensitivity 71.74%, specificity 57.69%). CONCLUSIONS: Patients with Angio-FF <0.7853 may be more prone to intracranial ischemic events. Angio-FF of 0.7853 can serve as a boundary for whether patients with ICAS exhibit clinical symptoms.