Symptomatic and asymptomatic intracranial atherosclerotic stenosis: 3 years' prospective study

Background Intracranial stenoses can cause TIA/ischaemic stroke. The purpose of this study was to assess vascular risk factors, clinical and imaging findings and outcome in Caucasians with intracranial stenosis under best prevention management. Methods In this prospective observational study (from 05/2012, to last follow-up 06/2017) we compared vascular risk factors, imaging findings and long-term outcome in Swiss patients with symptomatic versus asymptomatic intracranial atherosclerotic stenoses on best prevention management. Results 62 patients were included [35.5% women, median age 68.3 years], 33 (53.2%) with symptomatic intracranial stenoses. Vascular risk factors (p = 0.635) and frequency of anterior circulation stenoses (66.7% vs. 55.2%; p = 0.354) did not differ between symptomatic and asymptomatic patients, but CT/MR-perfusion deficits in the territory of the stenosis (81.8% vs. 51.7%; p = 0.011) were more common in symptomatic patients. Outcome in symptomatic and asymptomatic patients at last follow-up was similar (mRS 0-1:66.7% vs. 75%;(adj)p = 0.937, mRS (adj)p-shift = 0.354, survival:100% vs. 96.4%;(adj)p = 0.979). However, during 59,417 patient follow-up days, symptomatic patients experienced more cerebrovascular events (ischaemic stroke or TIA) [37.5% vs. 7.1%;adjHR 7.58;(adj)p = 0.012], mainly in the territory of the stenosis [31.3% vs. 3.6%;adjHR 12.69;(adj)p = 0.019], more vascular events (i.e. ischaemic stroke/TIA/TNA and acute coronary/peripheral vascular events) [62.5% vs. 14.3%;adjHR 6.37;(adj)p = 0.001]) and more multiple vascular events (p-trend = 0.006; >= 2:37.5% vs. 10.7%;(adj) OR 5.37;(adj)p = 0.022) than asymptomatic patients. Conclusions Despite best prevention management, one in three patients with a symptomatic intracranial stenosis suffered a cerebrovascular event, three in five a vascular event and two in five >= 2 vascular events. There is an unmet need for more rigorous and effective preventive strategies in patients with symptomatic intracranial stenoses.