Intracranial versus Extracranial Symptomatic Carotid Atherosclerosis in Chinese Patients: Risk Factors, Stroke Mechanisms, and Long-Term Prognosis

Abstract

Objectives: This study aims to investigate the clinical-radiological features and stroke mechanisms of symptomatic intracranial internal carotid artery (IICA) atherosclerosis and prognoses of patients with IICA atherosclosis, and compare these data with those from patients with symptomatic extranial carotid artery (EICA) atherosclerosis.

Methods: We prospectively recruited 155 patients with symptomatic IICA or EICA atherosclerosis (stenosis ≥50% or occlusion) from 1968 Chinese patients with a first-ever ischemic stroke or transient ischemic attack. The patients were followed up for stroke recurrence, cardiovascular events, and death.

Results: There were 80 and 75 patients in the IICA and EICA groups, respectively. Multivariate logistic regression analyses showed that the patients in the IICA group were associated with hypertension (odds ratio [OR], 5.980; 95% confidence interval [CI], 1.790-19.976) and asymptomatic intracranial atherosclerosis (OR, 2.564; 95% CI, 1.222-5.377), while the patients in the EICA group were associated with smoking (OR, 2.397; 95% CI, 1.150-4.998) and contralateral EICA disease (OR, 4.742; 95% CI, 1.455-15.455). Hemodynamic stroke alone was more common in the IICA group; artery-to-artery embolism was identified more often in the EICA group (P <.05). The cumulative incidences of ipsilateral stroke recurrence, stroke recurrence and cardiovascular events, and death at 5 years were 43.5%, 52.4%, and 27.3%, respectively, in the patients of the IICA group, which did not differ from those of the EICA group.

Conclusions: IICA atherosclerosis as well as EICA atherosclerosis is an important cause of stroke in Chinese patients. Patients with symptomatic IICA atherosclerosis had unique clinical-radiological features and stroke mechanisms compared with those with symptomatic EICA atherosclerosis; their long-term prognosis was poor.

Keywords: Internal carotid artery; atherosclerosis; prognosis; risk factor; stroke mechanisms; stroke recurrence.