Secondary prevention by stroke subtype: a nationwide follow-up study in 46 108 patients after acute ischaemic stroke

Abstract

Although use of antithrombotic agents is recommended after ischaemic stroke or transient ischaemic attack (TIA), long-term outcome of secondary prevention between stroke subtypes has not yet been explored. We used data from the Korean Stroke Registry (KSR), a nationwide, multicentre, prospective registry for acute stroke patients. Patients with acute ischaemic stroke or TIA within 7 days of onset were consecutively enrolled between January 2002 and September 2010. A total of 46 108 patients with ischaemic stroke and TIA were included in this study. Among the major stroke subtypes, stroke due to small vessel occlusion (SVO) showed the lowest mortality, whereas cardioembolic stroke (CE) was associated with the fatal prognosis during the follow-up [for SVO: hazard ratio (HR) 0.66, 95% CI 0.62-0.71; for CE: HR 1.41, 95% CI 1.30-1.53; large artery atherosclerosis (LAA) group as a reference]. Regarding secondary prevention, antiplatelet polytherapy was better than monotherapy in the patients with LAA-related stroke in prognosis [HR 0.89, 95% CI 0.80-0.98]. Anticoagulant therapy was associated with better outcome than antiplatelet monotherapy in CE-related stroke [HR 0.66, 95% CI 0.59-0.74]. In SVO-related stroke group, antiplatelet polytherapy failed to show benefits over monotherapy. Additionally, the risk of death was higher with anticoagulant therapy in the patients with SVO-related stroke [HR 1.44, CI 95% 1.06-1.97]. Our study demonstrated that stroke subtype affects prognosis and also determines the effectiveness of secondary prevention.