Stroke recurrence patterns are predicted by the subtypes and mechanisms of the past, non-cardiogenic stroke

Background and purpose: The association between past stroke subtypes and recurrent stroke subtypes in non-cardiogenic stroke remains unknown. Methods: Patients with ischaemic stroke who had a past history of large-artery disease (LAD) or small-artery disease (SAD) subtypes were assessed. LAD was subdivided into intracranial atherosclerosis (ICAS) and extracranial atherosclerosis (ECAS). LAD stroke mechanisms were categorized as artery-to-artery embolism, in situ thrombotic occlusion and local branch occlusion, while SAD was subdivided into lacunar infarction (LI) and branch atheromatous disease (BAD) on the basis of magnetic resonance imaging findings. The relationship between past and current strokes was analyzed. Results: Among the 202 patients enrolled, the LAD group (n=111) had 64 and 47 patients with ICAS and ECAS, and the SAD group (n=91) had 63 and 28 patients with LI and BAD, respectively, at the time of past stroke. Patients with LAD developed LAD-associated strokes most often (n=99, 89.2%), and patients with SAD developed SAD most often (n=69, 75.8%; P<0.001). Patients with ICAS were more likely to develop ICAS later (n=46, 79.3%), whereas those with ECAS developed ECAS more often (n=31, 75.6%; P<0.001). Patients with ICAS presenting with artery-to-artery embolism more often developed artery-to-artery embolism later (n=26, 72.2%), whereas those with local branch occlusion developed recurrent local branch occlusion most often (n=10, 66.7%, P=0.005). In the SAD group, patients with BAD developed LAD more frequently than the LI group (n=11, 39.3% vs. n=9, 14.3%, P=0.022). Conclusions: The subtypes and mechanisms of recurrent stroke are significantly influenced by those of the past stroke.