Patterns and predictors of early risk of recurrence after transient ischemic attack with respect to etiologic subtypes

Background and Purpose-The risk of recurrent stroke is highest within the first few weeks after a transient ischemic attack (TIA), and it is likely to be related to the underlying pathology. We sought to study the early risk of recurrent stroke by etiologic subtype. Methods-We prospectively studied 388 TIA patients. The cause of TIA was classified according to the Trial of ORG 10172 criteria: large-artery atherosclerosis (LAA, n=90), cardioembolism (n=87), small-vessel disease (n=68), undetermined (n=127), and other determined cause (n=16). Patients were followed up at 3 months. Risk factors and clinical symptoms for each subtype were recorded. Results-The duration of symptoms and clinical symptoms varied significantly among the different subtypes. LAA was associated with recurrent short episodes of weakness, whereas speech impairment and cortical symptoms were associated with cardioembolism (P < 0.05). The association of vascular risk factors was highest in LAA (P < 0.05). New strokes were recorded in 35 (9%) patients. Recurrent stroke risk varied among subtypes (P < 0.001): LAA, 20.0%; cardioembolism, 11.5%; undetermined, 4.7%; small-vessel disease, 1.5%; and other cause, 0%. Cox proportional-hazards multivariate analyses did not identify any independent predictor of further cerebral ischemic events for LAA, cardioembolism, undetermined, or small-vessel disease. Conclusions-The risk of early recurrent stroke is highest in patients with LAA. This supports the need for urgent carotid and transcranial imaging for identifying those patients at highest risk. Some risk factors and clinical symptoms are related to some etiologic subtypes, but stronger predictors of stroke recurrence are needed to identify those patients with highest risk for each TIA subtype.