Epidemiology of ischemic stroke subtypes according to TOAST criteria - Incidence, recurrence, and long-term survival in ischemic stroke subtypes: A population-based study

Background and Purpose-The purpose of this study was to determine the incid ence, recurrence, and long-term survival rates of ischemic stroke subtypes by a mechanism-based classification scheme (Trial of ORG 10172 in Acute Str oke Treatment, or TOAST). Methods-We identified all 583 residents of the city of Erlangen, Bavaria, G ermany, with a first ischemic stroke between 1994 and 1998. Multiple overla pping sources of information were used to ensure completeness of case ascer tainment. The cause of ischemic stroke was classified according to the TOAS T criteria. Patients were followed up at 3 months and 1 and 2 years after s troke onset. Results-The age-standardized incidence rates for the European population (p er 100 000) regarding ischemic stroke subtypes were as follows: cardioembol ism, 30.2 (95% CI 25.6 to 35.7); small-artery occlusion, 25.8 (95% CI 21.5 to 30.9): and large-artery atherosclerosis, 15.3 (95% CI 12 to 19.3). When age-adjusted to the European population, the incidence rate for large-arter y atherosclerosis was more than twice as high for men than for women (23.6/ 100 000 versus 9.2/100 000). Two years after onset, patients in the small-a rtery occlusion subgroup were 3 times more likely to be alive than those wi th cardioembolism. Ischemic stroke subtype according to the TOAST criteria was a significant predictor for long-term survival, whereas subtype was not a significant predictor of long-term recurrence up to 2 years, both before and after adjustment for age and sex. Conclusions-Epidemiological observational studies that possess wide access to appropriate diagnostic technologies and apply standardized etiologic cla ssifications provide a much better understanding of underlying risk factors for initial stroke, recurrence, and mortality.