Abstract P219: Constant Numbers but Change in Stroke Subtype of Patients with First-Ever Minor Stroke/TIA from 2002 to 2012 in London, Canada

Abstract

Introduction: In Canada, major stroke hospital admission decreased by 27.6% and stroke mortality decreased by 28.2% between 1994 and 2004. However, there are no regional data on rates of incident minor stroke/TIA. We hypothesized that there has been a decrease in minor stroke/TIA over time due to better management of cerebrovascular risk factors. Methods: We included patients who diagnosed with a minor stroke/TIA in the regional Urgent TIA Clinic in London, Ontario, Canada from 2002 to 2012. We used a valid and reliable classification system for subtypes of ischemic stroke (SPARKLE) to categorize patients into five etiological stroke subtypes. Secular trends of minor stroke/TIA and the five ischemic stroke subtypes, represented with Lattice Plots, were analyzed using Poisson regression analysis with spline trend function. Results: Between 2002 and 2012, we identified 3,445 eligible patients. There was no decrease in minor stroke/TIA during the study period (348 patients in 2002 versus 261 patients in 2012, p=0.65 for trend). However, there was a significant increase in cardioembolic stroke/TIA, with a corresponding decrease in all other ischemic stroke subtypes. Patients in 2012 were one year younger compared to patients in 2002 (p=0.04). Discussion: Stroke mortality and major stroke incidence have decreased over time, but numbers of patients who experience a first-ever minor stroke/TIA have remained constant. With more intensive medical therapy there may have been a shift from major to minor stroke occurrence, given that more recent patients are younger than patients presenting in previous years. Further investigation is required to identify prevailing stroke risk factors in this population to decrease the burden and incidence of stroke/TIA.