Abstract TMP104: Timing of Recurrence After Ischemic Stroke by Subtype: A Population-Based Study

Abstract

Introduction: Prior work suggests stroke recurrence timing may vary by subtype, with large vessel disease being associated with earlier recurrence; however, these studies were conducted prior to the current era of secondary stroke prevention strategies. We examined whether the timing of recurrence after ischemic stroke varied by subtype in a large population-based study. Methods: In 2015, we identified all acute ischemic stroke events from hospitals in the Greater Cincinnati and Northern Kentucky area. Events in the last 6 months of 2014 were oversampled for black patients. Trained nurses extracted clinical data, and stroke specialists subtyped and adjudicated cases. We tracked events for 3 years, considering only ischemic strokes after day 14 as a recurrence. To assess recurrence timing variations, we stratified strokes by subtype and analyzed their restricted mean survival times (RMST) at 1, 3, 12, 24, and 36 months. RMST is the area under the survival curve up to a specific follow up point, denoting the average event-free time during that interval. Results: Of 2577 patients with index stroke, 332 recurrent strokes were seen over the ensuing 3 years. Half of the recurrences occurred within 8 months from the index event. At 12 months, large vessel (LV), undetermined, and other identified cause showed a statistically significant smaller RMST compared to small vessel (SV). This difference was nonsignificant at later time points, suggesting later recurrence for SV. There were no statistically significant differences in RMST between cardioembolic, LV, undetermined, and other identified at any time point. Conclusions: Recurrence after initial SV stroke was less likely to occur in the first year when compared to LV, undetermined etiology, or other identified causes of stroke. There was no evidence of difference in recurrence timing between cardioembolic, LV, other identified, and undetermined etiology.