Early Recovery and Functional Outcome are Related with Causal Stroke Subtype: Data from the Tinzaparin in Acute Ischemic Stroke Trial

Introduction: Baseline severity and causal subtype are predictors of outcome in ischemic stroke. We used data from the Tinzaparin in Acute Ischemic Stroke Trial (TAIST) to further assess the relationship among stroke subtype, early recovery, and outcome. Methods: Patients with ischemic stroke (<48 hours ictus) and enrolled into TAIST were included. Severity was measured prospectively as the Scandinavian Neurological Stroke Scale (SNSS) at days 0, 4, 7, and 10. Causal subtype as large artery atherosclerosis (LAA), cardioembolism (CE), or small vessel occlusion (SVO) was assigned after standard investigations. The rate of recovery was calculated as the change in SNSS at each time point. Functional outcome was assessed using the modified Rankin Scale (mRS) and Barthel Index at day 90. Results: Analyses were performed on the 1190 patients in TAIST who met criteria for LAA, CE, and SVO. The largest change in SNSS score occurred between baseline and day 4 and was greatest in SVO (median improvement 4 U), compared with LAA (median improvement 2 U) and CE (median improvement 2 U) (P < .0001). If no improvement in SNSS had occurred by day 4, irrespective of subgroup, then early recovery (median SNSS improvement by day 10: 2) and functional outcome (mRS 4) tended to be limited; patients who recovered early tended to continue to improve (median SNSS improvement by day 10: 11) and had a better outcome at day 90 (median, mRS 2). Conclusions: Recovery is related to causal subtype. In all subtypes most recovery occurred by day 4, and was predictive of longer-term functional outcome.

Key Words: Acute stroke, ischemic stroke, recovery, functional outcome