Abstract W P65: Determinants of Favourable Response to Thrombolysis in Wake-Up Ischaemic Stroke

Abstract

Background and Purpose: Wake up Ischaemic Stroke (WUIS) patients may have the potential to benefit from thrombolysis. As the duration between stroke onset and treatment, the main determinant of response to thrombolysis, is unknown in these patients, a major consideration is to identify other clinical markers predictive of a favourable response. Methods: Subjects were selected by consecutive sampling of a prospective register a tertiary stroke centre between January 2009 and December 2010. The inclusion criteria were last seen normal <12 hours but >4.5 hours from symptom onset and met thrombolysis criteria apart from time. Data on baseline clinical characteristics, imaging and treatment were extracted from the register. Mortality and modified Rankin Scale (mRS) were assessed at 90 days. Symptomatic intracerebral haemorrhage (sICH) was assessed at 24 hours. Logistic regression was undertaken to identify independent determinants of these outcomes, and those significant at p<0.1 were stratified and assessed using Peto’s fixed odds ratio for thrombolysis versus no thrombolysis. Results: Of the 122 WUIS patients fulfilling inclusion criteria 68 were thrombolysed and 54 (44%) were not thrombolysed. There were no differences in the baseline characteristics between the two groups. Logistic regression showed an independent relationship of age and NIHSS score with 90 day mortality and mRS 0-2 (p<0.01 for all) and with stroke subtype (p<0.1). There were no independent predictors of sICH. Thrombolysis had the best outcomes in WUIS patients aged 80-89 years with cardio-embolic stroke and NIHSS scores of 10-19 (Fig 1). Conclusions: Older WUIS patients and those with embolic stroke appear to benefit most from thrombolysis.