Abstract T P104: Early Mobilization After Thrombolysis (rt-PA) in Acute Stroke: Are rt-PA Treated Patients Enrolled in a Trial of Early Mobilization (AVERT) Different From Those That Are Not?

Abstract

Background: A key treatment for acute ischaemic stroke is thrombolysis with recombinant tissue plasminogen activator (rtPA). However, treatment is not devoid of side effects and patients are carefully selected. AVERT (A Very Early Rehabilitation Trial) tests whether starting out of bed activity within 24 hours of stroke onset improves outcome. This international multi-center trial is powered (n=2104) to provide reliable evidence about the efficacy of early mobility training after stroke. Patients treated with rtPA can be recruited if the physician allows. The aim of this study was to identify factors that might influence the inclusion of rtPA treated patients in AVERT. Methods: Data from all patients thrombolysed at Austin Health between September 2007 and December 2011 were retrospectively extracted from medical records. Factors of interest included: demographic and stroke characteristics, 24 hour clinical response to rtPA treatment, cerebral imaging and process factors (day and time of admission). Results: Over the study period, 211 patients received rtPA at Austin Health. Fifty (24%) were recruited to AVERT (rtPA-AVERT). Of the 161 patients not recruited, 105 (65%) were eligible according to the inclusion/exclusion criteria, and could potentially have been included (pot-AVERT). There were no significant differences in demographics, Oxfordshire classification or stroke severity (NIHSS) on admission between groups. Size and localization of stroke on imaging and symptomatic intracerebral heamorrhage rate did not differ. Patients included in AVERT showed less change in NIHSS 24 hours post rtPA (median change=1, IQR (-1,4)) than those in the pot-AVERT group (median change=3, IQR (0,6)) by the median difference of 2 points (95%CI:0.3;p=0.03). A higher proportion of rtPA-AVERT patients were admitted on weekdays (p=0.04). Conclusion: Excluding a possible clinical instability, no significant clinical differences were identified between thrombolysed patients included in AVERT and those who were not. The study is ongoing and over 370 patients treated with rtPA have been included to date. These results suggest that data from rtPA treated patients in AVERT may be generalizable to the broader stroke population.