Eliquis Acute Stroke Safety Evaluation

Study Hypothesis: Investigators hypothesize that early initiation of apixaban within the first 14 days of stroke or TIA is not associated with increased symptomatic intracranial haemorrhage. Study Design: EASSE is an investigator-initiated prospective, open label, single arm phase IV study. Consecutive patients with AF (new onset or previous history) with acute ischemic stroke or TIA will be screened from Emergency Department or stroke unit. A total of 100 patients will be recruited within 24 hours of initiation of apixaban after TIA or stroke. All study participants will be followed for 90 days after apixaban initiation. A National Institute of Health Stroke Scale (NIHSS) score, modified Rankin Scale (mRS), and Montreal Cognitive Assessment (MoCA) will be collected at baseline, 7, and 90 days after enrolment. All patients will have a non-contrast CT scan at baseline (within 24 hours from study recruitment) and at 7±2 days after enrolment. In the event of clinical deterioration, a repeat CT scan will be performed immediately. Administrative Structure: Case report forms and data monitoring will be completed on site. All imaging data will be read centrally at the Stroke Imaging Laboratory at the University of Alberta. Procedures: Apixaban therapy: The apixaban dose will be determined by the treating physician, based on age, weight and renal function as per the product monograph. Patients with two of the following: Age \> 80, weight \< 60 kg, and creatinine ≥ 133 (1.5 mg/dl), will have received 2.5 mg twice a day. All other patients will have received 5 mg twice a day. Imaging Procedures and Analysis: Anonymized dicom CT data will be analyzed centrally. Baseline infarct volumes will be measured using planimetric techniques and recurrent infarctions will be identified. Any HT seen at baseline and day 7 will be graded using European Cooperative Acute Stroke Study (ECASS) criteria. Endpoints: The primary endpoint is the symptomatic HT, defined as PH2 associated with a ≥4-point increase in NIHSS score within 90 days of initiating apixaban therapy. Secondary outcomes include any HT at day 7, systemic hemorrhagic complications, and recurrent ischemic events within 90 days of enrolment. Investigators will report serious adverse events (SAE) within the study period using standardized event, resolution and association codes, and they will be reported to the local Human Research Ethics Board. Sample Size: A sample of 100 patients is planned in order to obtain estimates of the frequency of symptomatic and asymptomatic HT associated with early apixaban initiation. The maximum acceptable rate of symptomatic HT is considered 2%, based on a meta-analysis of low molecular weight heparin treatment in acute stroke, indicating the absolute symptomatic HT rate ranged from 2.4% to 2.9%.