Abstract 31: The ATTICUS Randomized Controlled Trial - Subgroup Analyses

Abstract

Background: ATTICUS is the third prospective randomized controlled trial that compared a direct oral anticoagulant (DOAC) vs. acetylsalicylic acid (ASA) for secondary prevention after embolic stroke of undetermined source (ESUS). Aim of ATTICUS was to determine whether apixaban, initiated within 28 days after ESUS, is superior to ASA in preventing new ischemic lesions on 12-month follow- up MRI (primary endpoint) in subjects with remote atrial fibrillation (AF) monitoring. Methods: Multicenter (14 German centers) open-label randomized (1:1) controlled trial with blinded endpoint assessment. ESUS patients with at least one risk factor for AF/cardiac thromboembolism (i.e., left atrium (LA) size > 45 mm, spontaneous echo contrast in LA appendage, LA appendage flow velocity ≤ 0.2 m/s, atrial high-rate episodes, CHA2DS2-VASc ≥ 4, patent foramen ovale (PFO)) were enrolled. Study drug was initiated 3 to 28 days after minor/moderate stroke and ≥ 14 to 28 days after major stroke. ClinicalTrials.gov: NCT02427126. Funding by Bristol Meyers Squibb-Pfizer Alliance (Euro 2.2 Mio.) and Medtronic. Results: 352 patients were available for final analysis. New ischemic lesion(s) were found in 13.6% vs. 16.0% of patients in the apixaban and the ASA arm, respectively (p=0.57), intention-to-treat. AF was detected in 25.6 % of patients. No difference between study arms was found for other thromboembolism, death, SAE, major and clinically relevant bleeds. Conclusions: ATTICUS was the first trial testing the concept of DOAC vs. ASA in an enriched ESUS population. Mandatory cardiac monitoring, vessel imaging, and MRI in all ATTICUS patients will help to better understand this complex condition. We will present secondary analyses including on-treatment analysis, prevention of embolic/disabling lesions/strokes, association of stroke pattern with AF occurrence/macroangiopathic changes.