Abstract WP110: Infarct Topography On MRI In Patients With Acute Ischemic Stroke And Atrial Fibrillation: Subgroup Analysis From PER DIEM Trial

Background: Atrial fibrillation (AF) is a common cause of ischemic stroke; however, it is often difficult to detect. It is unclear whether specific infarct topography on magnetic resonance imaging (MRI) is associated with underlying AF. We aimed to objectively assess the infarct patterns on MRI in patients with acute ischemic stroke and determine imaging characteristics that are associated with AF. Methods: We conducted a subgroup analysis on patients randomized in Post-Embolic Rhythm Detection with Implantable vs External Monitoring trial (PER DIEM; NCT02428140) who had brain MRI. Two raters blinded to clinical details reviewed the MRI findings. Patients were divided to two groups (AF and non-AF) and descriptive statistics were used to characterize findings. Variables associated with new AF were analyzed using logistic regression and reported as odds ratios (OR) with 95% confidence interval (CI) and p -values. Results: Of the 300 patients who were randomized in the trial, 249 (83%) patients (59.4% male) with a mean age of 64.3 ± 13.1 years had MRI brain and were included in the analysis. Median (IQR) NIHSS was 0 (0 - 1), number of lesions was 2 (1 - 3), and diameter of lesion (mm) was 10.4 (5.8 - 21.1) mm. In this cohort of patients, imaging characteristics were not significantly associated with the detection of AF. Conclusions: Association between infarct topography and AF detection was not found in this study. Imaging characteristics cannot be relied upon to predict or exclude an underlying AF. Large prospective studies are suggested to examine the link between infarct topography and underlying AF.