Risk of ischemic stroke recurrence in patients with atrial fibrillation diagnosed after stroke

Objective: We compared the risk of 1-year ischemic stroke recurrence between atrial fibrillation (AF) diagnosed after stroke (AFDAS) and sinus rhythm (SR), and we investigated whether underlying heart disease is as frequent in AFDAS as it is in AF known before stroke (KAF). Background: Ischemic stroke patients fall into 3 possible categories of heart rhythm: sinus rhythm: no history of atrial fibrillation (AF) and no arrhythmia identified after cardiac monitoring, AF known prior to the index stroke (KAF), or AF newly-diagnosed after stroke (AFDAS). AFDAS’ outcomes have been rarely investigated and its pathophysiology remains unknown. Design/Methods: In this retrospective cohort study, we included all ischemic stroke patients admitted to institutions participating in the Ontario Stroke Registry from July 1 st , 2003 to March 31 st , 2013. Based on heart rhythm assessed during admission, we classified patients as: AFDAS, KAF, or SR. We modelled the relationship between heart rhythm groups and 1-year ischemic stroke recurrence by using Cox regression adjusted for multiple covariates (eg, oral anticoagulants). We compared the prevalence of coronary artery disease, myocardial infarction, and heart failure, among the 3 groups. Results: Among 23376 ischemic stroke patients, 15885 had SR, 587 AFDAS, and 6904 KAF. At 1 year, 39 (7.0%) patients with AFDAS, 661 (9.6%) with KAF, and 1269 (8.0%) with SR had recurrent ischemic strokes (p Conclusions: The lack of difference in 1-year ischemic stroke recurrence between AFDAS and SR and the lower prevalence of heart disease in AFDAS compared to KAF suggest that the underlying pathophysiology of AFDAS may differ from that of KAF. Study Supported by: Edward and Alma Saraydar Neurosciences Fund (London Health Sciences Foundation, London, Ontario, Canada), Kathleen u0026 Dr Henry Barnett Research Chair in Stroke Research (Western University, London, Ontario, Canada), and Opportunities Fund of the Academic Health Sciences Centre Alternative Funding Plan of the Academic Medical Organization of Southwestern Ontario -AMOSO- (Ontario, Canada). This study was supported by the Institute for Clinical Evaluative Sciences, which is funded by an annual grant from the Ontario Ministry of Health and Long-Term Care. The opinions, results and conclusions reported in this paper are those of the authors and are independent from the funding sources. No endorsement by Institute for Clinical Evaluative Sciences or the Ontario Ministry of Health and Long-Term Care is intended or should be inferred. Parts of this material are based on data and/or information compiled and provided by the Canadian Institute for Health Information. However, the analyses, conclusions, opinions and statements expressed in the material are those of the author(s), and not necessarily those of the Canadian Institute for Health Information. Disclosure: Dr. Sposato has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Pfizer. Boehringer Ingelheim. Dr. Sposato has received research support from Boehringer Ingelhiem. Dr. Cerasuolo has nothing to disclose. Dr. Cipriano has nothing to disclose. Dr. Fang has nothing to disclose. Dr. Fridman has nothing to disclose. Dr. Paquet has nothing to disclose. Dr. Saposnik has nothing to disclose.