Abstract W P189: Cryptogenic Strokes and Second Ischemic Stroke Rates in Relation to the CHADS2 and CHA2DS2-VASc Risk Scores
Objective: A significant proportion of cryptogenic strokes may be due to undetected atrial fibrillation (AF) and this may be associated with an increased risk of stroke recurrence. Our goal was to determine the rate of AF detection and recurrent strokes in a large cohort of US patients with a probable diagnosis of cryptogenic stroke.
Methods: Patients with a first diagnosis of stroke or TIA between 01/2008 and 12/2011 were extracted from the Truven Health MarketScan® Commercial and Medicare Supplemental Databases. Patients were included if they had data available ±12 mo. around the index event. The stroke/TIA events, including “probable cryptogenic” status, along with CHADS2 and CHA2DS2-VASc risk scores, were derived from diagnosis codes, procedure codes, and prescription drug usage. The 12-mo. incidence of new AF diagnoses, new oral anticoagulation (OAC) prescriptions, and recurrent stroke, stratified by risk scores, were determined in patients with cryptogenic stroke and non-cryptogenic stroke.
Results: A total of 174,318 stroke/TIA patients were included, of whom 120,246 were likely to have cryptogenic diagnoses (age 64.5±15.6 years, 55.9% female). Due to the definition of cryptogenic stroke utilized, none of the patients had a diagnosis of AF or a prescription for OAC within the 12 months prior to their index stroke. Within 12 months after their index stroke, 4.1% had a new AF diagnosis and 4.4% had a new OAC prescription. The rate of recurrent stroke in the year after the index stroke was 31.7% (range: 27.4% to 36.2% and 27.7% to 38.5% with increasing CHADS2 and CHA2DS2-VASc scores, respectively). Of the recurrent strokes, 86.5% occurred less than 6 months after the index event.
Conclusion: One-third of all surviving cryptogenic stroke patients experienced second strokes in the year following their first stroke. Given the low rate of newly diagnosed AF, this suggests that undiagnosed AF may be an important contributor to the high recurrent stroke rate. Further study is required to determine if more rigorous post-stroke arrhythmia monitoring can lead to increased AF detection and OAC utilization, thus resulting in a reduction in recurrent stroke.
Author Disclosures: T.D. Hunter: Consultant/Advisory Board; Significant; Medtronic, Inc. G.Y.H. Lip: Speakers' Bureau; Significant; Bayer, BMS/Pfizer, Boehringer Ingelheim, Daiichi-Sankyo, Medtronic, Sanofi Aventis. Consultant/Advisory Board; Significant; Bayer, Astellas, Merck, Sanofi, BMS/Pfizer, Daiichi-Sankyo, Biotronik, Medtronic, Portola, Boehringer Ingelheim. M.E. Quiroz: Employment; Significant; Medtronic, Inc. S.A. Mollenkopf: Employment; Significant; Medtronic, Inc. M.P. Turakhia: Honoraria; Modest; St. Jude Medical, Boston Scientific. Consultant/Advisory Board; Modest; Medtronic, St. Jude Medical.
- © 2015 by American Heart Association, Inc.