Abstract 17746: Use of Aspirin in the Prevention of Ischemic Stroke in Atrial Fibrillation Patients With a Low Cha2ds2-vasc Score
Background: Atrial fibrillation (AF) is one of the most common types of arrhythmia. The role of anti-coagulation therapy has not been established in AF patients with low CHA2DS2-VASc scores. The objective of this study was to evaluate the benefit and risk profile of anti-platelet agents in these low-risk patients.
Methods: A retrospective cohort study using the Taiwan National Health Insurance claims database was conducted to identify AF patients with a CHA2DS2-VASc score 0-1 between 2003 and 2012. Patients with previous ischemic stroke or myocardial infarction or using any kind of anti-coagulation therapy were excluded. The patients who ever received aspirin therapy and who never used any anti-platelet therapy were 1:1 matched by propensity score. A proportional hazards Cox regression model was applied to examine the association between aspirin use and the first stroke. Since the mortality events outnumbered the number of stroke during the follow-up period, a formal competing risk analysis, based on the methods for estimating cumulative incidence function, was performed.
Results: There were both 1305 patients in the aspirin group and control group. During a median of 4.25-year follow-up, 25 patients experienced ischemic stroke and 201 died in the former group while 34 patients had stroke and 363 died in the latter. The analysis showed that, after considering mortality as a competing risk, aspirin was not associated with the risk of ischemic stroke (HR, 0.78, 95% CI, 0.46-1.20, p = 0.33). Besides, the analysis on the safety profile showed that aspirin was not associated with an increased risk of major bleeding or all types, intracranial hemorrhage, or even gastrointestinal hemorrhage.
Conclusion: The results do not support the use of aspirin in the prevention of ischemic stroke in AF patients with low thromboembolic risk. Further studies will be needed to optimize the therapeutic options in this subset of patients.
(Funding: grant from National Taiwan University Hospital Yun-Lin Branch [NTUHYL104.A001])
Author Disclosures: J. Lin: None. C. Chang: None. J. Hsu: None. F. Chiu: None.
- © 2016 by American Heart Association, Inc.