Abstract T MP107: Ischemic Strokes While on Aspirin: Initiation of Clopidogrel Is Better than Re-initiation of Aspirin for Prevention of Future Vascular Events
Background: It is currently unclear about what to do for the patient who has a breakthrough ischemic stroke while receiving aspirin, the so-called ‘aspirin treatment failure’.
Objective: To compare the effectiveness of clopidogrel vs. aspirin for vascular risk reduction among ischemic stroke patients who were on aspirin treatment at the time of the index stroke.
Methods: We analyzed the Taiwan National Health Insurance registry which comprises beneficiaries aged ≥ 18 years. Code ICD-9 was used to identify a primary hospitalization diagnosis of ischemic stroke among subjects encountered between 2003 and 2009, and continuously treated with aspirin ≥ 30 days before the index stroke. Follow-up was from time of the index stroke to admission for recurrent stroke or myocardial infarction; withdrawal from the registry; and last medical claim before 1/1/2011. Patients were categorized into 2 groups based on whether clopidogrel or aspirin was prescribed during follow-up period. Patients were excluded if their Medication Possession Ratio was < 80% or they not taking clopidogrel or aspirin within 30 days before an endpoint. Primary endpoints were a major adverse cardiovascular event (MACE: composite of stroke and myocardial infarction) and a recurrent stroke alone. Multivariate-adjusted hazard ratio (HR) and 95% CI for the development of events were estimated using Cox models.
Results: Among 2281 eligible patients, mean age was 72 years, 41% were female, and mean follow-up duration was 2.2 years. Compared to aspirin, clopidogrel was associated with a significantly lower occurrence of MACE (adjusted HR 0.67, 95% CI 0.55 to 0.81) and recurrent stroke (adjusted HR 0.67, 0.54 to 0.82). The pattern of benefit for clopidogrel users was consistent across several endpoints (Table).
Conclusion: Among ischemic stroke patients with so called ‘aspirin treatment failure’, clopidogrel may a better choice than aspirin for future vascular risk reduction.
Author Disclosures: M. Lee: None. Y. Wu: None. J.L. Saver: None. H. Lee: None. J. Lee: None. K. Chang: None. C. Wu: None. T. Lee: None. H. Wang: None. B. Ovbiagele: None.
- © 2014 by American Heart Association, Inc.