Article Text

Download PDFPDF

Is clopidogrel better than aspirin following breakthrough strokes while on aspirin? A retrospective cohort study
  1. Meng Lee1,
  2. Yi-Ling Wu1,
  3. Jeffrey L Saver2,
  4. Hsuei-Chen Lee3,
  5. Jiann-Der Lee1,
  6. Ku-Chou Chang4,
  7. Chih-Ying Wu1,
  8. Tsong-Hai Lee5,
  9. Hui-Hsuan Wang6,
  10. Neal M Rao2,
  11. Bruce Ovbiagele7
  1. 1Department of Neurology, Chang Gung University College of Medicine, Chang Gung Memorial Hospital, Chiayi Branch, Puzi, Taiwan
  2. 2Department of Neurology, Stroke Center, Geffen School of Medicine, University of California, Los Angeles, California, USA
  3. 3Department of Physical Therapy and Assistive Technology, National Yang-Ming University, Taipei, Taiwan
  4. 4Department of Neurology, Chang Gung University College of Medicine, Chang Gung Memorial Hospital, Kaohsiung Branch, Kaohsiung, Taiwan
  5. 5Department of Neurology, Chang Gung University College of Medicine, Chang Gung Memorial Hospital, Linkou Branch, Taoyuan, Taiwan
  6. 6Department of Healthcare Management, Chang Gung University, Taoyuan, Taiwan
  7. 7Department of Neurosciences, Medical University of South Carolina, Charleston, South Carolina, USA
  1. Correspondence to Professor Bruce Ovbiagele; Ovibes{at}


Objective There is insufficient evidence on which to base a recommendation for optimal antiplatelet therapy following a stroke while on aspirin. The objective was to compare clopidogrel initiation vs aspirin reinitiation for vascular risk reduction among patients with ischaemic stroke on aspirin at the time of their index stroke.

Design Retrospective.

Setting We conducted a nationwide cohort study by retrieving all hospitalised patients (≥18 years) with a primary diagnosis of ischaemic stroke between 2003 and 2009 from Taiwan National Health Insurance Research Database.

Participants Among 3862 patients receiving aspirin before the index ischaemic stroke and receiving either aspirin or clopidogrel after index stroke during follow-up period, 1623 were excluded due to a medication possession ratio <80%. Also, 355 were excluded due to history of atrial fibrillation, valvular heart disease or coagulopathy. Therefore, 1884 patients were included in our final analysis.

Interventions Patients were categorised into two groups based on whether clopidogrel or aspirin was prescribed during the follow-up period. Follow-up was from time of the index stroke to admission for recurrent stroke or myocardial infarction, death or the end of 2010.

Primary and secondary outcome measures The primary end point was hospitalisation due to a new-onset major adverse cardiovascular event (MACE: composite of any stroke or myocardial infarction). The leading secondary end point was any recurrent stroke.

Results Compared to aspirin, clopidogrel was associated with a lower occurrence of future MACE (HR=0.54, 95% CI 0.43 to 0.68, p<0.001, number needed to treat: 8) and recurrent stroke (HR=0.54, 95% CI 0.42 to 0.69, p<0.001, number needed to treat: 9) after adjustment of relevant covariates.

Conclusions Among patients with an ischaemic stroke while taking aspirin, clopidogrel initiation was associated with fewer recurrent vascular events than aspirin reinitiation.


This is an Open Access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:

View Full Text

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.