Comment Author: Antje Schmidt, Department of Neurology, University of Munster, Germany
Original Article: WardatiMazlan-Kepli et al. 2016. “Antiplatelet therapy following ischaemic stroke – Continue or change pre-existing therapy?” European Stroke Journal. Vol 2, Issue 1, pp. 31 – 36.
Antiplatelet therapy is broadly used for primary and secondary prevention of vascular disease. Accordingly, a meaningful proportion of stroke patients in our emergency rooms have a pre-existing antiplatelet therapy upon admission, most frequently aspirin. In noncardioembolic ischaemic stroke, the guideline-recommended secondary prevention for these patients would involve antiplatelet therapy (usually aspirin). But, does it feel right to prescribe aspirin for secondary stroke prevention to a patient, who had been on aspirin, when the first stroke occurred? Many practitioners disagree and switch the treatment regimen, based on their experiences and preferences, to clopidogrel, dipyridamole, dipyridamole plus aspirin, or clopidogrel plus aspirin. Are their patients better off? Does a change of the pre-existing antiplatelet therapy reduce the stroke recurrence rate? This issue was addressed in a recent analysis of the Virtual International Stroke Trial Archive (VISTA) database, which included 1129 stroke patients with pre-existing antiplatelet therapy. About half of these patients changed the antiplatelet therapy, whereas the other half continued the pre-existing treatment regimen. The results of the VISTA database analysis showed that the stroke recurrence rate was not altered by a change in antiplatelet regimen during the first 90 days (4.1% vs. 4.3%). Similarly, the incidences of intracranial and extracranial haemorrhages (2.4% vs. 2.6% and 4.7% vs. 2.9%) were not affected.
In contrast to these findings, another retrospective analysis, which included 1884 patients receiving aspirin before the index ischaemic stroke, reported significantly fewer vascular events after clopidogrel initiation compared to aspirin continuation.1 Further, the prospective, randomized and double-blind CHANCE trial showed that the combination of clopidogrel and aspirin was superior to aspirin for stroke reduction among patients with transient ischaemic attack and minor stroke.2
Conflictive neutral findings of the recent VISTA database analysis might be partly explained by the approach of dividing patients just into the two groups ‘change’ or ‘continue’, and not according to specific antiplatelet drugs. Moreover, the follow-up period of 90 days was relatively short, and the stroke recurrence rate was low in both groups. Finally, the VISTA collaborators report as a limitation that their analysis lacks statistical power to definitely exclude a difference between treatment groups. However, considering the number of patients and the results a huge difference between continuing or changing the antiplatelet seems unlikely.
Altogether, the question, whether a pre-existing antiplatelet therapy should be continued or changed, is still not conclusively answered. Anyway, we should not forget that in addition to the best antiplatelet therapy, when assessing a patient with stroke we should review many other factors that can affect the risk of recurrent events, such as compliance and the proper control of vascular risk factors, diet or exercise. The original article “Antiplatelet therapy following ischaemic stroke – continue or change pre-existing therapy?” is published in the current issue of the European Stroke Journal.
- Lee M, Wu Y-L, Saver JL, Lee H-C, Lee J-D, Chang K-C, Wu C-Y, Lee T-H, Wang H-H, Rao NM, Ovbiagele B. Is clopidogrel better than aspirin following breakthrough strokes while on aspirin? A retrospective cohort study. BMJ Open. 2014;4:e006672.
- Wang Y, Wang Y, Zhao X, Liu L, Wang D, Wang C, Wang C, Li H, Meng X, Cui L, Jia J, Dong Q, Xu A, Zeng J, Li Y, Wang Z, Xia H, Johnston SC, CHANCE Investigators. Clopidogrel with aspirin in acute minor stroke or transient ischemic attack. N. Engl. J. Med. 2013;369:11–19.