Time to antithrombotic therapy after transient ischaemic attack and ischaemic stroke

Thanh G Phan, Benjamin Clissold and Henry Ma
Med J Aust 2022; 216 (10): . || doi: 10.5694/mja2.51532
Published online: 6 June 2022

Aspirin and other antithrombotics are proven to be effective in reducing ischaemic stroke recurrence

Reperfusion therapy (mechanical thrombectomy or thrombolytic therapy) is highly effective and improves outcomes for appropriately selected patients presenting with ischaemic stroke to a comprehensive stroke centre. Unfortunately, the majority of such patients are not eligible for reperfusion therapy; however, patients with ischaemic stroke benefit from other aspects of stroke unit care, and this includes early antiplatelet therapy such as aspirin.1,2 Even though the number needed to treat (NNT) with aspirin to prevent recurrent ischaemic stroke is high, the drug cost is low and most patients are eligible.3 A meta‐analysis of trials evaluating early use of aspirin after transient ischaemic attack (TIA) or ischaemic stroke showed that the effect of aspirin on recurrence was significant by the second day of starting aspirin (hazard ratio [HR], 0.44; 95% CI, 0.25–0.76; P < 0.0034), and the NNT to prevent stroke on day 2 was 637 (95% CI, 475–1488).4 Among patients given aspirin before randomisation, the effect was seen within 24 hours (HR, 0.31; 95% CI, 0.11–0.85; P = 0.020). The effect of aspirin was greatest for mild (odds ratio [OR], 0.51 [95% CI, 0.34–0.75]; NNT, 118 [95% CI, 88–233]), followed by moderate (OR, 0.65 [95% CI, 0.44–0.98]; NNT, 123 [95% CI, 82–2318]) and severe ischaemic stroke (OR, 1.10; 95% CI 0.77–1.58).4 The importance of early antiplatelet therapy was reaffirmed by subsequent trials that enrolled patients with high risk TIA and mild to moderate ischaemic stroke within 24 hours and used combinations of aspirin and clopidogrel5 or aspirin and ticagrelor.6 Used early, these combination strategies had a similar impact on stroke recurrence.

  • 1 Monash Health, Melbourne, VIC
  • 2 Stroke and Ageing Research Group, Monash University, Melbourne, VIC
  • 3 Monash University, Melbourne, VIC



We are grateful to Professor Claiborne Johnston for providing insight into the THALES trial and Professor Peter Rothwell for insight into the International Stroke Trial (IST) and the Chinese Acute Stroke Trial (CAST).

Competing interests:

No relevant disclosures.

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