Evidence for clopidogrel in prevention of stroke

With respect to the use of the clopidogel following an ischaemic stroke, NICE have suggested that (1):

• clopidogrel is indicated as first line long-term antiplatelet treatment following an ischaemic stroke

Evidence from the Clopidogrel versus Aspirin in Patients at Risk of Ischaemic Events (CAPRIE) trial showed (2):

• after about two years, the risk of reaching the combined primary endpoint of ischaemic stroke, MI or vascular death was slightly lower with clopidogrel than aspirin (5.32% vs. 5.83%) - thus nearly 200 people would have to be treated with clopidogrel instead of aspirin to prevent one event
• on subgroup analysis, a statistically significant difference was only found in patients with peripheral arterial disease and not those who hand previously had a stroke (3) - however the trial was not powered to assess this (2)

Comparison of clopidogrel versus aspirin plus dipyridamole:

• the ProFESS trial compared the efficacy of 25 mg aspirin (ASA) and 200 mg extended-release dipyridamole (ER-DP) twice a day versus 75 mg clopidogrel once a day in patients with ischaemic stroke, both regimes resulted in similar rates of recurrent stroke (4)

Reference:

1. NICE (December 2010).Clopidogrel and modified-release dipyridamole for the prevention of occlusive vascular events
2. A randomised, blinded, trial of clopidogrel versus aspirin in patients at risk of ischaemic events (CAPRIE). CAPRIE Steering Committee. Lancet. 1996 Nov 16;348(9038):1329-39.
3. MeReC Bulletin (2003), 14 (2), 5-8
4. Diener HC et al. Effects of aspirin plus extended-release dipyridamole versus clopidogrel and telmisartan on disability and cognitive function after recurrent stroke in patients with ischaemic stroke in the Prevention Regimen for Effectively Avoiding Second Strokes (PRoFESS) trial: a double-blind, active and placebo-controlled study. Lancet Neurol. 2008 Oct;7(10):875-84.