Is clopidogrel better than aspirin following breakthrough strokes while on aspirin? A retrospective cohort study

Abstract

ObjectiveThere 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.DesignRetrospective.SettingWe 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.ParticipantsAmong 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.InterventionsPatients 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 measuresThe 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.ResultsCompared 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.ConclusionsAmong patients with an ischaemic stroke while taking aspirin, clopidogrel initiation was associated with fewer recurrent vascular events than aspirin reinitiation.

Trends in Incident and Recurrent Rates of First-Ever Ischemic Stroke in Taiwan between 2000 and 2011

“…6 The burden of stroke is greater in Asian countries than in the Western world, including a substantially higher incidence of stroke than myocardial infarction. [7][8][9] However, data on the extent to which several Asia countries have recently fared with regard to improvement in stroke outcomes are relatively sparse. One study suggested the incidence of stroke decreased from 1961 to 2000 in Japan 7 and an overview study revealed that recurrent stroke decreased in each decade from 1960 to 2010.…”

Different Antiplatelet Strategies in Patients With New Ischemic Stroke While Taking Aspirin

“…A recent retrospective cohort study based on a nationwide insurance claim database also reported that in the event of ischemic stroke while on aspirin, switching to clopidogrel might be better than aspirin reinitiation for the prevention of recurrent vascular events. 10 Clopidogrel (80.5%) was the most commonly used alternative antiplatelet agent in this study. In a clinical trial to compare the treatment effect of clopidogrel and aspirin for the prevention of the composite of stroke, MI, and vascular death, 8 point estimates showed an absolute difference of 0.56% and a relative risk reduction of 7.3% in favor of clopidogrel was observed in the subgroup of 12 033 patients who had recent ischemic stroke as their qualifying event.…”

“…Antiplatelet management options in these patients are to maintain aspirin monotherapy, replace aspirin with other antiplatelet agents, such as clopidogrel, or add other antiplatelet agents to aspirin. 1,[7][8][9][10] However, both randomized trial and large-scale registry data to guide this decision are sparse. Accordingly, the most recent American Heart Association/American Stroke Association guideline states that there is no evidence that switching or combining antiplatelet agents reduces the risk of subsequent vascular events in patients who have had stroke while receiving aspirin (Class IIb, Level of Evidence C).…”

Aspirin Versus Clopidogrel Monotherapy for the Secondary Prevention of Recurrent Cerebrovascular Attack Following Previous Ischemic Stroke in Patients with Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis

“…Finally, only six studies [11][12][13][14][15][16] were selected for this analysis (Fig. 1) (Table 1).…”