Patterns of antiplatelet therapy in patients with ischaemic stroke or transient ischaemic attack

Background: Antiplatelet drugs are indicated for the secondary prevention in ischaemic stroke or transient ischemic attack (TIA) patients. Objectives: This study aimed to assess the trend in antiplatelet drugs utilisation within 90 days after a first ischaemic stroke/TIA and to identify factors associated with the non-use of antiplatelet therapy. Methods: A cohort study was conducted using data from the UK Clinical Practice Research Datalink. A total of 21,064 patients aged 18 years or older diagnosed with a first ischaemic stroke/TIA between 1999 and 2013 were identified. Antiplatelet drug utilisation was evaluated based on the prescription in 90 days after ischaemic stroke/TIA. Age-adjusted prevalence rates of antiplatelet drug use were calculated. Trends over time were assessed using joinpoint regression. Multivariate logistic regression was used to estimate factors associated with non-use of antiplatelet therapy. Results: The age-adjusted prevalence rate of antiplatelet therapy were 77.5% (ischaemic stroke) and 78.2% (TIA). In the period 1999-2013, the average annual increase in antiplatelet prevalence rates were 2.0% (p <0.01) and 1.8% (p <0.01) in patients with ischaemic stroke and TIA, respectively. Aspirin monotherapy was most commonly used in 1999-2009, but the use declined with an increase in the use of aspirindipyridamole. From 2011, the clopidogrel monotherapy prevalence rates were the highest. Among patients with ischaemic stroke, factors significantly associated with non-use of antiplatelet therapy included female sex (OR 1.1), history of heart failure (OR 1.6), diabetes mellitus (OR 0.8), no prior use of antiplatelet (OR 2.3), previous use of oral anticoagulant (OR 9.2), and year of diagnosis (OR 0.95). As for patients with TIA, significant factors included increasing age (OR 0.91), history of heart failure (OR 1.38), hypertension (OR 0.80), no prior use of antiplatelet (OR 3.2), previous use of oral anticoagulant (OR 16.4), and year of diagnosis (OR 0.93). Conclusions: Antiplatelet drugs utilisation in 90 days after ischaemic stroke/TIA increased over time and the pattern of use were in accordance with the current recommendations. Sex, age, diagnosis year, comorbidity, and prior medications use were independently associated with non-use of antiplatelet therapy following ischaemic stroke/TIA.