Outcomes of Antiplatelet Therapy for Secondary Prevention in Patients with Ischaemic Stroke or Transient Ischaemic Attack

Background: This study aimed to assess effectiveness and safety outcomes of antiplatelet therapy for secondary prevention among patients with ischaemic stroke or transient ischaemic attack (TIA) in Malaysia.

Method: Patients aged ≥18 years diagnosed with a first ischaemic stroke/TIA between 2014 and 2017 were identified from stroke registry. Data in the registry was linked with other data sources for information on antiplatelet exposure and outcome events. Exposure was defined as treatment with an antiplatelet therapy at discharge from the index stroke hospitalisation and categorised into single antiplatelet therapy (SAPT) and dual antiplatelet therapy (DAPT) groups. Primary outcome was composite events of stroke, myocardial infarction, and all-cause death at up to one year after the index stroke in an intention-to-treat analysis. We used Cox proportional hazard models to calculate hazard ratios (HR) with 95% confidence interval (CI).  

Results: Among 4434 patients included in the analysis, mean age was 61.2 years and 57.5% were male. Two-hundred-ninety-nine (6.7%) of these patients were treated with DAPT while the remaining were in SAPT group. Composite events occurred in 8.1% of patients in DAPT group and in 17.8% of patients treated with SAPT (p<0.001). The rates of individual events were lower among DAPT compared to SAPT group: recurrent stroke (4.7% versus 6.1%), myocardial infarction (1.3% versus 2.3%), and all-cause death (2.1% versus 9.3%). Bleeding occurred in 2.0% of patients in DAPT group versus 1.6% of patients in SAPT group. Multivariable-adjusted Cox regression analysis showed that rates of composite outcome was lower among DAPT compared to SAPT group (HR 0.53, 95%CI 0.32 to 0.87). 

Conclusion: In patients with ischaemic stroke/TIA, treatment with DAPT following the index stroke was associated with reduced risk of the composite events of stroke, myocardial infarction, and death. There appears to be similar risk of bleeding with DAPT versus SAPT.