Dual versus single antiplatelet therapy for secondary prevention in
ischaemic stroke or transient ischaemic attack: A retrospective cohort
study using real-world data
Objective: 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 with a first ischaemic stroke/TIA between 2014 and 2017
were identified from stroke registry and data was linked with other data
sources for information on antiplatelet exposure and outcome events.
Exposure was defined as 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. Results: Of 4434 patients included in the analysis, 6.7% were
treated with DAPT and 93.3% were in SAPT group. During the 1-year
follow-up, composite events occurred in 5.7% of patients in DAPT group
and in 12.3% of SAPT (p<0.001). The rates of individual
events were lower in DAPT group compared to SAPT: recurrent stroke
(3.4% versus 4.8%), myocardial infarction (0.7% versus 1.9%), and
all-cause death (1.7% versus 6.0%). Bleeding occurred in 1.3% of the
DAPT group versus 1.6% of the SAPT. Multivariable-adjusted Cox
regression analysis showed that rates of composite outcome was lower in
the DAPT group compared to SAPT (HR 0.53, 95%CI 0.32, 0.86).
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.