Does DAPT Work as Well for Stroke as It Does for ACS?

Dual antiplatelet therapy (DAPT) with aspirin and another antiplatelet agent such as clopidogrel, prasugrel, or ticagrelor is the go-to preventive therapy for patients who have experienced certain cardiovascular events. Its effectiveness is particularly good among patients in the post-acute coronary syndrome (ACS) period up to and beyond 1 year.

Clinical hospital pharmacists at Jackson Memorial Hospital and the University of Florida recently conducted a comprehensive literature review addressing the safety and efficacy of DAPT with aspirin and clopidogrel (Plavix) for secondary stroke prevention.

Since the underlying pathophysiology of ACS, ischemic stroke, and transient ischemic attack (TIA) are similar, it would stand to reason that all 3 would respond to DAPT. Nevertheless, DAPT’s effectiveness is less defined in ischemic stroke and TIA than in ACS.

Three large studies (MATCH, CHARISMA, and SPS3) compared DAPT with single antiplatelet therapy in patients with ischemic events. Those who received DAPT were more likely to experience bleeding than those who did not. In addition, these studies did not demonstrate an appreciable reduction in ischemic events with DAPT.

In 2 other large studies (FASTER and CHANCE), researchers examined DAPT with aspirin and clopidogrel started within 24 hours of the primary ischemic event. They documented fewer secondary ischemic events, but both studies had flaws.

FASTER couldn't reach its enrollment target and was terminated early. CHANCE was conducted in an entirely Chinese group, and due to strict enrollment requirements, all patients were at low risk for hemorrhage.

Current guidelines recommend against routine DAPT use for secondary stroke prevention. Aspirin and clopidogrel DAPT appears effective only for patients with minor stroke or TIA when started within 24 hours of the ischemic event and continued for a maximum of 21 days.

Future studies may provide evidence that DAPT can prevent recurrent ischemic stroke. If they do, the durations of treatment will need to be defined, and pharmacists will need to ensure that DAPT is discontinued appropriately to minimize bleeding risk.

The current review titled “Dual antiplatelet therapy with clopidogrel and aspirin after ischemic stroke: A review of the evidence” was published in the October 1, 2015, edition of the Journal of the American Society of Health-System Pharmacists.