Stroke is a leading cause of death and disability worldwide. The annual incidence of new or recurrent
stroke is approximately 795,000 cases per year in the United States, of which 87% are ischemic in nature. In addition to the management of modifiable high-risk factors to reduce the risk of recurrent
stroke,
antithrombotic agents (antiplatelets and
anticoagulants) play an important role in secondary
stroke prevention. This review will discuss the published literature on the use of antiplatelets and
anticoagulants in
secondary prevention of
acute ischemic stroke and
transient ischemic attack (TIA), including their pharmacology, efficacy, and adverse effects. We will also highlight the role of dual antiplatelet
therapy (
DAPT) in secondary
stroke prevention, along with supporting literature.
RECENT FINDINGS: Single antiplatelet
therapy (SAPT) with
aspirin or
clopidogrel reduces the risk of recurrent
ischemic stroke in patients with non-cardioembolic
ischemic stroke or TIA. However, as shown in recent trials, short-term
DAPT with
aspirin and
clopidogrel or
ticagrelor for 21-30 days is more effective than SAPT in patients with minor acute non-
cardioembolic stroke or high-risk TIA. Although short-term
DAPT is highly effective in preventing recurrent
stroke, a more prolonged course can increase
bleeding risks without additional benefit.
DAPT for 90 days, followed by
aspirin monotherapy for patients with large vessel intracranial atherosclerotic disease, is suitable for secondary
stroke prevention. However, patients need to be monitored for both minor (e.g., bruising) and major (e.g., intracranial)
bleeding complications. Conversely, oral
warfarin and newer direct oral
anticoagulant (DOACs) such as
dabigatran,
rivaroxaban,
apixaban, and
edoxaban are the agents of choice for secondary
stroke prevention in patients with non-valvular
cardioembolic strokes. DOACs may be preferred over
warfarin due to decreased
bleeding risks, including ICH, lack of need for international normalized ratio monitoring, no
dietary restrictions, and limited drug-drug interactions. The choice between different antiplatelets and
anticoagulants for prevention of
ischemic stroke depends on the underlying
stroke mechanism,
cytochrome P450 2C19 polymorphisms,
bleeding risk profile, compliance, drug tolerance, and drug resistance. Physicians must carefully weigh each patient's relative benefits and
bleeding risks before initiating an antiplatelet/
anticoagulant treatment regimen. Further studies are warranted to study the optimal duration of
DAPT in symptomatic
intracranial atherosclerosis since the benefit is most pronounced in the short term while the
bleeding risk remains high during the extended
duration of therapy.