Antiplatelet and anticoagulant drugs for secondary prevention of atherosclerotic cardiovascular events
Antiplatelet drugs prevent thrombosis and reduce the incidence of myocardial infarction and death in patients with ASCVDChew, 2016.
The most appropriate antiplatelet regimen in the short term depends on the diagnosis. Following an acute coronary syndrome, dual antiplatelet therapy with aspirin and a P2Y12 inhibitor (clopidogrel, prasugrel or ticagrelor) is usually recommended for 12 months (see Long-term management of acute coronary syndromes). Therapy with a single antiplatelet drug is recommended for patients with peripheral artery disease (see Asymptomatic peripheral artery disease and intermittent claudication).
Regardless of the initial antiplatelet regimen, most patients with ASCVD benefit from long-term therapy with aspirin or clopidogrel1. Use:
1aspirin 100 to 150 mg orally, daily aspirin aspirin aspirin
OR (if intolerant of aspirin)
2clopidogrel 75 mg orally, daily. clopidogrel clopidogrel clopidogrel
Adding low-intensity rivaroxaban therapy to aspirin monotherapy reduces the risk of major adverse limb events, myocardial infarction, stroke and cardiovascular death in patients with stable coronary artery disease or peripheral artery diseaseEikelboom, 2017. Patients that derive the greatest benefit include those with polyvascular disease (ie more than one of coronary artery disease, peripheral artery disease or cerebrovascular disease) or additional risk factors (eg chronic kidney disease, heart failure, diabetes).
The clinical criteria for low-intensity rivaroxaban therapy are complex—see the Pharmaceutical Benefits Scheme (PBS) website for current information.
Adding low-intensity rivaroxaban increases bleeding risk (mostly gastrointestinal bleeding) compared with aspirin monotherapy. Consider the balance of potential harms and benefits for the secondary prevention of atherosclerotic cardiovascular events, and consult with or refer to a specialist before starting therapy. Use:
aspirin 100 mg orally, daily aspirin aspirin aspirin
PLUS
rivaroxaban 2.5 mg orally, twice daily. rivaroxaban rivaroxaban rivaroxaban
At the time of writing, rivaroxaban has not been studied in combination with clopidogrel for this indication.
If a patient is taking dual antiplatelet therapy, or a need for dual antiplatelet therapy arises, low-intensity rivaroxaban therapy should not be used.
If an indication for full-dose therapeutic anticoagulation arises in a patient with stable ASCVD, antiplatelet and low-intensity rivaroxaban therapy should usually be stopped when the full-dose anticoagulant is started. However, in some high-risk patients (eg recent coronary stenting), it may be appropriate to continue the antiplatelet drug with specialist advice. If full-dose therapeutic anticoagulation is only needed for a finite period (eg 3 months for treatment of venous thromboembolism), restart therapy for secondary prevention of ASCVD (antiplatelet monotherapy or aspirin plus low-intensity rivaroxaban therapy) after the full-dose therapeutic anticoagulation is stopped.