Does a patient with non-obstructive Coronary Artery Disease (CAD) require antiplatelet therapy while already on therapeutic anticoagulation?

From the Guidelines

Patients with non-obstructive coronary artery disease (CAD) who are already on therapeutic anticoagulation do not routinely need additional antiplatelet therapy, as the benefits of antiplatelet therapy do not outweigh the increased bleeding risk in this population. The 2018 European Heart Rhythm Association practical guide on the use of non-vitamin K antagonist oral anticoagulants in patients with atrial fibrillation suggests that anticoagulation only, without additional antiplatelet agents, is considered sufficient for most atrial fibrillation patients with stable CAD 1. This is because therapeutic anticoagulation already provides protection against thrombotic events by inhibiting the coagulation cascade, while the additional platelet inhibition from antiplatelet therapy may not offer enough incremental benefit to justify the increased bleeding risk in stable non-obstructive CAD.

Some key points to consider in this decision include:

• The patient's specific thrombotic risk factors, such as their CHA2DS2-VASc score, should be weighed against their bleeding risk.
• The type of anticoagulant being used, such as a vitamin K antagonist or a non-vitamin K antagonist oral anticoagulant (NOAC), may also influence the decision.
• The presence of other comorbidities, such as diabetes or hypertension, may also impact the decision to add antiplatelet therapy.
• Recent studies, such as the 2020 ESC guidelines for the management of acute coronary syndromes, suggest that dual antiplatelet therapy (DAPT) is recommended for patients with non-ST-elevation acute coronary syndromes (NSTE-ACS), but this may not apply to patients with non-obstructive CAD who are already on therapeutic anticoagulation 1.
• Older guidelines, such as the 2016 European guidelines on cardiovascular disease prevention, also suggest that antiplatelet therapy is not recommended in patients with stable CAD without a previous acute coronary syndrome (ACS) 1.

Overall, the decision to add antiplatelet therapy to therapeutic anticoagulation in patients with non-obstructive CAD should be made on a case-by-case basis, taking into account the individual patient's risk factors and comorbidities. However, in general, antiplatelet therapy is not necessary for patients with non-obstructive CAD who are already on therapeutic anticoagulation, as the benefits do not outweigh the increased bleeding risk in this population.

From the Research

Antiplatelet Therapy in Non-Obstructive CAD with Therapeutic Anticoagulation

• The use of antiplatelet therapy in patients with non-obstructive coronary artery disease (CAD) who are already on therapeutic anticoagulation is a topic of interest, with several studies providing insights into this issue 2, 3, 4, 5, 6.
• A study published in 2016 found that clopidogrel use as single antiplatelet therapy in outpatients with stable CAD was not beneficial compared to aspirin alone in terms of ischemic or bleeding events 2.
• Another study published in 2018 suggested that for patients with atrial fibrillation and stable CAD, the risk of thromboembolism, cardiovascular events, and bleeding should be assessed individually, and antiplatelet therapy might be added to anticoagulant therapy for those with low bleeding risk and high risk for cardiovascular events 3.
• A review published in 2004 summarized the current state of evidence regarding oral antiplatelet treatment in patients with cerebrovascular disease, coronary artery disease, and peripheral arterial disease, and found that aspirin, ticlopidine, clopidogrel, aspirin combined with clopidogrel, and aspirin combined with dipyridamole are effective in preventing recurrent vascular events among various subgroups of patients with vascular disease 4.
• A systematic literature review and indirect treatment comparison published in 2022 found that the use of rivaroxaban 2.5 mg twice daily + low-dose aspirin reduced the risk of major adverse cardiovascular events, cardiovascular death, and stroke compared to clopidogrel + low-dose aspirin in patients with or at high risk for chronic CAD and/or peripheral artery disease 5.
• A meta-analysis published in 2023 found that clopidogrel monotherapy was associated with reduced risk of major adverse cardiac and cerebrovascular events, myocardial infarction, stroke, and BARC major bleeding compared to aspirin monotherapy in patients with CAD 6.

Key Findings

• The decision to use antiplatelet therapy in patients with non-obstructive CAD who are already on therapeutic anticoagulation should be individualized, taking into account the patient's risk of thromboembolism, cardiovascular events, and bleeding 3.
• Clopidogrel may be a better option than aspirin for long-term antiplatelet monotherapy in patients with CAD, due to its association with reduced risk of major adverse cardiac and cerebrovascular events, myocardial infarction, stroke, and BARC major bleeding 6.
• The use of rivaroxaban 2.5 mg twice daily + low-dose aspirin may be a viable option for patients with or at high risk for chronic CAD and/or peripheral artery disease, due to its association with reduced risk of major adverse cardiovascular events, cardiovascular death, and stroke compared to clopidogrel + low-dose aspirin 5.