Is it recommended to add aspirin to a non-vitamin K antagonist oral anticoagulant (NOAC) in patients with atrial fibrillation (AF) and ischemic heart disease (IHD)?

Adding Aspirin to NOAC in Patients with AF and IHD

For patients with atrial fibrillation and stable ischemic heart disease (>12 months from ACS/PCI), do NOT add aspirin to NOAC therapy—use NOAC monotherapy alone. 1, 2

Stable Coronary Artery Disease (>12 Months Post-ACS/PCI)

NOAC monotherapy is the preferred strategy for patients with AF and stable IHD, as oral anticoagulation alone provides adequate protection against both stroke and myocardial ischemic events without the excess bleeding risk of combination therapy. 1, 2

• The European Society of Cardiology explicitly recommends against combining OAC with aspirin in stable CAD, as this increases bleeding risk 6.0- to 7.7-fold without clear additional protection against coronary events. 2

• Studies demonstrate that warfarin alone is superior to aspirin post-ACS, and adding aspirin to anticoagulation increases bleeding without providing additional benefit. 2

• Approximately one-third of patients in Phase III NOAC trials had coronary artery disease, with no interaction in efficacy or safety between those with or without prior MI. 2

Recent ACS or PCI (<12 Months)

The approach differs fundamentally when patients have undergone recent coronary intervention or experienced acute coronary syndrome:

Immediate Post-PCI Period (Peri-PCI)

• Triple therapy (NOAC + aspirin 75-100 mg + clopidogrel) should be initiated immediately after PCI, but this duration must be minimized due to bleeding risk. 1

• Aspirin is recommended in the peri-PCI phase given its irreversible platelet inhibition lasting 7-10 days. 1

Duration Strategy Based on Risk Profile

For most patients (default strategy):

• Triple therapy for 1 month maximum, then transition to dual therapy (NOAC + clopidogrel) up to 12 months. 1

• After 12 months, discontinue all antiplatelet therapy and continue NOAC monotherapy at full stroke-prevention doses. 1

For high bleeding risk patients (HAS-BLED ≥3):

• Consider dual therapy from hospital discharge (NOAC + clopidogrel, omitting aspirin entirely). 1

• Alternatively, use triple therapy for only 1-3 months, then dual therapy up to 12 months. 1

• In patients with unusually high bleeding risk and low thrombotic risk, use dual therapy for only 6 months, then NOAC monotherapy. 1

For high ischemic/thrombotic risk and low bleeding risk:

• Triple therapy may be extended up to 1 month (rarely beyond), then dual therapy up to 12 months. 1

• High thrombotic risk includes left main stent, multivessel PCI/stenting, or prior stent thrombosis. 1

Specific NOAC Regimens with Evidence

• Dabigatran 150 mg BID with clopidogrel (dual therapy) is the preferred choice for most patients based on RE-DUAL PCI trial results. 1

• Dabigatran 110 mg BID or rivaroxaban 15 mg daily (10 mg if CrCl 30-50 mL/min) with clopidogrel represents a viable alternative for high bleeding risk patients. 1

• Only dabigatran and rivaroxaban have clinical trial evidence supporting their use in this setting; other NOACs lack specific data. 1

Critical Implementation Details

Antiplatelet agent selection:

• Clopidogrel is the P2Y12 inhibitor of choice when combining with NOACs. 1

• Ticagrelor may be considered in selected high ischemic/low bleeding risk patients, though data are limited. 1

• Prasugrel or ticagrelor should be avoided as part of triple therapy beyond the first days post-PCI. 1

Aspirin dosing when used:

• Use low-dose aspirin 75-100 mg daily when combining with NOAC. 1

• Always prescribe proton pump inhibitors with any combination of antiplatelet and anticoagulant therapy to minimize gastrointestinal bleeding. 1

Discharge planning:

• Provide a written de-escalation schedule at hospital discharge specifying exact dates for stopping each antiplatelet agent. 1, 2

• This schedule must be prominently displayed in the discharge letter and reviewed at every follow-up visit. 1, 2

Common Pitfalls to Avoid

• Do not continue aspirin beyond 12 months in stable CAD patients—this substantially increases bleeding risk without benefit. 1, 2

• Do not use triple therapy beyond 6 months after PCI; much shorter regimens suffice for most patients. 1

• Do not switch NOACs to warfarin before or after elective PCI, as this may increase bleeding and thromboembolic risk. 1

• Do not use reduced-dose NOAC regimens long-term—if rivaroxaban 15 mg daily was used during dual therapy, resume full dose (20 mg daily) after discontinuing antiplatelet therapy. 1

• Recognize that combining aspirin with NOAC in stable CAD provides no benefit over NOAC alone and significantly increases major bleeding risk. 3, 4