What is the role of apixaban (eliquis) in a patient with new onset atrial fibrillation and a pre-existing left atrial appendage closure device from prior coronary artery bypass grafting (CABG)?

Anticoagulation After Left Atrial Appendage Closure in New Onset Atrial Fibrillation

Yes, apixaban should be initiated for new onset atrial fibrillation even with a pre-existing left atrial appendage closure device from prior CABG, as surgical LAA closure is recommended as an adjunct to—not a replacement for—oral anticoagulation. 1

Primary Recommendation

Surgical LAA closure is explicitly recommended as an adjunct to oral anticoagulation, not as a substitute. The 2024 ESC Guidelines state that surgical closure of the left atrial appendage is recommended "as an adjunct to oral anticoagulation in patients with AF undergoing cardiac surgery to prevent ischaemic stroke and thromboembolism" (Class I, Level B recommendation). 1 This means the device does not eliminate the need for anticoagulation—it supplements it.

• The guideline language is unambiguous: LAA closure during cardiac surgery should be performed in addition to continuing oral anticoagulation, not instead of it. 1
• Stand-alone endoscopic surgical LAA closure may be considered as an alternative to anticoagulation only in patients with contraindications for long-term anticoagulant treatment (Class IIb, Level C). 1
• Your patient does not have a contraindication to anticoagulation—they have new onset AF requiring stroke prevention. 1

Apixaban as the Preferred Agent

Direct oral anticoagulants, specifically apixaban, are recommended over warfarin for eligible patients with nonvalvular AF. 1, 2

• Apixaban demonstrated 21% reduction in stroke/systemic embolism, 31% reduction in major bleeding, and 11% reduction in all-cause mortality compared to warfarin. 2
• The FDA-approved indication for apixaban includes reduction of stroke and systemic embolism in patients with nonvalvular atrial fibrillation. 3
• Apixaban is particularly advantageous with only 27% renal excretion, making it safer in patients with declining renal function common in post-CABG populations. 2

Stroke Risk Assessment

Calculate the CHA₂DS₂-VASc score to quantify stroke risk:

• Score ≥2 in men or ≥3 in women: Oral anticoagulation is strongly recommended (Class I). 1, 2
• Score = 1 in men or 2 in women: Anticoagulation should be considered (Class IIa). 1
• The presence of a surgical LAA closure device does not modify this risk stratification. 1

Post-CABG patients often have multiple risk factors (age, hypertension, vascular disease) that elevate CHA₂DS₂-VASc scores, making anticoagulation clearly indicated. 2

Why the LAA Device Doesn't Replace Anticoagulation

Surgical LAA closure during CABG has different evidence and indications than percutaneous LAA occlusion devices studied as warfarin alternatives.

• The PROTECT-AF and PREVAIL trials that established percutaneous LAA closure (Watchman device) as an alternative to warfarin specifically enrolled patients who were suitable for warfarin but had appropriate rationale to seek a non-pharmacological alternative. 1
• These trials excluded patients who could not tolerate any anticoagulation and required post-procedural anticoagulation (warfarin followed by dual antiplatelet therapy). 1
• Surgical LAA closure during CABG is performed opportunistically as an adjunctive measure, not as a studied alternative to anticoagulation. 1
• Device-related thrombi occur in 1.7%–7.2% of percutaneous devices, and peri-device leaks (0–5 mm) are present in approximately 25% of cases, both associated with increased stroke risk. 1

Dosing Considerations

Standard apixaban dosing is 5 mg twice daily, with dose reduction to 2.5 mg twice daily only if the patient meets specific criteria. 2, 3

Reduce to 2.5 mg twice daily only if the patient has any 2 of the following 3 criteria: 3, 4

• Age ≥80 years

• Body weight ≤60 kg

• Serum creatinine ≥1.5 mg/dL

• Avoid inappropriate dose reduction, as underdosing leads to avoidable thromboembolic events (Class III recommendation). 1

• In patients with creatinine clearance 15–30 mL/min, the FDA-approved dose is 2.5 mg twice daily. 3

• Apixaban is contraindicated in patients with creatinine clearance <15 mL/min. 2

Critical Pitfalls to Avoid

Never discontinue apixaban without bridging to another anticoagulant unless pathological bleeding is present. 2, 3

• The FDA includes a black box warning about stroke risk clustering after apixaban discontinuation. 2
• Stopping apixaban increases stroke risk dramatically in AF patients. 3

Do not use antiplatelet therapy alone (aspirin or clopidogrel) for stroke prevention in AF. 1, 2

• Aspirin offers only 19% stroke reduction with minimal benefit for disabling cardioembolic strokes. 2
• Adding antiplatelet treatment to oral anticoagulation is not recommended in AF patients for stroke prevention (Class III recommendation). 1
• The only exception is if the patient has another indication such as acute coronary syndrome or recent stent placement, in which case time-limited dual therapy is appropriate. 1, 5

Do not assume the surgical LAA closure device provides adequate stroke protection. 1

• The device was placed as an adjunct during CABG, not as a studied alternative to anticoagulation in your patient's specific context. 1
• Surgical LAA closure techniques vary widely, and complete closure cannot be assumed without imaging confirmation. 1

Monitoring and Follow-up

• Assess renal function before initiating apixaban and at least annually thereafter, as declining renal function increases drug accumulation and bleeding risk. 2
• Evaluate modifiable bleeding risk factors at every patient contact: strict blood pressure control, avoidance of NSAIDs, and medication adherence. 1
• Consider proton pump inhibitor therapy if the patient has risk factors for gastrointestinal bleeding, though evidence is limited. 1