What is the duration of Eliquis (apixaban) therapy needed after tricuspid valve repair and patent foramen ovale (PFO) closure in a patient with a history of intravenous drug use (IVDU) and septic pulmonary emboli due to tricuspid valve endocarditis?

Duration of Apixaban After Tricuspid Valve Repair and PFO Closure

For this patient with tricuspid valve repair and PFO closure following endocarditis, anticoagulation with apixaban should be continued for a minimum of 3 months post-operatively, with strong consideration for extended therapy of 1-6 months for the PFO closure component, followed by transition to aspirin monotherapy.

Rationale Based on Multiple Indications

This clinical scenario requires addressing three distinct but overlapping indications for anticoagulation:

1. Post-Endocarditis Management

• Guidelines recommend against routine anticoagulation for native valve infective endocarditis unless a separate indication exists 1
• Once the active infection is treated and the patient undergoes valve repair, the endocarditis itself is no longer an indication for anticoagulation 1
• The history of septic pulmonary emboli does not require ongoing anticoagulation once the infection is eradicated and the valve is repaired 1

2. Post-Tricuspid Valve Repair

• For bioprosthetic valves or valve repairs, aspirin 50-100 mg daily is suggested over vitamin K antagonist therapy after the initial post-operative period 1
• While specific guidelines for tricuspid valve repair anticoagulation duration are limited, the general recommendation for valve repair patients is aspirin therapy rather than prolonged anticoagulation 1
• The tricuspid position carries lower thrombotic risk than left-sided valves 1

3. Post-PFO Closure (The Determining Factor)

• After PFO closure, 1-6 months of dual antiplatelet therapy (DAPT) is recommended, followed by single antiplatelet therapy (SAPT) for up to 5 years 1
• The most recent European consensus (2025) emphasizes that this recommendation is based on device endothelialization and residual shunt considerations 1
• In patients with cryptogenic stroke and PFO who undergo device closure, aspirin 50-100 mg daily is recommended as baseline therapy 1

Specific Anticoagulation Protocol

Months 0-3 Post-Operatively:

• Apixaban 5 mg twice daily (or 2.5 mg twice daily if dose-reduction criteria are met: age ≥80 years, weight ≤60 kg, or creatinine ≥1.5 mg/dL) 2
• This covers the critical period for both valve repair healing and initial PFO device endothelialization 1

Months 3-6 Post-Operatively:

• Consider continuing apixaban 2.5 mg twice daily for extended prophylaxis given the PFO closure component 1
• Alternatively, transition to DAPT (aspirin 81 mg + clopidogrel 75 mg daily) if bleeding risk is a concern 1

Beyond 6 Months:

• Transition to aspirin 81-100 mg daily indefinitely 1
• The 2025 guidelines note that prolongation beyond 5 years should be determined by stroke and bleeding risks 1

Critical Caveats for This IVDU Population

Ongoing IVDU Risk:

• The highest mortality risk in tricuspid valve endocarditis patients is ongoing intravenous drug use and recurrent endocarditis, not thromboembolic events 3
• Two-year mortality in surgically treated IVDU-related tricuspid endocarditis is 43%, primarily driven by recurrent infection rather than thrombosis 3
• If the patient continues IVDU, the risk of recurrent endocarditis far outweighs any benefit from prolonged anticoagulation 3

Paradoxical Embolism Context:

• The PFO closure was performed specifically because this patient had paradoxical systemic emboli (evidenced by the clinical presentation) 4, 5, 6
• Right-to-left shunting through PFO in tricuspid endocarditis with elevated right-sided pressures is a documented but rare complication 4, 5, 7, 6
• Once the PFO is closed and the valve is repaired, the mechanism for paradoxical embolism is eliminated 5, 6

Bleeding Risk Considerations:

• Apixaban should be avoided if hepatic impairment exists (transaminases >2× upper limit or bilirubin >1.5× upper limit) 2
• Use caution with CrCl <25 mL/min and avoid if CrCl <15 mL/min 2, 8
• Active IVDU increases bleeding risk from soft tissue infections and potential trauma 3

Monitoring and Follow-Up

• Echocardiographic surveillance at 1,3, and 6 months post-operatively to assess valve function and residual PFO shunt 1
• Reassess anticoagulation duration at 3 months based on device endothelialization, residual shunt, and patient's IVDU status 1
• If residual shunt persists beyond 6 months, consider extending anticoagulation duration 1
• Substance use disorder treatment is paramount, as ongoing IVDU is the primary determinant of long-term outcomes 3

Why Not Lifelong Anticoagulation?

• The repaired tricuspid valve (not a mechanical prosthesis) does not require lifelong anticoagulation 1
• The closed PFO eliminates the paradoxical embolism pathway 5, 6
• The history of septic emboli was a complication of active endocarditis, not a chronic thrombotic condition requiring indefinite anticoagulation 1
• Prolonged anticoagulation in active IVDU patients increases bleeding risk without clear mortality benefit 3