What anticoagulation regimen should a 65‑year‑old man with Crohn’s disease and active small‑bowel ulcerations, post‑mitral valve repair with left atrial appendage excision and surgical maze for atrial fibrillation, and recent transient amaurosis fugax with 50 % left internal carotid artery stenosis receive?

Anticoagulation Strategy for Post-Cardiac Surgery Patient with Crohn's Disease and Carotid Stenosis

This patient requires full-dose oral anticoagulation with warfarin (INR 2.0-3.0) indefinitely, given his multiple high-risk features: post-mitral valve repair with surgical maze procedure, recent amaurosis fugax (transient monocular blindness indicating retinal embolism), and 50% carotid stenosis. 1

Primary Anticoagulation Decision

Warfarin is the definitive choice over direct oral anticoagulants (DOACs) in this patient because:

• He has undergone mitral valve repair with surgical intervention, which falls under the category of valvular heart disease requiring warfarin rather than NOACs 1
• The 2014 AHA/ACC Valvular Heart Disease Guidelines specifically recommend warfarin for patients post-mitral valve surgery, particularly when combined with atrial fibrillation management procedures like the maze 1
• His recent embolic event (amaurosis fugax) represents a high-risk feature mandating therapeutic anticoagulation 1

Target INR and Monitoring

• Target INR: 2.5 (range 2.0-3.0) for mitral valve repair with maze procedure 1
• INR should be checked weekly during initiation, then monthly once stable 1
• The left atrial appendage excision does NOT eliminate the need for anticoagulation, as persistent atrial fibrillation (if present) or the valve repair itself requires ongoing therapy 1, 2

Management of Carotid Stenosis

The 50% left internal carotid stenosis with symptomatic disease (amaurosis fugax) requires urgent evaluation for carotid revascularization:

• Symptomatic carotid stenosis >50% warrants consideration for carotid endarterectomy or stenting 1, 3
• The risk of recurrent stroke is highest in the first few weeks following the presenting symptomatic event, so revascularization should be expedited 3
• After successful carotid revascularization, continue warfarin alone without adding long-term antiplatelet therapy 1
• Short-term antiplatelet therapy (1-3 months) may be used immediately post-revascularization, then discontinued 1

Critical Consideration: Crohn's Disease and Active Ulcers

The presence of active small bowel ulcers creates a significant bleeding risk that must be addressed before initiating full anticoagulation:

Immediate Management Algorithm

1. Gastroenterology consultation urgently to assess ulcer severity and bleeding risk

2. If ulcers are actively bleeding or high-risk:

   • Consider bridging with unfractionated heparin (easier to reverse) rather than starting warfarin immediately 1
   • Optimize Crohn's disease treatment to promote ulcer healing
   • Consider proton pump inhibitor therapy, though evidence is limited for small bowel protection 1

3. If ulcers are healing or low bleeding risk:

   • Initiate warfarin with close monitoring
   • The stroke risk from his recent embolic event and cardiac surgery outweighs bleeding risk in most scenarios 1

Balancing Stroke vs. Bleeding Risk

• His CHA₂DS₂-VASc score is elevated (age 65 = 1 point, plus likely additional points for the valve repair and recent TIA/stroke equivalent) 1, 4
• Recent amaurosis fugax represents a very high stroke risk requiring anticoagulation despite bleeding concerns 1
• Vitamin B6 and B12 levels should be checked given Crohn's disease, as deficiency can cause hyperhomocysteinemia and increase thrombotic risk 5

Antiplatelet Therapy: Critical Pitfall to Avoid

Do NOT use aspirin alone or as a substitute for anticoagulation in this patient 1, 4:

• Aspirin is significantly less effective than oral anticoagulation for stroke prevention in patients with valvular disease and AF 1
• The combination of warfarin plus aspirin increases bleeding risk substantially without proven benefit in this context 1
• After carotid revascularization, aspirin may be added for 1-3 months only, then discontinued 1

Post-Maze Procedure Considerations

Despite the maze procedure and left atrial appendage excision, anticoagulation remains mandatory:

• The maze procedure reduces but does not eliminate stroke risk, particularly in the early postoperative period 1, 2
• Studies show that even with successful maze procedures, patients with mitral valve disease require ongoing anticoagulation 1, 2
• Persistent or recurrent atrial fibrillation is the most significant risk factor for stroke post-mitral valve surgery, and anticoagulation must continue regardless of rhythm 2

Monitoring and Follow-Up

• Hemoglobin and stool guaiac testing every 1-2 weeks initially to detect GI bleeding early
• Coordinate closely with gastroenterology for Crohn's disease optimization
• Vascular surgery consultation for expedited carotid revascularization given symptomatic disease 3
• INR monitoring weekly until stable, then monthly 1
• Reassess bleeding risk factors at each visit, including blood pressure control and avoidance of NSAIDs 1

Duration of Therapy

Anticoagulation should be continued indefinitely based on:

• Post-mitral valve repair status 1
• History of systemic embolization (amaurosis fugax) 1
• Carotid atherosclerotic disease 1, 6