Can a patient be on Aspirin (ASA) 81mg, Heparin (Heparin) subcutaneously (SC) and Warfarin 5mg after a Surgical Aortic Valve Replacement (SAVR) while inpatient?

Anticoagulation Management After Surgical Aortic Valve Replacement (SAVR)

For patients with mechanical SAVR, a combination of warfarin (target INR 2.5), low-dose aspirin (75-100 mg), and subcutaneous heparin is appropriate during the inpatient period after surgery. 1, 2

Anticoagulation Regimen Based on Valve Type

Mechanical Valve SAVR

• Initial inpatient management:

  • Warfarin 5 mg daily (target INR 2.0-3.0)
  • Subcutaneous heparin (bridging until therapeutic INR achieved)
  • Low-dose aspirin 81 mg daily
  • Continue this triple therapy until therapeutic INR is reached

• Long-term management:

  • For bileaflet mechanical aortic valve without risk factors:
    • Warfarin with target INR 2.5 (range 2.0-3.0) plus aspirin 75-100 mg daily 1, 3
  • For mechanical aortic valve with risk factors (AF, previous thromboembolism, LV dysfunction, hypercoagulable state):
    • Warfarin with higher target INR 3.0 (range 2.5-3.5) plus aspirin 75-100 mg daily 1, 2

Bioprosthetic Valve SAVR

• Initial inpatient management:

  • Warfarin 5 mg daily (target INR 2.0-3.0)
  • Subcutaneous heparin (bridging until therapeutic INR achieved)
  • Low-dose aspirin 81 mg daily
  • Continue this triple therapy until discharge

• Post-discharge management:

  • Warfarin with target INR 2.5 (range 2.0-3.0) for 3-6 months 1
  • Lifelong aspirin 75-100 mg daily after warfarin is discontinued 1

Practical Considerations for Inpatient Management

1. Initiation timing:

   • Begin subcutaneous heparin once hemostasis is achieved post-surgery (typically 24-48 hours)
   • Start warfarin once oral intake is established
   • Add aspirin 81 mg once patient is stable and bleeding risk is acceptable

2. Monitoring:

   • Check INR daily until stable and therapeutic
   • Monitor for bleeding complications (surgical site, gastrointestinal, intracranial)
   • Assess platelet count if on heparin to monitor for heparin-induced thrombocytopenia

3. Transition to discharge:

   • Continue subcutaneous heparin until INR is therapeutic (≥2.0 for two consecutive days)
   • Ensure stable INR before discharge
   • Provide clear anticoagulation plan for outpatient follow-up

Common Pitfalls and Caveats

1. Bleeding risk:

   • Triple therapy (warfarin, heparin, aspirin) increases bleeding risk significantly
   • Consider holding aspirin in patients with high bleeding risk until stable
   • Monitor for signs of bleeding closely, especially at surgical sites

2. Medication interactions:

   • Many post-surgical medications can affect warfarin metabolism
   • Antibiotics, antifungals, and pain medications may increase INR
   • More frequent INR monitoring may be needed with medication changes

3. Direct oral anticoagulants (DOACs):

   • DOACs (dabigatran, rivaroxaban, apixaban) are contraindicated in patients with mechanical valves 1, 2
   • Never substitute warfarin with DOACs in mechanical valve patients

4. Bridging considerations:

   • Subcutaneous heparin bridging is appropriate in the immediate post-operative period
   • Once therapeutic INR is achieved, heparin should be discontinued

The 2020 ACC/AHA guidelines provide clear recommendations for antithrombotic therapy following valve replacement, supporting the use of warfarin, aspirin, and bridging heparin in the immediate post-operative period for mechanical valves 1. This approach balances the prevention of valve thrombosis and thromboembolic events while managing bleeding risk.