Is it safe to start Xarelto (rivaroxaban) in a patient with elevated von Willebrand factor, ristocetin cofactor, and factor VIII activity prior to cardiac ablation?

Management of Rivaroxaban in a Patient with Elevated von Willebrand Factor Prior to Cardiac Ablation

Rivaroxaban should be used with caution in this patient with elevated von Willebrand factor, ristocetin cofactor, and factor VIII activity prior to cardiac ablation, as these laboratory abnormalities may indicate an increased thrombotic risk rather than bleeding risk.

Assessment of Laboratory Findings

The patient's laboratory results show:

• Von Willebrand Factor Antigen: 252% (elevated above reference range of 50-217%)
• Ristocetin Cofactor: 363% (elevated above reference range of 42-200%)
• Factor VIII Activity: 210% (elevated above reference range of 50-180%)
• Normal CBC, APTT, and other coagulation parameters

These findings indicate:

• Elevated levels of von Willebrand factor and associated activity
• No evidence of von Willebrand disease (which would show decreased levels)
• Potential hypercoagulable state rather than bleeding tendency

Implications for Anticoagulation Management

Risk Assessment

• Elevated von Willebrand factor, ristocetin cofactor, and factor VIII are associated with increased thrombotic risk, not increased bleeding risk
• These elevations may actually reinforce the need for adequate anticoagulation before cardiac ablation
• The patient's CHA₂DS₂-VASc score should be calculated to determine baseline stroke risk

Anticoagulation Recommendations

1. Pre-Procedure Anticoagulation:

   • Rivaroxaban can be initiated as planned prior to cardiac ablation 1
   • For cardiac ablation, uninterrupted anticoagulation is recommended to reduce thromboembolic risk 1
   • The standard dose of rivaroxaban (20 mg daily with food, or 15 mg daily with food if CrCl 15-50 mL/min) is appropriate 2

2. Timing Considerations:

   • Last dose of rivaroxaban should be taken 12-24 hours before the procedure 1
   • This allows for some reduction in anticoagulant effect while maintaining protection against thromboembolism

3. Peri-Procedural Management:

   • During ablation, intravenous heparin should be administered to achieve an ACT of 300-350 seconds 1
   • Rivaroxaban can be resumed 3-5 hours after sheath removal if adequate hemostasis is established 1

Important Considerations

• The elevated von Willebrand factor and factor VIII levels may actually represent an increased thrombotic risk rather than bleeding risk
• These elevations are not a contraindication to anticoagulation; in fact, they may reinforce the need for adequate anticoagulation
• The decision for long-term anticoagulation after cardioversion should be based on the patient's thromboembolic risk profile (CHA₂DS₂-VASc score) and bleeding risk profile 1

Monitoring Recommendations

• Monitor for both bleeding and thrombotic complications during and after the procedure
• Consider more frequent follow-up in the immediate post-procedure period
• Ensure patient understands the importance of medication adherence, especially in the post-ablation period

Conclusion

The elevated von Willebrand factor, ristocetin cofactor, and factor VIII levels do not contraindicate the use of rivaroxaban before cardiac ablation. These elevations actually suggest a potential hypercoagulable state rather than increased bleeding risk, reinforcing the importance of appropriate anticoagulation for this procedure.