When can we test after discontinuation of Direct Oral Anticoagulants (DOACs)?

Testing After DOAC Discontinuation

DOAC testing should only be performed after a standardized interruption period of 1-2 days for low-to-moderate bleeding risk procedures and 2-4 days for high bleeding risk procedures, rather than routinely measuring DOAC levels before procedures. 1

Standardized DOAC Interruption Periods

The timing for testing after DOAC discontinuation depends on several factors:

Based on DOAC Type and Renal Function

• Dabigatran:

  • If CrCl ≥50 mL/min: 1 day off before low-to-moderate-bleed-risk procedures; 2 days off before high-bleed-risk procedures
  • If CrCl <50 mL/min: 2 days off before low-to-moderate-bleed-risk procedures; 4 days off before high-bleed-risk procedures 1

• Apixaban, Rivaroxaban, and Edoxaban:

  • 1 day off before low-to-moderate-bleed-risk procedures
  • 2 days off before high-bleed-risk procedures 1

DOAC Level Testing Considerations

• Routine DOAC level testing before elective procedures is not recommended 1
• In the PAUSE study, after following standardized interruption protocols:

  • 90% of patients had DOAC levels <50 ng/mL before procedures

  • For high bleeding risk procedures, >97% of patients had DOAC levels <50 ng/mL 1

When DOAC Testing May Be Appropriate

DOAC testing may be considered in specific non-elective clinical scenarios:

1. Urgent/emergency procedures (within 24 hours) where DOAC level testing may inform the need for reversal agents 1
2. Patients with impaired renal function, especially for dabigatran which is 75-80% renally cleared 2
3. Specialized coagulation testing (e.g., lupus anticoagulant) requires at least 24 hours after the last DOAC dose to avoid false-positive results 3

Testing Methods and Interpretation

• Standard coagulation tests (PT, aPTT) are inadequate for precise DOAC level assessment 1, 4
• Specific assays are required for accurate measurement:
  • Anti-Xa assays for apixaban, rivaroxaban, and edoxaban
  • Dilute thrombin time or ecarin clotting time for dabigatran 1
• For accurate determination of low rivaroxaban concentrations, LC-MS/MS is preferred 5

Resumption of DOACs After Procedures

• Resume DOACs at least 24 hours after low-to-moderate-bleed-risk procedures
• Resume DOACs 48-72 hours after high-bleed-risk procedures 1, 6
• DOACs have rapid onset (1-3 hours), requiring cautious post-procedure administration 6

Common Pitfalls to Avoid

1. Relying on routine coagulation tests (PT/aPTT) to assess DOAC activity - these are inadequate and may lead to misinterpretation 4
2. Performing specialized coagulation tests (e.g., lupus anticoagulant) too soon after DOAC discontinuation, which can lead to false-positive results 3, 7
3. Using heparin bridging with DOACs, which is unnecessary due to their rapid onset/offset and increases bleeding risk 1, 6
4. Ignoring renal function, especially for dabigatran, which requires longer discontinuation periods with reduced renal function 1, 2

In summary, standardized DOAC interruption periods based on bleeding risk and renal function are preferred over routine DOAC level testing before elective procedures. DOAC testing should be reserved for urgent/emergency situations where reversal may be needed.