HAS-BLED Score and Anticoagulation Decisions
No HAS-BLED score is prohibitive for anticoagulation therapy. A HAS-BLED score ≥3 indicates high bleeding risk and mandates more frequent monitoring and correction of modifiable risk factors, but it is rarely a reason to withhold anticoagulation 1.
Understanding the HAS-BLED Threshold
- A HAS-BLED score ≥3 defines "high bleeding risk" but should prompt action rather than anticoagulation avoidance 1.
- The score was designed to identify patients who need closer follow-up and correction of modifiable bleeding risk factors, not to exclude patients from anticoagulation 1.
- Patients with HAS-BLED ≥3 who continue anticoagulation have better outcomes than those who discontinue, including lower risks of ischemic stroke (HR 0.60), major bleeding (HR 0.78), and all-cause mortality (HR 0.88) 2.
Clinical Evidence Supporting Continued Anticoagulation
The relationship between bleeding risk and thrombotic risk is interconnected—patients at high bleeding risk are often simultaneously at high thrombotic risk 3. Research demonstrates that:
- Among anticoagulated AF patients whose HAS-BLED scores increased to ≥3, continuation of anticoagulation was associated with significantly better clinical outcomes across all endpoints 2.
- Crude bleeding rates only exceed thrombotic event rates when HAS-BLED score exceeds 3, and even then, the net clinical benefit favors continued anticoagulation in most cases 3.
- The HAS-BLED score predicts not only bleeding but also cardiovascular events and mortality, reinforcing that high-risk patients need anticoagulation most 3.
Modifiable Risk Factors to Address
When HAS-BLED ≥3, focus on correcting these modifiable components 1:
- Uncontrolled hypertension: Optimize blood pressure control
- Labile INR (if on warfarin): Increase monitoring frequency, address medication adherence, consider switching to NOACs
- Alcohol excess: Counsel on reduction or cessation
- Concomitant NSAIDs or aspirin: Discontinue if not absolutely necessary for another indication
- Bleeding predisposition: Treat gastric ulcers, optimize renal/liver function
Practical Management Algorithm
For HAS-BLED 0-2 (Low-Moderate Risk):
- Proceed with standard anticoagulation 1
- Routine follow-up intervals
For HAS-BLED ≥3 (High Risk):
- Do not withhold anticoagulation 1
- Implement more frequent reviews and follow-up 1
- Systematically address each modifiable risk factor 1
- Consider NOACs over warfarin, particularly apixaban, edoxaban, or dabigatran 110mg, which demonstrate less major bleeding than warfarin 1
- For patients with prior GI bleeding, prefer apixaban or dabigatran 110mg as they lack increased GI bleeding risk compared to warfarin 1
For "Unusually High" Bleeding Risk:
- This may include HAS-BLED ≥3 plus a recent acute bleeding event 1
- Even in these cases, anticoagulation is typically continued with modified antithrombotic strategies (e.g., shorter duration of dual/triple therapy in PCI patients) rather than complete avoidance 1
Special Considerations in Specific Contexts
Post-PCI/ACS with AF:
- HAS-BLED ≥3 shortens triple therapy duration to 1-3 months (versus 6 months for HAS-BLED 0-2) 1
- Anticoagulation itself is still maintained; only the duration of concomitant antiplatelet therapy is reduced 1
Patients on warfarin:
- HAS-BLED ≥3 should trigger consideration of switching to NOACs, which generally have better bleeding profiles 1
- If continuing warfarin, ensure TTR >65% through intensive INR monitoring 1
Common Pitfalls to Avoid
- Never use HAS-BLED ≥3 as a standalone reason to withhold anticoagulation 1. This is the most critical error in clinical practice.
- Do not assume that bleeding risk is static—reassess HAS-BLED at every patient contact, as dynamic changes in score are more predictive than baseline assessment 1.
- Avoid combining anticoagulation with aspirin or NSAIDs unless there is a compelling indication, as this dramatically increases bleeding risk without proportional benefit 1, 4.
- Do not withhold anticoagulation solely because a patient is at risk of falls 1.