What management approach should be taken for a patient with a history of bleeding, being assessed using the Hypertension, Abnormal Renal/Liver Function, Stroke, Bleeding History, Labile International Normalized Ratio (INR), Elderly Age, and Concomitant Medication Use (HAS-BLED) score, who is on anticoagulant therapy, such as warfarin, and may require adjustment to prevent future bleeding events?

HAS-BLED Score: Clinical Application and Management Strategy

Primary Recommendation

The HAS-BLED score should be calculated in all patients with atrial fibrillation on anticoagulation to identify modifiable bleeding risk factors and guide monitoring intensity—but a score ≥3 should never be used as a reason to withhold oral anticoagulation. 1, 2, 3

Understanding the HAS-BLED Score

The HAS-BLED scoring system assigns one point for each of the following risk factors (maximum 9 points): 1

• Hypertension (systolic BP >160 mmHg)
• Abnormal renal function (creatinine >2.26 mg/dL, dialysis, transplant) OR abnormal liver function (bilirubin >2× ULN, AST/ALT/ALP >3× ULN, or cirrhosis)
• Stroke history
• Bleeding history or predisposition
• Labile INR (time in therapeutic range <60% if on warfarin)
• Elderly (age ≥65 years)
• Drugs (antiplatelet agents, NSAIDs) or alcohol excess (≥8 units/week)

A score ≥3 defines "high bleeding risk" and mandates more frequent monitoring and aggressive correction of modifiable factors. 1, 2

Critical Management Algorithm

Step 1: Calculate HAS-BLED Score for All AF Patients

Calculate the score before initiating anticoagulation and reassess at every patient contact, as bleeding risk is dynamic. 1, 3 The HAS-BLED score is the only bleeding score predictive of intracranial hemorrhage in AF patients and has been validated across multiple clinical settings. 2, 4, 5

Step 2: Address ALL Modifiable Risk Factors (Regardless of Score)

These interventions are mandatory before and during anticoagulation: 1, 3

• Uncontrolled hypertension: Optimize blood pressure to <140/90 mmHg (target <130/80 mmHg if tolerated) 3
• Labile INR (if on warfarin): Increase monitoring frequency, address medication adherence, consider switching to a NOAC 3
• Concomitant NSAIDs/aspirin: Discontinue unless absolutely necessary for another indication (e.g., recent ACS/PCI) 1, 3
• Alcohol excess: Counsel on reduction to <8 units/week or cessation 1, 3
• Renal/hepatic dysfunction: Dose-adjust anticoagulants appropriately and monitor more frequently 1

Step 3: Implement Risk-Stratified Monitoring

For HAS-BLED 0-2 (Low-Moderate Risk): 1, 3

• Proceed with standard anticoagulation
• Routine follow-up every 3-6 months
• Standard laboratory monitoring per anticoagulant choice

For HAS-BLED ≥3 (High Risk): 1, 2, 3

• Do NOT withhold anticoagulation—the stroke prevention benefit typically outweighs bleeding risk
• Implement more frequent monitoring:
  • If CrCl >60 mL/min: Every 3 months 1
  • If CrCl 30-59 mL/min: Every 2 months 1
  • If CrCl <30 mL/min: Monthly monitoring 1
• Aggressively correct all modifiable factors listed above
• Consider NOAC over warfarin (see below)

Step 4: Choose Optimal Anticoagulant

For patients with HAS-BLED ≥3, strongly consider NOACs over warfarin: 1, 3

• Apixaban, edoxaban, or dabigatran 110 mg demonstrate less major bleeding than warfarin in clinical trials 3
• NOACs eliminate the "labile INR" component of bleeding risk 3
• If warfarin is used, target INR 2.0-3.0 and ensure time in therapeutic range >65% 1, 6

For patients on warfarin with HAS-BLED ≥3, consider switching to a NOAC to reduce bleeding risk while maintaining stroke prevention. 3

Special Clinical Scenarios

Post-PCI/ACS with AF and HAS-BLED ≥3

Shorten triple therapy duration to 1-3 months maximum, then transition to dual therapy (oral anticoagulant + P2Y12 inhibitor). 3 The anticoagulation itself must be maintained for stroke prevention—only the duration of triple therapy is shortened. 3

Patients with Prior Major Bleeding

Even patients with previous major bleeding should receive anticoagulation if stroke risk is elevated (CHA₂DS₂-VASc ≥2 in men, ≥3 in women), with aggressive modification of bleeding risk factors and consideration of left atrial appendage occlusion in select cases. 1, 2

Evidence Quality and Nuances

The HAS-BLED score demonstrates modest but consistent predictive ability for major bleeding, with C-statistics ranging from 0.59-0.72 across validation studies. 7, 4, 5 Importantly, the score also predicts cardiovascular events and mortality, reflecting the shared pathophysiology between thrombosis and bleeding. 7

The HAS-BLED score performs better than alternative bleeding scores (ATRIA, ORBIT) in predicting clinically relevant bleeding in anticoagulated AF patients. 4 When comparing bleeding risk scores, HAS-BLED had superior discrimination (C-statistic 0.65 for major bleeding) compared to ATRIA or ORBIT scores. 4

Critical Pitfalls to Avoid

1. Never use HAS-BLED ≥3 as justification to withhold anticoagulation—this is the most common and dangerous misapplication of the score. 1, 2, 3

2. Do not treat HAS-BLED as static—bleeding risk changes over time with new medications, worsening renal function, or development of comorbidities. Reassess at every encounter. 3

3. Do not ignore modifiable factors in low-risk patients—even patients with HAS-BLED 0-2 benefit from blood pressure optimization and avoidance of unnecessary antiplatelet agents. 1, 3

4. Do not assume aspirin is safer than anticoagulation—the bleeding risk with aspirin (especially in elderly patients) approaches that of oral anticoagulation without providing equivalent stroke protection. 1

5. For warfarin patients, do not calculate HAS-BLED before establishing baseline INR control—the "labile INR" component requires at least 2-3 months of INR data to assess accurately. 1, 8