HAS-BLED score

Uncontrolled hypertension

Systolic blood pressure >160 mmHg

Abnormal renal function

Dialysis, transplant or creatinine >200 µmol/L (>2.26 mg/dL)

Abnormal liver function

Cirrhosis, bilirubin >2× normal, or transaminases >3× normal

Prior stroke

Bleeding history or predisposition

Previous major bleed or anaemia

Labile INR

Time in therapeutic range <60% (vitamin K antagonists only)

Age >65 years

Concomitant antiplatelet or NSAID

Alcohol ≥8 units per week

Result0 points

Low to moderate bleeding risk. Continue to address modifiable risk factors.

Major bleeds: 1.13 per 100 patient-years

When to use

Patients with atrial fibrillation being considered for, or already taking, oral anticoagulation.
A high score should trigger correction of modifiable bleeding risk factors and closer follow-up, not avoidance of anticoagulation.

Formula

Hypertension (1) + Abnormal renal function (1) + Abnormal liver function (1) + Stroke (1) + Bleeding (1) + Labile INR (1) + Elderly >65 (1) + Drugs (1) + Alcohol (1). Maximum 9 points.

References

Pisters R, et al. A novel user-friendly score (HAS-BLED) to assess 1-year risk of major bleeding in patients with atrial fibrillation. Chest. 2010;138(5):1093–100.

The HAS-BLED score is a widely recognized and validated tool used to assess the one-year risk of major bleeding in patients with atrial fibrillation (AF) who are taking anticoagulants. It was developed in 2010, using data from the EuroHeart survey.

Components of the HAS-BLED Score

The HAS-BLED score is an acronym that stands for:

Hypertension
Abnormal renal/liver function
Stroke
Bleeding history or predisposition
Labile INR (International Normalized Ratio)
Elderly (age > 65 years)
Drugs/alcohol concomitantly

Each component is assigned 1 point, with a maximum score of 9. The score takes into account various risk factors that contribute to bleeding risk, including uncontrolled hypertension, impaired renal or liver function, previous stroke, history of bleeding, unstable anticoagulation control, advanced age, and the use of certain medications or alcohol.

Interpretation of HAS-BLED score

A score of 0-1 indicates low risk
A score of 2 suggests moderate risk
A score of 3 or higher indicates high risk of major bleeding

Note that a high HAS-BLED score should not be used as a reason to withhold anticoagulation therapy. Instead, it serves as a tool to identify patients who may require more careful monitoring and management of modifiable risk factors.

The HAS-BLED score has demonstrated moderate predictive abilities for bleeding risks in AF patients, regardless of the type of oral anticoagulant used. Studies have shown that it performs similarly or superiorly to other bleeding risk assessment tools, such as HEMORR2HAGES, ATRIA, ORBIT, and GARFIELD-AF scores. Moreover, the HAS-BLED score has been found to be predictive of intracranial hemorrhage, which is considered the most devastating complication related to anticoagulation use.