Understanding the HAS-BLED Score

What is the HAS-BLED Score?

The HAS-BLED score is a simple, validated clinical risk score used to assess the 1-year risk of major bleeding in patients taking anticoagulants, particularly those with atrial fibrillation. It helps clinicians weigh the benefits of anticoagulation against the risk of bleeding complications.

How is it Calculated?

The HAS-BLED score assigns one point for each of the following risk factors, for a maximum possible score of 9 points:

• Hypertension (uncontrolled, systolic BP > 160 mmHg)
• Abnormal renal and/or liver function (1 point for each, max 2 points)
• Stroke (previous)
• Bleeding (previous major bleeding or predisposition)
• Labile INRs (unstable INR values, if on Warfarin)
• Elderly (> 65 years)
• Drugs (concomitant use of antiplatelet agents or NSAIDs) or alcohol excess

Purpose of the HAS-BLED Score

The primary purpose of the HAS-BLED score is to identify patients at high risk of bleeding who may require closer monitoring or modification of their anticoagulant therapy. It serves as a warning score, prompting clinicians to be cautious and consider reversible bleeding risk factors.

Interpreting the Results

A higher HAS-BLED score indicates a higher risk of major bleeding. While there's no definitive cut-off, a score of ≥ 3 is generally considered to indicate a high risk of bleeding, warranting caution and regular review of the patient's condition and medication.

Approximate 1-year major bleeding risk:

• Score 0: 1.0%
• Score 1: 1.1%
• Score 2: 1.0%
• Score 3: 3.7%
• Score 4: 5.2%
• Score 5: 8.7%

Note: These percentages are approximate and can vary based on patient population.

Example Calculation

Let's consider a 70-year-old patient with atrial fibrillation who has uncontrolled hypertension, a history of a previous stroke, and is also taking NSAIDs for arthritis pain.

• Hypertension: Yes (1 point)
• Abnormal renal/liver function: No (0 points)
• Stroke: Yes (1 point)
• Bleeding: No (0 points)
• Labile INRs: Not applicable (assuming not on Warfarin) (0 points)
• Elderly (> 65 years): Yes (1 point)
• Drugs/Alcohol: NSAIDs use (1 point)

Total HAS-BLED Score: 1 + 0 + 1 + 0 + 0 + 1 + 1 = 4 points.

A score of 4 indicates a high risk of bleeding, prompting the clinician to carefully review the patient's medication, consider alternatives to NSAIDs, and ensure close monitoring.

Frequently Asked Questions

Q: Does a high HAS-BLED score mean I shouldn't take anticoagulants?

A: Not necessarily. The HAS-BLED score is a warning score, not a contraindication to anticoagulation. It helps identify patients who need closer monitoring and management of modifiable bleeding risk factors.

Q: Can the HAS-BLED score change over time?

A: Yes, it can. Some risk factors, like uncontrolled hypertension or drug use, are modifiable. As these factors change, so too can the patient's HAS-BLED score and their bleeding risk.

Q: Is HAS-BLED used for all types of anticoagulants?

A: While primarily validated for patients with atrial fibrillation on vitamin K antagonists (like Warfarin), it is also widely used for patients on direct oral anticoagulants (DOACs) and in other conditions requiring anticoagulation.