Toolbox – HAS-BLED

The tool

HAS-BLED is an extensively validated assessment of bleeding risk in patients with AF. It is used to support clinicians in the assessment of stroke prevention in people with AF. It focuses the clinician on the reversible risk factors for bleeding to assist them to minimise the risks to the patient. It should not be used to prevent patients’ access to anticoagulation therapy.

When to use it

The HAS-BLED score should be used when reviewing people with AF in the ongoing assessment of stroke and bleeding risk. It is a useful tool to use in conjunction with the CHA₂DS₂VASc stroke risk assessment.

It should not be used as exclusion criteria for intervention with anticoagulants, but to aid in minimising the risk and enabling an informed discussion with the patient about risk and benefit. In general, patients tend to accept the bleeding risk to prevent a stroke.

A typical scenario would be a 75-year-old patient presenting with AF and stroke risk factors, where anticoagulation therapy would clearly be the only practical intervention of value. The patient is a known hypertensive with poor control, using NSAIDs for osteoarthritis, and is a frequent alcohol drinker.

This situation would suggest benefit from anticoagulation but the HASBLED score would offer a score of 4, indicating significant risk of bleeding.

The HASBLED tool has indicated not only risk but also how this risk could be controlled:

• With a review of the medication so that an alternative to NSAIDs is prescribed, the score will drop one point.
• Better intervention on the hypertension, bringing the control to more acceptable levels, not only improves the patient’s overall cardiovascular risk but it also removes a further HASBLED point.
• A discussion about bleeding risk, stroke and alcohol consumption could reduce the risk further with the withdrawal of a further indicator.

Hence the HASBLED score has indicated risk, but with appropriate intervention that risk can be modified from a HASBLED score of 4 to a score of 1, with a corresponding reduction in potential bleeding.

At the next point of review, on warfarin therapy, it may be seen that INR control is poor and the HASBLED score could be seen to have climbed once again. This point can be modified by improved warfarin control through increased clinic attendance or patient self-testing, or changing to an alternative anticoagulant.

It should be noted that HASBLED predicts bleeding events as reliably in people with AF treated with antiplatelet agents such as aspirin, and the bleeding rates are comparable for the same level of HASBLED predicted risk.

HAS-BLED

For the patient not on warfarin, the INR is stable at 1 and so they would score zero for the ‘labile INRs’ criteria. Patients on aspirin will have a point added at ‘drugs or alcohol’ as aspirin is an NSAID.

A total score of 3 indicates risk of bleeding, and this risk increases with higher scores.

Many of the HASBLED indicators can be modified such as hypertension, not a persistent indicator as seen in CHA₂DS₂VASc.

Elderly is a reference to frailty and consideration should be given to clinical age and not just chronological age. In clinical practice patients could be seen to be frail at 60 years and robust at 85 years.

The evidence

HASBLED has been validated in AF populations and has been show to be predictive of bleeding in this cohort.^1,2

There are a several other bleeding risk scores available for use, such as ATRIA and this has been compared to HASBLED. This showed HASBLED to have a much higher predictive value in real world cohorts as well as commenting on ease of use.³

Using the HASBLED score to predict the bleeding risk and the CHADSVASc score to assess stroke risk, the net clinical benefit of intervention with anticoagulants has been assessed.

This found that even those with a significant HASBLED bleeding risk score (a score of 3 points or more), in those with a significant stroke risk predicted with a CHADSVASc score of 2 or greater, the net clinical benefit was always to intervene.⁴

HASBLED is the bleeding risk assessment tool of the European Society of Cardiology AF guideline update of 2012.

Dr Matthew Fay is a GP in Shipley West Yorkshire and a GPSI in cardiology. He is also a member of the AF Association Medical Advisory Committee.

The AF Association works to support patients and clinicians in the issues relating to AF. The Advisory Committee has made up of clinicians from different aspects of AF care. The recently developed Heart of AF web resource has been designed exclusively for clinicians to support their ongoing education through access to published information and video tutorials of clinical experts.

References

1 Pisters R, Lane DA, Nieuwlaat R et al. (2010) A novel user-friendly score (HAS-BLED) to assess 1-year risk of major bleeding in patients with atrial fibrillation: the Euro Heart Survey. Chest, 138 (5); 1093-1100

2 Lip GY, Banerjee A, Lagrenade I et al. (2012) Assessing the risk of bleeding in patients with atrial fibrillation: the Loire Valley Atrial Fibrillation project. Circulation. Arrhythmia and Electrophysiology, 5 (5); 941-948

3 Roldan V, Marin F, Fernandez H et al. (2013) Predictive value of the HAS-BLED and ATRIA bleeding scores for the risk of serious bleeding in a “real-world” population with atrial fibrillation receiving anticoagulant therapy. Chest, 143 (1): 179-184

4 Friberg L, Rosenqvist M, Lip GY. (2012) Net clinical benefit of warfarin in patients with atrial fibrillation: a report from the Swedish atrial fibrillation cohort study. Circulation, 125 (19); 2298-2307