Bayer Pharma AG

Essence of this Article

The use of anticoagulants to reduce the risk of stroke should be balanced against safety, compliance and monitoring issues, and clinical decisions must always balance the benefits and risks of any treatment option. The main complication associated with anticoagulant and antiplatelet use is bleeding. Bleeding risk varies with age and is substantially higher in older patients. HAS-BLED is one user-friendly score that is used to assess the 1-year risk of major bleeding in a patient. This tool has demonstrated good predictive accuracy, but it should only be used as one of several factors to be considered by clinicians.

Weighing up the benefits and risks of therapy

The use of anticoagulants to reduce the risk of stroke must be balanced against safety, compliance and (in the case of vitamin K antagonists [VKAs]) routine coagulation monitoring issues. Bleeding is the major complication associated with both oral anticoagulant and antiplatelet drug use. Clinical decision making must always balance the benefits and risks of treatment.

The risk of bleeding varies with age, and is substantially higher in patients ≥80 years of age (13.1%/year) compared with younger patients (4.7%/year).204

A ‘user-friendly’ score to assess the 1-year risk of major bleeding in a patient with AF has been proposed recently. The HAS-BLED score predicts the risk of bleeding based on a combination of risk factors,205 and is recommended by the updated ESC 2012 guidelines as the preferred score to assess bleeding risk.187 Furthermore, several studies have shown HAS-BLED to have better predictive value than other published risk scores.206, 207, 210

Bleeding risk according to HAS-BLED score

  Risk factor Description Points
H Hypertension Uncontrolled, >160 mm Hg systolic pressure 1
A Abnormal renal or liver function (1 point each) Abnormal renal function: chronic dialysis or renal transplantation or serum creatinine ≥200 µmol/l

Abnormal liver function: chronic hepatic disease or biochemical evidence of significant hepatic derangement
1 or 2
S Stroke Previous history, particularly lacunar stroke 1
B Bleeding history or predisposition Predisposition could include bleeding diathesis or anaemia 1
L Labile INR Therapeutic time in range <60% 1
E Elderly Age >65 years 1
D Drugs/alcohol concomitantly (1 point for drugs plus 1 point for alcohol excess) Drugs, including antiplatelet agents and non­steroidal anti-inflammatory medications 1 or 2
      Maximum:
9 points
Source: Adapted from Pisters et al. (2010).205
INR, international normalized ratio.

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Link to online HAS-BLED risk calculator:
http://www.mdcalc.com/has-bled-score-for-major-bleeding-risk/

Studies of the HAS-BLED score indicate that the annual risk of bleeding increases with the addition of each risk factor up to five risk factors. HAS-BLED has demonstrated good predictive accuracy.205 Nevertheless, the score should not be used alone to exclude patients from oral anticoagulant therapy but rather allows clinicians to make an informed judgement as to the risk of bleeding and to identify modifiable bleeding risks that need to be addressed. Patient preferences should also be taken into account when making therapy choices.187


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