Clinical Risk Scores in Cardiovascular and Gastrointestinal Medicine
The HAS-BLED score is the recommended tool for bleeding risk assessment in patients with atrial fibrillation, while CHA₂DS₂-VASc is the preferred score for stroke risk assessment, and the Glasgow-Blatchford score is the standard for upper GI bleeding risk stratification. 1, 2
HAS-BLED Score
The HAS-BLED score is a validated clinical tool for assessing bleeding risk in patients with atrial fibrillation (AF) who are being considered for or are receiving anticoagulation therapy.
Components of HAS-BLED:
- H: Hypertension (systolic blood pressure >160 mmHg) - 1 point
- A: Abnormal renal/liver function (1 point each) - 1-2 points
- S: Stroke (previous history) - 1 point
- B: Bleeding history or predisposition - 1 point
- L: Labile INR (if on warfarin) - 1 point
- E: Elderly (age >65 years) - 1 point
- D: Drugs/alcohol concomitantly (1 point each) - 1-2 points
- Maximum score: 9 points 1, 2
Clinical Application:
- A HAS-BLED score ≥3 indicates high bleeding risk requiring caution and regular review 1
- Importantly, a high HAS-BLED score is not a reason to withhold anticoagulation, as the net clinical benefit is even greater in those patients with high bleeding risk 1
- The score should prompt identification and correction of modifiable bleeding risk factors 1, 3
Evidence Supporting HAS-BLED:
- Multiple systematic reviews have demonstrated that HAS-BLED performs better than other bleeding risk scores (HEMORR₂HAGES, ATRIA) and is superior to stroke risk scores (CHADS₂, CHA₂DS₂-VASc) for bleeding prediction 1, 4, 5
- HAS-BLED has moderate predictive ability with C-statistic of 0.63 (0.61-0.65) for major bleeding in anticoagulated patients 4
- It is the only bleeding score validated to predict intracranial bleeding 1
CHA₂DS₂-VASc Score
The CHA₂DS₂-VASc score is the recommended tool for stroke risk assessment in patients with AF.
Components of CHA₂DS₂-VASc:
- C: Congestive heart failure/LV dysfunction - 1 point
- H: Hypertension - 1 point
- A₂: Age ≥75 years - 2 points
- D: Diabetes mellitus - 1 point
- S₂: Stroke/TIA/thromboembolism - 2 points
- V: Vascular disease - 1 point
- A: Age 65-74 years - 1 point
- Sc: Sex category (female) - 1 point
- Maximum score: 9 points 1, 2
Clinical Application:
- Oral anticoagulation is recommended for men with a score ≥2 and women with a score ≥3 2
- For patients with a score of 1 (excluding female sex as the only risk factor), anticoagulation should be considered 1, 2
- Female sex alone (score of 1) is not sufficient to recommend anticoagulation 2
Evidence Supporting CHA₂DS₂-VASc:
- The score has been validated in multiple populations, including those with heart failure 6
- It provides better discrimination of truly low-risk patients compared to the older CHADS₂ score 1
- Annual stroke risk increases significantly with higher scores, ranging from <1% for a score of 0 to >5% for scores ≥5 2
Glasgow-Blatchford Score
The Glasgow-Blatchford score is used to assess the risk of intervention or mortality in patients with upper gastrointestinal bleeding.
Components of Glasgow-Blatchford:
- Blood urea nitrogen level
- Hemoglobin level
- Systolic blood pressure
- Heart rate
- Presence of melena
- Presence of syncope
- Hepatic disease
- Cardiac failure
Clinical Application:
- Scores of 0-1 identify low-risk patients who may be suitable for outpatient management
- Higher scores indicate increased risk of needing intervention (transfusion, endoscopic therapy, or surgery) or death
Practical Approach to Using These Scores
For patients with AF:
- Calculate both CHA₂DS₂-VASc and HAS-BLED scores
- Use CHA₂DS₂-VASc to determine need for anticoagulation
- Use HAS-BLED to identify modifiable bleeding risk factors and determine follow-up frequency
- A high HAS-BLED score (≥3) warrants closer follow-up (e.g., 4 weeks rather than 4-6 months) 1
For patients with upper GI bleeding:
- Calculate Glasgow-Blatchford score to determine need for hospital admission and urgency of endoscopy
For patients undergoing ERCP:
- While specific scoring systems for post-ERCP bleeding are not as well established, risk factors include sphincterotomy, sphincter of Oddi dysfunction, and multiple cannulation attempts 7
Common Pitfalls and Caveats
- HAS-BLED: A high score should not lead to withholding anticoagulation but rather to addressing modifiable risk factors and closer monitoring 1, 3
- CHA₂DS₂-VASc: Female sex alone does not warrant anticoagulation; additional risk factors are needed 1, 2
- Risk Assessment: Using only modifiable bleeding risk factors without a formal scoring system is inferior to using validated scores like HAS-BLED 3
- Dynamic Nature: Bleeding risk is highly dynamic and requires regular reassessment 1, 2
- Biomarker-Based Scores: Performance of biomarker-based bleeding scores in real-world clinical practice has been disappointing 1
These risk scores provide valuable frameworks for clinical decision-making but should be considered alongside individual patient factors and preferences when determining management strategies.