Questions

1. What is the popular scoring system for determining a patient’s need for anticoagulation to prevent stroke in atrial fibrillation?
2. If you do start anticoagulation, what are some scoring systems to determine a patient’s risk for bleeding while on anticoagulation?

Answers

1. CHA₂DS₂-VASc is the most utilized scoring systems for determining anticoagulant selection to prevent stroke in patients with atrial fibrillation.  The components are as follows
   1. CHF (+1)
   2. HTN (+1)
   3. Age
      1. < 65yr (0)
      2. 65-74 (+1)
      3. ≥ 75 (+2)
   4. DM (+1)
   5. Stroke/TIA (+2)
   6. Vascular disease (+1)
   7. Sex category (+1 for female)
   8. Interpretation:
      1. 0 points (low risk) – consider antiplatelet only
      2. 1 point (low/moderate risk) – antiplatelet or anticoagulation
      3. ≥ 2 points (moderate/high risk) – anticoagulation
2. If you are deciding on whether to start anticoagulation or not, you should determine the bleeding risk of your patient on anticoagulation.  There are three scoring systems that can help with this:
   1. ATRIA
      1. Anemia (Hgb < 13g/dL in male and < 12g/dL in female)(+3)
      2. Severe renal disease (GFR < 30mL/min or dialysis)(+3)
      3. Age ≥ 75yr (+2)
      4. History of bleeding (+1)
      5. HTN (+1)
      6. Interpretation:
         1. < 4 points – low risk
         2. 4 points – intermediate risk
         3. > 4 points – high risk
   2. HASBLED
      1. HTN (uncontrolled or > 160mmHg)(+1)
      2. Renal disease (+1)
      3. Liver disease (+1)
      4. Stroke history (+1)
      5. Prior bleeding history (+1)
      6. Labile INR (+1)
      7. Age ≥ 65 (+1)
      8. Medications (+1)
      9. Alcohol (+1)
      10. Interpretation:
          1. 0 points – low risk
          2. 1-3 points – moderate risk
          3. ≥ 4 points – high risk
   3. HEMORR₂HAGES
      1. Hepatic or renal disease (+1)
      2. Ethanol use (+1)
      3. Malignancy (+1)
      4. Older than 75 (+1)
      5. Reduced platelet count/function (+1)
      6. Rebleeding risk (+2)
      7. HTN (+1)
      8. Anemia (+1)
      9. Genetics (+1)
      10. Excessive fall risk (+1)
      11. Stroke history (+1)
      12. Interpretation:
          1. 0-1 points – low risk
          2. 2-3 points – intermediate risk
          3. ≥ 4 points – high risk

References

1. Lip GY, Nieuwlaat R, Pisters R, Lane DA, Crijns HJ. Refining clinical risk stratification for predicting stroke and thromboembolism in atrial fibrillation using a novel risk factor-based approach: the euro heart survey on atrial fibrillation. Chest. 2010; 137(2):263-72. [pubmed]
2. Fang MC, Go AS, Chang Y, et al. A new risk scheme to predict warfarin-associated hemorrhage: The ATRIA (Anticoagulation and Risk Factors in Atrial Fibrillation) Study. Journal of the American College of Cardiology. 2011; 58(4):395-401. [pubmed]
3. Pisters R, Lane DA, Nieuwlaat R, de Vos CB, Crijns HJ, Lip GY. 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. 2010; 138(5):1093-100. [pubmed]
4. Gage BF, Yan Y, Milligan PE, et al. Clinical classification schemes for predicting hemorrhage: results from the National Registry of Atrial Fibrillation (NRAF). American heart journal. 2006; 151(3):713-9. [pubmed]
5. Ruff T.  Which risk score best predicts bleeding with warfarin in atrial fibrillation?.  Online – American College of Cardiology. Sept. 26, 2011 [link]