Source: Academic Life in Emergency Medicine
Anticoagulation in Atrial Fibrillation
Waldo AL. Cardiol Clin 2009; 27:125-35.
Atrial Fibrillation (AF) = 5x risk for CVA and increases with age
Stroke risk stratification for patients with AF:
- Prior CVA or TIA
- HTN
- Age ≥ 75
- CHF
- Poor LV function
- DM
CHADS2 stroke risk stratification scheme (Gage BF et al. JAMA 2001;285:2864–70.)
- C = Congestive heart failure (1 pt)
- H = Hypertension (1 pt)
- A = Age ≥ 75 (1 pt)
- D = DM (1 pt)
- S2 = prior Stroke or TIA (2 pts)
Deciding whether to anticoagulate with ASA or Warfarin:
(AHA/ ACC/ European Soc of Cardiology 2006 revised guidelines
for antithrombotic therapy based on stroke risk)
Weak Risk Factors Moderate Risk Factors High Risk Factors
Female gender Age > 75 Prior CVA, TIA, embolism
Age 65-74 HTN Mitral stenosis
CAD Heart failure Mechanical heart valve
Thyrotoxicosis LVEF ≤ 35%
DM
Treatment Treatment Treatment
ASA or Warfarin ASA or Warfarin (1 risk factor) Warfarin
Warfarin (≥ 2 risk factors)
* Anticoagulation goal with Warfarin is INR 2-3
* If age < 60 years and zero risk factors: No anticoagulation b/c low risk for CVA
