The CHADS2 score is a clinical prediction rule for estimating the risk of stroke in patients with non-rheumatic atrial fibrillation (AF), a common and serious heart arrhythmia associated with thromboembolic stroke. It is used to determine whether or not treatment is required with anticoagulation therapy or antiplatelet therapy, since AF can cause stasis of blood in the upper heart chambers, leading to the formation of a mural thrombus that can dislodge into the blood flow, reach the brain, cut off supply to the brain, and cause a stroke. A high CHADS2 score corresponds to a greater risk of stroke, while a low CHADS2 score corresponds to a lower risk of stroke.


The above description is from the relevant wikipedia entry, for more detail see:


The CHA2DS2VASc score includes the following risk factors:

  • C = Congestive heart failure (1 point)
  • H = Hypertension (1 point)
  • A = age ≥ 75 (2 points) 
  • D = Diabetes (1 point)
  • S = prior Stroke or TIA (2 points)
  • V = vascular disease (prior MI or peripheral artery disease) (1 point)
  • A = age 65-74 (1 point)
  • Sc = female gender (1 point)

The graph below shows how patients with an existing diagnosis of AF are scored according to the risk factors and the patient details can be displayed by double clicking on any part of the graph.

The risk ranges are:

green : 0 Male or 1 Female

yellow : 1 Male

red : >= 2 Male and Female

Patients with missing age/gender are displayed separately as no score can be calculated.