Atrial Fibrillation

Atrial fibrillation (AF) is the most common significnat cardiac arrhythmia and is a leading cause of stroke in the elderly. Stroke from AF is embolic. Numerous clinical trials have demonstrated that anticoagulation with warfarin is the most effective method of stroke prevention. However, anticoagulation treatment is associated with a higher requency of hemmorhagic complications and is more burdensome to admionister and monitor. It is often difficult to decide which patients with atrial fibrillation require systemic anticoagulation for stroke prevention. For those with frequent paroxysmal, persistent or chronic AF, two risk stratification schemes, the CHADS2 and CHADS2-VASc scores have been developed. These schemes provide an estimate pf the patients stroke risk and a guide to anticoagulation treatment.

Choose all stroke risk factors:present:

The CHADS2  score is the most widely used and best validated risk scheme, having been tested in more than a dozen cohorts.
Despite its widespread adoption however, the CHADS2  score has several mportant limitations. Among them are it's modest predictive ablility, and it's classification of a large group of patients as being indeterminate risk.
In an effort to identify truly low risk patients with AF, the CHADS2-VASc score was developed by incorporating additional risk factors. Although the overall predictive ability is similar to the CHADS2  score, the CHADS2-VASc score consistently improved the identification of “truly low risk” AF patients.

Annual stroke risk according to risk score

Stroke Score Annual Stroke Risk
0 1.9
1 2.8
2 4
3 5.9
4 8.5
5 12.5
6 18.2