[New international guidelines on antithrombotic therapy in atrial fibrillation].

BACKGROUND: The American College of Cardiology/American Heart Association/European Society of Cardiology and American College of Chest Physicians have recently revised international guidelines on antithrombotic therapy in atrial fibrillation. This may influence clinical practice in Norway.

MATERIAL AND METHODS: Potential impact on Norwegian clinical practice is discussed in light of the guidelines mentioned above and other relevant literature.

RESULTS: Several studies have indicated that the risk of stroke associated with atrial fibrillation is lower than previously anticipated, and the revised international guidelines have taken this into account. The new guidelines emphasize the CHADS2 score as a tool to decide which patients should receive warfarin. Points are assigned based on simple clinical characteristics of the patients: Congestive heart failure 1 point; Hypertension 1 point; Age > 75 years 1 point; Diabetes 1 point; Prior stroke or transitory ischemic attack 2 points. Aspirin is recommended to patients with a CHADS2 score of 0 points; warfarin or aspirin to patients with 1 point, and warfarin to patients with >or= 2 points.

INTERPRETATION: The new international guidelines give a slightly higher threshold for recommending warfarin to patients with atrial fibrillation. The CHADS2 score, which is based on simple clinical characteristics, has been shown to be reliable and may contribute to improved risk stratification in patients with atrial fibrillation.