The Net Clinical Benefit of Warfarin: Extending the Reach of Antithrombotic Therapy for Atrial Fibrillation
The decision to use antithrombotics for stroke prevention in atrial fibrillation (AF) requires assessment of an individual patient's risk of stroke balanced with their likelihood of bleeding on treatment. United States (U.S.) practice guidelines have recommended the use of the CHADS2 score (graded from 0 to 6 according to presence of major risk factors, see Table 1) for assessment of stroke risk in patients with AF.1 However, this score cannot precisely categorize all patients at different risks of thromboembolism.2 The CHADS2 model does not account for certain previously underappreciated risk factors, including the increase in stroke risk with age in patients less than 75 years old and in those with vascular disease, and thus allocates many patients to the low and intermediate risk categories who might actually be relatively stroke-prone.3 The 2010 European Society of Cardiology (ESC) guidelines for the management of AF4 recommend use of the more inclusive CHA2DS2-VASc score (graded 0 to 9, see Table 1), which incorporates additional risk factors including age 65-74 years and vascular disease. Validation studies have shown that the CHA2DS2-VASc score performs better than CHADS2 in distinguishing patients at low or intermediate thromboembolic risk.5 In a large Danish registry, thromboembolism rates at 1 year for patients at low risk (score = 0) were 0.78%/year with CHA2DS2-VASc and 1.67%/year with CHADS2.6 (SELECT FULL TEXT TO CONTINUE)
- Received April 10, 2012.
- Accepted April 11, 2012.
- Copyright © 2012, American Heart Association, Inc. All rights reserved. Unauthorized use prohibited