Wednesday, August 03, 2011
warfarin stroke
Summary and Comment
Stroke Risk-Stratification Scores Have Limited Prognostic Value in Elders with AF
The authors suggest anticoagulation for all elders with atrial fibrillation.
Several stroke risk-stratification scores are available to determine which patients with atrial fibrillation (AF) will benefit from long-term warfarin anticoagulation. However, these scores were based on populations in which elders — the group most likely to have AF — were underrepresented. In this study, U.K. investigators compared the predictive power of eight stroke risk-stratification scores (CHADS2 original, CHADS2 revised, Framingham, NICE, ACC/AHA/ESC, ACCP, CHA2DS2-VASchttp://general-medicine.jwatch.org/articles/JO2011030301.jpg, and Rietbrock modified CHADS2) among 665 participants (age, 
75; mean age, 81; 55% men) with AF who did not take warfarin throughout or for part of the Birmingham Atrial Fibrillation Treatment of the Aged (BAFTA) trial.
After median follow-up of 2.2 years, 54 participants (8.0%) experienced ischemic stroke, 13 (2.0%) had transient ischemic attacks, and 4 (0.6%) suffered systemic embolism. All scores performed poorly (C-statistic range, 0.55–0.62, indicating that prediction of stroke for any given person wasn't much better than chance).
Comment: In this study, various stroke risk-stratification scores had limited ability to predict ischemic stroke in elders with AF. The authors conclude that "until better scores are available," clinicians should consider all older patients (age, 75) with AF to be at high risk for stroke and should offer long-term anticoagulation to those who are appropriate candidates for this treatment (rather than prescribing aspirin, which is less effective in preventing stroke and is associated with an incidence of major bleeding events that is similar to warfarin's in this population).
— Paul S. Mueller, MD, MPH, FACP
Published in Journal Watch General Medicine August 2, 2011
