A widely used clinical score for predicting stroke risk in patients with atrial fibrillation also predicts bleeding risk in those taking anticoagulants, a large sub-group analysis shows.
In the RE-LY trial of 18,000 patients receiving anticoagulation with either warfarin or dabigatran, CHADS2 scores were given on the basis of one point each for congestive heart failure, hypertension, age over 75 and diabetes, and two points for previous stroke.
Annual rates of stroke were 0.93% for scores of zero to one, 1.22% for a score of two, and 2.24% for a score of three to six.
Those with higher CHADS2 scores were not only at higher risk of stroke as expected but were also at increased risk for severe bleeding complications and death during treatment with warfarin or dabigatran.
The risk of major bleeding was found to be 2.26% for those in the zero to one group, 3.11% in those with a score of two, and 4.42% in the three to six group.
Study leader Dr Jonas Oldgren, chief physician in the department of cardiology at Uppsala University Hospital in Uppsala, Sweden, said the results could guide doctors in assessing the risks and benefits of anticoagulant therapy in atrial fibrillation.
Annals of Internal Medicine 2011; 155:660-7
