Higher CHADS2 scores can indicate higher risk in patients on anticoagulants
Higher CHADS2 scores pointed to higher risk for adverse outcomes, including stroke, bleeding and death, in patients with atrial fibrillation receiving anticoagulation, according to a new study.
Higher CHADS2 scores pointed to higher risk for adverse outcomes, including stroke, bleeding and death, in patients with atrial fibrillation receiving anticoagulation, according to a new study.
Researchers performed a subgroup analysis of data from the RE-LY study, a randomized, controlled trial comparing dabigatran and warfarin in patients with atrial fibrillation, to determine the prognostic importance of CHADS2 for predicting thrombotic and bleeding complications in this population. The 18,112 study patients were receiving dabigatran, 150 mg or 110 mg twice daily, or open-label warfarin. CHADS2 score, which assigns 1 point each for congestive heart failure, hypertension, age at least 75 years and diabetes and 2 points for stroke, was assessed at baseline. The primary outcomes were stroke or systemic embolism, and the primary safety outcome was major bleeding. Secondary outcomes included intracranial hemorrhage, vascular death and total death. The results of the study, which was funded by Boehringer Ingelheim, appear in the Nov. 15 Annals of Internal Medicine.
Overall, 5,775 patients had a CHADS2 score of 0 to 1, 6,455 patients had a score of 2, and 5,882 patients had a score of 3 to 6. The annual rate of stroke or systemic embolism was 0.93% in patients with a CHADS2 score of 0 to 1, 1.22% in patients with a score of 2, and 2.24% in patients with a score of 3 to 6. Patients with higher CHADS2 scores also had higher annual rates of major bleeding and vascular mortality (P<0.001 for all comparisons). Rates of all adverse outcomes increased in both the warfarin and dabigatran groups as CHADS2 scores increased. Rates of stroke or systemic embolism were lower in patients taking 150 mg of dabigatran twice daily than in those taking warfarin, while rates of intracranial bleeding were lower in patients taking either dose of dabigatran than in those taking warfarin.
The authors cautioned that their study involved post hoc, exploratory analyses and that the levels of statistical significance must be interpreted carefully, among other limitations. However, they concluded that increasing CHADS2 scores were associated with increased risk for adverse outcomes, including death, in patients with atrial fibrillation receiving anticoagulation.