MONDAY, Sept. 24, 2018 (HealthDay News) -- There is variation in the net clinical benefit of anticoagulants based on variation in published atrial fibrillation (AF) stroke rates, according to a study published online Sept. 25 in the Annals of Internal Medicine.
Sachin J. Shah, M.D., M.P.H., from the University of California in San Francisco, and colleagues examined the effect of variation in published AF stroke rates on the net clinical benefit of anticoagulation among 33,434 adults with incident AF.
The researchers found that 27,179 of the patients had a congestive heart failure, hypertension, age, diabetes, stroke, and vascular disease (CHA2DS2-VASc) score of two or more. For these patients, the population benefit of warfarin anticoagulation was least using stroke rates from the Anticoagulation and Risk factors in Atrial Fibrillation (ATRIA) study and greatest using those from the Danish National Patient Registry (6,290 versus 24,110 quality-adjusted life-years). The optimal CHA2DS2-VASc score threshold for anticoagulation was three or more, two or more, one or more, and zero using stroke rates from ATRIA, the Swedish AF cohort study, the Stroke Prevention using Oral Thrombin Inhibitor in Atrial Fibrillation study, and the Danish National Patient Registry, respectively. Optimal CHA2DS2-VASc score thresholds were reduced after accounting for lower rates of non-vitamin K antagonist oral anticoagulants-associated intracranial hemorrhage.
"Guidelines should better reflect the uncertainty in current thresholds of stroke risk score for recommending anticoagulation," the authors write.
Several authors disclosed financial ties to the pharmaceutical industry.