UCSF

OBJECTIVES: We sought to investigate the prevalence and predictors of oral anticoagulation prescription among patients with atrial fibrillation (AF) at the lowest risk for thromboembolism, despite contemporary consensus guidelines that do not recommend anticoagulation therapy in this population. BACKGROUND: In young and healthy AF patients without significant thromboembolic risk factors, anticoagulant treatment carries bleeding risks that outweigh stroke prevention benefit. METHODS: Within a large contemporary registry of cardiology outpatients, we identified low-risk patients with AF meeting criteria for a contemporary consensus guideline class III indication against use of anticoagulation (age < 60 years, CHADS2 Score=0, and no structural heart disease) between 2008–2012, and a second cohort with the same criteria and a CHA2DS2-VASc Score of 0. Using hierarchical modified Poisson regression models adjusted for patient characteristics, we examined predictors of oral anticoagulation treatment in these low thromboembolic risk AF patients. RESULTS: Oral anticoagulation was prescribed in a total of 2,561 of 10,995 (23.2%) AF patients with a CHADS2 score of 0 and 1,787 of 6,730 (26.6%) AF patients with a CHA2DS2-VASc score of 0. In multivariable analysis, older age (RR 1.48 per 10 years; 95% CI, 1.41–1.56; p<0.0001), male sex (RR 1.34; 95% CI, 1.22–1.46; p<0.0001), higher body mass index (RR 1.18 per 5 kg/m2; 95% CI, 1.14–1.22; p<0.0001), and Medicare insurance (reference: private insurance; RR,1.32; 95% CI, 1.17–1.49; overall p<0.0001) were associated with a higher likelihood of oral anticoagulant prescription, whereas treatment in Southern states (reference: Northeast; RR 0.69; 95% CI, 0.49–0.98;overall p=0.1187) was associated with a lower likelihood of oral anticoagulant prescription. CONCLUSIONS: In a large, real-world population of AF patients with the lowest thrombotic risk, approximately 1 in 4 were treated with oral anticoagulation against contemporary guideline recommendations.