Use of the CHA2DS2-VASc score instead of the CHADS2 score for thromboembolic risk stratification and initiation of oral anticoagulation (OAC) was recommended in the 2014 American Heart Association/American College of Cardiology/Heart Rhythm Society atrial fibrillation (AF) guidelines. We sought to define the proportion of patients with AF qualifying for and receiving OAC in contemporary practice by applying the CHA2DS2-VASc score to patients with a low CHADS2 score.Methods and Results—
Among patients with AF enrolled in the American College of Cardiology National Cardiovascular Data Registry’s outpatient Practice Innovation and Clinical Excellence registry (2008–2014) CHADS2 score of 0 or 1, we calculated the impact of adoption of the CHA2DS2-VASc score on the proportion of patients with an indication for OAC. We examined trends in prescription of OAC overall, direct OAC (dabigatran/rivaroxaban/apixaban), and multivariable associations between clinical characteristics and OAC use. Of 346 068 patients with AF aged 65±12 years, 61% were men and 65% were white. In total, 24% of those with CHADS2=0 and 81% of those with a CHADS2=1 were reclassified as having a definite indication for OAC (CHA2DS2-VASc score ≥2). OAC use increased from 37% to 48% during the study period, and direct OAC use increased from 5% to 30%. Increasing CHA2DS2-VASc score (odds ratio, 2.07; 95% confidence interval, 1.97–2.19 for score of 4 versus 0) and rhythm control strategy (odds ratio, 1.34; 95% confidence interval, 1.30–1.39) were associated with increased OAC use.Conclusions—
Adoption of the CHA2DS2-VASc score reclassifies 64.5% of patients with AF with low CHADS2 scores into a class I indication for OAC prescription. Overall OAC prescription increased between 2011 and 2014.