Early therapeutic persistence on dabigatran versus warfarin therapy in patients with atrial fibrillation: results from the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT-AF) registry

Anticoagulation is highly effective for the prevention of stroke in patients with atrial fibrillation (AF) but it is dependent on patients continuing therapy. While studies have demonstrated suboptimal therapeutic persistence on warfarin, few have studied persistence rates with non vitamin K antagonist oral anticoagulants (NOACs) such as dabigatran. We examined rates of continued use of dabigatran versus warfarin over 1 year among AF patients in the ORBIT-AF registry between June 29, 2010 and August 09, 2011. Multivariable logistic regression analysis was used to identify characteristics associated with 1-year persistent use of dabigatran therapy or warfarin. At baseline, 6.4 and 93.6% of 7150 AF patients were on dabigatran and warfarin, respectively. At 12 months, dabigatran-treated patients were less likely to have continued their therapy than warfarin-treated patients [Adjusted persistence rates: 66% (95% CI 60-72) vs. 82% (95% CI 80-84), p < .0001]. Predictors of dabigatran persistence included: CHA₂DS₂-VASc risk scores ≥ 2 OR 5.69, (95% CI 1.50-21.6) and BMI greater than 25 mg/m² but less than 38 kg/m² 1.05 (1.01-1.09). Predictors of persistence on warfarin included: African American race (vs. White) 1.53 (1.07-2.19), Hispanic ethnicity (vs. White) 1.66 (1.06-2.60), paroxysmal and persistent AF (vs. new-onset) 1.68 (1.21-2.33) and 1.91 (1.35-2.69) respectively, LVH 1.40 (1.08-1.81), and CHA₂DS₂-VASc risk scores ≥ 2 1.94 (1.18-3.19). While 1-year persistence rates for dabigatran were lower than warfarin, persistence rates for both agents were not ideal. Future studies evaluating contemporary persistence are needed in order to assist in better targeting interventions aimed to improve anticoagulation persistence.