Patterns of long-term use of non-vitamin K antagonist oral anticoagulants for non-valvular atrial fibrillation: Quebec observational study.

Abstract

Studies on long-term utilization of non-vitamin K antagonist oral anticoagulants (NOACs) in non-valvular atrial fibrillation (NVAF) are scarce. We evaluated predictors of use and long-term persistence of NOACs in a real-world setting. This population-based cohort study used the computerized databases of the Canadian Province of Quebec's health insurance. Patients with a first NVAF diagnosis from 2011 until 2014 were included. A logistic regression model yielded adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for predictors of treatment initiation with NOACs versus VKAs. Cox proportional hazards models yielded adjusted hazard ratios (HRs) and 95% CIs for predictors of switching from VKAs to NOACs versus remaining on VKAs, and for predictors of discontinuation of anticoagulation treatment. Of the 62867 newly diagnosed NVAF patients, 14646 initiated NOACs and 17685 VKAs. Initiation with NOACs was less likely for patients ≥ 80 years old (OR 0.55, 95% CI 0.41-0.73) or with CHA2 DS2 -VASc ≥ 2 (OR 0.49, 95% CI 0.42-0.57). Switching from VKAs to NOACs was less likely for patients with chronic kidney disease (HR 0.53, 95% CI 0.48-0.59). After 3 years, persistence was 54% with NOACs and 25% with VKAs. Discontinuation of anticoagulation treatment was less likely for patients ≥ 80 years old (HR 0.47, 95% CI 0.40-0.55) or with CHA2 DS2 -VASc ≥ 2 (HR 0.64, 95% CI 0.57-0.70). Older, high-risk patients are less likely to initiate NOACs than VKAs. NOAC users show a higher long-term persistence than VKA users, and older, high-risk patients are less likely to discontinue anticoagulation treatment.