Anticoagulant Use in Patients With Nonvalvular Atrial Fibrillation: Has Prescribing Improved?

Abstract

Discordance between international guideline recommendations and anticoagulant prescribing patterns among patients with nonvalvular atrial fibrillation (NVAF) has been frequently reported. This study was designed to compare the anticoagulant utilization pattern to earlier data in the same population and identify predictors of anticoagulant prescribing among patients with NVAF. We reviewed patients with NVAF admitted to Tasmania's 3 major hospitals between January 2011 and June 2012 and compared the anticoagulant utilization pattern to earlier data. Patients were excluded if they had only 1 episode of NVAF that reverted spontaneously or upon cardioversion. Multivariate logistic regression analysis was used to identify predictors of anticoagulant prescribing. Overall, 53.8% of patients received anticoagulant treatment compared to 40.4% 15 years ago. Among eligible patients at high-risk of stroke, 52.5% were receiving anticoagulant therapy (vs 42.1% 15 years ago). Approximately 10% of patients with a CHADS score ≥2 were not receiving any antithrombotic treatment, reduced from 18.2% in the earlier cohort, whereas anticoagulant use increased among those at low risk (score 0) to 48.5% from 14.2%. Younger age (odds ratio [OR] 0.99, 95% confidence interval [CI] 0.97-1.0; P = .04); CHADS = 1, relative to 0 (OR 1.68, 95% CI 1.07-2.63; P = .02); CHF (OR 1.56, 95% CI 1.12-2.15; P = .008); and embolic disease history (OR 1.77, 95% CI 1.09-2.86; P = .02) were significant predictors of anticoagulant prescribing. While there has been improvement over the past 15 years, suboptimal use of anticoagulant therapy among high-risk patients with NVAF remains common. There is significant potential for improvement in the quality of stroke prophylaxis in patients with NVAF.

The Tasmanian atrial fibrillation study: Transition to direct oral anticoagulants 2011‐2015

“…Despite controversy regarding its efficacy and safety, some guidelines continue to suggest low‐dose aspirin in patients with low to moderate risk of stroke (CHA 2 DS 2 ‐VASc score=0‐1) as an alternative to OAC therapy . Observational studies have typically demonstrated under‐use of anticoagulants in patients who are eligible to receive them and that antiplatelet agents are commonly used among patients with AF including those at higher risk of stroke (CHADS 2 or CHA 2 DS 2 ‐VASc≥2) …”

“…8,9 Observational studies have typically demonstrated underuse of anticoagulants in patients who are eligible to receive them and that antiplatelet agents are commonly used among patients with AF including those at higher risk of stroke (CHADS 2 or CHA 2 DS 2 -VASc≥2). [10][11][12][13] Since the 1950s, vitamin K antagonists (VKAs) were the only available OACs and most widely used antithrombotic agents for stroke prophylaxis in patients with AF. 14,15 In recent years, four direct oral anticoagulants (DOACs), namely dabigatran, rivaroxaban, apixaban, and edoxaban, have been approved for the prevention of stroke associated with nonvalvular AF (NVAF).…”

Anticoagulant Initiation During Hospital Admissions for Atrial Fibrillation in South-East Queensland, Australia

“…Interestingly, after the introduction of the DOACs, similar rates of anticoagulant prescribing to high-risk patients have been reported by Pandya et al [28] of 54% from a hospital in New South Wales. Three Tasmanian studies have also reported comparable rates with studies by Bista et al in the early post-DOAC era finding 52.5% [29] and 55.6% [30] of high-risk patients received anticoagulants, while Admassie et al [20] found this increased to 60.7% in a study ranging from 2010 to 2015. Further to this, in rural Western Australia Bellinge et al [31] found 69% of patients with AF received oral anticoagulant therapy during hospital admission, but this was for patients with a CHA₂DS₂VASc scores ≥ 1.…”

Thromboembolism and Mortality in the Tasmanian Atrial Fibrillation Study

“…A recent analysis of OAC prescribing in AF in the same population showed the proportion of patients with AF receiving OACs increased significantly over the study period. 11,19 Second, DOACs are increasingly used in patients with nonvalvular AF in preference to warfarin. 4,10 Comparative analysis involving warfarin-treated patients in this study also indicated no significant difference in the overall TE, IS/TIA, and all-cause mortality incidence rates between the 2 eras (data not shown).…”