Improved persistence with non-vitamin-K oral anticoagulants compared with warfarin in patients with atrial fibrillation: recent Australian experience

Abstract

Objective: Long-term anticoagulant therapy in patients with non-valvular atrial fibrillation (AF) is essential to prevent thromboembolic complications, especially ischemic stroke, but treatment persistence with warfarin is poor. This study examines Australian nationwide persistence in AF patients using a non-vitamin-K oral anticoagulant (NOAC) drug.

Research design and methods: We assessed national Pharmaceutical Benefit Scheme records November–December 2013 through March 2015 for prescription of NOAC drugs in a 10% random sample of long-term concession card holders. An historical comparison was made with patients prescribed warfarin in 2008. Key outcome measures were (i) the proportion not filling first repeat prescription and (ii) discontinuation within 12 months.

Results: A total of 1471 patients with AF were new users of a NOAC drug (228 apixaban, 645 dabigatran, 598 rivaroxaban) and 1348 were new users of warfarin. Mean age on a NOAC was 76 years (58% male), on warfarin 74 years (54% male). Only 9% (95% CI 7–10) failed to collect the first repeat prescription on a NOAC, 30% (27–32) discontinued within 12 months; corresponding proportions on warfarin were 14% (12–16) and 62% (60–65). In a regression model adjusted for age, gender, heart failure, hypertension and diabetes, warfarin-treated patients were 2.5 times more likely to discontinue over 12 months than those who were NOAC treated (hazard ratio =2.47 [95% CI 2.19–2.79]).

Conclusions: Persistence with NOAC drugs in patients with AF appears to be superior to warfarin. If continued long-term, this alone will be of clinical importance in the prevention of stroke and death.

Keywords:

• Adherence
• Anticoagulants
• Medication persistence
• NOAC drugs
• Non-valvular atrial fibrillation
• Thromboembolic stroke
• Warfarin

Transparency

Declaration of funding

Raw data for the study were supplied by the Australian Department of Human Services. The study was partially supported by a research grant from Bristol-Myers Squibb Australia Pty Ltd and Pfizer Australia Pty Ltd, companies that market apixaban. The sponsors made no direct input to study design, analysis or content of this paper.

Author contributions: All authors contributed equally to study design, interpretation and manuscript preparation. B.J.W. conducted data extraction and analysis.

Declaration of financial/other relationships

L.A.S. has disclosed that he is a consultant to Amgen Australia and serves on a speaker bureau for Merck Sharpe & Dohme Australia. M.O. and B.J.W. have disclosed that they are paid consultants to the study. S.B.F. and D.C. have disclosed that they have received sponsorship, research grants and speaker fees from the manufacturers of NOAC drugs and other pharmaceutical companies. G.T. has disclosed that he is an employee of Pfizer Australia.

CMRO peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Acknowledgments

Previous presentation: Preliminary results were presented in a poster to the Cardiac Society of Australia and New Zealand scientific meeting, Melbourne, Australia, 14–16 August 2015. Abstract in Heart Lung and Circulation 2015;24:S457.