Medium- to long-term persistence with non-vitamin-K oral anticoagulants in patients with atrial fibrillation: Australian experience

Abstract

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

Research design and methods: We assessed national Pharmaceutical Benefit Scheme records December 2013 through September 2016 for initial prescription of a NOAC in a 10% random sample of concessional patients. Key outcome measures were: (a) proportions filling first repeat prescription, (b) proportions persisting with NOAC over 12 and 30 months and (c) proportions switching to another NOAC or warfarin.

Results: A total of 8656 patients with AF initiated a NOAC (3352 apixaban, 1340 dabigatran, 3964 rivaroxaban). Mean age was 77 years, 53% male; 91% collected the first repeat prescription for any NOAC, 70% and 57% collected any NOAC or subsequent warfarin prescription over 12 months and 30 months respectively; 8.9% had switched to warfarin. The proportions switching from apixaban, dabigatran and rivaroxaban to a different NOAC were 14%, 31% and 17% respectively. In a regression model adjusting for age, gender and comorbidity, apixaban-initiated patients over 30 months were 28% more likely to persist with any anticoagulant therapy compared with dabigatran-initiated patients (hazard ratio [95% CI] 1.28 [1.16–1.42]) and 15% more likely to persist compared with rivaroxaban-initiated (1.15 [1.06–1.24]). Rivaroxaban-initiated patients were 12% more likely to persist compared with dabigatran-initiated patients (1.12 [1.02–1.24]).

Conclusions: Long-term persistence with anticoagulation in patients with AF remains a concern, even with NOACs. Patients initiated to apixaban appear to experience better medium-term persistence compared with rivaroxaban or dabigatran.

Keywords:

• Non-valvular atrial fibrillation
• thromboembolic stroke
• anticoagulants
• NOAC drugs
• persistence

Transparency

Declaration of funding

Raw data for the study was 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 MSD Australia. M.O. and B.J.W. have disclosed that they are paid consultants to the study. 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.

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