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: NOAC drugs; Non-valvular atrial fibrillation; anticoagulants; persistence; thromboembolic stroke.