Evolving antithrombotic treatment patterns in patients with newly diagnosed atrial fibrillation: UK findings from the GARFIELD-A

Problem

Atrial fibrillation (AF) is an independent risk factor for stroke. Oral anticoagulation has been proven as an effective therapy for stroke prevention in AF; however, there has been a longstanding problem of suboptimal use of anticoagulation in patients with AF. There is limited evidence relating to the period following the commencement of non-vitamin K antagonist oral anticoagulants (NOACs) in the UK, and it is unclear if there have been any changes in current management of AF. Using UK data from the GARFIELD-AF registry, we investigated the evolving pattern of antithrombotic therapy in newly diagnosed AF patients with ≥1 additional risk factor for stroke.

Approach

GARFIELD-AF is an ongoing, observational, international registry of newly diagnosed AF patients with ≥1 additional risk factor for stroke. Data collected at baseline include patient demographics, medical history and treatments initiated at diagnosis. Between 2010 and 2015, 2972 UK patients were enrolled in four sequential cohorts to the GARFIELD-AF registry: C1 (2010–2011) n=397, C2 (2011–2013) n=833, C3 (2013–2014) n=902, C4 (2014–2015) n=840. Baseline characteristics and antithrombotic therapy initiated at diagnosis were analysed by cohort for C2 to C4 (n=2575). C1 was excluded as it consisted predominantly of a retrospective validation cohort.

Findings

Overall, 42.9% of patients were female, the mean age ± SD was 74.4 ± 9.7 years and 89.9% had a CHA2DS2-VASc score of ≥2. From C2 to C4, the proportion of patients on anticoagulant therapy increased (C2 54.5%, C3 60.1%, C4 72.9%). The use of vitamin k antagonist (VKA) ± antiplatelet drugs (AP) decreased from C2 to C4 (C2 53.2%, C3 52.2%, C4 49.9%), while the use of NOACs ± AP increased (C2 1.3%, C3 8.0%, C4 23.0%). The increase in the use of anticoagulant was mainly in patients with CHA2DS2-VASc ≥2. The use of AP only decreased (C2 36.5%, C3 25.3%, C4 11.9%), as did the combination therapy of VKA+AP (C2 13.5%, C3 10.8%, C4 9.5%).

Consequences

These data indicate a steady and progressive improvement in the management of AF, with newly diagnosed at-risk AF patients more often receiving guideline-recommended therapy. This is significant, given the increasing prevalence of AF in the UK. The most recent data from C4 suggest an unprecedented uptake of oral anticoagulation in UK patients with AF, driven by the availability of NOACs. There is also a noteworthy decrease in the use of AP only, which is no longer recommended for AF patients.