Temporal trends in antithrombotic treatment of real-world UK patients with newly diagnosed atrial fibrillation: findings from the GARFIELD-AF registry

Abstract

Objective: To investigate evolving patterns in antithrombotic treatment in UK patients with newly diagnosed non-valvular atrial fibrillation (AF).

Design: Prospective, multicentre, international registry.

Setting: 186 primary care practices in the UK.

Participants: 3482 participants prospectively enrolled in four sequential cohorts (cohort 2 (C2) n=830, diagnosed September 2011 to April 2013; cohort 3 (C3) n=902, diagnosed April 2013 to June 2014; cohort 4 (C4) n=850, diagnosed July 2014 to June 2015; cohort 5 (C5) n=900, diagnosed June 2015 to July 2016). Participants had newly diagnosed non-valvular AF and at least one risk factor for stroke, were aged ≥18, and provided informed consent.

Main outcome measures: Antithrombotic treatment initiated at diagnosis, overall and according to stroke and bleeding risks. Stroke risk was retrospectively calculated using CHA₂DS₂-VASc (cardiac failure, hypertension, age ≥75 (doubled), diabetes, stroke (doubled)-vascular disease, age 65-74 and sex category (female)) and bleeding risk using HAS-BLED (hypertension, abnormal renal/liver function (1 point each), stroke, bleeding history or predisposition, elderly (>65), drugs/alcohol concomitantly (1 point each)).

Results: 42.7% were women and the mean age was 74.5 years. The median CHA₂DS₂-VASc score was 3 in all cohorts and the median HAS-BLED score was 2 in all cohorts. There was a statistically significant increase in the use of anticoagulant therapy from C2 to C5 (C2 54.7%, C3 60.3%, C4 73.1%, C5 73.9%; P value for trend <0.0001). The increase in the use of anticoagulant was mainly in patients with CHA₂DS₂-VASc ≥2. The use of vitamin K antagonists (VKAs)±antiplatelet (AP) drugs decreased from C2 to C5 (C2 53.3%, C3 52.1%, C4 50.3%, C5 30.6%), while the use of non-vitamin K antagonist oral anticoagulants (NOACs)±AP increased (C2 1.3%, C3 8.0%, C4 22.7%, C5 43.3%). The use of AP only decreased (C2 36.4%, C3 25.5%, C4 11.9%, C5 10.5%), as did the combination therapy of VKA+AP (C2 13.6%, C3 11.0%, C4 9.6%, C5 5.8%).

Conclusion: There has been a progressive increase in the proportion of patients newly diagnosed with AF receiving guideline-recommended therapy in the UK, potentially driven by the availability of NOACs.

Trial registration number: NCT01090362; Pre-results.

Keywords: anticoagulation; antithrombotic therapy; atrial fibrillation; newly diagnosed; stroke prophylaxis.

Figure 1

Antithrombotic treatment at diagnosis by cohort. AP, antiplatelet; DTI, direct thrombin inhibitor; FXaI, factor Xa inhibitor; VKA, vitamin K antagonist.

Figure 2

Antithrombotic treatment at diagnosis by CHA₂DS₂-VASc and cohort, for patients with a score of 0, 1 and ≥2. *Includes women with no other risk factors. The total population represented by n excludes unknowns. Patients with missing CHA₂DS₂-VASc score: C2, 35; C3, 58; C4, 49; C5, 65. AP, antiplatelet; CHA₂DS₂-VASc, cardiac failure, hypertension, age ≥75 (doubled), diabetes, stroke (doubled)–vascular disease, age 65–74 and sex category (female); DTI, direct thrombin inhibitor; FXaI, factor Xa inhibitor; VKA, vitamin K antagonist.

Figure 3

Antithrombotic treatment at diagnosis by HAS-BLED score and cohort, for patients with a score of 0–2 and ≥3. AP, antiplatelet; DTI, direct thrombin inhibitor; FXaI, factor Xa inhibitor; HAS-BLED, hypertension, abnormal renal/liver function (1 point each), stroke, bleeding history or predisposition, elderly (>65), drugs/alcohol concomitantly (1 point each); VKA, vitamin K antagonist.