BackgroundPatients with both atrial fibrillation (AF) and cardiovascular disease (CVD) may receive dual-antithrombotic therapy (DAT) with both an anticoagulant and one or more antiplatelet agents. Avoiding prolonged duration of therapy and use of gastroprotective therapies reduces bleeding risk.AimTo describe the extent and duration of DAT and use of gastroprotection in a primary care cohort of patients with AF.Design & settingObservational study in 1.2 million people registered with general practitioners across four east London Clinical Commissioning Groups, covering prescribing from January 2020 to June 2021.MethodIn patient with AF, we characterised factors associated with DAT prescription, prolonged DAT prescription (>12 months), and gastroprotective prescription using logistic regression.ResultsThere were 8,881 patients with AF of whom 4.7% (416) were on DAT. Of these, 65.9% (274) were prescribed DAT for >12 months and 84.0% (351) were prescribed concomitant gastroprotection. Independent of all other factors, women with AF were less likely to receive DAT than men [OR =0.61 (0.49–0.77)]. Similarly, older (≥75 years) individuals [OR =0.79 (0.63–0.98)]) were less likely to receive DAT than younger patients. Amongst those with AF on DAT, people with CVD [OR =3.33 (1.71–6.47)] or South Asian ethnicity [OR =2.70 (1.15–6.32)] were associated with increased gastroprotection prescriptions. Gastroprotection prescription [OR =1.80 (1.01–3.22)] was associated with prolonged DAT prescription.ConclusionAlmost two thirds of patients with AF on DAT were prescribed prolonged durations of therapy. Prescription of gastroprotection therapies was suboptimal in 1 in 6 patients. Treatment decisions varied by sex, age, ethnicity, and comorbidity. Duration of DAT and gastroprotection in patients with AF requires improvement.