Thromboprophylaxis of elderly patients with AF in the UK: an analysis using the General Practice Research Database (GPRD) 2000-2009

Objective To assess use of thromboprophylaxis in UK general practise among patients with atrial fibrillation (AF); to investigate whether elderly patients are less likely to receive anticoagulation therapy than younger patients. Design Retrospective cohort study Setting UK General Practice Research Database (GPRD) Patients Aged >= 60 years with a new diagnosis of AF (2000-2009). Interventions None. Main outcome measures The main outcome measure was initiation of warfarin in the first year following diagnosis. Patients were categorised by stroke risk (CHADS(2) score) and bleeding risk (HAS-BLED score). Results 81 381 patients were identified (21% aged 60-69 years, 37% aged 70-79 years, 42% aged 80+ years). Patients aged 80+ years were significantly less likely to be initiated on warfarin than younger patients, adjusted for gender, practice and comorbidities; 32% of patients aged 80+ years received warfarin compared with 57% aged 60-69 years (p<0.0001), and 55% aged 70-79 years (p<0.0001). For all strata of CHADS(2)/HASBLED scores, patients aged 80+ years were significantly less likely to be treated with warfarin than younger patients. Logistic regression showed that female sex, low Basal Metabolic Index (BMI), age over 80 years, increasing HAS-BLED score and dementia were independently associated with reduced use of warfarin. Stroke/Transient Ischaemic Attack (TIA), hypertension, heart failure and left ventricular systolic dysfunction were associated with increased use. Patients with HASBLED>CHADS(2) were less likely to be initiated on warfarin. Higher CHADS(2) scores were associated with increased anticoagulation use. Conclusions Anticoagulation is being under-used in patients with AF aged 80+ years, even after taking into account increased bleeding risk in this age group.