Burden of atrial fibrillation in Māori and Pacific people in New Zealand: a cohort study

Background Atrial fibrillation (AF) is a major risk factor for ischaemic stroke and cardiovascular events. In New Zealand (NZ), Māori (indigenous New Zealanders) and Pacific people experience higher rates of AF compared with non‐Māori/non‐Pacific people. Aim To describe a primary care population with AF in NZ. Stroke risk and medication adherence according to ethnicity are also detailed. Methods Electronic medical records for adults (≥20 years, n = 135 840, including 19 918 Māori and 43 634 Pacific people) enrolled at 37 NZ general practices were analysed for AF diagnosis and associated medication prescription information. Results The overall prevalence of non‐valvular AF (NVAF) in this population was 1.3% (1769), and increased with age (4.4% in people ≥55 years). Māori aged ≥55 years were more likely to be diagnosed with NVAF (7.3%) than Pacific (4.0%) and non‐Māori/non‐Pacific people (4.1%, P < 0.001). Māori and Pacific NVAF patients were diagnosed with AF 10 years earlier than non‐Māori/non‐Pacific patients (median age of diagnosis: Māori = 60 years, Pacific = 61 years, non‐Māori/non‐Pacific = 71 years, P < 0.001). Overall, 67% of NVAF patients were at high risk for stroke (CHA2DS2‐VASc ≥ 2) at the time of AF diagnosis. Almost half (48%) of Māori and Pacific NVAF patients aged <65 years were at high risk for stroke, compared with 22% of non‐Māori/non‐Pacific (P < 0.001). Irrespective of ethnic group, adherence to AF medication was suboptimal in those NVAF patients with a high risk of stroke or with stroke history. Conclusion AF screening and stroke thromboprophylaxis in Māori and Pacific people could start below the age of 65 years in NZ.