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

BackgroundAtrial fibrillation (AF) is a major risk factor for ischaemic stroke and cardiovascular events. In New Zealand (NZ), maori (indigenous New Zealanders) and Pacific people experience higher rates of AF compared with non-maori/non-Pacific people. AimTo describe a primary care population with AF in NZ. Stroke risk and medication adherence according to ethnicity are also detailed. MethodsElectronic medical records for adults (20 years, n = 135840, including 19918 maori and 43634 Pacific people) enrolled at 37 NZ general practices were analysed for AF diagnosis and associated medication prescription information. ResultsThe overall prevalence of non-valvular AF (NVAF) in this population was 1.3% (1769), and increased with age (4.4% in people 55 years). maori aged 55 years were more likely to be diagnosed with NVAF (7.3%) than Pacific (4.0%) and non-maori/non-Pacific people (4.1%, P < 0.001). maori and Pacific NVAF patients were diagnosed with AF 10 years earlier than non-maori/non-Pacific patients (median age of diagnosis: maori = 60 years, Pacific = 61 years, non-maori/non-Pacific = 71 years, P < 0.001). Overall, 67% of NVAF patients were at high risk for stroke (CHA(2)DS(2)-VASc 2) at the time of AF diagnosis. Almost half (48%) of maori and Pacific NVAF patients aged <65 years were at high risk for stroke, compared with 22% of non-maori/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. ConclusionAF screening and stroke thromboprophylaxis in maori and Pacific people could start below the age of 65 years in NZ.