The Prevalence and Management of Atrial Fibrillation in New Zealand Maori Detected through an Abdominal Aortic Aneurysm Screening Programme

BackgroundAtrial fibrillation (AF) screening was incorporated into an abdominal aortic aneurysm screening (AAA) programme for New Zealand (NZ) M[a]ori. MethodsAF screening was performed as an adjunct to AAA screening of M[a]ori men aged 60-74 and women aged 65-74 registered with primary health care practices in Auckland, NZ. Pre-existing AF was determined through coded diagnoses or medications in the participants primary care record. Subsequent audit of the record assessed accuracy of pre-screening coding, medication use and clinical follow-up. ResultsAmong 1955 people screened, the prevalence of AF was 144 (7.4%), of which 46 (2.4% of the cohort) were patients without AF coded in the medical record. More than half of these were revealed to be known AF but that was not coded. Thus, the true prevalence of newly detected AF was 1.1% (n=21). An additional 48 (2.5%) of the cohort had been coded as AF but were not in AF at the time of screening. Among the 19 at-risk screen-detected people with AF, 10 started appropriate anticoagulation within 6 months. Of the 9 who did not commence anticoagulation, five had a subsequent adverse clinical outcome in the follow-up period, including one with ischaemic stroke; two had contraindications to anticoagulants. Among those with previously diagnosed AF, the proportion receiving anticoagulation rose from 57% pre-screening to 83% at 6 months post-screening (p<0.0001); among new AF the proportion rose from 0% to 53% (p<0.01). ConclusionsThere is a high prevalence of AF in NZ M[a]ori. AF screening is a feasible low-cost adjunct to AAA screening with potential to detect previously undiagnosed AF and reduce ethnic inequities in stroke. It may also prompt better coding and management of previously diagnosed AF. However, effective fail-safe measures are needed to ensure that high-risk newly diagnosed AF is managed according to best practice guidelines.