Background: Oral anticoagulants decrease the risk of stroke associated with atrial fibrillation (AF). ARCOS IV reported a 26.5% anticoagulant rate among AF related stroke admissions, but this data is nearly 10 years old. Little is known about potential ethnic and regional differences in anticoagulation patterns for AF in Aotearoa New Zealand.
Aims: To describe AF patient characteristics and anticoagulation patterns in Aotearoa.
Methods: REGIONS Care is a prospective, nationwide, observational study of consecutive adult stroke patients admitted to hospital between 1 May and 31 October 2018. AF and anticoagulation prescribing, intracerebral haemorrhage (ICH), and differences by Māori ethnicity and hospital location are described.
Results: Of 2379 patients, 807 (34.3%) had a diagnosis of AF. AF patients were older than non-AF patients (mean 79.9 (SD 11) versus 72.5 (14.2), P<0.0001). AF was diagnosed before stroke in 666 patients (82.5%) and of these 442 (66.4%) were taking an anticoagulant at the time of their stroke. The most common documented reasons for non-anticoagulation were prior bleeding (20.5%), patient preference (18.1%), frailty, comorbidities, or side effects (13.2%), and falls (6.8%). The ICH rate was similar for AF patients on versus not on an anticoagulant (aOR 0.99, 95% CI 0.55-1.80). Anticoagulant use was not associated with a higher rate of ICH. Rates and reasons for anticoagulation non-prescribing were similar for Māori, non-Māori, urban, and non-urban populations although Māori were younger (68.7(13.2) vs 81.1(10.1)).
Discussion: Although anticoagulation prescribing in AF has improved over the past decade, one third of stroke patients with known AF were not taking an anticoagulant prior to admission requiring further efforts to optimize stroke prevention. The lack of increased ICH rate with anticoagulation is reassuring. There were no significant ethnic or geographic differences in anticoagulant prescribing although Māori stroke patients with AF were younger indicting a high priority population.