Burden of atrial fibrillation and stroke risk among octagenarian and nonagenarian women in Australia.

Purpose: To determine the prevalence and incidence of atrial fibrillation (AF) among older Australian women from 2000 to 2015, determine factors associated with AF, and to calculate risk of stroke at the time of AF diagnosis.

Methods: This is a retrospective analysis of 6671 women of the 1921-1926 birth cohort of the Australian Longitudinal Study on Women's Health, linked to data from hospital admissions to identify AF and National Death Index to determine date of death. Yearly prevalence and incidence proportions of AF, and stroke risk using CHADS-VA scheme, were calculated. Factors associated with AF were assessed using logistic regression.

Results: From 2000 to 2015, a total of 1827 women with AF were identified. AF prevalence increased every year as women aged from 2.71% (95% CI 1.62%-3.80%) in 2000 among women aged 74-79 years to 24.83% (95% CI = 23.23%-26.44%) in 2015 among women aged 89-94 years. The incidence proportion remained constant (between 3% and 5%) throughout the study period. Sedentary lifestyle (OR = 1.24, 95% CI = 1.04-1.49), hypertension (OR = 1.24, 95% CI = 1.09-1.42), arthritis (OR = 1.24, 95% CI = 1.09-1.41), heart attack (OR = 1.62, 95% CI = 1.18-2.24), and angina (OR = 1.39, 95% CI = 1.14-1.70) were independently associated with AF. Mean CHADS-VA score for women with AF was 3.43 (SD ± 1.23).

Conclusions: The prevalence of AF reported in Australian women is among the highest compared to previous estimations from other countries and regions. According to the findings, about one in four women over the age of 90 years had AF. These women were also at high risk of stroke. This has significant public health implications especially with changing demographics of increase in the aging population. Further research is required on understanding how women with AF are treated in Australia and their health outcomes.