Incidence of first heart failure hospitalisation and mortality in Aboriginal and non-Aboriginal patients in Western Australia, 2000-2009

Objectives: To compare the incidence of first heart failure (HF) hospitalisation, antecedent risk factors and 1-year mortality between Aboriginal and non-Aboriginal populations in Western Australia (2000-2009).

Methods: A population-based cohort aged 20-84 years comprising Aboriginal (n=1013; mean 54±14 years) and non-Aboriginal patients (n=16,366; mean 71±11 years) with first HF hospitalisation was evaluated. Age and sex-specific incidence rates and HF antecedents were compared between subpopulations. Regression models were used to examine 30-day and 1-year (in 30-day survivors) mortality.

Results: Aboriginal patients were younger, more likely to reside in rural/remote areas (76% vs 23%) and to be women (50.6% vs 41.7%, all p<0.001). Aboriginal (versus non-Aboriginal) HF incidence rates were 11-fold higher in men and 23-fold in women aged 20-39 years, declining to about 2-fold in patients aged 70-84 years. Ischaemic and rheumatic heart diseases were more common antecedents of HF in younger (<55 years) Aboriginal versus non-Aboriginal patients (p<0.001). Hypertension, diabetes, chronic kidney disease, renal failure, chronic obstructive pulmonary disease, and a high Charlson comorbidity index (>=3) were also more prevalent in younger and older Aboriginal patients (p<0.001). Although 30-day mortality was similar in both subpopulations, Aboriginal patients aged<55 years had a 1.9 risk-adjusted hazard ratio (HR) for 1-year mortality (p=0.015).

Conclusions: Aboriginal people had substantially higher age and sex-specific HF incidence rate and prevalence of HF antecedents than their non-Aboriginal counterparts. HR for 1-year mortality was also significantly worse at younger ages, highlighting the urgent need for enhanced primary and secondary prevention of HF in this population.