Presentation and outcomes of indigenous Australians with peripheral artery disease

Tejas P. Singh, Joseph V. Moxon, Genevieve N. Healy, Yvonne Cadet-James, Jonathan Golledge

The risk factors for peripheral artery disease (PAD) are more common in Indigenous than non-Indigenous Australians, however the presentation and outcome of PAD in Indigenous Australians has not been previously investigated. The aim of this prospective cohort study was to compare the presenting characteristics and clinical outcome of Indigenous and non-Indigenous Australians with PAD. PAD patients were prospectively recruited and followed-up since 2003 from an outpatient vascular clinic in Townsville, Australia. Presenting symptoms and risk factors in Indigenous and non-Indigenous patients were compared using Pearson's χ2 test and Mann Whitney U test. Kaplan Meier survival analysis and Cox proportional hazard analysis were used to compare the incidence of myocardial infarction (MI), stroke or death (major cardiovascular events) among Indigenous and non-Indigenous patients. Four hundred and one PAD patients were recruited, of which 16 were Indigenous and 385 were non-Indigenous Australians. Indigenous Australians were younger at entry (median age 63.3 [54.7-67.8] vs 69.6 [63.3-75.4]), more commonly current smokers (56.3% vs 31.4%), and more frequently had insulin-treated diabetes (18.8% vs 5.2%). During a median follow-up of 2.5 years, five and 45 major cardiovascular events were recorded amongst Indigenous and non-Indigenous Australians, respectively. Indigenous Australians were at ~ 5-fold greater risk of major cardiovascular events (adjusted hazard ratio 4.72 [95% confidence intervals 1.41-15.78], p = 0.012) compared to non-Indigenous Australians. These findings suggest that Indigenous Australians with PAD present at a younger age, have higher rates of smoking and insulin-treated diabetes, and poorer clinical outcomes compared to non-Indigenous Australians.