Cohort Study Examining the Presentation, Distribution, and Outcomes of Peripheral Artery Disease in Aboriginal, Torres Strait Islander, and Non-Indigenous Australians.

ABSTRACT

OBJECTIVE: This retrospective cohort study investigated the anatomical distribution, severity, and outcome of peripheral artery disease (PAD) in Aboriginal and Torres Strait Islanders compared with non-indigenous Australians. METHODS: The distribution, severity, and outcome of PAD were assessed using a validated angiographic scoring system and review of medical records in a cohort of Aboriginal and Torres Strait Islander and non-indigenous Australians. The relationship between ethnicity and PAD severity, distribution, and outcome were examined using non-parametric statistical tests, Kaplan-Meier and Cox proportional hazard analyses. RESULTS: Seventy-three Aboriginal and Torres Strait Islanders and 242 non-indigenous Australians were included and followed for a median of 6.7 [IQR 2.7, 9.3] years. Aboriginal and Torres Strait Islander patients were more likely to present with symptoms of chronic limb threatening ischaemia (81% vs. 25%; p < .001), had greater median [IQR] angiographic scores for the symptomatic limb (7 [5, 10] vs. 4 [2, 7]) and tibial arteries (5 [2, 6] vs. 2 [0, 4]) and had higher risk of major amputation (HR 6.1, 95% CI 3.6 - 10.5; p < .001) and major adverse cardiovascular events (HR 1.5, 95% CI 1.0 - 2.3; p = .036) but not for revascularisation (HR 0.8, 95% CI 0.5 - 1.3; p = .37) compared with non-indigenous Australians. The associations with major amputation and major adverse cardiovascular events were no longer statistically significant when adjusted for limb angiographic score. CONCLUSION: Compared with non-indigenous patients, Aboriginal and Torres Strait Islander Australians had more severe tibial artery disease and a higher risk of major amputation and major adverse cardiovascular events.