Prevalence and burden of coronary artery disease on computed tomography coronary angiography and its correlation with high-density lipoprotein in the Northern Territory, Australia.

Indigenous Australians are known to have a higher prevalence of coronary artery disease (CAD) than non-Indigenous counterparts. Atherogenic lipid profiles, characterised by low serum levels of high-density lipoprotein (HDL) and higher serum triglycerides, have been shown to be more prevalent in Indigenous Australians. The use of computed tomography coronary angiography (CTCA) for risk stratification and diagnosis of CAD has been validated in moderate risk populations, but limited data exists in specific high-risk populations such as Indigenous Australians. Through a retrospective study of patient records, we aimed to confirm if an atherogenic lipid profile occurred in Indigenous Australians undergoing CTCA in the Northern Territory of Australia and if so, whether this correlated with the prevalence or burden of CAD. We demonstrate that Indigenous Australians have similar prevalence (52.6% vs. 50.3%, P=0.80) and burden of CAD (Leaman score 6.03±4.66 vs. 6.96±4.82, P=0.44) on CTCA as non-Indigenous patients, but were 8 years younger (41.9±8.9 vs. 50.0±11.9 years, P<0.001) at the time of examination. We confirmed the presence of an atherogenic lipid profile in Indigenous patients and showed low serum-HDL was associated with very premature (patients aged 18-35 years) CAD in comparison to premature (patients aged 36-55 years) and mature-onset (patients aged 56 years and older) CAD (0.71±0.25 vs. 1.09±0.35 vs. 1.18±0.36 mmol/L, P=0.009). Future clinical guidelines should consider the role of CTCA in Indigenous Australians and whether younger patients may benefit. The causes of premature CAD, including atherogenic lipid profiles, require an ongoing focus in order to achieve equitable cardiovascular outcomes for Indigenous and non-Indigenous Australians.