LAUSR

Introduction: Indigenous Australians have a higher cardiovascular burden than non-indigenous persons. Whether this is associated with more prevalent cardiovascular risk factors or other reasons is not well defined. Hypothesis: Indigenous Australians with acute coronary syndrome (ACS) have more cardiovascular risk factors than non-indigenous Australians. Methods: We performed a retrospective analysis of our ACS registry comparing indigenous and non-indigenous Australian patients who presented with ACS and underwent percutaneous coronary intervention (PCI) between 2006-2019. Results: We treated 9436 patients and 239 (2.4%) were indigenous Australians. On average, Indigenous patients presented 9 years earlier (mean age 55 v 64 years, p<0.0001). In indigenous Australian patients, 32% were under 50 compared with 13% in non-indigenous group (p<0.0001). Comparing the prevalence of traditional cardiovascular risk factors between indigenous Australians and non-indigenous patients, diabetes mellitus (27% v 21%, p=0.016), hypertension (61% v 53%, p=0.028), smoking (54% v 24%, p<0.0001), family history of IHD (43% v 32%, pp=0.0009) and obesity with BMI>30 (46% v 33%, p=0.0001) were higher amongst the indigenous Australians while prevalence of dyslipidemia was similar between the two groups (45% v 46%, p=0.79). Indigenous Australian patients with ACS had worse outcome including higher incidence of acute myocardial infarction within 12 months (11.3% v 4.6% p<0.0001), stent thrombosis (2.51% v 1.06%, p=0.03) and major adverse cardiovascular events (23.8% v 17.2%, p=0.01); however, 12 months mortality (11.7% v 8.7%, p=0.12) was not statistically different between the two groups. Conclusions: Indigenous Australians present with ACS 9 years earlier than non-indigenous patients. This is largely explained by significantly higher prevalence of major cardiovascular risk factors. Moreover, Indigenous Australians had higher MACE rates. Closer attention to risk factor management is required in indigenous Australians for primary and secondary prevention.