Acute Coronary Syndromes in Indigenous Australians: Opportunities for Improving Outcomes Across the Continuum of Care

doi:10.1016/j.hlc.2010.02.011

Heart, Lung and Circulation

Volume 19, Issues 5–6, May–June 2010, Pages 325-336

https://doi.org/10.1016/j.hlc.2010.02.011 Get rights and content

Background

Amongst a long list of health issues driving the disparity experienced by Indigenous Australians, cardiovascular disease (CVD) remains the primary target. It is the principal cause of death and of excess death among Indigenous people in Australia, and accounts for almost one-third of the life expectancy gap. Most attention has focused on the higher burden of traditional risk factors experienced by Indigenous people to explain CVD disparity. Far less attention has focused on the quality and outcomes of health system performance in explaining these differentials.

The CASPA study was a retrospective, mixed-methods clinical registry and quality improvement program established in the NT of Australia, focused on the patterns, burdens, provision of care, experience of services, adverse outcomes and their determinants among 492 patients (214 Indigenous and 278 non-Indigenous).

Results

Indigenous patients were significantly younger and more likely to have existing CVD risk factors and co-morbid chronic disease. During hospitalisation they received similar rates of evidence-based care with the exception of lower rates of diagnostic angiography (36.2% vs. 47.6%, p = 0.012), lower rates of in-patient cardiac rehabilitation (8.9% vs. 15.3%, p = 0.03) and lower prescription of discharge statin (44.8% vs. 57.8%, p = 0.006). Indigenous patients were more likely to die during two years of follow-up (30% vs. 17.8%, p = 0.002). Both Indigenous and non-Indigenous patients were similarly under-prescribed evidence based therapy after discharge. Exploratory qualitative examination of the experience of Indigenous patients in Alice Springs identified significant barriers to care across the continuum.

Conclusion

Improvements in the delivery of known effective therapies will make a significant impact on adverse outcomes in Indigenous and non-Indigenous patients alike. Comprehensive and sustained prospective data collection to compliment system reform is essential to improve outcomes and reduce disparity in CVD outcomes experienced by Indigenous Australians.

Section snippets

The Burden of CVD in Indigenous Australians

Cardiovascular disease (CVD) is the leading cause of death and one of the principal contributors to disability in most economically developed countries throughout the world, across all ethnic, racial, social and gender groups [1], [2], [3]. Despite the documented falls in cardiovascular mortality in Australia, CVD remain the leading cause of death, accounting for 36% of all deaths in 2004 [4] and conservatively costing Australian society $14 billion in direct and indirect health costs [5].

Methods

The CASPA Project was a mixed-methods clinical registry and quality improvement program established in Alice Springs in the Northern Territory of Australia.

Baseline Characteristics

In total, 492 individual patients fulfilled the study criteria for ACS, and had suffered an index event during the eligibility window period (Table 1). 43.5% (n = 214) of the cohort were Indigenous. The Indigenous group were significantly younger than their non-Indigenous counterparts, with a mean age of 50.1 (±12.5) years compared to 59.3 (±12.5) years (p < 0.001). Just over half of the Indigenous group were male (57%), compared to almost 70% of the non-Indigenous group (p = 0.003). Indigenous

Discussion

In this retrospective, mixed-methods ACS clinical registry and quality improvement study within the Northern Territory, Indigenous people were over-represented in hospitalisations for ACS. Despite making up 28% of the Northern Territory population [10], Indigenous patients made up over 40% of all ACS hospitalisations, and of index ACS during the period of study.

Importantly this study identified that Indigenous people experiencing ACS (and surviving to hospital): (i) demonstrate a markedly

Conclusion

The CASPA study provides an important insight into the real world clinical patterns, provision of care and outcomes of ACS among Indigenous and non-Indigenous patients in the Northern Territory of Australia. This is critical for identifying opportunities for system reform focused on the reduction in disparities between Indigenous and non-Indigenous people.

Despite the similarities in the level of care for Indigenous patients experiencing ACS, disparity in the provision of invasive management,

Acknowledgements

Bart Currie and Tarun Weeramanthri were critical to the development of the project outline and Simon Stewart in analyses. Thanks to Warwick Beever, Michael Howard, Bernadette Rickards, ICU staff at Alice Springs Hospital and CCU Royal Darwin Hospital for their assistance with data collection, and clinical coders at Alice Springs Hospoital and Royal Darwin Hospital. This study was funded in part by a CVL Grant from Pfizer.

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Mind The Gap, Aboriginal and Torres Strait Islander Cardiovascular Health: A Narrative Review
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Citation Excerpt :
First Nations Peoples generally experienced worse adjusted outcomes following AMI events, including a case fatality ratio at 28 days of 1.6 and 1.4 for males and females respectively aged 55–74 [7,8]. Curiously, an observed trend in several studies has been that First Nations cohorts comprise a higher percentage of females compared to the wider community [7,9,10]. Considering IHD and systolic heart failure (HF) predominately affect men at a younger age than women, it is possible this reflects that men may fail to present to medical services, representing an unknown and unmeasured gap.
Australia’s First Nations Peoples, Aboriginal and Torres Strait Islanders, have reduced life expectancy compared to the wider community. Cardiovascular diseases, mainly driven by ischaemic heart disease, are the leading contributors to this disparity. Despite over a third of First Nations Peoples living in New South Wales, the bulk of the peer-reviewed literature is from Central Australia and Far North Queensland. Regardless of the site of publication, First Nations Peoples are significantly younger at disease onset and have higher rates of comorbidities, in turn driving adverse health events. On top of this, very few First Nations Peoples specific cardiovascular interventions or programs have been shown to improve outcomes. The traditional biomedical model of care is less efficacious and non-traditional models of communication such as clinical yarning may benefit both clinicians and patients. The key purpose of this review is to highlight the deficiencies of our knowledge of cardiovascular burden of disease for First Nations Peoples; and to serve as a catalyst for more dedicated research. We need to have relationships with communities and concentrate on community improvement and partnerships. By involving First Nations Peoples researchers in collaboration with local communities in all levels of health care design and intervention will improve outcomes.
A Comparison of Clinical Characteristics and Outcomes Between Indigenous and Non-Indigenous Patients Presenting to Townsville Hospital Emergency Department With Chest Pain
2022, Heart Lung and Circulation
Indigenous Australians have a high rate of ischaemic heart disease (IHD). There is a paucity of local data for North Queensland regarding the clinical characteristics of Indigenous people who present to the emergency department (ED) with chest pain. The aim of the study is to compare the cardiovascular risk factors, social characteristics, and the clinical outcomes between Indigenous and non-Indigenous patients who presented with cardiac-related chest pain.
This is a retrospective single-centre audit. The data was collected through chart reviews of chest pain presentations to the Townsville University Hospital Emergency Department, Queensland, Australia, from January to December 2017. We categorised the patients into Indigenous and non-Indigenous groups and compared their cardiac risk factors and social characteristics. We further classified the patients into three diagnosis groups and we measured the clinical outcomes in the patients with a diagnosis of cardiac-related chest pain. We used a data linkage to the Registry of Births, Deaths and Marriages for the death outcomes. A multivariable analysis was done to determine the risk of major adverse cardiac event (MACE) for Indigenous vs non-Indigenous patients.
Indigenous patients were over-represented making up 19.1% of the total cohort (compared with 11.1% of the North Queensland Indigenous population) and presented at a younger age (median age: 45 vs 52, p<0.005). Traditional cardiovascular risk factors were significantly higher in Indigenous patients. The incidence of discharge against medical advice was also higher (6.5% vs 2.7%, p<0.005). There was an underutilisation of the local chest pain pathway amongst the Indigenous group (35.8% vs 44.7%, p<0.005). In patients with a diagnosis of cardiac-related chest pain, the rate of receiving invasive coronary angiogram procedures was similar in both cohorts (44.5% vs 43.7%, p=0.836).
With regards to outcomes, Indigenous patients suffered from acute coronary syndrome (ACS) at a younger median age (51 vs 64, p<0.005) and were more likely to have severe three vessel disease (17% vs 6%, p<0.005) leading to coronary bypass graft surgery (CABG) (19% vs 6%, p<0.005). When adjusted for age, gender, and comorbidities, Indigenous patients were more likely to have MACE within 1 year of their chest pain presentation, compared with non-Indigenous patients with the same diagnosis (adjusted odds ration [AOR]=2.0, 95% CI [1.1, 3.8], p=0.03).
In our study, Indigenous patients carried a heavier burden of cardiovascular risk factors, presented at a younger age, with more severe coronary disease and had a higher rate of CABG. We found an underutilisation of the local chest pain protocol amongst the Indigenous cohort, which suggests a need to improve support structures in the ED. In our multivariable analysis, Indigenous patients suffered from a significantly higher MACE compared to non-Indigenous patients which indicates that more collaborative efforts are needed to improve the cardiovascular health of local Aboriginal and Torres Strait Islander people.
Indigenous Australians have a greater prevalence of heart, stroke, and vascular disease, are younger at death, with higher hospitalisation and more aeromedical retrievals from remote regions
2021, eClinicalMedicine
Citation Excerpt :
Others have shown that that Indigenous Australians are also less likely to receive a HSVD diagnostic procedure in hospital such as coronary angiography [30], thus limiting revascularisation (PCI or CABG) rates following angiography, potential leading to higher mortality rates for Indigenous Australians. However, similar findings in the Northern Territory of Australia [25], found that remote Indigenous Australians who did undergo angiography were subsequently prescribed evidence‐based therapies on discharge at comparable rates to non-Indigenous patients. This reflects similar findings in the United States where the greatest racial disparity was found to be in the referral for coronary angiography [31,32].
We aimed to determine whether heart, stroke, and vascular disease (HSVD) prevalence and emergency primary evacuation (EPE), hospitalisation, and mortality differ by patient characteristics.
An Australian-wide incidence population based study, with prospective data collected form the 1 July 2019 to the 30 October 2020.
Indigenous Australians reported significantly higher prevalence of HSVD at 229.0 per-1000 as compared to 152.0 per-1000 non-Indigenous Australians: risk ratio 1.5 (95% CI 1.2-1.8). 583 remote patients received an EPE for HSVD, consisting of 388 (66.6%; 95% CI: 62.6-70.4) males and 195 (33.0%; 95% CI: 29.6-37.4) females. There were 289 (49.6%; 95% CI 45.4- 53.7) patients who identified as Indigenous, and 294 (50.4%; 95% CI 46.3- 54.6) as non-Indigenous. The mean Indigenous age during EPE was 48.0 (95% CI 45.9-50.1) years old, significantly lower than the non-Indigenous mean age of 55.6 (95% CI 53.8-57.4). Indigenous patients hospitalised for HSVD were younger, the majority younger than 65 years (n=21175; 73.7% 95% CI 73.2-74.2) as compared to non-Indigenous patients (n= 357654; 33.1% 95% CI 33.0-33.15). When adjusted for HSVD prevalence, remote Indigenous patients had a higher hospitalisation rate as compared to non-remote Indigenous patients (rate ratio: 1.6; 95% CI 1.3-2.0) and remote non-Indigenous patients (rate ratio: 1.2; 95% CI 1.0-1.5). More Indigenous patients died of HSVD before the age of 65 years (n=1875; 56.5% 95% CI 54.8-58.2) as compared to non-Indigenous patients (n= 16161; 10.6% 95% CI 10.45-10.8).
Indigenous Australians have a higher prevalence, and younger age during EPE, and hospitalisation for HSVD than non-Indigenous Australians.
This is a self/internally-funded study, with the lead organisation being the Royal Flying Doctor Service (RFDS) of Australia. For the duration of the study period, the RFDS provided in-kind support including one full-time equivalent (FTE) and resources (office space, computer, research software, and office equipment). There was no external funding source that had a role in study design or data analysis or interpretation.
Where are the opportunities to address system barriers preventing equitable cardiovascular outcomes for indigenous populations?
2021, The Lancet Global Health
Left atrial, pulmonary vein, and left atrial appendage anatomy in Indigenous individuals: Implications for atrial fibrillation
2021, IJC Heart and Vasculature
Indigenous Australians experience a greater burden of AF. Whether this is in-part due to differences in arrhythmogenic structures that appear to contribute to AF differences amongst other ethnicities is not known.
We studied forty individuals matched for ethnicity and other AF risk factors. Computed tomography imaging was used to characterise left atrial (LA), pulmonary vein (PV), and left atrial appendage (LAA) anatomy.
There were no significant differences in LA diameters or volumes between Indigenous and non-Indigenous Australians. Similarly, we could not detect any consistent differences in PV number, morphology, diameters, or ostial characteristics according to ethnicity. LAA analyses suggested that Indigenous Australians may have a greater proportion of non chickenwing LAA type, and a tendency for eccentric, oval-shaped LAA ostia; however, there were no other differences seen with regards to LAA volume or depth. Indexed values for LA, PV and LAA anatomy corrected for body size were broadly similar.
In a cohort of individuals matched for AF risk factors, we could find no strong evidence of ethnic differences in LA, PV, and LAA characteristics that may explain a predisposition of Indigenous Australians for atrial arrhythmogenesis. These findings, in conjunction with our previous data showing highly prevalent cardiometabolic risk factors in Indigenous Australians with AF, suggest that it is these conditions that are more likely responsible for the AF substrate in these individuals. Continued efforts should therefore be directed towards risk factor management in an attempt to prevent and minimise the effects of AF in Indigenous Australians.
Primary Prevention of Cardiovascular Disease in Minority Indigenous Populations: A Systematic Review
2020, Heart Lung and Circulation
Cardiovascular disease (CVD) is the commonest cause of death across the globe; incidence and prevalence rates are increasing. Together, CVD and diabetes mellitus are responsible for a quarter of the health gap observed between Aboriginal Australians and Torres Strait Islanders, and non-Indigenous Australians. Numerous programs have been proposed and implemented to Close the Gap; ideally, these should be evidence-based.
The aim of this review is to evaluate primary prevention measures and programs that aim to reduce CVD risk in minority Indigenous populations around the world.
A search of PubMed, the Cochrane Library and the Elsevier Scopus Database was initially conducted using the terms “cardiovascular disease”, “population groups”, “primary prevention”, "health services, indigenous”, "indigenous health", "risk assessment" and “risk management”. Results were then assessed per inclusion/exclusion criteria. A second reviewer independently evaluated the publications and review process to ensure agreement.
The initial search produced 37 publications; 19 met the inclusion criteria and were incorporated into a comparative table. Most were descriptive, mixed-methods, audit or intervention studies. Heterogeneity of study design prevented statistical analysis.
Addressing CVD risk in minority Indigenous populations is a multifactorial challenge; there is substantial room for improvement in routine risk assessment and management. Holistic approaches need to embrace local cultural perceptions of health and wellbeing. Validated risk reduction tools, individualised management plans, polypills and computer based decision support tools are promising to improve outcomes for those at risk.

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Original ArticleAcute Coronary Syndromes in Indigenous Australians: Opportunities for Improving Outcomes Across the Continuum of Care

Background

Results

Conclusion

Section snippets

The Burden of CVD in Indigenous Australians

Methods

Baseline Characteristics

Discussion

Conclusion

Acknowledgements

Prev Med

Lancet

Heart Lung Circul

Aust N Z J Public Health

J Am Coll Cardiol

J Am Coll Cardiol

Am J Cardiol

Am Heart J

Am J Cardiol

Global burden of cardiovascular diseases. Part I. general considerations, the epidemiologic transition, risk factors, and impact of urbanization

Circulation

The Health and Welfare of Australia's Aboriginal and Torres Strait Islander Peoples

Causes of inequality in life expectancy between Indigenous and non-Indigenous people in the Northern Territory, 1981–2000: a decomposition analysis

Med J Aust

Is the Framingham coronary heart disease absolute risk function applicable to Aboriginal people?

Med J Aust

An updated coronary risk profile. A statement for health professionals

Circulation

Delay times and management of acute myocardial infarction in indigenous and non-indigenous people in the Northern Territory

Med J Aust

Original Article
Acute Coronary Syndromes in Indigenous Australians: Opportunities for Improving Outcomes Across the Continuum of Care