Initial hospitalisation for atrial fibrillation in Aboriginal and non-Aboriginal populations in Western Australia

2023 Cardiac Society of Australia and New Zealand Expert Position Statement on Catheter and Surgical Ablation for Atrial Fibrillation

Catheter ablation for atrial fibrillation (AF) has increased exponentially in many developed countries, including Australia and New Zealand. This Expert Position Statement on Catheter and Surgical Ablation for Atrial Fibrillation from the Cardiac Society of Australia and New Zealand (CSANZ) recognises healthcare factors, expertise and expenditure relevant to the Australian and New Zealand healthcare environments including considerations of potential implications for First Nations Peoples. The statement is cognisant of international advice but tailored to local conditions and populations, and is intended to be used by electrophysiologists, cardiologists and general physicians across all disciplines caring for patients with AF. They are also intended to provide guidance to healthcare facilities seeking to establish or maintain catheter ablation for AF.

Mind The Gap, Aboriginal and Torres Strait Islander Cardiovascular Health: A Narrative Review

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.

Can the CHA2 DS2 -VA schema be used to decide on anticoagulant therapy in Aboriginal and other Australians with non-valvular atrial fibrillation?

The Australasian guidelines recommend use of the CHA₂ DS₂ -VA schema to stratify ischaemic stroke risk in patients with non-valvular atrial fibrillation (N-VAF) and determine risk thresholds for recommending oral anticoagulant (OAC) therapy. However, the CHA₂ DS₂ -VA score has not been validated in a representative Australian population cohort with N-VAF, including in Aboriginal people who are known to have a higher age-adjusted stroke risk than other Australians. In a retrospective data-linkage study of 49 114 patients aged 24-84 years with N-VAF, 40.0% women and 2.5% Aboriginal, we found that patients with a CHA₂ DS₂ -VA score >2 had high annual stroke rates (>2%) that would justify OAC therapy. This occurred regardless of Aboriginal status. Non-Aboriginal patients with a CHA₂ DS₂ -VA score of 0 had a mean annual stroke rate of 0.4%, and hence were not likely to benefit from antithrombotic therapy. However, Aboriginal patients with a zero CHA₂ DS₂ -VA score had a significantly higher annual stroke rate of 0.9%, and could potentially obtain net clinical benefit from anticoagulation, primarily with the safer non-vitamin K antagonist OAC. We conclude that clinicians can confidently use the CHA₂ DS₂ -VA score to make decisions regarding anticoagulation in accordance with stroke risk in patients with N-VAF, except in Aboriginal people in whom the risk score was unable to identify those at truly low risk of stroke.

Left atrial, pulmonary vein, and left atrial appendage anatomy in Indigenous individuals: Implications for atrial fibrillation

Background

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.

Methods

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.

Results

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.

Conclusions

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.

Atrial Fibrillation in Remote Indigenous and Non-Indigenous Individuals Hospitalised in Central Australia

BACKGROUND

The epidemiology of atrial fibrillation (AF) amongst Indigenous populations remains poorly characterised. We studied hospitalisations for AF in Central Australia, the most populous Indigenous region in the country.

METHODS

Patients with a diagnosis of AF admitted to Alice Springs Hospital, the only secondary health care facility and provider of cardiac care in remote Central Australia, were identified from 2006 to 2016. Age and gender-specific hospitalised AF prevalence, comorbidities, and CHA₂DS₂-VASc scores were ascertained.

RESULTS

Of 57,056 admitted patients over the study period, 1,210 (2.1%; 46% Indigenous) had a diagnosis of AF. For Indigenous and non-Indigenous individuals <45 years, hospitalised AF prevalence per 10,000 population was 105 (CI 84-131) and 50 (CI 36-68) in males (ratio=2.10), and 98 (CI 77-123) and 12 (CI 6-23) in females (ratio=7.92), respectively. For Indigenous and non-Indigenous individuals ≥65 years, hospitalised AF prevalence per 10,000 was 1,577 (CI 1,194-2,026) and 2,326 (CI 2,047-2,623) in males (ratio=0.68), and 1,713 (CI 1,395-2,069) and 1,897 (1,623-2,195) in females (ratio=0.90). Indigenous individuals had higher rates of cardiometabolic comorbidities, particularly at younger ages. CHA₂DS₂-VASc scores were greater in Indigenous individuals, particularly those <45 years (2.5±1.5 versus 0.7±1.1, p<0.001).

CONCLUSIONS

The prevalence of hospitalised AF amongst Indigenous people in remote Central Australia was significantly higher than in non-Indigenous individuals, particularly in younger age groups and females. Indigenous individuals with hospitalised AF also had a markedly greater prevalence of cardiometabolic comorbidities and elevated stroke risk. These data suggest that AF may be contributing to the gap in morbidity and mortality experienced by Indigenous Australians.

Long-term cost-effectiveness of a disease management program for patients with atrial fibrillation compared to standard care - a multi-state survival model based on a randomized controlled trial

AIM

To assess the long-term cost-effectiveness of an atrial fibrillation disease management program (i.e. the SAFETY program) from the Australian healthcare system perspective.

METHODS

A multistate Markov model was developed based on patient-level data from the SAFETY randomized controlled trial. Predicted long-term survival, dependent on hospital admission history, was estimated by extrapolating parametric survival models. Quality-adjusted life years (QALY) and life years (LY) were the primary and secondary outcome measures used to estimate the incremental cost-utility/effectiveness ratio (ICUR/ICER). Both deterministic and probabilistic sensitivity analyses (PSA) were undertaken.

RESULTS

The SAFETY program was associated with both higher costs ($94,953 vs. $78,433) and benefits [QALY (3.99 vs 3.60); LY (5.86 vs 5.24)], with an ICUR of $42,513/QALY or ICER of $26,356/LY, compared to standard care. Due to the extended survival, the SAFETY was associated with a greater number of hospitalizations (14.85 vs 11.65) and higher costs for medications ($25,084 vs $22,402) and outpatient care ($12,904 vs $11,524). The cost per hospitalization for an average length of stay, analytical time horizon, and cost of medication are key determinants of ICUR. The PSA showed that the intervention has a 70.4% probability of being cost-effective at a threshold of $50,000/QALY.

CONCLUSIONS

The SAFETY program has a high probability of being cost-effective for patients with atrial fibrillation. It is associated with uncertainty that further research could potentially eliminate; implementation with further evidence collection is recommended.

Predictors of Anticoagulation Use in Indigenous and Non-Indigenous Australians With Atrial Fibrillation

OBJECTIVE

Prior studies have demonstrated that anticoagulation underutilisation for atrial fibrillation (AF) and elevated stroke risk is common. However, there is little data on factors associated with appropriate anticoagulation, particularly in Indigenous Australians who face a disproportionate burden of AF and stroke. We thus sought to determine factors associated with anticoagulation use in Australians with AF.

DESIGN

Administrative, clinical, prescriptive and laboratory data were linked and aggregated over a 12-year period.

SETTING

Single tertiary teaching hospital.

PARTICIPANTS

19,305 (98%) and 308 (2%) consecutive non-Indigenous and Indigenous Australians with AF identified from administrative databases.

MAIN OUTCOME MEASURES

Associations of anticoagulation use according to ethnicity.

RESULTS

Significant independent predictors of anticoagulation use included hypertension (odds ratio [OR] 1.25, 95% confidence interval [CI] 1.17-1.34; p<0.001), diabetes (OR 1.14, 95% CI 1.05-1.24; p=0.002), heart failure (OR 1.54 95% CI 1.43-1.66; p<0.001) and prior stroke or transient ischaemic attack (OR 2.07, 95% CI 1.84-2.33; p<0.001). In contrast, increasing age (OR 0.99, 95% CI 0.98-0.99; p<0.001), female gender (OR 0.88, 95% CI 0.82-0.93; p<0.001), and vascular disease (OR 0.72, 95% CI 0.64-0.80; p<0.001) were significant predictors of no anticoagulation. Hypertension was associated with less anticoagulation use in Indigenous compared to non-Indigenous Australians (p=0.02).

CONCLUSIONS

Anticoagulation for AF was suboptimal in both Indigenous and non-Indigenous Australians. Older age, female gender, and comorbid vascular disease were found to be negatively associated with anticoagulation. Importantly, hypertension may also be under-recognised as a stroke risk factor in Indigenous Australians. Future efforts to encourage anticoagulation use in accordance with guideline recommendations is likely to reduce the burden of AF-related stroke in both Indigenous and non-Indigenous populations.

Contemporary Incidence and Prevalence of Rheumatic Fever and Rheumatic Heart Disease in Australia Using Linked Data: The Case for Policy Change

Background In 2018, the World Health Organization prioritized control of acute rheumatic fever (ARF) and rheumatic heart disease (RHD), including disease surveillance. We developed strategies for estimating contemporary ARF/RHD incidence and prevalence in Australia (2015-2017) by age group, sex, and region for Indigenous and non-Indigenous Australians based on innovative, direct methods. Methods and Results This population-based study used linked administrative data from 5 Australian jurisdictions. A cohort of ARF (age <45 years) and RHD cases (<55 years) were sourced from jurisdictional ARF/RHD registers, surgical registries, and inpatient data. We developed robust methods for epidemiologic case ascertainment for ARF/RHD. We calculated age-specific and age-standardized incidence and prevalence. Age-standardized rate and prevalence ratios compared disease burden between demographic subgroups. Of 1425 ARF episodes, 72.1% were first-ever, 88.8% in Indigenous people and 78.6% were aged <25 years. The age-standardized ARF first-ever rates were 71.9 and 0.60/100 000 for Indigenous and non-Indigenous populations, respectively (age-standardized rate ratio=124.1; 95% CI, 105.2-146.3). The 2017 Global Burden of Disease RHD prevalent counts for Australia (<55 years) underestimate the burden (1518 versus 6156 Australia-wide extrapolated from our study). The Indigenous age-standardized RHD prevalence (666.3/100 000) was 61.4 times higher (95% CI, 59.3-63.5) than non-Indigenous (10.9/100 000). Female RHD prevalence was double that in males. Regions in northern Australia had the highest rates. Conclusions This study provides the most accurate estimates to date of Australian ARF and RHD rates. The high Indigenous burden necessitates urgent government action. Findings suggest RHD may be underestimated in many high-resource settings. The linked data methods outlined here have potential for global applicability.

Atrial Fibrillation in Indigenous Australians: A Multisite Screening Study Using a Single-Lead ECG Device in Aboriginal Primary Health Settings

BACKGROUND

Circulatory diseases continue to be the greatest cause of mortality for Australian Aboriginal and Torres Strait Islander people, and a major cause of persistently lower life expectancy compared with non-Aboriginal Australians. The limited information that exists on atrial fibrillation (AF) prevalence in Aboriginal and Torres Strait Islander communities is mostly based on hospital admission data. This shows AF as principal or additional admission diagnosis was 1.4 times higher compared to non-Aboriginal Australians, a higher incidence of AF across the adult life span after age 20 years and a significantly higher prevalence among younger patients. Our study estimates the first national community prevalence and age distribution of AF (including paroxysmal) in Australian Aboriginal people. A handheld single-lead electrocardiograph (ECG) device (iECG), known to be acceptable in this population, was used to record participant ECGs.

METHODS

This co-designed, descriptive cross-sectional study was conducted in partnership with 16 Aboriginal Community Controlled Health organisations at their facilities and/or with their services delivered elsewhere. The study was also conducted at one state community event. Three (3) Australian jurisdictions were involved: New South Wales, Western Australia and the Northern Territory. Study sites were located in remote, regional and urban areas. Opportunistic recruitment occurred between June 2016 and December 2017. People <45 years of age were excluded.

RESULTS

Thirty (30) of 619 Aboriginal people received a 'Possible AF' and 81 an 'Unclassified' result from a hand-held smartphone ECG device. A final diagnosis of AF was made in 29 participants (4.7%; 95%CI 3.0-6.4%), 25 with known AF (five paroxysmal), and four with previously unknown AF. Three (3) of the four with unknown AF were aged between 55-64 years, consistent with a younger age of AF onset in Aboriginal people. Estimated AF prevalence increased with age and was higher in those aged >55 years than the general population (7.2% compared with 5.4%). Slightly more men than women were diagnosed with AF.

CONCLUSIONS

This study is a significant contribution to the evidence which supports screening for AF in Aboriginal and Torres Strait Islander people commencing at a younger age than as recommended in the Australian guidelines (>65 years). We recommend the age of 55 years. Consideration should be given to the inclusion of AF screening in the Australian Government Department of Health annual 'Aboriginal and Torres Strait Islander Health Assessment'.

CLINICAL TRIAL REGISTRATION

ACTRN12616000459426.

Quality of Warfarin Anticoagulation in Indigenous and Non-Indigenous Australians With Atrial Fibrillation

BACKGROUND

Studies have shown that suboptimal anticoagulation quality, as measured by time in therapeutic range (TTR), affects a significant percentage of patients with atrial fibrillation (AF). However, TTR has not been previously characterised in Indigenous Australians who experience a greater burden of AF and stroke.

METHOD

Indigenous and non-Indigenous Australians with AF on warfarin anticoagulation therapy were identified from a large tertiary referral centre between 1999 and 2012. Time in therapeutic range was calculated as a proportion of daily international normalised ratio (INR) values between 2 and 3 for non-valvular AF and 2.5 to 3.5 for valvular AF. INR values between tests were imputed using the Rosendaal technique. Linear regression models were employed to characterise predictors of TTR.

RESULTS

Five hundred and twelve (512) patients with AF on warfarin were included (88 Indigenous and 424 non-Indigenous). Despite younger age (51±13 vs 71±12 years, p<0.001), Indigenous Australians had greater valvular heart disease, diabetes, and alcohol excess compared to non-Indigenous Australians (p<0.05 for all). Time in therapeutic range was significantly lower in Indigenous compared to non-Indigenous Australians (40±29 vs 50±31%, p=0.006). Univariate predictors of poorer TTR included Indigenous ethnicity, younger age, diuretic use, and comorbidities, such as valvular heart disease, heart failure and chronic obstructive pulmonary disease (p<0.05 for all). Valvular heart disease remained a significant predictor of poorer TTR in multivariate analyses (p=0.004).

CONCLUSION

Indigenous Australians experience particularly poor warfarin anticoagulation quality. Our data also suggest that many non-Indigenous Australians spend suboptimal time in therapeutic range. These findings reinforce the importance of monitoring warfarin anticoagulation quality to minimise stroke risk.

Challenges in Managing Acute Cardiovascular Diseases and Follow Up Care in Rural Areas: A Narrative Review

This narrative review explores relevant literature that is related to the challenges in implementing evidence-based management for clinicians in rural and remote areas, while primarily focussing on management of acute coronary syndrome (ACS) and follow up care. A targeted literature search around rural/urban differences in the management of ACS, cardiovascular disease, and cardiac rehabilitation identified multiple issues that are related to access, including the ability to pay, transport and geographic distances, delays in patients seeking care, access to diagnostic testing, and timely treatment in an appropriate facility. Workforce shortages or lack of ready access to relevant expertise, cultural differences, and complexity that arises from comorbidities and from geographical isolation amplified diagnostic challenges. Given the urgency in management of ACS, rural clinicians must act quickly to achieve optimal patient outcomes. New technologies and quality improvement approaches enable better access to rapid diagnosis, as well as specialist input and care. Achieving an uptake of cardiac rehabilitation in rural and remote settings poses challenges that may reduce with the use of alternative models to centre-based rehabilitation and use of modern technologies. Expediting improvement in cardiovascular outcomes and reducing rural disparities requires system changes and that clinicians embrace attention to prevention, emergency management, and follow up care in rural contexts.

Within trial cost-utility analysis of disease management program for patients hospitalized with atrial fibrillation: results from the SAFETY trial

Background: The potential impact of disease management to optimize quality of care, health outcomes, and total healthcare costs across a range of cardiac disease states is unknown. Methods: A trial-based cost-utility analysis was conducted alongside a randomized controlled trial of 335 patients with chronic, non-valvular AF (without heart failure; the SAFETY Trial) discharged to home from three tertiary referral hospitals in Australia. A home-based disease management intervention (the SAFETY intervention) that involved community-based AF care including home visits was compared to routine primary healthcare and hospital outpatient follow-up (standard management). Bootstrapped incremental cost-utility ratios were computed based on quality-adjusted life-years (QALYs) and total healthcare costs. Cost-effectiveness acceptability curves were constructed to explore the probability of the SAFETY intervention being cost-effective. Sub-group analyses were performed based on age and sex to determine differential cost-effectiveness. Results: During median follow-up of 1.75 years, the SAFETY intervention was associated with a non-statistically significant increase in QALYs (0.02 per person) and lower total healthcare costs (-$4,375 per person). Although each of these findings were not statistically significant, the SAFETY intervention was found to be dominant (more effective and cost saving) in 58.8% of the bootstrapped iterations and cost-effective (more effective and gains in QALYs achieved at or below $50,000 per QALY gained) in 61.5% of the iterations. Males and those aged less than 78 years achieved greater gains in QALYs and savings in healthcare costs. The estimated value of perfect information in Australia (the monetized value of removing uncertainty in the cost-effectiveness results) was A$51 million, thus demonstrating the high potential gain from further research. Conclusions: Compared with standard management, the SAFETY intervention is potentially a dominant strategy for those with chronic, non-valvular AF. However, there would be substantial value in reducing the uncertainty in these estimates from further research.

‘I’ve got to row the boat on my own, more or less’: aboriginal australian experiences of traumatic brain injury

Background:

The overarching cultural context of the brain injury survivor, particularly that related to minority peoples with a history of colonisation and discrimination, has rarely been referred to in the research literature, despite profoundly influencing a person’s recovery journey in significant ways, including access to services. This study highlights issues faced by Australian Aboriginal traumatic brain injury (TBI) survivors in terms of real-life consequences of the high incidence of TBI in this population, current treatment and long-term challenges.

Method:

A case study approach utilised qualitative interview and file review data related to five male Aboriginal TBI survivors diagnosed with acquired communication disorders. The five TBI survivors were from diverse areas of rural and remote Western Australia, aged between 19 and 48 years at the time of injury, with a range of severity.

Case Reports:

Common themes included: significant long-term life changes; short-term and long-term dislocation from family and country as medical intervention and rehabilitation were undertaken away from the person’s rural/remote home; family adjustments to the TBI including permanent re-location to a metropolitan area to be with their family member in residential care; challenges related to lack of formal rehabilitation services in rural areas; poor communication channels; poor cultural security of services; and lack of consistent follow-up.

Discussion and Conclusion:

These case reports represent some of the first documented stories of Aboriginal Australian TBI survivors. They supplement available epidemiological data and highlight different contexts for Aboriginal people after TBI, contributing to an overall profile that is relevant for rehabilitation service planning.

Management of stroke in the Australian Indigenous population: from hospitals to communities

BACKGROUND

Ischaemic strokes lead to significant morbidity and mortality within the Australian Indigenous population, with known variances in the management of strokes between indigenous and non-indigenous populations.

AIMS

To compare investigations and management of indigenous and non-indigenous patients presenting to a New South Wales rural referral hospital with an ischaemic stroke to the national stroke standards across inpatient and outpatient settings.

METHODS

Historical cohort study of 43 indigenous and 167 non-indigenous patients admitted to Tamworth Rural Referral Hospital with an ischaemic cerebrovascular accident.

RESULTS

Indigenous patients were significantly less likely to have investigations completed, including carotid imaging (93.8% vs 100%, P = 0.012) and echocardiography (73.3% vs 97.7%, P = 0.004). Discharge follow up was significantly lower for the indigenous population (74.4% vs 87.4%, P = 0.034). Indigenous stroke patients were 15.8 years younger than non-indigenous subjects (56.8 vs 72.6 years old; P < 0.001). Indigenous patients were more likely to have stroke risk factors, including smoking (51.2% vs 15.0%; P < 0.001), diabetes mellitus (37.2% vs 16.8%, P = 0.003) and past history of cerebrovascular accident or transient ischaemic attack (50.2% vs 31.1%, P = 0.032).

CONCLUSIONS

The investigation and post-discharge care of indigenous ischaemic stroke patients is inferior to non-indigenous patients. Indigenous patients within rural NSW have a higher prevalence of preventable disease, including those that confer a higher stroke risk. Further research is needed to investigate the cause of these discrepancies and to improving indigenous stroke care between hospitals and primary care providers.

Burden of atrial fibrillation in Māori and Pacific people in New Zealand: a cohort study

BACKGROUND

Atrial fibrillation (AF) is a major risk factor for ischaemic stroke and cardiovascular events. In New Zealand (NZ), Māori (indigenous New Zealanders) and Pacific people experience higher rates of AF compared with non-Māori/non-Pacific people.

AIM

To describe a primary care population with AF in NZ. Stroke risk and medication adherence according to ethnicity are also detailed.

METHODS

Electronic medical records for adults (≥20 years, n = 135 840, including 19 918 Māori and 43 634 Pacific people) enrolled at 37 NZ general practices were analysed for AF diagnosis and associated medication prescription information.

RESULTS

The overall prevalence of non-valvular AF (NVAF) in this population was 1.3% (1769), and increased with age (4.4% in people ≥55 years). Māori aged ≥55 years were more likely to be diagnosed with NVAF (7.3%) than Pacific (4.0%) and non-Māori/non-Pacific people (4.1%, P < 0.001). Māori and Pacific NVAF patients were diagnosed with AF 10 years earlier than non-Māori/non-Pacific patients (median age of diagnosis: Māori = 60 years, Pacific = 61 years, non-Māori/non-Pacific = 71 years, P < 0.001). Overall, 67% of NVAF patients were at high risk for stroke (CHA₂ DS₂ -VASc ≥ 2) at the time of AF diagnosis. Almost half (48%) of Māori and Pacific NVAF patients aged <65 years were at high risk for stroke, compared with 22% of non-Māori/non-Pacific (P < 0.001). Irrespective of ethnic group, adherence to AF medication was suboptimal in those NVAF patients with a high risk of stroke or with stroke history.

CONCLUSION

AF screening and stroke thromboprophylaxis in Māori and Pacific people could start below the age of 65 years in NZ.

Complexity in disease management: A linked data analysis of multimorbidity in Aboriginal and non-Aboriginal patients hospitalised with atherothrombotic disease in Western Australia

BACKGROUND

Hospitalisation for atherothrombotic disease (ATD) is expected to rise in coming decades. However, increasingly, associated comorbidities impose challenges in managing patients and deciding appropriate secondary prevention. We investigated the prevalence and pattern of multimorbidity (presence of two or more chronic conditions) in Aboriginal and non-Aboriginal Western Australian residents with ATDs.

METHODS AND FINDINGS

We used population-based de-identified linked administrative health data from 1 January 2000 to 30 June 2014 to identify a cohort of patients aged 25-59 years admitted to Western Australian hospitals with a discharge diagnosis of ATD. The prevalence of common chronic diseases in these patients was estimated and the patterns of comorbidities and multimorbidities empirically explored using two different approaches: identification of the most commonly occurring pairs and triplets of comorbid diseases, and through latent class analysis (LCA). Half of the cohort had multimorbidity, although this was much higher in Aboriginal people (Aboriginal: 79.2% vs. non-Aboriginal: 39.3%). Only a quarter were without any documented comorbidities. Hypertension, diabetes, alcohol abuse disorders and acid peptic diseases were the leading comorbidities in the major comorbid combinations across both Aboriginal and non-Aboriginal cohorts. The LCA identified four and six distinct clinically meaningful classes of multimorbidity for Aboriginal and non-Aboriginal patients, respectively. Out of the six groups in non-Aboriginal patients, four were similar to the groups identified in Aboriginal patients. The largest proportion of patients (33% in Aboriginal and 66% in non-Aboriginal) was assigned to the "minimally diseased" (or relatively healthy) group, with most patients having less than two conditions. Other groups showed variability in degree and pattern of multimorbidity.

CONCLUSION

Multimorbidity is common in ATD patients and the comorbidities tend to interact and cluster together. Physicians need to consider these in their clinical practice. Different treatment and secondary prevention strategies are likely to be useful for management in these cluster groups.

Patterns of Medicare-funded primary health and specialist consultations in Aboriginal and non-Aboriginal Australians in the two years before hospitalisation for ischaemic heart disease

BACKGROUND

Ischaemic heart disease (IHD) remains the leading cause of morbidity and mortality for both Aboriginal and non-Aboriginal Australians. Patterns of primary and specialist care in patients leading up to the first hospitalisation for IHD potentially impact on prevention and subsequent outcomes. We investigated the differences in general practice (GP), specialist and emergency department (ED) consultations, and associated resource use in Aboriginal and non-Aboriginal people in the two years preceding hospitalisation for IHD.

METHODS

Linked-data were used to identify first IHD admissions for Western Australians aged 25-74 years in 2002-2007. Person-linked GP, specialist and ED consultations were obtained from the Medicare Benefits Schedule (MBS) and ED records to assess health care access and costs for the preceding 2 years.

RESULTS

Aboriginal people constituted 4.7% of 27,230 IHD patients, 3.5% of 1,348,238 MBS records, and 14% of 33,170 ED presentations. Aboriginal (vs. non-Aboriginal) people were younger (mean 50.2 vs 60.5 years), more commonly women (45.2% vs 28.4%), had more comorbidities [Charlson index≥1, 35.2% vs 26.3%], were more likely to have had GP visits (adjusted rate-ratio 1.07, 95% CI 1.02-1.12), long/prolonged (16.0% vs 11.9%) consults and non-vocationally registered GP consults (17.1% vs 3.2%), but less likely to received specialist consults (mean 1.0 vs 4.1). Mean number of urgent/semi-urgent ED presentations in the year preceding the IHD admission was higher in Aboriginal people (2.9 vs 1.9). Aboriginal people incurred 2.7% of total associated MBS expenditure (estimated at $59.7 million). Mean total cost per person was 43.3% lower in Aboriginal patients, with cost differentials being greatest in diabetic and chronic kidney disease patients.

CONCLUSIONS

Despite being over-represented in urgent/semi-urgent ED presentations and admissions for IHD, Aboriginal people were under-resourced compared with the rest of the population, particularly in terms of specialist care prior to first IHD hospitalisation. The findings underscore the need for better primary and specialist shared care delivery models particularly for Aboriginal people.

Rheumatic heart disease: infectious disease origin, chronic care approach

BACKGROUND

Rheumatic heart disease (RHD) is a chronic cardiac condition with an infectious aetiology, causing high disease burden in low-income settings. Affected individuals are young and associated morbidity is high. However, RHD is relatively neglected due to the populations involved and its lower incidence relative to other heart diseases.

METHODS AND RESULTS

In this narrative review, we describe how RHD care can be informed by and integrated with models of care developed for priority non-communicable diseases (coronary heart disease), and high-burden communicable diseases (tuberculosis). Examining the four-level prevention model (primordial through tertiary prevention) suggests primordial and primary prevention of RHD can leverage off existing tuberculosis control efforts, given shared risk factors. Successes in coronary heart disease control provide inspiration for similarly bold initiatives for RHD. Further, we illustrate how the Chronic Care Model (CCM), developed for use in non-communicable diseases, offers a relevant framework to approach RHD care. Systems strengthening through greater integration of services can improve RHD programs.

CONCLUSION

Strengthening of systems through integration/linkages with other well-performing and resourced services in conjunction with policies to adopt the CCM framework for the secondary and tertiary prevention of RHD in settings with limited resources, has the potential to significantly reduce the burden of RHD globally. More research is required to provide evidence-based recommendations for policy and service design.

Epidemiology of Atrial Fibrillation: The Australian and Asia-Pacific Perspective

The epidemic of atrial fibrillation (AF) is increasingly recognised as a growing health problem worldwide. Although epidemiological studies on AF in the Asia-Pacific region are scarce, given the increasing age and size of populations in this region, the burden of AF is expected to be far greater than in North America and Europe. This is not only due to the growing, ageing population but also an increased incidence of risk factors for AF, such as hypertension, obesity, metabolic syndrome and diabetes, in the Asia-Pacific region. While further, high quality data on such aspects as risk factors, racial disparities and clinical implications is urgently required, there is an immediate need for increased focus on appropriate stroke prophylaxis and risk factor management to minimise the clinical complications and societal burden of AF.

Improving cardiovascular outcomes among Aboriginal Australians: Lessons from research for primary care

BACKGROUND

The Aboriginal people of Australia have much poorer health and social indicators and a substantial life expectancy gap compared to other Australians, with premature cardiovascular disease a major contributor to poorer health. This article draws on research undertaken to examine cardiovascular disparities and focuses on ways in which primary care practitioners can contribute to reducing cardiovascular disparities and improving Aboriginal health.

METHODS

The overall research utilised mixed methods and included data analysis, interviews and group processes which included Aboriginal people, service providers and policymakers. Workshop discussions to identify barriers and what works were recorded by notes and on whiteboards, then distilled and circulated to participants and other stakeholders to refine and validate information. Additional engagement occurred through circulation of draft material and further discussions. This report distils the lessons for primary care practitioners to improve outcomes through management that is attentive to the needs of Aboriginal people.

RESULTS

Aspects of primordial, primary and secondary prevention are identified, with practical strategies for intervention summarised. The premature onset and high incidence of Aboriginal cardiovascular disease make prevention imperative and require that primary care practitioners understand and work to address the social underpinnings of poor health. Doctors are well placed to reinforce the importance of healthy lifestyle at all visits to involve the family and to reduce barriers which impede early care seeking. Ensuring better information for Aboriginal patients and better integrated care for patients who frequently have complex needs and multi-morbidities will also improve care outcomes.

CONCLUSION

Primary care practitioners have an important role in improving Aboriginal cardiovascular care outcomes. It is essential that they recognise the special needs of their Aboriginal patients and work at multiple levels both outside and inside the clinic for prevention and management of disease. A toolkit of proactive and holistic opportunities for interventions is proposed.

Opportunistic screening to detect atrial fibrillation in Aboriginal adults in Australia

INTRODUCTION

There is a 10-year gap in life expectancy between Aboriginal and non-Aboriginal Australians. The leading cause of death for Aboriginal Australians is cardiovascular disease, including myocardial infarction and stroke. Although atrial fibrillation (AF) is a known precursor to stroke there are no published studies about the prevalence of AF for Aboriginal people and limited evidence about AF in indigenous populations globally.

METHODS AND ANALYSIS

This mixed methods study will recruit and train Aboriginal health workers to use an iECG device attached to a smartphone to consecutively screen 1500 Aboriginal people aged 45 years and older. The study will quantify the proportion of people who presented for follow-up assessment and/or treatment following a non-normal screening and then estimate the prevalence and age distribution of AF of the Australian Aboriginal population. The study includes semistructured interviews with the Aboriginal health workers about the effectiveness of the iECG device in their practice as well as their perceptions of the acceptability of the device for their patients. Thematic analysis will be undertaken on the qualitative data collected in the study. If the device and approach are acceptable to the Aboriginal people and widely adopted, it may help prevent the effects of untreated AF including ischaemic stroke and early deaths or impairment in Aboriginal people.

ETHICS AND DISSEMINATION

This mixed methods study received ethics approval from the Aboriginal Health and Medical Research Council (1135/15) and the Australian Health Council of Western Australia (HREC706). Ethics approval is being sought in the Northern Territory. The findings of this study will be shared with Aboriginal communities, in peer reviewed publications and at conferences. There are Aboriginal investigators in each state/territory where the study is being conducted who have been actively involved in the study. They will also be involved in data analysis, dissemination and research translation.

TRIAL REGISTRATION NUMBER

ACTRN12616000459426.

Cardiac Rehabilitation for Aboriginal and Torres Strait Islander people in Western Australia

BACKGROUND

Cardiovascular disease (CVD) is a leading cause of morbidity and mortality in Australia. Australian Aboriginal and Torres Strait Islander (Indigenous) people have higher levels of CVD compared with non-Indigenous people. Cardiac Rehabilitation (CR) is an evidence-based intervention that can assist with reducing subsequent cardiovascular events and rehospitalisation. Unfortunately, attendance rates at traditional CR programs, both globally and in Australia, are estimated to be as low as 10-30 % and Indigenous people are known to be particularly under-represented. An in-depth assessment was undertaken to investigate the provision of CR and secondary preveniton services in Western Australia (WA) with a focus on rural, remote and Indigenous populations. This paper reports on the findings for Indigenous people.

METHODS

Cardiac rehabilitation and Aboriginal Medical Services (n = 38) were identified for interview through the Heart Foundation Directory of Western Australian Cardiac Rehabilitation and Secondary Prevention Services 2012. Semi-structured interviews with CR coordinators were conducted and included questions specific to Indigenous people.

RESULTS

Interviews with coordinators from 34 CR services (10 rural, 12 remote, 12 metropolitan) were conducted. Identification of Indigenous status was reported by 65 % of coordinators; referral and attendance rates of Indigenous patients differed greatly across WA. Efforts to meet the cultural needs of Indigenous patients varied and included case management (32 %), specific educational materials (35 %), use of a buddy or mentoring system (27 %), and access to an Aboriginal Health Worker (71 %). Staff cultural awareness training was available for 97 % and CR guidelines were utilised by 77 % of services.

CONCLUSION

The under-representation of Indigenous Australians participating in CR, as reported in the literature and more specifically in this study, mandates a concerted effort to improve services to better meet the needs of Indigenous patients with CVD as part of closing the gap in life expectancy. Improving access to culturally appropriate CR and secondary prevention in WA must be an important component of this effort given the high rates of premature cardiovascular disease affecting Indigenous people. Our findings also highlight the importance of good systematic data collection across services. Health pathways that ensure continuity of care and alternative methods of CR delivery with dedicated resources are needed.

Atrial fibrillation in the Indigenous populations of Australia, Canada, New Zealand, and the United States: a systematic scoping review

Background

The epidemiology of atrial fibrillation (AF) among Indigenous minorities in affluent countries is poorly delineated, despite the high cardiovascular disease burden in these populations. We undertook a systematic scoping review examining the epidemiology of AF in the Indigenous populations of Australia, Canada, New Zealand (NZ) and the United States (US).

Methods

PubMed, Scopus, EMBASE and CINAHL-Plus databases were systematically searched in May 2014. Supplementary full-text searches of Google Scholar and government website searches were also undertaken.

Results

Key findings from 27 publications with diverse aims and methods were included. Small studies from Canada and NZ suggest higher AF prevalence in Indigenous than other populations. However, this was not reflected in a large sample of US male military veterans. No data were identified on community-based incidence rates of AF in Indigenous populations. Australian and Canadian studies indicate higher first-ever and overall AF hospitalisation rates among Indigenous than other populations, at younger ages and with more comorbidity. Studies in stroke, heart failure and other clinical groups demonstrate AF as a common comorbidity, with AF possibly more prevalent at younger ages in Indigenous people. Indigenous patients have similar early post-hospitalisation adjusted mortality but higher 1-year risk-adjusted mortality than non-Indigenous patients.

Conclusions

No clear epidemiological pattern of AF frequency across the considered Indigenous populations emerges from the limited available evidence. AF should be included in key conditions reported in national surveillance reports, although Indigenous identifiers are required in administrative data from Canada and the US. Sufficiently powered, community-based studies of AF epidemiology in diverse Indigenous populations are needed.

Electronic supplementary material

The online version of this article (doi:10.1186/s12872-015-0081-6) contains supplementary material, which is available to authorized users.