Associations of dietary patterns, ultra-processed food and nutrient intake with incident atrial fibrillation.

OBJECTIVE: To examine the associations between specific dietary patterns and incident atrial fibrillation (AF). METHODS: Using data from the UK Biobank, dietary intakes were calculated from 24-hour diet recall questionnaires. Indices representing adherence to dietary patterns (Mediterranean-style, Dietary Approaches to Stop Hypertension (DASH) and plant-based diets) were scored, and ultra-processed food consumption was studied as a percentage of total food mass consumed. Incident AF hospitalisations were assessed in Cox regression models. RESULTS: A total of 121 300 individuals were included, with 4 579 incident AF cases over a median follow-up of 8.8 years. Adherence to Mediterranean-style or DASH diets was associated with a lower incidence of AF in minimally adjusted analyses (HR for highest vs lowest quintile 0.87 (95% CI 0.80-0.96) and HR 0.78 (95% CI 0.71-0.86), respectively). However, associations were no longer significant after accounting for lifestyle factors (HR 0.95 (95% CI 0.87-1.04) and 0.94 (95% CI 0.86-1.04) respectively), with adjustment for body mass index responsible for approximately three-quarters of the effect size attenuation. Plant-based diets were not associated with AF risk in any models. Greatest ultra-processed food consumption was associated with a significant increase in AF risk even in fully adjusted models (HR 1.13 (95% CI 1.02-1.24)), and a 10% increase in absolute intake of ultra-processed food was associated with a 5% increase in AF risk (HR 1.05 (95% CI 1.01-1.08)). CONCLUSION: With the possible exception of reducing ultra-processed food consumption, these findings suggest that attention to other modifiable risk factors, particularly obesity, may be more important than specific dietary patterns for the primary prevention of AF.

Alcohol and Arrhythmias.

The association between alcohol consumption and abnormalities of heart rate and rhythm has long been recognized. Significant attention has focused on the risk of atrial fibrillation (AF) and sudden cardiac death (SCD) with excessive alcohol intake. Recent studies have advanced our understanding of these relationships and provided additional insights into potentially arrhythmogenic mechanisms. However, considerable uncertainty remains, such as the level of consumption at which harm begins and whether alcohol plays a role in other arrhythmias. This review characterizes the spectrum of conduction abnormalities and heart rhythm disorders in relation to alcohol consumption. In addition, it discusses the latest epidemiologic and experimental evidence, the potential importance of beverage type and constituent ingredients, and conflicting information on drink definitions, thresholds, and recommendations.

Incident Atrial Fibrillation in Relation to Ventilatory Parameters: A Prospective Cohort Study.

BACKGROUND: There is a paucity of data on the association between respiratory function and atrial fibrillation (AF). This study aimed to assess the relationship between forced expiratory volume (FEV1), forced vital capacity (FVC), and FEV1/FVC and incident AF. METHODS: We performed an analysis of prospectively collected data from the UK Biobank. We included all participants with available spirometry and excluded those with prior AF. Incident AF was ascertained through hospitalisation and death records, and dose-response associations were assessed by means of multivariable Cox regression analysis with adjustment for known AF risk factors. RESULTS: We studied 348,219 white individuals (54.1% female) with a median age of 58.1 years (interquartile range [IQR] 50.8-63.5 years). Over a median follow-up time of 11.5 years (IQR 11.0-12.6 years), a total of 18,188 incident AF events occurred. After standardisation to sex, age, and height, the risk of AF consistently increased with decreasing FEV1 percentage predicted, FEV1 z score, and FVC z score. The risk of AF linearly increased with decreasing FEV1/FVC ratio, and those that had airway obstruction as defined by FEV1/FVC ratio < 0.70 had a 23% greater risk of incident AF (adjusted hazard ratio [aHR] 1.23, 95% confidence interval [CI] 1.19-1.28) compared with those without airway obstruction. Patients with known chronic obstructive pulmonary disease and asthma were at 40% (aHR 1.40, 95% CI 1.29-1.51) and 17% (aHR 1.17, 95% CI 1.12-1.22) increased risk of incident AF respectively. CONCLUSIONS: These findings indicate that reduced ventilatory function is associated with increased risk of AF independently from age, sex, smoking, and other known AF risk factors.

Cardiac resynchronization therapy in an orthotopic heart transplant recipient.

Although cardiac resynchronization therapy (CRT) is an established therapy in selected patients with heart failure with reduced ejection fraction (HFrEF), its role in orthotopic heart transplant (OHT) recipients remains understudied. We describe a case of successful CRT implantation in an OHT recipient for HFrEF and high-grade atrioventricular block. This case highlights the deliberations made given the lack of clinical trial and observational evidence for this therapy in OHT recipients. Learning Objective: This case demonstrates the feasibility of cardiac resynchronization therapy (CRT) in an orthotopic heart transplant (OHT) recipient and adds to the scarcely reported data on the utility of CRT in this population. Given the exclusion of OHT recipients from the major CRT trials, further research is required to refine the indications for CRT implantation in this population.

Trends in myocardial infarction and coronary revascularisation procedures in Australia, 1993-2017.

OBJECTIVE: Prior data have shown rising acute myocardial infarction (MI) trends in Australia; whether these increases have continued in recent years is not known. This study thus sought to characterise contemporary nationwide trends in MI hospitalisations and coronary procedures in Australia and their associated economic burden. METHODS: The primary outcome measure was the incidence and time trends of total MI, ST-elevation myocardial infarction (STEMI) and non-ST-elevation myocardial infarction (NSTEMI) hospitalisations from 1993 to 2017. The incidence and time trends of coronary procedures were additionally collected, alongside MI hospitalisation costs. RESULTS: Adjusted for population changes, annual MI incidence increased from 216.2 cases per 100 000 to a peak of 270.4 in 2007 with subsequent decline to 218.7 in 2017. Similarly, NSTEMI incidence increased from 68.0 cases per 100 000 in 1993 to a peak of 192.6 in 2007 with subsequent decline to 162.6 in 2017. STEMI incidence decreased from 148.3 cases per 100 000 in 1993 to 56.2 in 2017. Across the study period, there were annual increases in MI hospitalisations of 0.7% and NSTEMI hospitalisations of 5.6%, and an annual decrease in STEMI hospitalisations of 4.8%. Angiography and percutaneous coronary intervention increased by 3.4% and 3.3% annually, respectively, while coronary artery bypass graft surgery declined by 2.2% annually. MI hospitalisation costs increased by 100% over the study period, despite a decreased average length of stay by 45%. CONCLUSIONS: The rising incidence of MI hospitalisations appear to have stabilised in Australia. Despite this, associated healthcare expenditure remains significant, suggesting a need for continual implementation of public health policies and preventative strategies.

Blood Pressure Measures and Incident Primary Open-Angle Glaucoma.

Purpose: To investigate the association of systemic blood pressure and incident primary open-angle glaucoma (POAG) using a large open-access database. Methods: Prospective cohort study included 484,268 participants from the UK Biobank without glaucoma at enrollment. Incident POAG events were recorded through assessment visits, hospital inpatient admissions, and primary care data. Blood pressure measures included systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse pressure (PP), and mean arterial pressure (MAP). Repeated measurements throughout the study period were analyzed as time-varying covariables. The parameters were modeled as both categorical and continuous nonlinear variables. The primary outcome measure was the relative hazard of incident POAG. Results: There were 2390 incident POAG events over 5,715,480 person-years of follow-up. Median follow-up was 12.08 years. In multivariable analyses, compared to SBP and PP in the normal range (SBP, 120-130 mmHg; PP, 40-50 mmHg), higher SBP and PP were associated with an increased risk of incident POAG (linear trend P = 0.038 for SBP, P < 0.001 for PP). Specifically, SBP of 130 to 140 mmHg or 140 to 150 mmHg was associated with a 1.16 higher hazard of incident POAG (95% CI, 1.01-1.32 and 1.01-1.33, respectively), whereas a PP of greater than 70 mmHg was associated with a 1.13 higher hazard of incident glaucoma (95% CI, 1.00-1.29). In multivariable models, no statistically significant associations were found for DBP or MAP with incident glaucoma. These findings were similar when blood pressure measures were modeled as continuous variables. Conclusions: Higher SBP and PP were associated with an increased risk of incident POAG. Further studies are required to characterize these relationships better.

Anemia and iron deficiency in patients with atrial fibrillation.

Atrial fibrillation (AF) is the most common cardiac tachyarrhythmia and has a rising global prevalence. Given the increasing burden of AF-related symptoms and complications, new approaches to management are required. Anemia and iron deficiency are common conditions in patients with AF. Furthermore, emerging evidence suggests that the presence of anemia may be associated with worse outcome in these patients. The role of anemia and iron deficiency has been extensively explored in other cardiovascular states, such as heart failure and ischemic heart disease. In particular, the role of iron repletion amongst patients with heart failure is now an established treatment modality. However, despite the strong bidirectional inter-relationship between AF and heart failure, the implications of anemia and iron-deficiency in AF have been scarcely studied. This area is of mechanistic and clinical relevance given the potential that treatment of these conditions may improve symptoms and prognosis in the increasing number of individuals with AF. In this review, we summarise the current published literature on anemia and iron deficiency in patients with AF. We discuss AF complications such as stroke, bleeding, and heart failure, in addition to AF-related symptoms such as exercise intolerance, and the potential impact of anemia and iron deficiency on these. Finally, we summarize current research gaps on anemia, iron deficiency, and AF, and underscore potential research directions.

Alcohol intake and bradyarrhythmia risk: a cohort study of 407 948 individuals.

AIMS: There is a paucity of epidemiological evidence on alcohol and the risk of bradyarrhythmias. We thus characterized associations of total and beverage-specific alcohol consumption with incident bradyarrhythmias using data from the UK Biobank. METHODS AND RESULTS: Alcohol consumption reported at baseline was calculated as UK standard drinks (8 g alcohol)/week. Bradyarrhythmia events were defined as sinus node dysfunction (SND), high-level atrioventricular block (AVB), and permanent pacemaker implantations. Outcomes were assessed through hospitalization and death records, and dose-response associations were characterized using Cox regression models with correction for regression dilution bias. We studied 407 948 middle-aged individuals (52.4% female). Over a median follow-up time of 11.5 years, a total of 8 344 incident bradyarrhythmia events occurred. Increasing total alcohol consumption was not associated with an increased risk of bradyarrhythmias. Beer and cider intake were associated with increased bradyarrhythmia risk up to 12 drinks/week; however, no significant associations were observed with red wine, white wine, or spirit intake. When bradyarrhythmia outcomes were analysed separately, a negative curvilinear was observed for total alcohol consumption and risk of SND, but no clear association with AVB was observed. CONCLUSION: In this predominantly White British cohort, increasing total alcohol consumption was not associated with an increased risk of bradyarrhythmias. Associations appeared to vary according to the type of alcoholic beverage and between different types of bradyarrhythmias. Further epidemiological and experimental studies are required to clarify these findings.

Alcohol consumption and risk of ventricular arrhythmias and sudden cardiac death: An observational study of 408,712 individuals.

BACKGROUND: Although previous studies have demonstrated a U-shaped relationship between alcohol and sudden cardiac death (SCD), there is a paucity of evidence on the role of alcohol specifically on incident ventricular arrhythmias (VAs). OBJECTIVE: The purpose of this study was to characterize associations of total and beverage-specific alcohol consumption with incident VA and SCD using data from the UK Biobank. METHODS: Alcohol consumption reported at baseline was calculated as UK standard drinks (8 g of alcohol) per week. Outcomes were assessed through hospitalization and death records. Alcohol consumption was modeled as restricted cubic splines in multivariate Cox regression models and corrected for regression dilution bias. RESULTS: We studied 408,712 middle-aged individuals (52.1% female) over a median follow-up time of 11.5 years. A total of 1733 incident VA events and 2044 SCDs occurred. For incident VA, no clear association was seen with total alcohol consumption. Although consumption of greater amounts of spirits was associated with increased VA risk, no other significant beverage-specific associations were observed. For SCD, a U-shaped association was seen for total alcohol consumption, such that consumption of <26 drinks per week was associated with lowest risk. Consumption of greater amounts of beer, cider, and spirits was potentially associated with increasing SCD risk, whereas increasing red and white wine intake was associated with reduced risk. CONCLUSION: In this predominantly white cohort, no association of total alcohol consumption was observed with VA, whereas a U-shaped association was present for SCD. Additional studies utilizing accurately defined VA and SCD events are required to provide further insights into these contrasting findings.

Rationale and design of the IRON-AF study: a double-blind, randomised, placebo-controlled study to assess the effect of intravenous ferric carboxymaltose in patients with atrial fibrillation and iron deficiency.

INTRODUCTION: Atrial fibrillation (AF) is associated with significantly impaired quality-of-life. Iron deficiency (ID) is prevalent in patients with AF. Correction of ID in other patient populations with intravenous iron supplementation has been shown to be a safe, convenient and effective way of improving exercise tolerance, fatigue and quality-of-life. The IRON-AF (Effect of Iron Repletion in Atrial Fibrillation) study is designed to assess the effect of iron repletion with intravenous ferric carboxymaltose in patients with AF and ID. METHODS AND ANALYSIS: The IRON-AF study is a double-blind, randomised controlled trial that will recruit at least 84 patients with AF and ID. Patients will be randomised to receive infusions of either ferric carboxymaltose or placebo, given in repletion and then maintenance doses. The study will have follow-up visits at weeks 4, 8 and 12. The primary endpoint is change in peak oxygen uptake from baseline to week 12, as measured by cardiopulmonary exercise testing (CPET) on a cycle ergometer. Secondary endpoints include changes in quality-of-life and AF disease burden scores, blood parameters, other CPET parameters, transthoracic echocardiogram parameters, 6-minute walk test distance, 7-day Holter/Event monitor burden of AF, health resource utilisation and mortality. ETHICS AND DISSEMINATION: The study protocol has been approved by the Central Adelaide Local Health Network Human Research Ethics Committee, Australia. The results of this study will be disseminated through publications in peer-reviewed journals and conference presentations. TRIAL REGISTRATION NUMBER: Australian New Zealand Clinical Trials Registry (ACTRN12620000285954).

Risk Thresholds for Total and Beverage-Specific Alcohol Consumption and Incident Atrial Fibrillation.

OBJECTIVES: This study sought to characterize associations of total and beverage-specific alcohol consumption with incident atrial fibrillation (AF). BACKGROUND: Although binge drinking and moderate to high consumption of alcohol are both established risk factors for AF, comparatively less is known about the effect of low alcohol consumption and whether associations differ by specific alcoholic beverages. METHODS: Using data from the UK Biobank, total and beverage-specific alcohol consumption was calculated as UK standard drinks (8 g alcohol) per week. Past drinkers and those with a history of AF were excluded. Incident AF events were assessed through hospitalization and death records, and dose-response associations were characterized using Cox regression models with correction for regression dilution bias. RESULTS: We studied 403,281 middle-aged individuals (52.4% female). Over a median follow-up time of 11.4 years (IQR: 10.7-12.3 years), a total of 21,312 incident AF events occurred. A J-shaped association of total alcohol consumption was observed, with lowest risk of AF with fewer than 7 drinks/week. Beverage-specific analyses demonstrated harmful associations of beer/cider consumption with any consumption. In contrast, consumption of red wine, white wine, and spirits up to 10, 8, and 3 drinks/week, respectively, was not associated with increased risk. CONCLUSIONS: In this predominantly White population, low levels of alcohol consumption (<7 U.K. standard drinks [56 g alcohol]/week) were associated with lowest AF risk. Low consumption of red and white wine and very low consumption of spirits may not be associated with increased AF risk, whereas any consumption of beer/cider may be associated with harm. These findings may have important implications for the primary prevention of AF that should be explored in future studies.

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.

Associations of anemia with stroke, bleeding, and mortality in atrial fibrillation: A systematic review and meta-analysis.

BACKGROUND: Anemia frequently coexists with atrial fibrillation (AF) and has been variably associated with worse outcomes. We performed a systematic review and meta-analysis to comprehensively assess the effect of anemia on mortality, stroke/systemic thromboembolism, and bleeding events in patients with AF. METHODS: MEDLINE and Embase were searched from inception until May 2020. Studies examining associations of anemia with the above outcomes in AF patients were included, and maximally adjusted hazard ratios (HRs) meta-analysed. PROSPERO registration number CRD42020171113. RESULTS: Twenty-eight studies involving 365 484 patients (41% female, mean age 74.7 years) were included. The average study follow-up ranged from 0.2 to 4.0 years, and the prevalence of anemia was 16%. Anemia was associated with a 78% increase in all-cause mortality (HR, 1.78; 95% confidence interval [CI], 1.44-2.20), 60% increase in cardiovascular mortality (HR, 1.60; 95% CI, 1.17-2.19), 134% increase in noncardiovascular mortality (HR, 2.34; 95% CI, 1.58-3.47) 15% increase in stroke/systemic thromboembolism (HR, 1.15; 95% CI, 1.01-1.31), 78% increase in major bleeding (HR, 1.78; 95% CI, 1.54-2.05), and 77% increase in gastrointestinal bleeding (HR, 1.77; 95% CI, 1.23-2.55). Sensitivity analyses including studies that reported odds ratios did not result in any material change. CONCLUSION: Anemia is a frequently observed comorbidity in patients with AF, and is associated with an increased risk of all-cause, cardiovascular and noncardiovascular mortality, stroke/systemic thromboembolism, and major and gastrointestinal bleeding. Future studies are required to explore the causes of anemia in AF, and whether investigation and treatment may be clinically beneficial in affected individuals.

Trends in the use, complications, and costs of permanent pacemakers in Australia: A nationwide study from 2008 to 2017.

OBJECTIVE: To characterize contemporary pacemaker procedure trends. METHODS: Nationwide analysis of pacemaker procedures and costs between 2008 and 2017 in Australia. The main outcome measures were total, age- and gender-specific implant, replacement, and complication rates, and costs. RESULTS: Pacemaker implants increased from 12,153 to 17,862. Implantation rates rose from 55.3 to 72.6 per 100,000, a 2.8% annual increase (incidence rate ratio [IRR] 1.028; 95% CI, 1.02-1.04; p < .001). Pacemaker implants in the 80+ age group were 17.37-times higher than the < 50 group (95% CI 16.24-18.59; p < .001), and in males were 1.48-times higher than in females (95% CI 1.42-1.55; p < .001). However, there were similar increases according to age (p = .10) and gender (p = .68) over the study period. Left ventricular lead rates were stable (IRR 0.995; 95% CI 0.98-1.01; p = .53). Generator replacements decreased from 20.5 to 18.3 per 100,000 (IRR 0.975; 95% CI 0.97-0.98; p < .001). Although procedures for generator-related complications were stable (IRR 0.995; 95% CI 0.98-1.01; p = .54), those for lead-related complications decreased (IRR 0.985; 95% CI 0.98-0.99; p < .001). Rates for all pacemaker procedures were consistently greater in males (p < .001). Although annual costs of all pacemaker procedures increased from $178 million to $329 million, inflation-adjusted costs were more stable, rising from $294 million to $329 million. CONCLUSIONS: Increasing demand for pacemaker implants is driven by the ageing population and rising rates across all ages, while replacement and complication procedure rates appeared more stable. Males have consistently greater pacemaker procedure rates than females. Our findings have significant clinical and public health implications for healthcare resource planning.

Prognostic value of coronary artery calcium scoring and computed tomography coronary angiography in remote Indigenous and non-Indigenous Australians.

BACKGROUND: The long-term prognostic utility of coronary calcification and coronary artery disease on computed tomography coronary angiography (CTCA) in remote Indigenous and non-Indigenous Australians is not known. METHODS: Consecutive patients undergoing CTCA from 2013 to 2017 in Central Australia were followed-up for major adverse cardiovascular events (MACE). RESULTS: 347 patients were included (50 ± 12 years; 47% female; 39% Indigenous). 172 (50.0%) exhibited coronary calcification. CTCA demonstrated no coronary artery disease (CAD) in 137 (39.5%), non-obstructive CAD in 149 (42.9%), and obstructive CAD in 61 (17.6%) patients. Although Indigenous ethnicity was associated with coronary calcification and baseline CAD in age- and gender-adjusted models, this association was non-significant after accounting for comorbidities. Over 4.6 years (IQR 3.52-5.68) of follow-up, MACE incidence rates per 100 person-years were 2.92 (CI 1.92-4.44) and 0.48 (CI 0.18-1.27) in those with and without calcification respectively (p = 0.001), and 0.15 (CI 0.02-1.09), 1.32 (CI 0.69-2.54), and 6.23 (CI 3.81-10.16) in patients with no, non-obstructive, and obstructive CAD respectively (p < 0.001). Coronary calcification and obstructive CAD were associated with 5-fold (HR 5.25, 95% CI 1.66-16.59, p = 0.005) and 6-fold (HR 6.35, 95% CI 2.70-14.89, p < 0.001) greater hazards of MACE respectively in multivariable models, with no significant interaction by ethnicity in these associations seen. CONCLUSIONS: The prognostic value of coronary calcification and CAD on CTCA amongst remote Indigenous individuals appears similar to that seen in non-Indigenous populations. Our data suggest that coronary artery calcium scoring and CTCA can be used to risk-stratify in remote settings where a normal study is associated with an excellent prognosis for at least two years.

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.