Search

Key Points: Question: Does atrial fibrillation catheter ablation have an impact on mental health? Findings: In this randomized clinical trial of 100 patients with symptomatic atrial fibrillation, catheter ablation with reduction in arrhythmia burden and antiarrhythmic drug use was associated with improvement in markers of psychological distress compared with medical therapy alone. Meaning: Improvement of severe psychological distress may be an additional benefit of catheter ablation treatment for atrial fibrillation. Importance: The impact of atrial fibrillation (AF) catheter ablation on mental health outcomes is not well understood. Objective: To determine whether AF catheter ablation is associated with greater improvements in markers of psychological distress compared with medical therapy alone. Design, Setting, and Participants: The Randomized Evaluation of the Impact of Catheter Ablation on Psychological Distress in Atrial Fibrillation (REMEDIAL) study was a randomized trial of symptomatic participants conducted in 2 AF centers in Australia between June 2018 and March 2021. Interventions: Participants were randomized to receive AF catheter ablation (n = 52) or medical therapy (n = 48). Main Outcomes and Measures: The primary outcome was Hospital Anxiety and Depression Scale (HADS) score at 12 months. Secondary outcomes included follow-up assessments of prevalence of severe psychological distress (HADS score >15), anxiety HADS score, depression HADS score, and Beck Depression Inventory-II (BDI-II) score. Arrhythmia recurrence and AF burden data were also analyzed. Results: A total of 100 participants were randomized (mean age, 59 [12] years; 31 [32%] women; 54% with paroxysmal AF). Successful pulmonary vein isolation was achieved in all participants in the ablation group. The combined HADS score was lower in the ablation group vs the medical group at 6 months (8.2 [5.4] vs 11.9 [7.2]; P =.006) and at 12 months (7.6 [5.3] vs 11.8 [8.6]; between-group difference, −4.17 [95% CI, −7.04 to −1.31]; P =.005). Similarly, the prevalence of severe psychological distress was lower in the ablation group vs the medical therapy group at 6 months (14.2% vs 34%; P =.02) and at 12 months (10.2% vs 31.9%; P =.01), as was the anxiety HADS score at 6 months (4.7 [3.2] vs 6.4 [3.9]; P =.02) and 12 months (4.5 [3.3] vs 6.6 [4.8]; P =.02); the depression HADS score at 3 months (3.7 [2.6] vs 5.2 [4.0]; P =.047), 6 months (3.4 [2.7] vs 5.5 [3.9]; P =.004), and 12 months (3.1 [2.6] vs 5.2 [3.9]; P =.004); and the BDI-II score at 6 months (7.2 [6.1] vs 11.5 [9.0]; P =.01) and 12 months (6.6 [7.2] vs 10.9 [8.2]; P =.01). The median (IQR) AF burden in the ablation group was lower than in the medical therapy group (0% [0%-3.22%] vs 15.5% [1.0%-45.9%]; P <.001). Conclusion and Relevance: In this trial of participants with symptomatic AF, improvement in psychological symptoms of anxiety and depression was observed with catheter ablation, but not medical therapy. Trial Registration: ANZCTR Identifier: ACTRN12618000062224 This randomized clinical trial evaluates the prevalence of psychological distress in participants referred for atrial fibrillation treatment. [ABSTRACT FROM AUTHOR]

Background: Sudden cardiac death (SCD) during physical exercise is devastating. Aims: To evaluate causes and circumstances of exercise‐related SCD in the young in Australia. Methods: We reviewed the National Coronial Information System database for deaths in Australia relating to cardiovascular disease in cases aged 10–35 years between 2000 and 2016. Cases who had undertaken physical exercise at the time of the event were included. We collected demographics, circumstances of death, type of physical exercise, bystander cardiopulmonary resuscitation (CPR) and automated external defibrillator (AED) use prior to ambulance arrival. Results: Over a 17‐year period, 1925 SCD cases were identified, of which 110 (6%) cases (median age 27 years (interquartile range 21–32 years); 92% male) were related to sports/physical exercise. Thirteen (12%) cases occurred in active athletes. Most common causes were coronary artery disease (CAD; 37%) and sudden arrhythmic death syndrome (SADS; 20%). Among Aboriginal and Torres Strait Islanders (n = 10), all deaths were related to CAD. Australian Rules Football (24%), running/jogging (14%) and soccer (14%) were the most frequent physical exercise activities. Prior symptoms were present in 39% (chest pain 37%, pre‐syncope/syncope 26%). Most (87%) were witnessed, with bystander CPR in 70%. AED use prior to ambulance arrival was 8%. Conclusions: The present study demonstrates the high occurrence of CAD and SADS in SCD in the young related to physical exercise. Aboriginal and Torres Strait Islanders were disproportionately affected by CAD. Although events were commonly witnessed, AED was seldom used prior to ambulance arrival and highlights an important opportunity to improve outcomes in the post‐arrest chain of survival. [ABSTRACT FROM AUTHOR]

Background: Patient-reported outcome measures are important in person-centered care, providing valuable information about patients' experiences. Disease-specific questionnaires add important information about a certain disease in comparison to generic questionnaires. Questionnaires need to be validated in the targeted population to achieve reliable data. The purpose with the study was to use Rasch measurement theory to evaluate the English version of the ASTA questionnaire. Methods: The Rasch model theory was used to evaluate global and item fit, targeting, response category functioning, local independency, unidimensionality, differential item functioning (DIF) for gender and age, and reliability. Results: The study included 202 patients undergoing DC conversion or catheter ablation at the Centre for Heart Rhythm Disorders at the University of Adelaide, Australia. The mean age was 67 years and 30% were women. Most patients had atrial fibrillation (n = 179), others had atrial flutter or had a combination. One of nine items demonstrated unsatisfactory model fit in the ASTA Symptom scale and two of 13 in the ASTA Health-Related Quality of Life (HRQoL) scale. Unidimensionality was supported for both scales. The targeting was acceptable except for the lower end of the scales. Both scales showed reversed thresholds for the response categories "quite a lot" and "a lot" (eight of ASTA symptoms and 12 of ASTA HRQoL items). Some problems with local dependency were detected in both scales. The reliability (person separation index) was satisfactory: 0.75 for the ASTA symptom scale and 0.77 for the ASTA HRQoL scale. No DIF for gender and age were detected. Conclusions: The English version of the ASTA questionnaire demonstrated satisfactory measurement properties according to the Rasch model. However, it needs to be evaluated in patients with other arrhythmias. The response categories should be considered as well as DIF in further validation. The ASTA questionnaire can be used for assessments of symptoms and HRQoL between groups of different ages and genders in patients with arrhythmia. [ABSTRACT FROM AUTHOR]

Objective: To summarize data on the prevalence/incidence, risk factors and prognosis of atrial fibrillation (AF) in patients with acute coronary syndromes (ACS). Methods: MEDLINE, Embase, and Web of Science were searched to identify all published studies providing relevant data through August 23, 2020. Random‐effects meta‐analysis method was used to pool estimates. Results: We included 109 studies reporting data from a pooled population of 8 239 364 patients. The prevalence rates were 5.8% for pre‐existing AF, 7.3% for newly diagnosed AF, and 11.3% for prevalent (total) AF, in patients with ACS. Predictors of newly diagnosed AF included age (per year increase) (adjusted odds ratio [aOR]: 1.05), C‐reactive protein (aOR: 1.49), left atrial (LA) diameter (aOR: 1.08), LA dilatation (aOR: 2.32), left ventricular ejection fraction <40% (aOR: 1.82), hypertension (aOR: 1.87), and Killip ˃ 1 (aOR: 1.85), p <.01 in all analyzes. Newly diagnosed AF was associated with an increased risk of acute heart failure (adjusted hazard ratio [aHR]: 3.20), acute kidney injury (aHR: 3.09), re‐infarction (aHR: 1.96), stroke (aHR: 2.15), major bleeding (aHR: 2.93), and mortality (aHR: 1.80) in the short term; and with an increased risk of heart failure (aHR: 2.21), stroke (aHR: 1.75), mortality (aHR: 1.67), CV mortality (aHR: 2.09), sudden cardiac death (aHR: 1.53), and a composite of major adverse cardiovascular events (aHR: 1.54) in the long term (beyond 1 month), p <.05 in all analyzes. Conclusion: One in nine patients with ACS has AF, with a high proportion of newly diagnosed AF. AF, in particular newly diagnosed AF, is associated with poor short‐term and long‐term outcomes in patients with ACS. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background: Atrial fibrillation (AF) is a growing epidemic. Current models of care delivery are inadequate in meeting the needs of the population with AF. Furthermore, quality of life is known to be poor in patients with AF and is associated with adverse patient outcomes. Objective: The aim of this study was to determine if nurse-led education and cardiovascular risk factor modification, undertaken using the principles of motivational interviewing, facilitated by an electronic decision support tool to ensure the appropriate use of oral anticoagulation (OAC), could improve health-related quality of life (HRQoL), guideline adherence to OAC, and cardiovascular risk factor profiles in individuals with AF. Methods: This was a multicenter, prospective, randomized controlled feasibility study of 72 individuals with AF. The intervention involved 1 face-to-face nurse-delivered education and risk factor management session with 4 follow-up telephone calls over a 3-month period to monitor progress. The primary outcome measure was HRQoL as assessed by the Short Form-12 survey. Results: A total of 72 participants were randomized, with 36 individuals in each arm completing follow-up.Mean age was 65 ± 11 years and 44%were women. At 3 months follow-up, no significant differences between groups were observed for the physical or mental component summary scores of the Short Form-12, nor any of the subscales. Appropriate use of OAC did not differ between groups at final follow-up. Conclusions: A brief nurse-delivered educational intervention did not significantly impact on HRQoL or risk factor status in individuals with AF. Further research should focus on interventions of greater intensity to improve outcomes in this population. Trial Registration: ACTRN12615000928516 [ABSTRACT FROM AUTHOR]

Background: Insertable cardiac monitors (ICMs) are used to continuously monitor the patient's electrocardiogram. In response to patient activation or based on automated device algorithms, arrhythmia episodes are stored and automatically transmitted daily to the clinician. Thus, ICMs can be used to diagnose arrhythmias in at-risk patients and in those with symptoms potentially attributable to arrhythmias. The ICM described in this report has undergone a dramatic change in size and method of insertion. Methods: To evaluate the safety profile of the ICM procedure, we analyzed procedure-related adverse events (AEs) from two separate trials: A controlled, nonrandomized multicenter study (Reveal LINQTM Usability study) and a multicenter registry (Reveal LINQTM Registry) evaluating real-world experience. For the Registry we reported all procedure-related AEs upon occurrence, whereas for the Usability study, we reported events occurring during the first month of follow-up. Results: The Usability study enrolled 151 patients (age 56.6 ± 12.1 years; male 67%) at 16 centers; during follow-up, an infection was observed in 1.3% patients and a procedure-related serious AE (SAE) in 0.7% patients. The Registry enrolled 122 patients (age 61.0 ± 17.8 years; male 47%) at seven centers; during follow-up, an infection was observed in 1.6% patients and a procedure-related SAE in 1.6% patients. Conclusions: The cumulative experience from a controlled clinical trial and a "real-world" registry demonstrate that the new ICM can be inserted with very low incidence of AEs. [ABSTRACT FROM AUTHOR]

Background: Pulsed field ablation (PFA) is a novel form of ablation using electrical fields to ablate cardiac tissue. There are only limited data assessing the feasibility and safety of this type of ablation in humans.Methods: PULSED AF (Pulsed Field Ablation to Irreversibly Electroporate Tissue and Treat AF; https://www.clinicaltrials.gov; unique identifier: NCT04198701) is a nonrandomized, prospective, multicenter, global, premarket clinical study. The first-in-human pilot phase evaluated the feasibility and efficacy of pulmonary vein isolation using a novel PFA system delivering bipolar, biphasic electrical fields through a circular multielectrode array catheter (PulseSelect; Medtronic, Inc). Thirty-eight patients with paroxysmal or persistent atrial fibrillation were treated in 6 centers in Australia, Canada, the United States, and the Netherlands. The primary outcomes were ability to achieve acute pulmonary vein isolation intraprocedurally and safety at 30 days.Results: Acute electrical isolation was achieved in 100% of pulmonary veins (n=152) in the 38 patients. Skin-to-skin procedure time was 160±91 minutes, left atrial dwell time was 82±35 minutes, and fluoroscopy time was 28±9 minutes. No serious adverse events related to the PFA system occurred in the 30-day follow-up including phrenic nerve injury, esophageal injury, stroke, or death.Conclusions: In this first-in-human clinical study, 100% pulmonary vein isolation was achieved using only PFA with no PFA system-related serious adverse events. Graphic Abstract: A graphic abstract is available for this article. [ABSTRACT FROM AUTHOR]

Optimal Right Ventricular Pacing Introduction: Long-term right ventricular apical (RVA) pacing has been associated with adverse effects on left ventricular systolic function; however, the comparative effects of right ventricular outflow tract (RVOT) pacing are unknown. Our aim was therefore to examine the long-term effects of septal RVOT versus RVA pacing on left ventricular and atrial structure and function. Methods: Fifty-eight patients who were prospectively randomized to long-term pacing either from the right ventricular apex or RVOT septum were studied echocardiographically. Left ventricular (LV) and atrial (LA) volumes were measured. LV 2D strain and tissue velocity images were analyzed to measure 18-segment time-to-peak longitudinal systolic strain and 12-segment time-to-peak systolic tissue velocity. Intra-LV synchrony was assessed by their respective standard deviations. Interventricular mechanical delay was measured as the difference in time-to-onset of systolic flow in the RVOT and LV outflow tract. Septal A' was measured using tissue velocity images. Results: Following 29 ± 10 months pacing, there was a significant difference in LV ejection fraction (P < 0.001), LV end-systolic volume (P = 0.007), and LA volume (P = 0.02) favoring the RVOT-paced group over the RVA-paced patients. RVA-pacing was associated with greater interventricular mechanical dyssynchrony and intra-LV dyssynchrony than RVOT-pacing. Septal A' was adversely affected by intra-LV dyssynchrony (P < 0.05). Conclusions: Long-term RVOT-pacing was associated with superior indices of LV structure and function compared with RVA-pacing, and was associated with less adverse LA remodeling. If pacing cannot be avoided, the RVOT septum may be the preferred site for right ventricular pacing. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1120-1126) [ABSTRACT FROM AUTHOR]

Background: Historically, the majority of insertable cardiac monitor (ICM) procedures were performed in the cardiac catheterization (cath) lab, electrophysiology (EP) lab, or operating room (OR). The miniaturization of ICMs allows the procedure to be relocated within the hospital without compromising patient safety. We sought to estimate the rate of untoward events associated with procedures performed within the hospital but outside the traditional settings and to characterize resource utilization, procedure time intervals, and physician experience.Methods: The Reveal LINQ in-Office 2 (RIO 2) International study was a single arm, multicenter, prospective study. Patients indicated for an ICM and willing to undergo device insertion outside the cath/EP lab or OR were eligible and followed for 90 days after insertion.Results: A total of 191 patients (45.5% female aged 63.8 ± 26.9 years) underwent successful Reveal LINQ ICM insertion at 17 centers in Europe, Canada and Australia. The median total visit duration was 106 min (interquartile range [IQR]: 55-61). Patient preparation and patient education accounted for 10 min (IQR: 5-20) and 10 min (IQR: 8-15) of total visit duration, respectively. Preparation and education occurred in the procedure room for 90.6 and 60.2% of patients, respectively. There were no untoward events (0.0, 95% CI: 0.0-2.1%) though four patients presented with procedure-related adverse events that did not require invasive intervention. Physicians rated procedure location as convenient or very convenient.Conclusions: The Reveal LINQ™ ICM insertion can be safely and efficiently performed in the hospital outside the cath/EP lab or OR.Trial Registration: ClinicalTrials.gov identifier NCT02412488 ; registered on April 9, 2015. [ABSTRACT FROM AUTHOR]

The article states that National Heart Foundation of Australia, an independent non-profit health organisation, came up with the consensus statement to manage Atrial Fibrillation (AF) by using therapeutic strategy Catheter Ablation. It mentions the things which should be considered in selecting patients for catheter ablation and also discusses the dominant source of activation AF is the pulmonary veins. It was concluded that pulmonary veins isolation is the vital element in management of AF.

The article discusses a study on nationwide trends in atrial fibrillation (AF) hospitalizations across Australia over a 15-year period and contrast them with 2 other common cardiovascular conditions namely myocardial infarction (MI) and heart failure (HF). Data were taken from the National Hospital Morbidity Data set and in-patient information at every hospital in Australia. It concludes that AF is continuing to increase at a greater rate than other common cardiovascular conditions.

The growth in methamphetamine usage worldwide continues to present increasing societal and health care challenges. With the escalation of its usage in a variety of social demographics, the entity of methamphetamine-associated cardiomyopathy (MA-CMP) has emerged. This entity is increasingly responsible for an important proportion of heart failure burden in both admissions to hospital and in those individuals requiring chronic heart failure care. MA-CMP poses some unique challenges including its recognition, particularly in younger patients presenting with new-onset heart failure, its severity at presentation and complications as well as management options. The challenging nature of methamphetamine addiction and the necessity to achieve abstinence is a fundamental aspect of management of this condition. As methamphetamine use continues at high levels in Australia, the burden of MA-CMP will inevitably increase and, therefore, all clinicians responsible for heart failure management require an awareness of this disease entity and the specific clinical challenges of its care. [ABSTRACT FROM AUTHOR]

Background: The use of cardiac implantable electronic devices (CIED), which includes pacemakers, implantable cardioverter-defibrillators (ICD), cardiac resynchronisation therapy pacemakers (CRT-P) and cardiac resynchronisation therapy defibrillators (CRT-D) has increased over the past 20 years, but there is a lack of real world evidence on the longevity of these devices in the older population which is essential to inform health care delivery and support clinical decisions.Methods and Results: We conducted a retrospective cohort study using data from the Australian Government Department of Veterans' Affairs database. The cohort consisted of people who had a CIED procedure between 2005 and 2015. The cumulative risk of generator replacement/reoperations was estimated accounting for the competing risk of death. A total of 16,662 patients were included. In pacemaker recipients with an average age of 85 years, the 5-year risk of reoperation ranged from 2.8% in single chamber, 3.6% in dual chamber to 7.6% in CRT-P recipients, while the 5-year risk of dying with the index pacemaker in situ was 63% in single chamber, 46% in dual chamber and 56% in CRT-P recipients. In defibrillator recipients with an average age of 80 years, the 5-year risk of reoperation ranged from 11% in single chamber, 13% in dual chamber to 24% in CRT-D recipients, while the 5-year risk of dying with the index defibrillator in situ was 46% in single chamber, 40% in dual chamber and 41% in CRT-D recipients.Conclusion: In this cohort of older patients the 5-year risk of generator reoperation was low in pacemaker recipients whereas up to one in four CRT-D recipients would have a reoperation within 5 years. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background: Remote Central Australia has a large Indigenous population and a significant burden of cardiovascular disease. Stress echocardiography has been previously validated as a useful investigation for long-term prognostication. However, there are no prior studies assessing its utility in remote or Indigenous populations.Method: Consecutive individuals undergoing stress echocardiography in Central Australia between 2007 and 2017 were included. Stress echocardiography was performed and reported via standard protocols. Individuals were followed up for all-cause mortality.Results: One-thousand and eight patients (1,008) (54% Indigenous Australian) were included. After a mean follow-up of 3.5±2.4 years, 54 (5%) patients were deceased. Overall, 797 (79%) patients had no abnormalities during rest or stress echocardiography, with no difference according to ethnicity (p>0.05). In patients with a normal test, annual mortality averaged 1.3% over 5 years of follow-up, with annual mortality significantly higher in Indigenous compared to non-Indigenous individuals (1.8% vs 0.6% respectively). In those with an abnormal test, annual mortality was 4.4% vs 1.3% in Indigenous and non-Indigenous individuals respectively. Increasing age, Indigenous ethnicity and cardiometabolic comorbidities were associated with mortality in univariate analyses (p<0.05 for all). In multivariate models, only chronic kidney disease remained predictive of mortality, with other associations (including Indigenous ethnicity) becoming attenuated.Conclusion: This is the first study to report on the use of stress echocardiography in a remote or Indigenous population. A normal stress echocardiogram in remote Indigenous individuals was able to identify a lower risk group of patients in this setting. Although Indigenous individuals with a normal test still had a higher annual rate of mortality compared to non-Indigenous individuals, this association appeared to be mediated by cardiometabolic comorbidities. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The COVID-19 pandemic poses a significant stress on health resources in Australia. The Heart Rhythm Council of the Cardiac Society of Australia and New Zealand aims to provide a framework for efficient resource utilisation balanced with competing risks when appropriately treating patients with cardiac arrhythmias. This document provides practical recommendations for the electrophysiology (EP) and cardiac implantable electronic devices (CIED) services in Australia. The document will be updated regularly as new evidence and knowledge is gained with time. [ABSTRACT FROM AUTHOR]

Introduction: Recent registry data suggests oral anticoagulation (OAC) usage remains suboptimal in atrial fibrillation (AF) patients. The aim of our study was to determine if rates of appropriate use of OAC in individuals with AF differs between the emergency department (ED) and cardiac outpatient clinic (CO).Methods: This was a retrospective study of consecutive AF patients over a 12-month period. Data from clinical records, discharge summaries and outpatient letters were independently reviewed by two investigators. Appropriateness of OAC was assessed according to the CHA2DS2-VASc score.Results: Of 455 unique ED presentations with AF as a primary diagnosis, 115 patients who were treated and discharged from the ED were included. These were compared to 259 consecutively managed AF patients from the CO. Inappropriate OAC was significantly higher in the ED compared to the CO group (65 vs. 18%, p<0.001). Treatment in the ED was a significant multivariate predictor of inappropriate OAC (odds ratio 8.2 [4.8-17.7], p<0.001).Conclusions: This patient level data highlights that significant opportunity exists to improve disparities in the use of guideline adherent therapy in the ED compared to CO. There is an urgent need for protocol-driven treatment in the ED or streamlined early follow-up in a specialised AF clinic to address this treatment gap. [ABSTRACT FROM AUTHOR]

In the context of the current global COVID-19 pandemic, this Consensus Statement provides current recommendations for patients with, or at risk of developing, genetic heart disease, and for their health care management and service provision in Australia and New Zealand. Apart from general recommendations, there are specific recommendations for the following conditions: cardiomyopathy, Brugada syndrome (including in children), long QT syndrome (LQTS) and catecholaminergic polymorphic ventricular tachycardia (CPVT). Other recommendations are relevant to patient self-care and primary health care. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Although most of the additional increases in coronary heart disease morbidity and mortality are estimated to occur outside developed regions such as North America and Europe, few nationwide studies have been published of acute myocardial infarction (MI) epidemiology from other regions. We thus sought to expand the global data regarding MI trends. Nationwide trends of incident MI, ST-segment elevation MI (STEMI), and noneST-segment MI (non-STEMI) were analyzed during a 17-year period in Australia. We identified 714,262 hospitalizations for MI from 1993 to 2010, representing 331,871,389 person-years. During the study period, the age- and gender-adjusted incidence of all MIs increased from 215 to 251 cases per 100,000 person-years, a relative increase of 76% (p <0.0001 for trend). The adjusted incidence of STEMI decreased from 147 to 70 cases per 100,000 person-years, a relative decrease of 30% (p <0.0001 for trend). In contrast, the adjusted incidence of non-STEMI increased from 67 to 182 cases per 100,000 person-years, a relative increase of 315% (p <0.0001 for trend). Age-specific analyses suggested that statistically significant increases in MI incidence were present in those aged <50 and 80 years. In conclusion, although it has previously been suggested that declining trends in MI incidence in North American and European reports might be generalizable given the seemingly consistent observations thus far, the present results highlight the possibility that other global populations might have less favorable trends. The incidence of MI in Australia might not be decreasing as rapidly as that seen in other regions and requires additional exploration. [ABSTRACT FROM AUTHOR]

Background: Anticoagulation can prevent most strokes in individuals with atrial fibrillation (AF); however, many people presenting with stroke and known AF are not anticoagulated. Language barriers and poor health literacy have previously been associated with decreased patient medication adherence. The association between language barriers and initiation of anticoagulation therapy for AF is uncertain., Aims: The aims of this study were to determine whether demographic factors, including non-English primary language, were (1) associated with not being initiated on anticoagulation for known AF prior to admission with stroke, and (2) associated with non-adherence to anticoagulation in the setting of known AF prior to admission with stroke., Methods: A multicentre retrospective cohort study was conducted for consecutive individuals admitted to the three South Australian tertiary hospitals with stroke units over a 5-year period., Results: There were 6829 individuals admitted with stroke. These cases included 5835 ischaemic stroke patients, 1333 of whom had pre-existing AF. Only 40.0% presenting with ischaemic stroke in the setting of known pre-existing AF were anticoagulated. When controlling for demographics, socioeconomic status and past medical history (including the components of the CHADS2VASC score and anticoagulation contraindications), having a primary language other than English was associated with a lower likelihood of having been commenced on anticoagulant for known pre-stroke AF (odds ratio: 0.52, 95% confidence interval: 0.36-0.77, P = 0.001), but was not associated with a differing likelihood of anticoagulation adherence., Conclusions: A significant proportion of patients with stroke have pre-existing unanticoagulated AF; these rates are substantially higher if the primary language is other than English. Targeted research and interventions to minimise evidence-treatment gaps in this cohort may significantly reduce stroke burden., (© 2023 Royal Australasian College of Physicians.)

Background: Remote monitoring (RM) can facilitate early detection of subclinical and symptomatic atrial fibrillation (AF), providing an opportunity to evaluate the need for stroke prevention therapies. We aimed to characterize the burden of RM AF alerts and its impact on anticoagulation of patients with device-detected AF., Methods: Consecutive patients with a cardiac implantable electronic device, at least one AF episode, undergoing RM were included and assigned an estimated minimum CHA 2 DS 2 -VASc score based on age and device type. RM was provided via automated software system, providing rapid alert processing by device specialists and systematic, recurrent prompts for anticoagulation., Results: From 7651 individual, 389,188 AF episodes were identified, 3120 (40.8%) permanent pacemakers, 2260 (29.5%) implantable loop recorders (ILRs), 987 (12.9%) implantable cardioverter defibrillators, 968 (12.7%) cardiac resynchronization therapy (CRT) defibrillators, and 316 (4.1%) CRT pacemakers. ILRs transmitted 48.8% of all AF episodes. At twelve-months, 3404 (44.5%) AF < 6 min, 1367 (17.9%) 6 min-6 h, 1206 (15.8%) 6-24 h, and 1674 (21.9%) ≥ 24 h. A minimum CHA 2 DS 2 -VASc score of 2 was assigned to 1704 (63.1%) of the patients with an AF episode of ≥ 6 h, 531 (31.2%) who were not anticoagulated at 12-months, and 1031 (61.6%) patients with an AF episode duration of ≥ 24 h, 290 (28.1%) were not anticoagulated., Conclusions: Despite being intensively managed via RM software system incorporating cues for anticoagulation, a substantial proportion of patients with increased stroke risk remained unanticoagulated after a device-detected AF episode of significant duration. These data highlight the need for improved clinical response pathways and an integrated care approach to RM., Trial Registration: Australian New Zealand Clinical Trial Registry: ACTRN12620001232921., (© 2023. Crown.)

Importance: Randomised trials have shown that catheter ablation (CA) is superior to medical therapy for ventricular tachycardia (VT) largely in patients with ischaemic heart disease. Whether this translates to patients with all forms and stages of structural heart disease (SHD-e.g., non-ischaemic heart disease) is unclear. This trial will help clarify whether catheter ablation offers superior outcomes compared to medical therapy for VT in all patients with SHD., Objective: To determine in patients with SHD and spontaneous or inducible VT, if catheter ablation is more efficacious than medical therapy in control of VT during follow-up., Design: Randomised controlled trial including 162 patients, with an allocation ratio of 1:1, stratified by left ventricular ejection fraction (LVEF) and geographical region of site, with a median follow-up of 18-months and a minimum follow-up of 1 year., Setting: Multicentre study performed in centres across Australia., Participants: Structural heart disease patients with sustained VT or inducible VT (n=162)., Intervention: Early treatment, within 30 days of randomisation, with catheter ablation (intervention) or initial treatment with antiarrhythmic drugs only (control)., Main Outcomes, Measures, and Results: Primary endpoint will be a composite of recurrent VT, VT storm (≥3 VT episodes in 24 hrs or incessant VT), or death. Secondary outcomes will include each of the individual primary endpoints, VT burden (number of VT episodes in the 6 months preceding intervention compared to the 6 months after intervention), cardiovascular hospitalisation, mortality (including all-cause mortality, cardiac death, and non-cardiac death) and LVEF (assessed by transthoracic echocardiography from baseline to 6-, 12-, 24- and 36-months post intervention)., Conclusions and Relevance: The Catheter Ablation versus Anti-arrhythmic Drugs for Ventricular Tachycardia (CAAD-VT) trial will help determine whether catheter ablation is superior to antiarrhythmic drug therapy alone, in patients with SHD-related VT., Trial Registry: Australian New Zealand Clinical Trials Registry (ANZCTR) TRIAL REGISTRATION ID: ACTRN12620000045910 TRIAL REGISTRATION URL: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=377617&isReview=true., (Copyright © 2022 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). All rights reserved.)

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., Competing Interests: Competing interests: DHL reports that the University of Adelaide received on his behalf lecture and/or consulting fees from Abbott Medical, Boehringer Ingelheim, Biotronik, Medtronic, MicroPort CRM and Pfizer. PS reports having served on the advisory board of Medtronic, Abbott Medical, Boston Scientific, CathRx and PaceMate. PS reports that the University of Adelaide has received on his behalf lecture and/or consulting fees from Medtronic, Abbott Medical and Boston Scientific. PS reports that the University of Adelaide has received on his behalf research funding from Medtronic, Abbott Medical, Boston Scientific and Microport. CXW reports that the University of Adelaide has received on his behalf lecture, travel and/or research funding from Abbott Medical, Bayer, Boehringer Ingelheim, Medtronic, Novartis, Servier, St Jude Medical and Vifor Pharma. The other authors have nothing to disclose., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

Aims: The aim of this study is to determine the association between the coronavirus disease 2019 (COVID-19) pandemic and atrial fibrillation (AF) occurrence in individuals with cardiac implantable electronic devices (CIEDs)., Method and Results: Multi-centre, observational, cohort study over a 100-day period during the COVID-19 pandemic (COVID-19) in the USA. Remote monitoring was used to assess AF episodes in patients with a CIED (pacemaker or defibrillator; 20 centres, 13 states). For comparison, the identical 100-day period in 2019 was used (Control). The primary outcomes were the AF burden during the COVID-19 pandemic, and the association of the pandemic with AF occurrence, as compared with 1 year prior. The secondary outcome was the association of AF occurrence with per-state COVID-19 prevalence. During COVID-19, 10 346 CIEDs with an atrial lead were monitored. There were 16 570 AF episodes of ≥6 min transmitted (16 events per 1000 patient days) with a significant increase in proportion of patients with AF episodes in high COVID-19 prevalence states compared with low prevalence states [odds ratio 1.34, 95% confidence interval (CI) 1.21-1.48, P < 0.001]. There were significantly more AF episodes during COVID-19 compared with Control [incident rate ratio (IRR) 1.33, 95% CI 1.25-1.40, P < 0.001]. This relationship persisted for AF episodes ≥1 h (IRR 1.65, 95% CI 1.53-1.79, P < 0.001) and ≥6 h (IRR 1.54, 95% CI 1.38-1.73, P < 0.001)., Conclusion: During the first 100 days of COVID-19, a 33% increase in AF episodes occurred with a 34% increase in the proportion of patients with AF episodes observed in states with higher COVID-19 prevalence. These findings suggest a possible association between pandemic-associated social disruptions and AF in patients with CIEDs., Clinical Trial Registration: Australian New Zealand Clinical Trial Registry: ACTRN12620000692932., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2021. For permissions, please email: journals.permissions@oup.com.)

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)., Competing Interests: Competing interests: DL reports the University of Adelaide has received on his behalf lecture and/or consulting fees from Abbott Medical, Bayer, Biotronik, Boehringer Ingelheim, Medtronic, Microport and Pfizer/BMS. PS reports having served on the advisory board of Medtronic, Abbott Medical, Boston Scientific, CathRx and PaceMate. PS reports that the University of Adelaide has received on his behalf lecture and/or consulting fees from Medtronic, Abbott Medical and Boston Scientific. PS reports that the University of Adelaide has received on his behalf research funding from Medtronic, Abbott Medical, Boston Scientific and Microport. CXW reports that the University of Adelaide has received on his behalf lecture, travel and/or research funding from Abbott Medical, Bayer, Boehringer Ingelheim, Medtronic, Novartis, Servier, St Jude Medical and Vifor Pharma., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Atrial fibrillation (AF) screening using mobile single-lead electrocardiogram (ECG) devices has demonstrated variable sensitivity and specificity. However, limited data exists on the use of such devices in low-resource countries., Objective: The goal of the research was to evaluate the utility of the KardiaMobile device's (AliveCor Inc) automated algorithm for AF screening in a semirural Ethiopian population., Methods: Analysis was performed on 30-second single-lead ECG tracings obtained using the KardiaMobile device from 1500 TEFF-AF (The Heart of Ethiopia: Focus on Atrial Fibrillation) study participants. We evaluated the performance of the KardiaMobile automated algorithm against cardiologists' interpretations of 30-second single-lead ECG for AF screening., Results: A total of 1709 single-lead ECG tracings (including repeat tracing on 209 occasions) were analyzed from 1500 Ethiopians (63.53% [953/1500] male, mean age 35 [SD 13] years) who presented for AF screening. Initial successful rhythm decision (normal or possible AF) with one single-lead ECG tracing was lower with the KardiaMobile automated algorithm versus manual verification by cardiologists (1176/1500, 78.40%, vs 1455/1500, 97.00%; P<.001). Repeat single-lead ECG tracings in 209 individuals improved overall rhythm decision, but the KardiaMobile automated algorithm remained inferior (1301/1500, 86.73%, vs 1479/1500, 98.60%; P<.001). The key reasons underlying unsuccessful KardiaMobile automated rhythm determination include poor quality/noisy tracings (214/408, 52.45%), frequent ectopy (22/408, 5.39%), and tachycardia (>100 bpm; 167/408, 40.93%). The sensitivity and specificity of rhythm decision using KardiaMobile automated algorithm were 80.27% (1168/1455) and 82.22% (37/45), respectively., Conclusions: The performance of the KardiaMobile automated algorithm was suboptimal when used for AF screening. However, the KardiaMobile single-lead ECG device remains an excellent AF screening tool with appropriate clinician input and repeat tracing., Trial Registration: Australian New Zealand Clinical Trials Registry ACTRN12619001107112; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=378057&isReview=true., (©Bradley M Pitman, Sok-Hui Chew, Christopher X Wong, Amenah Jaghoori, Shinsuke Iwai, Gijo Thomas, Andrew Chew, Prashanthan Sanders, Dennis H Lau. Originally published in JMIR mHealth and uHealth (https://mhealth.jmir.org), 19.05.2021.)

Importance: Catheter ablation is effective in reducing atrial fibrillation (AF), but the association of ablation for AF with quality of life is unclear., Objective: To evaluate whether the procedural outcome of ablation for AF is associated with quality of life (QOL) measures., Design, Setting, and Participants: This was a prespecified secondary analysis of the Substrate and Trigger Ablation for Reduction of Atrial Fibrillation-Part II (STAR AF II) prospective randomized clinical trial, which compared 3 strategies for ablation of persistent AF. This analysis included 549 of the 589 patients enrolled in the trial who underwent ablation. Enrollment occurred at 35 centers in Europe, Canada, Australia, China, and Korea from November 2010 to July 2012. Data for the current study were analyzed on December 11, 2019., Interventions: Patients underwent AF ablation with 1 of 3 ablation strategies: (1) pulmonary vein isolation (PVI), (2) PVI plus complex fractionated electrograms, or (3) PVI plus linear lesions., Main Outcomes and Measures: Quality of life was assessed at baseline and at 6, 12, and 18 months after ablation for AF using the 36-Item Short Form Health Survey and the EuroQol Health-Related Quality of Life 5-Dimension 3-Level questionnaire. Scores were also converted to a physical health component score (PCS) and a mental health component score (MCS). Individual AF burden was calculated by the total time with AF from Holter monitors and the percentage of transtelephonic monitor recordings showing AF., Results: Among the 549 patients included in this secondary analysis, QOL was assessed in 466 (85%) at baseline and at 6, 12, and 18 months after ablation for AF. The mean (SD) age of the study population was 60 (9) years; 434 (79%) individuals were men, and 417 (76%) had continuous AF for 6 months or more before ablation. The AF burden significantly decreased from a mean (SD) of 82% (36%) before ablation to 6.6% (23%) after ablation (P < .001). Significant improvements in mean (SD) PCS (68.3 [20.7] to 82.5 [18.6]) and MCS (35.3 [8.6] to 37.5 [7.6]) occurred 18 months after ablation (P < .05 for both). Significant QOL improvement occurred in all 3 study arms and regardless of AF recurrence, defined as AF episodes lasting more than 30 seconds: for no recurrence, mean (SD) PCS increased from 66.5 (20.9) to 79.1 (19.4) and MCS from 35.3 (8.7) to 37.7 (7.7); for recurrence, mean (SD) PCS increased from 70.2 (20.4) to 86.4 (16.8) and MCS from 35.3 (8.6) to 37.1 (7.4) (P < .05 for all). When outcome was defined by AF burden reduction, in patients with less than 70% reduction in AF burden, the increase in PCS was significantly less than in those with greater than 70% reduction, and only 3 of 8 subscales showed significant improvement., Conclusions and Relevance: In this secondary analysis, decreases in AF burden after ablation for AF were significantly associated with improvements in QOL. Quality of life changes were significantly associated with the percentage of AF burden reduction after ablation., Trial Registration: ClinicalTrials.gov Identifier: NCT01203748.

Background: Sudden cardiac death (SCD) in the young is devastating. Contemporary incidence remains unclear with few recent nationwide studies and limited data addressing risk factors for causes. We aimed to determine incidence, trends, causes, and risk factors for SCD in the young., Methods and Results: The National Coronial Information System registry was reviewed for SCD in people aged 1 to 35 years from 2000 to 2016 in Australia. Subjects were identified by the International Classification of Diseases , Tenth Revision code relating to circulatory system diseases (I00-I99) from coronial reports. Baseline demographics, circumstances, and cause of SCD were obtained from coronial and police reports, alongside autopsy and toxicology analyses where available. During the study period, 2006 cases were identified (median age, 28±7 years; men, 75%; mean body mass index, 29±8 kg/m 2 ). Annual incidence ranged from 0.91 to 1.48 per 100 000 age-specific person-years, which was the lowest in 2013 to 2015 compared with previous 3-year intervals on Poisson regression model ( P =0.001). SCD incidence was higher in nonmetropolitan versus metropolitan areas (0.99 versus 0.53 per 100 000 person-years; P <0.001). The most common cause of SCD was coronary artery disease (40%), followed by sudden arrhythmic death syndrome (14%). Incidence of coronary artery disease-related SCD decreased from 2001-2003 to 2013-2015 ( P <0.001). Proportion of SCD related to sudden arrhythmic death syndrome increased during the study period ( P =0.02) although overall incidence was stable ( P =0.22). Residential remoteness was associated with coronary artery disease-related SCD (odds ratio, 1.44 [95% CI, 1.24-1.67]; P <0.001). For every 1-unit increase, body mass index was associated with increased likelihood of SCD from cardiomegaly (odds ratio, 1.08 [95% CI, 1.05-1.11]; P <0.001) and dilated cardiomyopathy (odds ratio, 1.04 [95% CI, 1.01-1.06]; P =0.005)., Conclusions: Incidence of SCD in the young and specifically coronary artery disease-related SCD has declined in recent years. Proportion of SCD related to sudden arrhythmic death syndrome increased over the study period. Geographic remoteness and obesity are risk factors for specific causes of SCD in the young.

Background The association between mitral valve prolapse (MVP) and sudden death remains controversial. We aimed to describe histopathological changes in individuals with autopsy-determined isolated MVP (iMVP) and sudden death and document cardiac arrest rhythm. Methods and Results The Australian National Coronial Information System database was used to identify cases of iMVP between 2000 and 2018. Histopathological changes in iMVP and sudden death were compared with 2 control cohorts matched for age, sex, height, and weight (1 group with noncardiac death and 1 group with cardiac death). Data linkage with ambulance services provided cardiac arrest rhythm for iMVP cases. From 77 221 cardiovascular deaths in the National Coronial Information System database, there were 376 cases with MVP. Individual case review yielded 71 cases of iMVP. Mean age was 49±18 years, and 51% were women. Individuals with iMVP had higher cardiac mass (447 g versus 355 g; P <0.001) compared with noncardiac death, but similar cardiac mass (447 g versus 438 g; P =0.64) compared with cardiac death. Individuals with iMVP had larger mitral valve annulus compared with noncardiac death (121 versus 108 mm; P <0.001) and cardiac death (121 versus 110 mm; P =0.002), and more left ventricular fibrosis (79% versus 38%; P <0.001) compared with noncardiac death controls. In those with iMVP and witnessed cardiac arrest, 94% had ventricular fibrillation. Conclusions Individuals with iMVP and sudden death have increased cardiac mass, mitral annulus size, and left ventricular fibrosis compared with a matched cohort, with cardiac arrest caused by ventricular fibrillation. The histopathological changes in iMVP may provide the substrate necessary for development of malignant ventricular arrhythmias.

Aims: To investigate the composition of nocturnal hypoxaemic burden and its prognostic value for cardiovascular (CV) mortality in community-dwelling older men., Methods and Results: We analysed overnight oximetry data from polysomnograms obtained in 2840 men from the Outcomes of Sleep Disorders in Older Men (MrOS Sleep) study (ClinicalTrials.gov Identifier: NCT00070681) to determine the number of acute episodic desaturations per hour (oxygen desaturation index, ODI) and time spent below 90% oxygen saturation (T90) attributed to acute desaturations (T90desaturation) and to non-specific drifts in oxygen saturation (T90non-specific), respectively, and their relationship with CV mortality. After 8.8 ± 2.7 years follow-up, 185 men (6.5%) died from CV disease. T90 [hazard ratio (HR) 1.21, P < 0.001], but not ODI (HR 1.13, P = 0.06), was significantly associated with CV death in univariate analysis. T90 remained significant when adjusting for potential confounders (HR 1.16, P = 0.004). Men with T90 > 12 min were at an elevated risk of CV mortality (HR 1.59; P = 0.006). Approximately 20.7 (5.7-48.5) percent of the variation in T90 could be attributed to non-specific drifts in oxygen saturation. T90desaturation and T90non-specific were individually associated with CV death but combining both variables did not improve the prediction., Conclusion: In community-dwelling older men, T90 is an independent predictor of CV mortality. T90 is not only a consequence of frank desaturations, but also reflects non-specific drifts in oxygen saturation, both contributing towards the association with CV death. Whether T90 can be used as a risk marker in the clinical setting and whether its reduction may constitute a treatment target warrants further study., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2018. For permissions, please email: journals.permissions@oup.com.)

Background: Atrial fibrillation (AF) management guidelines recommend screening for symptoms of sleep-disordered breathing (SDB). We aimed to assess the role of self-reported daytime sleepiness in detection of patients with SDB and AF., Methods: A total of 442 consecutive ambulatory patients with AF who were considered candidates for rhythm control and underwent polysomnography comprised the study population. The utility of daytime sleepiness (quantified by the Epworth Sleepiness Scale [ESS]) to predict any (apnea-hypopnea index [AHI] ≥ 5), moderate-to-severe (AHI ≥ 15), and severe (AHI ≥ 30) SDB on polysomnography was tested., Results: Mean age was 60 ± 11 years and 69% patients were men. SDB was present in two-thirds of the population with 33% having moderate-to-severe SDB. Daytime sleepiness was low (median ESS = 8/24) and the ESS poorly predicted SDB, regardless of the degree of SDB tested (area under the curve: 0.48-0.56). Excessive daytime sleepiness (ESS ≥ 11) was present in 11.9% of the SDB population and had a negative predictive value of 43.1% and a positive predictive value of 67.5% to detect moderate-to-severe SDB. Male gender (odds ratio [OR]: 2.3, 95% confidence interval [CI]: 1.4-3.8, P = 0.001), obesity (OR: 3.5, 95% CI: 2.3-5.5, P < 0.001), diabetes (OR: 2.3, 95% CI: 1.2-4.4, P = 0.08), and stroke (OR: 4.6, 95% CI: 1.7-12.3, P = 0.002) were independently associated with an increased likelihood of moderate-to-severe SDB., Conclusions: In an ambulatory AF population, SDB was common but most patients reported low daytime sleepiness levels. Clinical features, rather than daytime sleepiness, were predictive of patients with moderate-to-severe SDB. Lack of excessive daytime sleepiness should not preclude patients from being investigated for the potential presence of concomitant SDB., (Copyright © 2019 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.)

Objective: The aim of this study is to characterise hospitalisations due to atrial fibrillation (AF) compared with two other common cardiovascular conditions, myocardial infarction (MI) and heart failure (HF), in addition to the associated economic burden of these hospitalisations and contribution of AF-related procedures., Methods: The primary outcome measure was the rate of increase of AF, MI and HF hospitalisations from 1993 to 2013. The rate of increase of AF-related procedures including cardioversion and ablation were also collected, in addition to direct costs associated with hospitalisations for each of these three conditions., Results: AF hospitalisations increased 295% over the 21-year period to a total of 61 424 in 2013. In comparison, MI and HF hospitalisations increased by only 73% and 39%, respectively, over the same period. Considering population changes, there was an annual increase in AF hospitalisations of 5.2% (incidence rate ratio [IRR] 1.052; 95% CI 1.046 to 1.059; p<0.001). In contrast, there was a 2.2% increase per annum for MI (IRR 1.022; 95% CI 1.017 to 1.027; p<0.001) and negligible annual change for HF hospitalisations (IRR 1.000; 95% CI 0.997 to 1.002; p=0.78). Cardioversion and AF ablation increased by 10% and 26% annually, respectively. AF hospitalisation costs rose by 479% over the 21-year period, an increase that was more than double that of MI and HF., Conclusions: The burden of AF hospitalisations continues to rise unabated. AF has now surpassed both MI and HF hospitalisations and represents a growing cost burden. New models of healthcare delivery are required to stem this growing healthcare burden., Competing Interests: Competing interests: PS reports having served on the advisory board of Biosense-Webster, Medtronic, St Jude Medical, Boston Scientific and CathRx. PS reports that the University of Adelaide has received on his behalf lecture and/or consulting fees from Biosense-Webster, Medtronic, St Jude Medical and Boston Scientific. PS reports that the University of Adelaide has received on his behalf research funding from Medtronic, St Jude Medical, Boston Scientific, Biotronik and LivaNova. CXW reports that the University of Adelaide has received on his behalf lecture, travel and/or research funding from Novartis, Servier, Boehringer-Ingelheim and Medtronic., (© Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

Aims: Antiarrhythmic drugs (AADs) for the treatment of atrial fibrillation (AF) are associated with limited efficacy and adverse effects. Inhibition of the atrial current IKur, absent from the ventricle, is expected to be antiarrhythmic, without adverse cardiac effects, particularly ventricular pro-arrhythmic effects., Methods and Results: A randomized clinical trial in symptomatic paroxysmal AF patients being considered for ablation. The primary endpoint was AF burden (AFB) as measured by insertable continuous monitoring (ICM) devices. Screened patients had an ICM implanted and were included if AFB was between 1% and 70% after 4 weeks of recording. They were randomly allocated to 4-week treatment of a selective IKur inhibitor S66913 (5 mg, 25 mg, or 100 mg orally per day) or placebo. The study was to enroll 160 patients. The study was terminated prematurely, due to non-study related preclinical safety concerns, after 58 patients had been enrolled. The median AFB ranged from 4.3% to 10.3% at baseline in the four treatment groups. S66913 had no significant effect on AFB or on AFB plus atrial tachycardia (AT) burden, at any dosage; nor on any secondary endpoints including the number and duration of AT or AF episodes, and symptoms. The drug was well tolerated with no safety concern during the treatment or the extended clinical follow-up., Conclusions: DIAGRAF-IKUR was the first study to show that using ICM to assess the effect of an AAD is feasible. The selective IKur inhibitor S66913 was safe but had no clinically meaningful effect at the time of early termination of the study.

Introduction: A large number of older people receive pacemakers each year but broad population-based studies that describe complications following pacemaker implantation in this population are lacking., Methods: We conducted a retrospective cohort study using data from the Australian Government Department of Veterans' Affairs database. The cohort consisted of patients who received a pacemaker from 2005 to 2014. The outcomes were subsequent rehospitalizations for infections, procedure-related complications, thromboembolism, cardiovascular events (heart failure, myocardial infarction, and atrial fibrillation), and reoperation of pacemaker, and mortality., Results: There were 10 883 pacemakers recipients, the median age was 86 years (interquartile range 83-89), 61% were males, and 74% received a dual-chamber pacemaker. Within 90 days postdischarge, rehospitalizations were occasioned by pacemaker infection in 0.5%, device-related complications in 1.5%, cerebral infarction in 0.7%, and heart failure in 6% of single-chamber pacemaker recipients. In dual-chamber pacemaker recipients rehospitalizations were occasioned by pacemaker infection in 0.4%, septicemia in 0.4%, device-related complications in 1.2%, cerebral infarction in 0.3%, and heart failure in 3%. Rehospitalizations for pacemaker adjustment occurred in 1.5% of patients. The 90-day postdischarge mortality was 5% and 3% in patients with single- and dual-chamber pacemaker, respectively., Conclusion: Rehospitalizations for infection, procedure-related complications, or thromboembolism occurred in 1% to 2% of patients within 90 days postdischarge, while 10% of single chamber and 7% of dual-chamber recipients experienced a rehospitalization for a cardiovascular event., (© 2018 Wiley Periodicals, Inc.)

Aims: Real-time contact force (CF)-sensing radiofrequency ablation catheter for treatment of paroxysmal atrial fibrillation (PAF) allows optimization of electrode-tissue contact, which correlates with long-term success. This prospective, multicentre observational registry assessed the real-world clinical effectiveness of a CF-sensing catheter for ablation of drug-refractory PAF., Methods and Results: Patients were followed-up at 3, 6, and 12 months after ablation. Outcome measures included isolation of targeted pulmonary veins (PVs) confirmed by entrance block (acute success), patient-reported freedom from symptomatic atrial fibrillation (AF) at 12 months (long-term effectiveness), Atrial Fibrillation Effect on Quality-of-life scores at 6 and 12 months, and incidence of predefined procedural complications. The registry enrolled 261 PAF patients (mean age 58.8 ± 11.3 years; 70.7% men; 91.7% Caucasian). Acute PV isolation was reported in 98.8% of patients [95% confidence interval (CI): 96.4-99.7%], and 12-month success for freedom from symptomatic AF was 75.7% (95% CI: 69.7-80.7%). Average CF for the evaluable cohort was 16.4 ± 3.9 g. There was a significant correlation between long-term effectiveness and stability of CF use [percentage of time CF was within investigator-selected working range; odds ratio (95% Wald CI), 1.0 (1.00-1.1); P = 0.030]. Average CF did not correlate with 12-month success. Clinically meaningful quality of life (QoL) improvements were observed at 6 and 12 months. Primary adverse events occurred in 2.7% patients., Conclusion: This observational registry showed that PAF ablation with a CF-sensing catheter had high acute success rates, favourable 12-month outcomes, and a good safety profile. Patients' QoL improved significantly. Long-term effectiveness significantly correlated with stable CF with adequate catheter-tissue contact (NCT01677052).

Introduction: Atrial fibrillation (AF) is increasing in prevalence and is associated with significant morbidity and mortality. The optimal diagnostic and treatment strategies for AF are continually evolving and care for patients requires confidence in integrating these new developments into practice. These clinical practice guidelines will assist Australian practitioners in the diagnosis and management of adult patients with AF. Main recommendations: These guidelines provide advice on the standardised assessment and management of patients with atrial fibrillation regarding: screening, prevention and diagnostic work-up; acute and chronic arrhythmia management with antiarrhythmic therapy and percutaneous and surgical ablative therapies; stroke prevention and optimal use of anticoagulants; and integrated multidisciplinary care. Changes in management as a result of the guideline: Opportunistic screening in the clinic or community is recommended for patients over 65 years of age. The importance of deciding between a rate and rhythm control strategy at the time of diagnosis and periodically thereafter is highlighted. β-Blockers or non-dihydropyridine calcium channel antagonists remain the first line choice for acute and chronic rate control. Cardioversion remains first line choice for acute rhythm control when clinically indicated. Flecainide is preferable to amiodarone for acute and chronic rhythm control. Failure of rate or rhythm control should prompt consideration of percutaneous or surgical ablation. The sexless CHA2DS2-VA score is recommended to assess stroke risk, which standardises thresholds across men and women; anticoagulation is not recommended for a score of 0, and is recommended for a score of ≥ 2. If anticoagulation is indicated, non-vitamin K oral anticoagulants are recommended in preference to warfarin. An integrated care approach should be adopted, delivered by multidisciplinary teams, including patient education and the use of eHealth tools and resources where available. Regular monitoring and feedback of risk factor control, treatment adherence and persistence should occur.

Background An association between atrial fibrillation ( AF ), anxiety, and depression is recognized, but the spectrum of psychological distress remains unclear. We aimed to characterize the severity and predictors of distress associated with AF in a tertiary population and its response to AF management. Methods and Results Seventy-eight patients with symptomatic AF underwent evaluation, including of AF symptom severity, health-related quality of life, psychological distress, suicidal ideation, and specific personality traits. Twenty participants underwent AF ablation and 58 were managed medically, with repeat assessments at 4, 8, and 12 months. Severe distress (Hospital Anxiety and Depression Scale score, ≥15/42) was identified in 27 of 78 (35%). Independent predictors were a personality marked by vulnerability to stress (Perceived Stress Scale: R 2 , 0.54; β=0.7±0.1; t=7.8; P<0.001) and 1 marked by negativity/social inhibition (Type D Personality Scale: R 2 , 0.47; β=0.7±0.1; t=6.7; P<0.001). Suicidal ideation was reported by 16 of 78 (20%) and was predicted by personality traits (Perceived Stress Scale score: R 2 , 0.35; odds ratio, 1.22±0.06; P<0.001; Type D Personality Scale score: R 2 , 0.48; odds ratio, 1.43±0.14; P<0.001). Effective AF ablation (median AF burden 1% [0-1%] over 12 months) was associated with significant reductions in distress (Hospital Anxiety and Depression Scale score, 13.9±1.8 to 4.3±1.8; P<0.05) and prevalence of suicidal ideation (30-5%; P=0.02). Conclusions There was a high prevalence of severe psychological distress (35%) and of suicidal ideation (20%) in a tertiary AF population, with personality traits predicting both. Effective AF ablation was associated with significant improvements, suggesting AF itself may be a treatable causative factor of distress.

Background: Obesity begets atrial fibrillation (AF). Although cardiorespiratory fitness is protective against incident AF in obese individuals, its effect on AF recurrence or the benefit of cardiorespiratory fitness gain is unknown., Objectives: This study sought to evaluate the role of cardiorespiratory fitness and the incremental benefit of cardiorespiratory fitness improvement on rhythm control in obese individuals with AF., Methods: Of 1,415 consecutive patients with AF, 825 had a body mass index ≥27 kg/m(2) and were offered risk factor management and participation in a tailored exercise program. After exclusions, 308 patients were included in the analysis. Patients underwent exercise stress testing to determine peak metabolic equivalents (METs). To determine a dose response, cardiorespiratory fitness was categorized as: low (<85%), adequate (86% to 100%), and high (>100%). Impact of cardiorespiratory fitness gain was ascertained by the objective gain in fitness at final follow-up (≥2 METs vs. <2 METs). AF rhythm control was determined using 7-day Holter monitoring and AF severity scale questionnaire., Results: There were no differences in baseline characteristics or follow-up duration between the groups defined by cardiorespiratory fitness. Arrhythmia-free survival with and without rhythm control strategies was greatest in patients with high cardiorespiratory fitness compared to adequate or low cardiorespiratory fitness (p < 0.001 for both). AF burden and symptom severity decreased significantly in the group with cardiorespiratory fitness gain ≥2 METs as compared to <2 METs group (p < 0.001 for all). Arrhythmia-free survival with and without rhythm control strategies was greatest in those with METs gain ≥2 compared to those with METs gain <2 in cardiorespiratory fitness (p < 0.001 for both)., Conclusions: Cardiorespiratory fitness predicts arrhythmia recurrence in obese individuals with symptomatic AF. Improvement in cardiorespiratory fitness augments the beneficial effects of weight loss. (Evaluating the Impact of a Weight Loss on the Burden of Atrial Fibrillation [AF] in Obese Patients; ACTRN12614001123639)., (Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: Atrial fibrillation (AF) is a leading cause of preventable stroke in Australia. Given that anticoagulation therapy can significantly reduce this stroke risk, we sought to characterise anticoagulation use in Indigenous and non-Indigenous Australians with AF., Methods: Administrative, clinical and prescription data from patients with AF were linked. Anticoagulation use was characterised according to guideline-recommended risk scores and Indigenous status., Results: 19,613 individuals with AF were studied. Despite a greater prevalence of other risk factors, Indigenous Australians were significantly younger than their non-Indigenous counterparts (p<0.001) and thus had lower CHADS₂- (1.19±0.32 vs 1.99±0.47, p<0.001) and CHA₂DS₂VASc-scores (1.47 ± 0.03 vs 2.82 ± 0.08, p<0.001). Correspondingly, the percentage of Indigenous Australians with CHADS₂ ≥ 2 (39.6% vs 44.1%, p<0.001) and CHA₂DS₂VASc-scores ≥ 2 (62.9% vs 78.8%, p<0.001) was also lower. Indigenous Australians, however, had greater rates of under- and over-anticoagulation. Overall, 72.1% and 68.9% of Indigenous and non-Indigenous Australians with CHADS₂ scores ≥2, and 76.3% and 71.3% with CHA₂DS₂VASc scores ≥2, were under-anticoagulated. Similarly, 27.4% and 24.1% of Indigenous and non-Indigenous Australians with CHADS₂ scores=0, and 24.0% and 16.7% with CHA₂DS₂VASc-scores=0, were over-anticoagulated. In multivariate analyses, Indigenous Australians were more likely to receive under- or over-anticoagulation according to CHADS₂- or CHA₂DS₂VASc-score (p=0.045 and p<0.001 respectively)., Conclusion: Anticoagulation for AF is frequently not prescribed in accordance with guideline recommendations. Under-anticoagulation in those at high stroke risk, and over-anticoagulation in those at low risk, is common and more likely in Indigenous patients with AF. Improving adherence to guideline recommendations for anticoagulation in AF may reduce both ischaemic and haemorrhagic strokes in Indigenous and non-Indigenous Australians., (Crown Copyright © 2015. Published by Elsevier Ireland Ltd. All rights reserved.)

Congestive Heart Failure (CHF) is an ambulatory care sensitive condition, associated with significant morbidity and mortality, rarely with cure. Outpatient based pharmacological management represents the main and most important aspect of care, and is usually lifelong. This narrative styled opinion review looks at the pharmacological agents recommended in the guidelines in context of the Northern Territory (NT) of Australia. We explore the concept of validity, a term used to describe the basis of standardising a particular trial or study and the population to which it is applicable. We aim to highlight the problems of the current guidelines based approach. We also present alternatives that could utilise the core principles from major trials, while incorporating regional considerations, which could benefit clients living in the NT and remote Australia., (Copyright © 2015 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.)

Purpose: In recent years, there has been a shift away from performing electrophysiologic study (EPS) to guide implantable cardioverter-defibrillator (ICD) implantation with a reliance on left ventricular ejection fraction (LVEF) alone., Methods: ICD patients were prospectively recruited from the multicentre COMFORT (Concept of Optimal Management of ventricular Fibrillation Or Very fast ventricular Tachycardia) trial. Primary prevention ICD patients (n = 260, groups 1 and 2) were compared to secondary prevention ICD patients (n = 210, group 3). Primary prevention ICDs were implanted in patients with ischemic cardiomyopathy based on LVEF ≤ 40 % and inducible ventricular tachycardia (VT) at EPS (n = 123, group 1) or impaired LVEF alone (LVEF ≤ 30 % or LVEF ≤ 35 % with NYHA class II or III; n = 137, group 2). EPS was performed in 61 % of secondary prevention ICD patients (n = 129). Patients were followed up for >12 months with a primary endpoint of spontaneous VT/ventricular fibrillation (VF)., Results: A significantly higher rate of spontaneous VT/VF occurred in secondary versus primary prevention ICD patients (P < 0.001) and in EPS-guided versus LVEF-guided primary prevention ICD patients (P = 0.029). At 2 years, the proportion of patients with ≥1 VT/VF episode was 24.6 ± 4.2 %, 19.9 ± 4.6 % and 37.1 ± 3.9 % for groups 1, 2 and 3, respectively. In the secondary prevention, patients who underwent EPS, VT/VF occurred in 44.4 ± 5.9 % and 14.1 ± 6.6 % with a positive versus negative result, respectively (P = 0.02)., Conclusions: Secondary prevention ICD patients have more spontaneous VT/VF than primary prevention ICD patients. Secondary and primary prevention ICD patients with inducible VT at EPS have more VT/VF than patients without inducible VT or impaired LVEF alone.

Objective: To examine the prevalence of atrial fibrillation (AF) and cardiac structural characteristics in Indigenous and non-Indigenous Australians., Design: Retrospective cross-sectional study linking clinical, echocardiography and administrative databases over a 10-year period., Setting: A tertiary, university teaching hospital in Adelaide, Australia., Participants: Indigenous and non-Indigenous Australians., Main Outcome Measures: AF prevalence and echocardiographic characteristics., Results: Indigenous Australians with AF were significantly younger compared to non-Indigenous Australians (55±13 vs 75±13 years, p<0.001). As a result, racial differences in AF prevalence and left atrial diameter varied according to age. In those under 60 years of age, Indigenous Australians had a significantly greater AF prevalence (2.57 vs1.73%, p<0.001) and left atrial diameters (39±7 vs 37±7 mm, p<0.001) compared to non-Indigenous Australians. In those aged 60 years and above, however, non-Indigenous Australians had significantly greater AF prevalence (9.26 vs 4.61%, p<0.001) and left atrial diameters (39±7 vs 37±7 mm, p<0.001). Left ventricular ejection fractions were less in Indigenous Australians under 60 years of age (49±14 vs 55±11%, p<0.001) and not statistically different in those aged 60 years and above (47±11 vs 52±13, p=0.074) compared to non-Indigenous Australians. Despite their younger age, Indigenous Australians with AF had similar or greater rates of cardiovascular comorbidities than non-Indigenous Australians with AF., Conclusions: Young Indigenous Australians have a significantly greater prevalence of AF than their non-Indigenous counterparts. In contrast, older non-Indigenous Australians have a greater prevalence of AF compared to their Indigenous counterparts. These observations may be mediated by age-based differences in comorbid cardiovascular conditions, left atrial diameter and left ventricular ejection fraction. Our findings suggest that AF is likely to be contributing to the greater burden of morbidity and mortality experienced by young Indigenous Australians. Further study is required to elucidate whether strategies to prevent and better manage AF in Indigenous Australians may reduce this burden., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Implantable cardioverter-defibrillator therapy in the form of high-energy shock (HES) is associated with adverse effects. This study evaluated an alternative therapy to HES, including antitachycardia pacing (ATP) for very fast ventricular tachycardia (VFVT) and low-energy shock (LES) ≤5 J for ventricular tachycardia (VT) of any cycle length (CL). This multicenter study recruited 602 patients with standard indications for an implantable cardioverter-defibrillator. Programming was standardized into 3 zones: (1) ventricular fibrillation (VF) CL of <200 ms treated with HES; (2) VFVT defined within the VF zone (CL, 200 to 250 ms) treated with 2 ATP bursts, LES, and HES; and (3) fast ventricular tachycardia (CL, 251 to 320 ms) and slow VT (CL, >320 ms) treated with 3 ATP bursts, LES, and HES. The primary end point was ATP and LES efficacy and safety. After a mean follow-up of 19 ± 8 months, 2,815 device activations were recorded in 152 patients. Of 67 VFVT episodes, 34 reverted with combined ATP and LES (success rate 50.7%) with first and second ATPs successful in 36% and 13.8%, respectively. LES was used in 39 fast ventricular tachycardia and 60 slow VT episodes with success rates of 53.8% and 73.3%, respectively. Syncope occurred in 19.4%, 16.2%, and 1% of episodes because of VFVT, VF, and VT CL >250 ms, respectively. In conclusion, tiered ATP and LES therapy terminates >50% of VFVT episodes (CL, 200 to 250 ms), which otherwise would fall within the VF zone and be treated exclusively with HES. LES is efficacious and safe in patients with VT CL >250 ms with extremely low syncope rates. Limitation of ATP to a single burst in VFVT is recommended to minimize syncope., (Copyright © 2013 Elsevier Inc. All rights reserved.)