External validation of a rapid algorithm using high-sensitivity troponin assay results for evaluating patients with suspected acute myocardial infarction.

OBJECTIVE: We sought to validate the clinical performance of a rapid assessment pathway incorporating the Siemens Atellica IM high sensitivity cardiac troponin I (hs-cTnI) assay in patients presenting to the emergency department (ED) with suspected acute myocardial infarction (AMI). METHODS: This was a multicentre prospective observational study of adult ED patients presenting to five Australian hospitals between November 2020 and September 2021. Participants included those with symptoms of suspected AMI (without ST-segment elevation MI on presentation ECG). The Siemen's Atellica IM hs-cTnI laboratory-based assay was used to measure troponin concentrations at admission and after 2-3 hours and cardiologists adjudicated final diagnoses. The HighSTEACS diagnostic algorithm was evaluated, incorporating hs-cTnI concentrations at presentation and absolute changes within the first 2 to 3 hours. The primary outcome was index AMI, including type 1 or 2 non-ST segment elevation MI (NSTEMI) or ST-elevation MI (STEMI) following presentation. 30-day major adverse cardiac outcomes (including AMI, urgent revascularisation or cardiac death) were also reported. The trial was registered with the Australian and New Zealand Clinical Trials Registry. RESULTS: 1994 patients were included. The average age was 56.2 years (SD=15.6), and 44.9% were women. 118 (5.9%) patients had confirmed index AMI. The 2-hour algorithm defined 61.3% of patients as low risk. Sensitivity was 99.1% (94.0%-99.9%) and negative predictive value was 99.9% (99.3%-100%). 24.4% of patients were deemed intermediate risk. When applying the parameters for high risk, 252 (14.3%) were identified, with a specificity of 91.5% (88.7%-93.6%) and a PPV of 42.0% (35.6-48.7%). CONCLUSIONS: A 2-hour algorithm based on the HighSTEACS strategy using the Siemens Atellica IM hs-cTnI laboratory-based assay enables safe and efficient risk assessment of emergency patients with suspected AMI. TRIAL REGISTRATION NUMBER: ACTRN12621000053820.

Implementing neurodevelopmental follow-up care for children with congenital heart disease: A scoping review with evidence mapping.

AIM: To identify and map evidence describing components of neurodevelopmental follow-up care for children with congenital heart disease (CHD). METHOD: This was a scoping review of studies reporting components of neurodevelopmental follow-up programmes/pathways for children with CHD. Eligible publications were identified through database searches, citation tracking, and expert recommendations. Two independent reviewers screened studies and extracted data. An evidence matrix was developed to visualize common characteristics of care pathways. Qualitative content analysis identified implementation barriers and enablers. RESULTS: The review included 33 studies. Twenty-one described individual care pathways across the USA (n = 14), Canada (n = 4), Australia (n = 2), and France (n = 1). The remainder reported surveys of clinical practice across multiple geographical regions. While heterogeneity in care existed across studies, common attributes included enrolment of children at high-risk of neurodevelopmental delay; centralized clinics in children's hospitals; referral before discharge; periodic follow-up at fixed ages; standardized developmental assessment; and involvement of multidisciplinary teams. Implementation barriers included service cost/resourcing, patient burden, and lack of knowledge/awareness. Multi-level stakeholder engagement and integration with other services were key drivers of success. INTERPRETATION: Defining components of effective neurodevelopmental follow-up programmes and care pathways, along with enhancing and expanding guideline-based care across regions and into new contexts, should continue to be priorities. WHAT THIS PAPER ADDS: Twenty-two different neurodevelopmental follow-up care pathways/programmes were published, originating from four countries. Twelve additional publications described broad practices for neurodevelopmental follow-up across regions Common attributes across eligibility, service structure, assessment processes, and care providers were noted. Studies reported programme acceptability, uptake, cost, and effectiveness. Implementation barriers included service cost/resourcing, patient burden, and lack of knowledge/awareness.

Cost-effectiveness of left atrial appendage closure for stroke prevention in atrial fibrillation: a systematic review appraising the methodological quality.

BACKGROUND: The increasing global prevalence of atrial fibrillation (AF) has led to a growing demand for stroke prevention strategies, resulting in higher healthcare costs. High-quality economic evaluations of stroke prevention strategies can play a crucial role in maximising efficient allocation of resources. In this systematic review, we assessed the methodological quality of such economic evaluations. METHODS: We searched electronic databases of PubMed, EMBASE, CINAHL, Cochrane Central Register of Controlled Trials, and Econ Lit to identify model-based economic evaluations comparing the left atrial appendage closure procedure (LAAC) and oral anticoagulants published in English since 2000. Data on study characteristics, model-based details, and analyses were collected. The methodological quality was evaluated using the modified Economic Evaluations Bias (ECOBIAS) checklist. For each of the 22 biases listed in this checklist, studies were categorised into one of four groups: low risk, partial risk, high risk due to inadequate reporting, or high risk. To gauge the overall quality of each study, we computed a composite score by assigning + 2, 0, - 1 and - 2 to each risk category, respectively. RESULTS: In our analysis of 12 studies, majority adopted a healthcare provider or payer perspective and employed Markov Models with the number of health states varying from 6 to 16. Cost-effectiveness results varied across studies. LAAC displayed a probability exceeding 50% of being the cost-effective option in six out of nine evaluations compared to warfarin, six out of eight evaluations when compared to dabigatran, in three out of five evaluations against apixaban, and in two out of three studies compared to rivaroxaban. The methodological quality scores for individual studies ranged from 10 to - 12 out of a possible 24. Most high-risk ratings were due to inadequate reporting, which was prevalent across various biases, including those related to data identification, baseline data, treatment effects, and data incorporation. Cost measurement omission bias and inefficient comparator bias were also common. CONCLUSIONS: While most studies concluded LAAC to be the cost-effective strategy for stroke prevention in AF, shortcomings in methodological quality raise concerns about reliability and validity of results. Future evaluations, free of these shortcomings, can yield stronger policy evidence.

Global, regional, and national burden of heart failure associated with atrial fibrillation.

BACKGROUND: Heart failure is a leading cause of mortality and morbidity worldwide, and Atrial fibrillation (AF) is among many modifiable risk factors for heart failure. No estimates are available on the magnitude of the burden of heart failure associated with AF, and this study estimated the global, regional, and national burdens associated with AF. METHODS: We used the comparative risk assessment method to estimate the disease burden in terms of prevalence and years lived with disability (YLD). The population-attributable fraction for heart failure and AF was calculated from prevalence estimates of AF and the recalculated relative risks of heart failure associated with AF from a systematic review summarising the longitudinal association between AF and outcomes. The burden of heart failure was retrieved from the Global Burden of Disease database. RESULTS: Globally, 2.6% (95% uncertainty interval 1.3 to 4.7%) of the burden of heart failure is associated with AF. This was 1.5 (95% UI 0.6 to 3.2) million people in 2019, a 49.8% increase from 1990. The highest prevalence was from South-East Asia, East Asia and Oceania. The highest YLD was estimated for Central Europe, Eastern Europe and Central Asia. High-income countries showed a sharp decline in the age standardised prevalence and YLD rates from 1990 to 2019. CONCLUSION: The burden of heart failure associated with AF has increased substantially over the past two decades despite the advances in AF management. However, falling prevalence and YLD rates of heart failure associated with AF in high-income countries over time indicate that reducing this burden is possible.

Global and regional burden of ischemic stroke associated with atrial fibrillation, 2009-2019.

The extent of the preventable burden of ischaemic stroke associated with atrial fibrillation (AF) remains uncertain to date. To address this knowledge gap, we utilised the comparative risk assessment methodology to estimate the burden of ischaemic stroke associated with AF at both global and regional levels. The population attributable fraction for ischaemic stroke and AF was obtained from published literature, while data on the prevalence, incidence, deaths, and disability-adjusted life years (DALY) associated with ischaemic stroke were sourced from the Global Burden of Disease study database. Our analysis revealed that in 2019, globally, there were an estimated 0.7 (95% uncertainty interval [UI] of 0.55 to 0.83) million incident cases, 6.9 (5.81 to 8.12) million prevalence cases, 0.3 0.25 to 0.34) million deaths and 5.7 (4.91 to 6.57) million DALY resulting from ischaemic stroke associated with AF. The age-standardised death and DALY rates declined between 2009 and 2019 in all regions to varying degrees. Conversely, the age-standardised incidence and prevalence rates reduced only in high-income countries, Central Europe, Eastern Europe and Central Asia and Latin America and Caribbean regions. It is likely that our findings under-estimated the true burden of ischaemic stroke associated with AF due to limitations such as the use of a fixed population attributable fraction and poor quality of data. Nevertheless, we believe that our estimates provide valuable insights and highlight the urgent need for optimised management of AF through the implementation of efficacious interventions. Such efforts can help reduce the occurrence of preventable ischaemic strokes.

Personalized diagnosis in suspected myocardial infarction.

BACKGROUND: In suspected myocardial infarction (MI), guidelines recommend using high-sensitivity cardiac troponin (hs-cTn)-based approaches. These require fixed assay-specific thresholds and timepoints, without directly integrating clinical information. Using machine-learning techniques including hs-cTn and clinical routine variables, we aimed to build a digital tool to directly estimate the individual probability of MI, allowing for numerous hs-cTn assays. METHODS: In 2,575 patients presenting to the emergency department with suspected MI, two ensembles of machine-learning models using single or serial concentrations of six different hs-cTn assays were derived to estimate the individual MI probability (ARTEMIS model). Discriminative performance of the models was assessed using area under the receiver operating characteristic curve (AUC) and logLoss. Model performance was validated in an external cohort with 1688 patients and tested for global generalizability in 13 international cohorts with 23,411 patients. RESULTS: Eleven routinely available variables including age, sex, cardiovascular risk factors, electrocardiography, and hs-cTn were included in the ARTEMIS models. In the validation and generalization cohorts, excellent discriminative performance was confirmed, superior to hs-cTn only. For the serial hs-cTn measurement model, AUC ranged from 0.92 to 0.98. Good calibration was observed. Using a single hs-cTn measurement, the ARTEMIS model allowed direct rule-out of MI with very high and similar safety but up to tripled efficiency compared to the guideline-recommended strategy. CONCLUSION: We developed and validated diagnostic models to accurately estimate the individual probability of MI, which allow for variable hs-cTn use and flexible timing of resampling. Their digital application may provide rapid, safe and efficient personalized patient care. TRIAL REGISTRATION NUMBERS: Data of following cohorts were used for this project: BACC ( www. CLINICALTRIALS: gov ; NCT02355457), stenoCardia ( www. CLINICALTRIALS: gov ; NCT03227159), ADAPT-BSN ( www.australianclinicaltrials.gov.au ; ACTRN12611001069943), IMPACT ( www.australianclinicaltrials.gov.au , ACTRN12611000206921), ADAPT-RCT ( www.anzctr.org.au ; ANZCTR12610000766011), EDACS-RCT ( www.anzctr.org.au ; ANZCTR12613000745741); DROP-ACS ( https://www.umin.ac.jp , UMIN000030668); High-STEACS ( www. CLINICALTRIALS: gov ; NCT01852123), LUND ( www. CLINICALTRIALS: gov ; NCT05484544), RAPID-CPU ( www. CLINICALTRIALS: gov ; NCT03111862), ROMI ( www. CLINICALTRIALS: gov ; NCT01994577), SAMIE ( https://anzctr.org.au ; ACTRN12621000053820), SEIGE and SAFETY ( www. CLINICALTRIALS: gov ; NCT04772157), STOP-CP ( www. CLINICALTRIALS: gov ; NCT02984436), UTROPIA ( www. CLINICALTRIALS: gov ; NCT02060760).

Machine learning for diagnosis of myocardial infarction using cardiac troponin concentrations.

Although guidelines recommend fixed cardiac troponin thresholds for the diagnosis of myocardial infarction, troponin concentrations are influenced by age, sex, comorbidities and time from symptom onset. To improve diagnosis, we developed machine learning models that integrate cardiac troponin concentrations at presentation or on serial testing with clinical features and compute the Collaboration for the Diagnosis and Evaluation of Acute Coronary Syndrome (CoDE-ACS) score (0-100) that corresponds to an individual's probability of myocardial infarction. The models were trained on data from 10,038 patients (48% women), and their performance was externally validated using data from 10,286 patients (35% women) from seven cohorts. CoDE-ACS had excellent discrimination for myocardial infarction (area under curve, 0.953; 95% confidence interval, 0.947-0.958), performed well across subgroups and identified more patients at presentation as low probability of having myocardial infarction than fixed cardiac troponin thresholds (61 versus 27%) with a similar negative predictive value and fewer as high probability of having myocardial infarction (10 versus 16%) with a greater positive predictive value. Patients identified as having a low probability of myocardial infarction had a lower rate of cardiac death than those with intermediate or high probability 30 days (0.1 versus 0.5 and 1.8%) and 1 year (0.3 versus 2.8 and 4.2%; P < 0.001 for both) from patient presentation. CoDE-ACS used as a clinical decision support system has the potential to reduce hospital admissions and have major benefits for patients and health care providers.

Hybrid cardiac telerehabilitation for coronary artery disease in Australia: a cost-effectiveness analysis.

BACKGROUND: Traditional cardiac rehabilitation programs are centre-based and clinically supervised, with their safety and effectiveness well established. Notwithstanding the established benefits, cardiac rehabilitation remains underutilised. A possible alternative would be a hybrid approach where both centre-based and tele-based methods are combined to deliver cardiac rehabilitation to eligible patients. The objective of this study was to determine the long-term cost-effectiveness of a hybrid cardiac telerehabilitation and if it should be recommended to be implemented in the Australian context. METHODS: Following a comprehensive literature search, we chose the Telerehab III trial intervention that investigated the effectiveness of a long-term hybrid cardiac telerehabilitation program. We developed a decision analytic model to estimate the cost-effectiveness of the Telerehab III trial using a Markov process. The model included stable cardiac disease and hospitalisation health states and simulations were run using one-month cycles over a five-year time horizon. The threshold for cost-effectiveness was set at $AU 28,000 per quality-adjusted life-year (QALY). For the base analysis, we assumed that 80% completed the programme. We tested the robustness of the results using probabilistic sensitivity and scenario analyses. RESULTS: Telerehab III intervention was more effective but more costly and was not cost-effective, at a threshold of $28,000 per QALY. For every 1,000 patients who undergo cardiac rehabilitation, employing the telerehabilitation intervention would cost $650,000 more, and 5.7 QALYs would be gained, over five years, compared to current practice. Under probabilistic sensitivity analysis, the intervention was cost-effective in only 18% of simulations. Similarly, if the intervention compliance was increased to 90%, it was still unlikely to be cost-effective. CONCLUSION: Hybrid cardiac telerehabilitation is highly unlikely to be cost-effective compared to the current practice in Australia. Exploration of alternative models of delivering cardiac telerehabilitation is still required. The results presented in this study are useful for policymakers wanting to make informed decisions about investment in hybrid cardiac telerehabilitation programs.

Cost-Effectiveness of Screening to Identify Patients With Atrial Fibrillation: A Systematic Review.

BACKGROUND: Screening for Atrial Fibrillation (AF) is recommended for people aged above 65 years. Screening for AF in asymptomatic individuals can be beneficial by enabling earlier diagnosis and the commencement of interventions to reduce the risk of early events, thus improving patient outcomes. This study systematically reviews the literature about the cost-effectiveness of various screening methods for previously undiagnosed AF. METHODS: Four databases were searched to identify articles that are cost-effectiveness studies conducted on screening for AF published from January 2000 to August 2022. The Consolidated Health Economic Evaluation Reporting Standards 2022 checklist was used to assess the quality of the selected studies. A previously published approach was used to assess the usefulness of each study for health policy makers. RESULTS: The database search yielded 799 results, with 26 articles meeting the inclusion criteria. Articles were categorised into four subgroups: (i) population screening, (ii) opportunistic screening, (iii) targeted, and (iv) mixed methods of screening. Most of the studies screened adults ≥65 years of age. Most studies were performed from a 'health care payer perspective' and almost all studies used 'not screening' as a comparator. Almost all screening methods assessed were found to be cost-effective in comparison to 'not screening'. The reporting quality varied between 58% to 89%. The majority of the studies were found to be of limited usefulness for health policy makers, as none of the studies made any clear statements about policy change or implementation direction. CONCLUSION: All approaches of AF screening were found to be cost-effective compared with no screening, while opportunistic screening was found to be the optimal approach in some studies. However, screening for AF in asymptomatic individuals is context specific and likely to be cost-effective depending on the population screened, screening approach, frequency, and the duration of screening.

Clinical characteristics of Aboriginal and Torres Strait Islander emergency department patients with suspected acute coronary syndrome.

OBJECTIVES: To describe the demographics, presentation characteristics, clinical features and cardiac outcomes for Aboriginal and Torres Strait Islander patients who present to a regional cardiac referral centre ED with suspected acute coronary syndrome (ACS). METHODS: This was a single-centre observational study conducted at a regional referral hospital in Far North Queensland, Australia from November 2017 to September 2018 and January 2019 to December 2019. Study participants were 278 Aboriginal and Torres Strait Islander people presenting to an ED and investigated for suspected ACS. The main outcome measure was the proportion of patients with ACS at index presentation and differences in characteristics between those with and without ACS. RESULTS: ACS at presentation was diagnosed in 38.1% of patients (n = 106). The mean age of patients with ACS was 53.5 years (SD 9.5) compared with 48.7 years (SD 12.1) in those without ACS (P = 0.001). Patients with ACS were more likely to be male (63.2% vs 39.0%, P < 0.001), smokers (70.6% vs 52.3%, P = 0.002), have diabetes (56.6% vs 38.4%, P = 0.003) and have renal impairment (24.5% vs 10.5%, P = 0.002). CONCLUSIONS: Aboriginal and Torres Strait Islander patients with suspected ACS have a high burden of traditional cardiac risk factors, regardless of whether they are eventually diagnosed with ACS. These patients may benefit from assessment for coronary artery disease regardless of age at presentation.

Developing an Australian utility value set for MacNew-7D health states.

BACKGROUND: A new preference-based measure (MacNew-7D) has recently been developed to allow condition-specific data to be used to capture the quality of life in health economic evaluations in cardiology; however, a general population value set has not yet been developed. This study developed a population utility value set for the MacNew-7D heart disease-specific instrument. METHODS: The discrete choice experiments (DCE) technique was chosen as the preference-elicitation method. The DCE asked respondents to compare two options and to state their preferences. The survey was conducted using an online panel of respondents, with quota sampling using age groups, sex and jurisdictions to achieve representativeness of the Australian population. The total design consisted of 200 choice sets, of which each respondent answered eight. Additionally, each respondent answered two quality control choice sets. The best-fitting models were selected on the basis of consistency, parsimony, and goodness of fit. RESULTS: In total, 1903 respondents were included in the analyses. The MacNew-7D utility value set ranged from -0.4456 to 1.000 for health states defined by the classification system. The best-fitting model retained all levels for five dimensions and collapsed one adjacent level for the other two dimensions. Findings were robust to sensitivity analyses related to the inclusion or exclusion of dominancy and repeat tasks. CONCLUSION: Findings indicated that the MacNew-7D utility value set is likely suitable for estimating quality-adjusted life years derived from the MacNew heart disease health-related quality-of-life questionnaire. This value set was derived from an Australian population-based sample and may not be generalisable to dissimilar populations.

Snapshot of suspected acute coronary syndrome assessment processes in the emergency department: A national cross-sectional survey.

OBJECTIVE: The Snapshot of Suspected ACS Assessment (SSAASY) study aims to describe the assessment processes for patients with suspected acute coronary syndrome (ACS) in Australian EDs, and to compare these processes with the National Heart Foundation of Australia and Cardiac Society of Australia and New Zealand (NHFA/CSANZ) guidelines. METHODS: Between March and May 2021, a cross-sectional survey of Australian EDs was undertaken to investigate the assessment strategies used within the ED. All public and private hospitals identified as having dedicated EDs were invited to participate. Respondents provided data on hospital, ED and cardiac service characteristics. They also provided data on the risk stratification process recommended within their department (risk scores, troponin testing, objective testing for coronary artery disease). Awareness of the NHFA/CSANZ guidelines was assessed. RESULTS: Responses were received from 109/162 departments (67%). Most sites (n = 100, 92%) reported using dedicated protocols developed by ED clinicians that included risk stratification scores. Highly sensitive troponin assays were used at 103 (94%) sites. Serial troponin testing was performed over 2 h for low-risk patients in 53 (49%) sites and 2-3 h for intermediate and high-risk patients in 74 (68%) sites. Further investigations included exercise stress tests (48%) and stress echocardiography (38%), with 45% of sites ordering outpatient investigations. CONCLUSIONS: The SSAASY study reported the strategies used to assess suspected ACS. In line with current NHFA/CSANZ guidelines, highly sensitive troponin assays are widely utilised. However, serial sampling intervals were longer than guideline recommendations, suggesting a translational gap between guidelines and clinical practice.

Diagnostic and prognostic performance of the ratio between high-sensitivity cardiac troponin I and troponin T in patients with chest pain.

BACKGROUND: Elevations of high-sensitivity cardiac troponin (hs-cTn) concentrations not related to type 1 myocardial infarction are common in chest pain patients presenting to emergency departments. The discrimination of these patients from those with type 1 myocardial infarction (MI) is challenging and resource-consuming. We aimed to investigate whether the hs-cTn I/T ratio might provide diagnostic and prognostic increment in this context. METHODS: We calculated the hs-cTn I/T ratio in 888 chest pain patients having hs-cTnI (Abbott Laboratories) or hs-cTnT (Roche Diagnostics) concentrations above the respective 99th percentile at 2 hours from presentation. All patients were followed for one year regarding mortality. RESULTS: The median hs-cTn I/T ratio was 3.45 (25th, 75th percentiles 1.80-6.59) in type 1 MI patients (n = 408 ☯46.0%]), 1.18 (0.81-1.90) in type 2 MI patients (n = 56 ☯6.3%]) and 0.67 (0.39-1.12) in patients without MI. The hs-cTn I/T ratio provided good discrimination of type 1 MI from no type 1 MI (area under the receiver-operator characteristic curve 0.89 ☯95% confidence interval 0.86-0.91]), of type 1 MI from type 2 MI (area under the curve 0.81 ☯95% confidence interval 0.74-0.87]), and was associated with type 1 MI in adjusted analyses. The hs-cTn I/T ratio provided no consistent prognostic value. CONCLUSIONS: The hs-cTn I/T ratio appears to be useful for early diagnosis of type 1 MI and its discrimination from type 2 MI in chest pain patients presenting with elevated hs-cTn. Differences in hs-cTn I/T ratio values may reflect variations in hs-cTn release mechanisms in response to different types of myocardial injury.

Single High-Sensitivity Point-of-Care Whole-Blood Cardiac Troponin I Measurement to Rule Out Acute Myocardial Infarction at Low Risk.

BACKGROUND: High-sensitivity cardiac troponin (hs-cTn) laboratory assays are used to rule out myocardial infarction (MI) on presentation, but prolonged result turnaround times can delay patient management. Our primary aim was to identify patients at low risk of index MI using a rapid point-of-care (POC) whole-blood hs-cTnI assay at presentation with potential early patient discharge. METHODS: Consecutive patients presenting to the emergency department from 2 prospective observational studies with suspected acute coronary syndrome were enrolled. A POC hs-cTnI assay (Atellica VTLi) threshold using whole blood at presentation, which resulted in a negative predictive value of ≥99.5% and sensitivity of >99% for index MI, was derived (SEIGE [Safe Emergency Department Discharge Rate]) and validated with plasma (SAMIE [Suspected Acute Myocardial Infarction in Emergency]). Event adjudications were established with hs-cTnI assay results from routine clinical care. The primary outcome was MI at 30 days. RESULTS: A total of 1086 patients (8.1% with MI) were enrolled in a US derivation cohort (SEIGE) and 1486 (5.5% MI) in an Australian validation cohort (SAMIE). A derivation whole-blood POC hs-cTnI concentration of <4 ng/L provided a sensitivity of 98.9% (95% CI, 93.8%-100%) and negative predictive value of 99.5% (95% CI, 97.2%-100%) for ruling out MI. In the validation cohort, the sensitivity was 98.8% (95% CI, 93.3%-100%), and negative predictive value was 99.8% (95% CI, 99.1%-100%); 17.8% and 41.8%, respectively, were defined as low risk for discharge. The 30-day adverse cardiac events were 0.1% (n=1) for SEIGE and 0.8% (n=5) for SAMIE. CONCLUSIONS: A POC whole-blood hs-cTnI assay permits accessible, rapid, and safe exclusion of MI and may expedite discharge from the emergency department. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT04772157. URL: https://www.australianclinicaltrials.gov.au/anzctr_feed/form; Unique identifier: 12621000053820.

Chest pain workup in the presence of atrial fibrillation: impacts on troponin testing, myocardial infarction diagnoses, and long-term prognosis.

AIMS: Patients presenting to the emergency department (ED) with chest pain require evaluation for acute coronary syndrome (ACS). Atrial fibrillation (AF) can lead to troponin (cTn) elevation in the absence of ACS. There is limited evidence informing the impact of AF on the diagnostic performance of cTn testing for the diagnosis of Type 1 myocardial infarction (T1MI), or the association between AF and long-term outcomes in this context. METHODS AND RESULTS: This study used the IMPACT and ADAPT study databases to compile a combined cohort of 3496 adults presenting to ED with chest pain between 2007 and 2014, with early cTn testing during ED workup. The mean age was 56.6 years, and 40.2% were female. Outcomes included adjudicated diagnoses for the index admission and mortality to 1-year after presentation. The specificity of initial cTn testing for T1MI diagnosis was lower for patients in AF compared with those not in AF (79.2% vs. 95.4%, P < 0.001), largely due to a relative increase in Type 2 myocardial infarction diagnoses. Sensitivity for T1MI did not differ between patients with or without AF (88.5% vs. 91.5%, P = 0.485). AF was associated with increased 1-year mortality (10.4% vs. 2.3%, P < 0.001), although this was not significant on multivariable analysis. CONCLUSION: The specificity of serial cTn testing for the diagnosis of T1MI in patients presenting to ED with chest pain is reduced in the presence of AF. Further studies are needed to establish whether optimised cTn thresholds for patients with AF can improve workup and outcomes.

Financial Costs of Emergency Department Presentations for Australian Patients With Heart Disease in the Last 3 Years of Life.

Aims: This study described emergency department (ED) resource use patterns and associated costs among patients with heart disease in their last 3 years of life in a high-income country. Methods: This study used linked data from ED and death registry databases in Australia. A random sample of 1000 patients who died due to any cause in 2017, and who had been living with heart disease for at least the prior 10-years were included. The outcomes of interest were number of ED presentations over each of the last 3 years prior to death and relative cost contributions of ED-related items. Results: The number of patients needing ED care and number of ED presentations per patient increased as patients were closer to death, with 85% experiencing at least one ED presentation in their last year of life. Mean per patient ED presentation cost increased with each year closer to death. Costs related to labor, pathology, patient travel, and goods and services contributed more than 85% of the total cost in each of the 3 years. Conclusion: The increase in cost burden as patients neared death was attributable to more frequent ED presentations per person rather than more expensive ED presentations. The scope of this study was limited to ED presentations, and may not be representative of heart-disease-related end-of-life care more broadly.

Emergency Department Assessment of Suspected Acute Coronary Syndrome Using the IMPACT Pathway in Aboriginal and Torres Strait Islander People.

OBJECTIVES: The Improved Assessment of Chest pain Trial (IMPACT) pathway is an accelerated strategy for the assessment of emergency patients presenting with suspected acute coronary syndrome (ACS). The objective of this study was to report outcomes for Aboriginal and Torres Strait Islander patients deemed low-, intermediate-, or high-risk according to this pathway. DESIGN: This was a prospective observational trial conducted between November 2017 and December 2019. SETTING: Regional hospital in Far North Queensland. PARTICIPANTS: Aboriginal and Torres Strait Islander people presenting to the Emergency Department with suspected ACS were asked to participate. Participants were stratified as low-, intermediate- or high-risk of ACS according to the IMPACT pathway. High-and intermediate risk patients were managed according to the IMPACT pathway. Management of low-risk patients included additional inpatient cardiac testing, which was not part of the original IMPACT pathway. MAIN OUTCOME MEASURES: The primary outcome was acute coronary syndrome within 30-days. Secondary outcomes included length of stay and prevalence of objective testing. RESULTS: A total of 155 participants were classified as either at low-risk (n=18 11.6%), intermediate-risk (n=87 56.1%), or high-risk (n=50 32.3%) of ACS. Thirty-day (30-day) ACS occurred in 29 (18.6%) patients, which included 26 (52.0%) high-risk patients and three (3.4%) intermediate-risk patients. No patients in the low-risk group were diagnosed with ACS during their index presentation or by 30-days. Median hospital length-of-stay was 11.9 hours (interquartile range [IQR] 5.3-20.2 hrs) for low- and 15.5 hours (IQR 5.9-29.2 hrs) for intermediate-risk patients. CONCLUSION: The IMPACT pathway, which has been associated with reduced LOS in other settings, could be safely implemented for patients of Aboriginal and Torres Strait Islander origin, classifying two-thirds as low- or intermediate risk. However, a clinically significant proportion of Aboriginal and Torres Strait Islander patients experience cardiac events, which supports the need to provide early objective testing for coronary artery disease.