Tandem lesions associate with angiographic progression of coronary artery stenoses.

Background: Although the clinical factors associated with progression of coronary artery disease have been well studied, the angiographic predictors are less defined. Objectives: Our objective was to study the clinical and angiographic factors that associate with progression of coronary artery stenoses. Methods: We conducted a retrospective analysis of consecutive patients undergoing multiple, clinically indicated invasive coronary angiograms with an interval greater than 6 months, between January 2013 and December 2016. Lesion segments were analysed using Quantitative Coronary Angiography (QCA) if a stenosis ≥ 20 % was identified on either angiogram. Stenosis progression was defined as an increase ≥ 10 % in stenosis severity, with progressor groups analysed on both patient and lesion levels. Mixed-effects regression analyses were performed to evaluate factors associated with progression of individual stenoses. Results: 199 patients were included with 881 lesions analysed. 108 (54.3 %) patients and 186 (21.1 %) stenoses were classified as progressors. The median age was 65 years (IQR 56-73) and the median interval between angiograms was 2.1 years (IQR 1.2-3.0). On a patient level, age, number of lesions and presence of multivessel disease at baseline were each associated with progressor status. On a lesion level, presence of a stenosis downstream (OR 3.07, 95 % CI 2.04-4.63, p < 0.001) and circumflex artery stenosis location (OR 1.81, 95 % CI 1.21-2.7, p = 0.004) were associated with progressor status. Other lesion characteristics did not significantly impact progressor status or change in stenosis severity. Conclusion: Coronary lesions which have a downstream stenosis may be at increased risk of stenosis progression. Further research into the mechanistic basis of this finding is required, along with its implications for plaque vulnerability and clinical outcomes.

Anti-Anginal Efficacy of Zibotentan in the Coronary Slow-Flow Phenomenon.

BACKGROUND: Patients with coronary microvascular disorders often experience recurrent angina for which there are limited evidence-based therapies. These patients have been found to exhibit increased plasma levels of endothelin; thus, selective endothelin-A (Et-A) receptor blockers such as zibotentan may be an effective anti-anginal therapy in these patients. The study evaluated the impact of a 10 mg daily dose of zibotentan on spontaneous angina episodes in patients with the coronary slow-flow phenomenon who had refractory angina (i.e., experiencing angina at least three times/week despite current anti-anginal therapy). METHODS: Using a randomized, double-blind, placebo-controlled, crossover trial design with 4-week treatment periods, 18 patients (63.2 ± 9.9 years, 33% females) were recruited. The primary endpoint was angina frequency as measured by an angina diary, with secondary endpoints including nitrate consumption, angina duration/severity and the Seattle Angina Questionnaire (SAQ) domains. RESULTS: During the 4 weeks of therapy, angina frequency significantly improved with zibotentan therapy (placebo 41.4 (58.5) vs. zibotentan 29.2 (31.6), p < 0.05), and sublingual nitrate consumption significantly reduced (placebo 11.8 (15.2) vs. zibotentan 8.8 (12.9), p < 0.05. CONCLUSIONS: Zibotentan improved the frequency of spontaneous angina episodes and reduced sublingual nitrate consumption in patients unresponsive to standard anti-anginal therapy.

Angina and Non-Obstructive Coronary Artery (ANOCA) Patients with Coronary Vasomotor Disorders.

Angina and Non-Obstructive Coronary Artery (ANOCA) patients often lack a clear explanation for their symptoms, and are frequently discharged with the label of "unspecified chest pain", despite the availability of functional coronary angiography (provocative spasm and microvascular function testing) to identify potential underlying coronary vasomotor disorders. This study compared the outcomes of ANOCA patients with a coronary vasomotor disorder diagnosis post elective coronary angiography to patients discharged with unspecified chest pain. Using the CADOSA (Coronary Angiogram Database of South Australia) registry, consecutive symptomatic patients (n = 7555) from 2012 to 2018 underwent elective angiography; 30% had ANOCA (stenosis <50%). Of this cohort, 9% had documented coronary vasomotor disorders diagnosed, and 91% had unspecified chest pain. Patients with coronary vasomotor disorders were younger and had a similar female prevalence compared with those with unspecified chest pain. New prescriptions of calcium channel blockers and long-acting nitrates were more common for the coronary vasomotor cohort at discharge. In the 3 years following angiography, both groups had similar all-cause mortality rates. However, those with coronary vasomotor disorders had higher rates of emergency department visits for chest pain (39% vs. 15%, p < 0.001) and readmissions for chest pain (30% vs. 10%, p < 0.001) compared with those with unspecified chest pain. This real-world study emphasizes the importance of identifying high-risk ANOCA patients for personalized management to effectively address their symptoms.

Do Chest Pain Characteristics in Patients with Acute Myocardial Infarction Differ between Those with and without Obstructive Coronary Artery Disease?

The universal definition of acute myocardial infarction (MI) requires both evidence of myocardial injury and myocardial ischaemia. In MINOCA (MI with non-obstructive coronary arteries), patients must fulfil this MI criteria, but is their chest pain similar to those who have MI with obstructive CAD (MICAD)? This study compares prospectively collected chest pain features between patients with MINOCA and MICAD. Utilising the Coronary Angiogram Database of South Australia (CADOSA), consecutive MI patients were categorized as MINOCA or MICAD based on angiographic findings. Chest pain data were collected via direct patient interviews by trained staff members. Of 6811 consecutive patients fulfilling a clinical MI diagnosis, 411 (6.0%) were MINOCA, and 5948 MICAD. The MINOCA patients were younger, more often female and had less cardiovascular risk factors than those with MICAD. There were no significant differences in chest pain characteristics between the MINOCA and MICAD cohorts in relation to pain location, quality, associated symptoms, or duration. In conclusion, MINOCA patients have chest pain characteristics that are indistinguishable from MICAD patients, suggesting that their pain is ischaemic in nature. Thus, in the presence of positive myocardial injury markers, ischaemic chest pain fulfils the universal criteria for MI, despite the absence of obstructive coronary artery disease.

Implementation and prospective evaluation of the Country Heart Attack Prevention model of care to improve attendance and completion of cardiac rehabilitation for patients with cardiovascular diseases living in rural Australia: a study protocol.

INTRODUCTION: Despite extensive evidence of its benefits and recommendation by guidelines, cardiac rehabilitation (CR) remains highly underused with only 20%-50% of eligible patients participating. We aim to implement and evaluate the Country Heart Attack Prevention (CHAP) model of care to improve CR attendance and completion for rural and remote participants. METHODS AND ANALYSIS: CHAP will apply the model for large-scale knowledge translation to develop and implement a model of care to CR in rural Australia. Partnering with patients, clinicians and health service managers, we will codevelop new approaches and refine/expand existing ones to address known barriers to CR attendance. CHAP will codesign a web-based CR programme with patients expanding their choices to CR attendance. To increase referral rates, CHAP will promote endorsement of CR among clinicians and develop an electronic system that automatises referrals of in-hospital eligible patients to CR. A business model that includes reimbursement of CR delivered in primary care by Medicare will enable sustainable access to CR. To promote CR quality improvement, professional development interventions and an accreditation programme of CR services and programmes will be developed. To evaluate 12-month CR attendance/completion (primary outcome), clinical and cost-effectiveness (secondary outcomes) between patients exposed (n=1223) and not exposed (n=3669) to CHAP, we will apply a multidesign approach that encompasses a prospective cohort study, a pre-post study and a comprehensive economic evaluation. ETHICS AND DISSEMINATION: This study was approved by the Southern Adelaide Clinical Human Research Ethics Committee (HREC/20/SAC/78) and by the Department for Health and Wellbeing Human Research Ethics Committee (2021/HRE00270), which approved a waiver of informed consent. Findings and dissemination to patients and clinicians will be through a public website, online educational sessions and scientific publications. Deidentified data will be available from the corresponding author on reasonable request. TRIAL REGISTRATION NUMBER: ACTRN12621000222842.

Predictors of Obstructive Sleep Apnoea (OSA) Population in the Coronary Angiogram Database of South Australia (CADOSA).

Obstructive sleep apnoea (OSA) is increasingly recognized to be a risk factor for cardiovascular disease. This study assessed the prevalence and clinical predictors of OSA in patients undergoing coronary angiography. Consecutive patients undergoing coronary angiography in South Australian public hospitals from 2015 to 2018 were included. Clinical details for consecutive patients undergoing coronary angiography in South Australian public hospitals were captured by the Coronary Angiogram Database of South Australia (CADOSA) registry staff, with OSA identified by patient report. Among the 9,885 patients undergoing coronary angiography for the investigation of chest pain, 11% (n = 1,089) were documented as having OSA. Independent clinical predictors of OSA included male gender (OR 2.22, 1.86-2.65, P < 0.001), diabetes mellitus (OR 1.84, 1.58-2.14, P < 0.001), depression (OR 1.81, 1.55-2.12, P < 0.001), prior heart failure (OR 1.63, 1.22-2.18, P = 0.001), hypertension (OR 1.61, 1.32-1.95, P ≤ 0.001), asthma (OR 1.61, 1.34-1.93, P < 0.001), not a current smoker (OR 1.60, 1.30-1.96, P < 0.001), dyslipidaemia (OR 1.46, 1.22-1.76, P < 0.001), non-acute coronary syndrome presentation (OR 1.45, 1.25-1.69, P < 0.001), chronic lung disease (OR 1.40, 1.12-1.73, P = 0.003), cerebrovascular disease (OR 1.36, 1.07-1.73, P = 0.012), non-obstructive coronary artery disease (NOCAD) (OR 1.30, 1.10-1.55, P = 0.003) and atrial fibrillation/flutter (OR 1.30, 1.06-1.60, P = 0.012). Finally, stable angina (32.1% vs 22.7%) and NOCAD (29.1% vs 26.3%, P = 0.051) were trended more common in patients with OSA versus no OSA. In addition to established risk factors for OSA, this study found NOCAD to be independent predictor of OSA; especially in those presenting with a stable angina presentation. This suggests that coronary vasomotor disorders may be associated with OSA, although further detailed studies are required.

Survival in Patients With Suspected Myocardial Infarction With Nonobstructive Coronary Arteries: A Comprehensive Systematic Review and Meta-Analysis From the MINOCA Global Collaboration.

BACKGROUND: Suspected myocardial infarction (MI) with nonobstructive coronary arteries (MINOCA) occurs in ≈5% to 10% of patients with MI referred for coronary angiography. The prognosis of these patients may differ to those with MI and obstructive coronary artery disease (MI-CAD) and those without a MI (patients without known history of MI [No-MI]). The primary objective of this study is to evaluate the 12-month all-cause mortality of patients with MINOCA. METHODS: Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, the terms "MI," "nonobstructive," "angiography," and "prognosis" were searched in PubMed and Embase databases from inception to December 2018, including original, English language MINOCA studies with >100 consecutive patients. Publications with a heterogeneous cohort, unreported coronary stenosis, or exclusively focusing on MINOCA-mimicking conditions, were excluded. Unpublished data were obtained from the MINOCA Global Collaboration. Data were pooled and analyzed using Paule-Mandel, Hartung, Knapp, Sidik & Jonkman, or restricted maximum-likelihood random-effects meta-analysis methodology. Heterogeneity was assessed using Cochran's Q and I2 statistics. The primary outcome was 12-month all-cause mortality in patients with MINOCA, with secondary comparisons to MI-CAD and No-MI. RESULTS: The 23 eligible studies yielded 55 369 suspected MINOCA, 485 382 MI-CAD, and 33 074 No-MI. Pooled meta-analysis of 14 MINOCA studies accounting for 30 733 patients revealed an unadjusted 12-month all-cause mortality rate of 3.4% (95% CI, 2.6%-4.2%) and reinfarction (n=27 605; 10 studies) in 2.6% (95% CI, 1.7%-3.5%). MINOCA had a lower 12-month all-cause mortality than those with MI-CAD (3.3% [95% CI, 2.5%-4.1%] versus 5.6% [95% CI, 4.1%-7.0%]; odds ratio, 0.60 [95% CI, 0.52-0.70], P<0.001). In contrast, there was a statistically nonsignificant trend towards increased 12-month all-cause mortality in patients with MINOCA (2.6% [95% CI, 0%-5.9%]) compared with No-MI (0.7% [95% CI, 0.1%-1.3%]; odds ratio, 3.71 [95% CI, 0.58-23.61], P=0.09). CONCLUSIONS: In the largest contemporary MINOCA meta-analysis to date, patients with suspected MINOCA had a favorable prognosis compared with MI-CAD, but statistically nonsignificant trend toward worse outcomes compared to those with No-MI. Registration: URL: https://www.crd.york.ac.uk/PROSPERO/; Unique identifier: CRD42020145356.

Randomized Evaluation of Beta Blocker and ACE-Inhibitor/Angiotensin Receptor Blocker Treatment for Post Infarct Angina in Patients With Myocardial Infarction With Non-obstructive Coronary Arteries: A MINOCA-BAT Sub Study Rationale and Design.

Introduction: Myocardial infarction with non-obstructive coronary arteries (MINOCA) occurs in ~10% of all patients with acute myocardial infarction (AMI), with an over-representation amongst women. Remarkably, it is estimated that as many as 1 in 4 patients with MINOCA experience ongoing angina at 12 months despite having no flow-restricting stenoses in their epicardial arteries. This manuscript presents the rationale behind Randomized Evaluation of Beta Blocker and Angiotensin-converting enzyme inhibitors/Angiotensin Receptor Blocker Treatment (ACEI/ARB) for Post Infarct Angina in MINOCA patients-The MINOCA BAT post infarct angina sub study. Methods: This trial is a registry-based, randomized, parallel, open-label, multicenter trial with 2 × 2 factorial design. The primary aim is to determine whether oral beta blockade compared with no oral beta blockade, and ACEI/ARB compared with no ACEI/ARB, reduce post infarct angina in patients discharged after MINOCA without clinical signs of heart failure and with left ventricular ejection fraction ≥40%. A total of 664 patients will be randomized into four groups; (i) ACEI/ARB with beta blocker, (ii) beta blocker only, (iii) ACEI/ARB only, or (iv) neither ACEI/ARB nor beta blocker and followed for 12 months. Results: The trial is currently recruiting in Australia and Sweden. Fifty six patients have been recruited thus far. Both sexes were equally distributed (52% women and 48% men) and the mean age was 56.3 ± 9.9 years. Conclusions: It remains unclear whether conventional secondary preventive therapies are beneficial to MINOCA patients in regard to post infarct angina. Existing registry-based literature suggest cardioprotective agents are less likely to be used in MINOCA patients. Thus, results from this trial will provide insights for future treatment strategies and guidelines specific to MINOCA patients.

The LACE Index: A Predictor of Mortality and Readmission in Patients With Acute Myocardial Infarction.

INTRODUCTION: Improving patient outcomes after acute myocardial infarction (AMI) may be facilitated by identifying patients at a high risk of adverse events before hospital discharge. We aimed to determine the accuracy of the LACE (Length of stay, Acuity, Comorbidities, Emergency presentations within prior 6 months) index score (a prediction tool) for predicting 30-day all-cause mortality and readmission rates (independently and combined) in South Australian AMI patients who had an angiogram. METHODS: All consecutive AMI patients enrolled in the Coronary Angiogram Database of South Australia Registry at two major tertiary hospitals and discharged alive between July 2016 to June 2017. A LACE score was calculated for each patient, and receiver operating characteristic curve analysis was performed. RESULTS: Analysis of registry patients found a 30-day unplanned readmission rate of 11.8% and mortality rate of 0.7%. Moreover, the LACE index was a moderate predictor (C-statistic = 0.62) of readmissions in this cohort, and a score ≥10 indicated moderate discriminatory capacity to predict 30-day readmissions. CONCLUSION: The LACE index shows moderate discriminatory capacity to predict 30-day readmissions and mortality. A cut-off score of nine to optimize sensitivity may assist clinicians in identifying patients at a high risk of adverse outcomes.

Impact of Young Age and Gender on Outcomes of Transradial Versus Transfemoral Access Coronary Angiography.

The differential impact of young age and female gender on transradial access (TRA) outcomes remains to be confirmed. The primary objective was to assess the impact of young age and female gender on in-hospital net adverse cardiovascular events (NACE). Among 12 346 patients from the Coronary Angiogram Database of South Australia (CADOSA) Registry, the impact of gender; men (transfemoral access [TFA] 1995, TRA 6168) and women (TFA 1249, TRA 2934), and a median split of age, ≤63 years (TFA 1617, TRA 4727) and >63 years (TFA 1627, TRA 4375) were analyzed on in-hospital outcomes by creating 5 separate propensity-matched cohorts (entire cohort, men, women, ≤63 and > 63 years). Net adverse cardiovascular event reduction with TRA was limited to the >63 years old cohort (odds ratio [OR] = 0.56, 95% CI: 0.34-0.93, P = .02) and women (OR = 0.37, 95% CI: 0.18-0.76, P = .007). In both the age groups and genders, TRA was associated with a lower risk of bleeding and all-cause mortality. On multivariate logistic regression, TRA was associated with a significant reduction in NACE, major bleeding, and mortality in the overall cohort. In conclusion, a reduction in bleeding and mortality was noted with TRA in all the subgroups in this observational study.

Frequency, trends and institutional variation in 30-day all-cause mortality and unplanned readmissions following hospitalisation for heart failure in Australia and New Zealand.

AIMS: National 30-day mortality and readmission rates after heart failure (HF) hospitalisations are a focus of US policy intervention and yet have rarely been assessed in other comparable countries. We examined the frequency, trends and institutional variation in 30-day mortality and unplanned readmission rates after HF hospitalisations in Australia and New Zealand. METHODS AND RESULTS: We included patients >18 years hospitalised with HF at all public and most private hospitals from 2010-15. The primary outcomes were the frequencies of 30-day mortality and unplanned readmissions, and the institutional risk-standardised mortality rate (RSMR) and readmission rate (RSRR) evaluated using separate cohorts. The mortality cohort included 153 592 patients (mean age 78.9 ± 11.8 years, 51.5% male) with 16 442 (10.7%) deaths within 30 days. The readmission cohort included 148 704 patients (mean age 78.6 ± 11.9 years, 51.7% male) with 33 158 (22.3%) unplanned readmission within 30 days. In 392 hospitals with at least 25 HF hospitalisations, the median RSMR was 10.7% (range 6.1-17.3%) with 59 hospitals significantly different from the national average. Similarly, in 391 hospitals with at least 25 HF hospitalisations, the median RSRR was 22.3% (range 17.7-27.1%) with 24 hospitals significantly different from the average. From 2010-15, the adjusted 30-day mortality [odds ratio (OR) 0.991/month, 95% confidence interval (CI) 0.990-0.992, P < 0.01] and unplanned readmission (OR 0.998/month, 95% CI 0.998-0.999, P < 0.01) rates declined. CONCLUSION: Within 30 days of a HF hospitalisation, one in 10 patients died and almost a quarter of those surviving experienced an unplanned readmission. The risk of these outcomes varied widely among hospitals suggesting disparities in HF care quality. Nevertheless, a substantial decline in 30-day mortality and a modest decline in readmissions occurred over the study period.

Depression Mediates the Relationship between Food Insecurity and Pain Interference in College Students.

Food insecurity (FI) typically produces unfavorable health conditions. Research shows the high prevalence of FI among college students, and depression is one of the adverse effects of FIamong them. It is possible that FI may increase the risk of pain via depression; however, it is currently unclear whether FI is linked to pain among college students. Therefore, this study compared pain experiences between students with and without FI, and examined the relationship between FI, depression, and pain. One hundred seventy-six college students at a Hispanic-serving institution in the southwestern region of US completed self-report measures to assess FI, depression, pain severity, and pain interference. Results indicated that approximately 24% of the students were categorized as food insecure, and those students scored higher on pain interference compared to food-secure students. FI was positively associated with depression and pain interference scores, and depression scores were positively associated with pain interference scores. The mediation analyses based on the counterfactual framework demonstrated a significant mediation effect of depression, where 50.59% of the total effect of FI on pain interference was attributable to the depression. These results suggest that FI extends its negative effects into pain interference among college students, but better management of depression may help alleviate the effects of FI on pain interference.

Clinical and coronary haemodynamic determinants of recurrent chest pain in patients without obstructive coronary artery disease - A pilot study.

BACKGROUND: Coronary haemodynamic testing frequently identifies abnormal pathophysiological parameters in patients with angina and non-obstructed coronaries on angiography (NoCAD) but the clinical utility of these measures has received limited attention. OBJECTIVE: This study aims to identify the clinical and coronary haemodynamic determinants of recurrent chest pain at one month in patients with NoCAD. METHODS: Patients with angina, NoCAD (<50% stenosis) and normal LV systolic function underwent invasive coronary haemodynamic testing involving: (1) angiographic TIMI frame and opacification rate, (2) microvascular functional measures including coronary flow reserve (CFR) and hyperaemic microvascular resistance (HMR), (3) coronary endothelial function assessment with low dose intracoronary acetylcholine (IC-ACh) infusions (0.18 µg/min & 1.8 µg/min over 2 min), and (4) Provocative spasm testing with high dose IC-ACh boluses (25, 50 and 100 µg). Clinical and health status were assessed at baseline and one month. RESULTS: In the 49 NoCAD patients (78% female, mean age of 54 ±â€¯11) undergoing comprehensive coronary haemodynamic testing, 33 (67%) continued to experience chest pain at one month. Determinants of recurrent chest pain on univariate analysis included baseline chest pain status or a HMR > 1.9. Multivariate logistic regression analysis identified frequent angina at baseline (OR: 68.9 [4.1, 1165.0], p = 0.003), previous unstable angina admission (OR: 43.9 [3.5, 547.9], p = 0.003) and a HMR > 1.9 (OR: 15.6 [2.1, 114.0], p = 0.007) as independent predictors of recurrent chest pain. CONCLUSION: In this small pilot study, an abnormal HMR was the only coronary haemodynamic parameter that was a determinant of ongoing angina at short-term follow-up.

Early Use of N-acetylcysteine With Nitrate Therapy in Patients Undergoing Primary Percutaneous Coronary Intervention for ST-Segment-Elevation Myocardial Infarction Reduces Myocardial Infarct Size (the NACIAM Trial [N-acetylcysteine in Acute Myocardial Infarction]).

BACKGROUND: Contemporary ST-segment-elevation myocardial infarction management involves primary percutaneous coronary intervention, with ongoing studies focusing on infarct size reduction using ancillary therapies. N-acetylcysteine (NAC) is an antioxidant with reactive oxygen species scavenging properties that also potentiates the effects of nitroglycerin and thus represents a potentially beneficial ancillary therapy in primary percutaneous coronary intervention. The NACIAM trial (N-acetylcysteine in Acute Myocardial Infarction) examined the effects of NAC on infarct size in patients with ST-segment-elevation myocardial infarction undergoing percutaneous coronary intervention. METHODS: This randomized, double-blind, placebo-controlled, multicenter study evaluated the effects of intravenous high-dose NAC (29 g over 2 days) with background low-dose nitroglycerin (7.2 mg over 2 days) on early cardiac magnetic resonance imaging-assessed infarct size. Secondary end points included cardiac magnetic resonance-determined myocardial salvage and creatine kinase kinetics. RESULTS: Of 112 randomized patients with ST-segment-elevation myocardial infarction, 75 (37 in NAC group, 38 in placebo group) underwent early cardiac magnetic resonance imaging. Median duration of ischemia pretreatment was 2.4 hours. With background nitroglycerin infusion administered to all patients, those randomized to NAC exhibited an absolute 5.5% reduction in cardiac magnetic resonance-assessed infarct size relative to placebo (median, 11.0%; [interquartile range 4.1, 16.3] versus 16.5%; [interquartile range 10.7, 24.2]; P=0.02). Myocardial salvage was approximately doubled in the NAC group (60%; interquartile range, 37-79) compared with placebo (27%; interquartile range, 14-42; P<0.01) and median creatine kinase areas under the curve were 22 000 and 38 000 IU·h in the NAC and placebo groups, respectively (P=0.08). CONCLUSIONS: High-dose intravenous NAC administered with low-dose intravenous nitroglycerin is associated with reduced infarct size in patients with ST-segment-elevation myocardial infarction undergoing percutaneous coronary intervention. A larger study is required to assess the impact of this therapy on clinical cardiac outcomes. CLINICAL TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry. URL: http://www.anzctr.org.au/. Unique identifier: 12610000280000.

Cost effectiveness of high-sensitivity troponin compared to conventional troponin among patients presenting with undifferentiated chest pain: A trial based analysis.

BACKGROUND: Patients with low and intermediate risk chest pain features comprise the greatest proportion presenting to emergency services for evaluation of suspected acute coronary syndromes (ACS). The efficient and timely identification of patients with these features remains a major challenge within clinical practice. Troponin assays are increasingly being used for the determination of risk among patients presenting with chest pain potentially facilitating more appropriate care. To date, no economic evaluation comparing high-sensitivity troponin T (hs-TnT) reporting to standard troponin T (c-TnT) reporting in the routine management of suspected ACS and based on longer-term clinical outcomes has been conducted. METHODS AND RESULTS: An economic evaluation was conducted with 1937 participants randomized to either hs-TnT (n=973) or c-TnT (n=964) with 12month follow-up. The primary outcome measure was the number of cumulative combined outcomes of all-cause mortality and new or recurrent ACS avoided. Mean per participant Australian Medicare costs were higher in the hs-TnT arm compared to the c-TnT arm (by $1285/patient). Mean total adverse clinical outcomes avoided were higher in the hs-TnT arm (by 0.0120/patient) resulting in an incremental cost-effectiveness ratio (ICER) of $108,552/adverse clinical outcome avoided. An ICER of $49,030/adverse clinical outcome avoided was obtained when the analysis was restricted to patients below the threshold of normal Troponin testing (actual c-TnT levels <30ng/L). CONCLUSIONS: hs-TnT reporting leads to fewer adverse clinical events but at a high ICER. For the routine implementation of hs-TnT to be more cost-effective, substantial changes in clinical practice will be required. CLINICAL TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry (ACTRN12614000189628). https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=365726.