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Aims Coronary artery calcification is a marker of cardiovascular risk, but its association with qualitatively and quantitatively assessed plaque subtypes is unknown. Methods and results In this post-hoc analysis, computed tomography (CT) images and 5-year clinical outcomes were assessed in SCOT-HEART trial participants. Agatston coronary artery calcium score (CACS) was measured on non-contrast CT and was stratified as zero (0 Agatston units, AU), minimal (1–9 AU), low (10–99 AU), moderate (100–399 AU), high (400–999 AU), and very high (≥1000 AU). Adverse plaques were investigated by qualitative (visual categorization of positive remodelling, low-attenuation plaque, spotty calcification, and napkin ring sign) and quantitative (calcified, non-calcified, low-attenuation, and total plaque burden; Autoplaque) assessments. Of 1769 patients, 36% had a zero, 9% minimal, 20% low, 17% moderate, 10% high, and 8% very high CACS. Amongst patients with a zero CACS, 14% had non-obstructive disease, 2% had obstructive disease, 2% had visually assessed adverse plaques, and 13% had low-attenuation plaque burden >4%. Non-calcified and low-attenuation plaque burden increased between patients with zero, minimal, and low CACS (P 1000 AU and low-attenuation plaque burden were the only predictors of myocardial infarction, independent of obstructive disease, and 10-year cardiovascular risk score. Conclusion In patients with stable chest pain, zero CACS is associated with a good but not perfect prognosis, and CACS cannot rule out obstructive coronary artery disease, non-obstructive plaque, or adverse plaque phenotypes, including low-attenuation plaque.

Coronary artery disease (CAD) remains the leading cause of adult mortality globally. Targeting known modifiable risk factors has had substantial benefit, but there remains a need for new approaches. Improvements in invasive and noninvasive imaging techniques have enabled an increasing recognition of distinct quantitative phenotypes of coronary atherosclerosis that are prognostically relevant. There are marked differences in plaque phenotype, from the high-risk, lipid-rich, thin-capped atheroma to the low-risk, quiescent, eccentric, nonobstructive calcified plaque. Such distinct phenotypes reflect different pathophysiologic pathways and are associated with different risks for acute ischemic events. Noninvasive coronary imaging techniques, such as computed tomography, positron emission tomography, and coronary magnetic resonance imaging, have major potential to accelerate cardiovascular drug development, which has been affected by the high costs and protracted timelines of cardiovascular outcome trials. This may be achieved through enrichment of high-risk phenotypes with higher event rates or as primary end points of drug efficacy, at least in phase 2 trials, in a manner historically performed through intravascular coronary imaging studies. Herein, we provide a comprehensive review of the current technology available and its application in clinical trials, including implications for sample size requirements, as well as potential limitations. In its effort to accelerate drug development, the US Food and Drug Administration has approved surrogate end points for 120 conditions, but not for CAD. There are robust data showing the beneficial effects of drugs, including statins, on CAD progression and plaque stabilization in a manner that correlates with established clinical end points of mortality and major adverse cardiovascular events. This, together with a clear mechanistic rationale for using imaging as a surrogate CAD end point, makes it timely for CAD imaging end points to be considered. We discuss the importance of global consensus on these imaging end points and protocols and partnership with regulatory bodies to build a more informed, sustainable staged pathway for novel therapies.

Ticagrelor is a potent and orally active P2Y12 inhibitor. Ticagrelor has been extensively tested in Phase II and Phase III trials in patients with coronary artery disease. The pharmacokinetics and pharmacodynamics of ticagrelor result in more rapid and effective inhibition of platelet activation compared with other P2Y12 inhibitors. This has resulted in a reduction in recurrent major cardiovascular events in initial randomized controls trials comparing ticagrelor with clopidogrel. More recently, clinical trials have investigated the use of ticagrelor in patients with stable coronary artery disease and a high residual risk of coronary thrombotic events. In patients with stable coronary artery disease, the potent antiplatelet effect of ticagrelor is counterbalanced by an increased risk of major bleeding. Further research is ongoing to determine the optimal duration of ticagrelor therapy.

BACKGROUND: We aimed to establish the observer repeatability and interscan reproducibility of coronary (18)F-sodium-fluoride positron emission tomography (PET) uptake using, a novel semi-automated approach, coronary microcalcification activity (CMA). METHODS: Patients with multivessel coronary artery disease underwent repeated hybrid PET and computed tomography angiography (CTA) imaging (PET/CTA). CMA was defined as the integrated standardized uptake values (SUV) in the entire coronary tree exceeding 2 standard deviations above the background SUV. Coefficients of repeatability between the same observer (intraobserver repeatability), between 2 observers (interobserver repeatability) and coefficient of reproducibility between 2 scans (interscan reproducibility), were determined at vessel and patient level. RESULTS: In 19 patients, CMA was assessed twice in 43 coronary vessels on two PET/CT scans performed 12±5 days apart. There was excellent intraclass correlation for intraobserver and interobserver repeatability as well as interscan reproducibility (all ≥0.991). There was 100% intraobserver, interobserver and interscan agreement for the presence (CMA>0) or absence (CMA=0) of coronary(18)F-NaF uptake. Mean CMA was 3.12±0.62 with coefficients of repeatability of ≤10% for all measures: intraobserver 0.24 and 0.22, interobserver 0.30 and 0.29 and interscan 0.33 and 0.32 at a per-vessel and per-patient level respectively. CONCLUSIONS: CMA is a repeatable and reproducible global measure of coronary atherosclerotic activity.

Supplemental Digital Content is available in the text., Background: The future risk of myocardial infarction is commonly assessed using cardiovascular risk scores, coronary artery calcium score, or coronary artery stenosis severity. We assessed whether noncalcified low-attenuation plaque burden on coronary CT angiography (CCTA) might be a better predictor of the future risk of myocardial infarction. Methods: In a post hoc analysis of a multicenter randomized controlled trial of CCTA in patients with stable chest pain, we investigated the association between the future risk of fatal or nonfatal myocardial infarction and low-attenuation plaque burden (% plaque to vessel volume), cardiovascular risk score, coronary artery calcium score or obstructive coronary artery stenoses. Results: In 1769 patients (56% male; 58±10 years) followed up for a median 4.7 (interquartile interval, 4.0–5.7) years, low-attenuation plaque burden correlated weakly with cardiovascular risk score (r=0.34; P

OBJECTIVES: The aim of this study was to describe the potential of 18F-sodium fluoride ( 18F-NaF) positron emission tomography (PET) to identify graft vasculopathy and to investigate the influence of coronary artery bypass graft (CABG) surgery on native coronary artery disease activity and progression. BACKGROUND: As well as developing graft vasculopathy, CABGs have been proposed to accelerate native coronary atherosclerosis.METHODS: Patients with established coronary artery disease underwent baseline 18F-NaF PET, coronary artery calcium scoring, coronary computed tomographic angiography, and 1-year repeat coronary artery calcium scoring. Whole-vessel coronary microcalcification activity (CMA) on 18F-NaF PET and change in calcium scores were quantified in patients with and without CABG surgery. RESULTS: Among 293 participants (mean age 65 ± 9 years, 84% men), 48 (16%) underwent CABG surgery 2.7 years [IQR: 1.4-10.4 years] previously. Although all arterial and the majority (120 of 128 [94%]) of vein grafts showed no 18F-NaF uptake, 8 saphenous vein grafts in 7 subjects had detectable CMA. Bypassed native coronary arteries had 3 times higher CMA values (2.1 [IQR: 0.4-7.5] vs 0.6 [IQR: 0-2.7]; P < 0.001) and greater progression of 1-year calcium scores (118 Agatston unit [IQR: 48-194 Agatston unit] vs 69 [IQR: 21-142 Agatston unit]; P = 0.01) compared with patients who had not undergone CABG, an effect confined largely to native coronary plaques proximal to the graft anastomosis. In sensitivity analysis, bypassed native coronary arteries had higher CMA (2.0 [IQR: 0.4-7.5] vs 0.8 [IQR: 0.3-3.2]; P < 0.001) and faster disease progression (24% [IQR: 16%-43%] vs 8% [IQR: 0%-24%]; P = 0.002) than matched patients (n = 48) with comparable burdens of coronary artery disease and cardiovascular comorbidities in the absence of bypass grafting. CONCLUSIONS: Native coronary arteries that have been bypassed demonstrate increased disease activity and more rapid disease progression than nonbypassed arteries, an observation that appears independent of baseline atherosclerotic plaque burden. Microcalcification activity is not a dominant feature of graft vasculopathy.

Background: We recently introduced the myocardial-ischemic-injury-index (MI3), a machine learning algorithm that predicts the likelihood of myocardial infarction in patients with suspected acute coronary syndrome. Whether this algorithm performs well in routine clinical practice or predicts subsequent events is unknown.Methods: MI3 was validated in a prespecified exploratory analysis from a multi-centre randomised trial that included consecutive patients with suspected acute coronary syndrome undergoing serial high-sensitivity cardiac troponin I measurement. Patients with ST-segment elevation myocardial infarction were excluded. MI3 incorporates age, sex, and two troponin measurements to compute a value (0-100) reflecting an individual’s likelihood of myocardial infarction during the index visit and estimates diagnostic performance metrics at the computed score. Model performance for an index diagnosis of myocardial infarction, and for subsequent myocardial infarction or cardiovascular death at one year was determined using previously defined low- and high-probability MI3 thresholds (1·6 and 49·7, respectively). Findings: In total, 20,761 patients (64±16 years, 46% women) were included of whom 3,272 (15·8%) had myocardial infarction. MI3 had an area under the receiver-operating-characteristic curve of 0·949 (95% confidence interval 0·946-0·952) identifying 12,983 (62·5%) patients as low-probability (sensitivity 99·3% [99·0-99·6%], negative predictive value 99·8% [99·8-99·9%]), and 2,961 (14·3%) as high-probability (specificity 95·0% [94·6-95·3%], positive predictive value 70·4% [68·7-72·0%]). At one year, subsequent myocardial infarction or cardiovascular death occurred more often in high-probability compared to low-probability patients (17·6% [520/2,961] versus 1·5% [197/12,983], PInterpretation: In consecutive patients undergoing serial cardiac troponin measurement for suspected acute coronary syndrome, the MI3 algorithm accurately estimates the likelihood of myocardial infarction and predicts subsequent adverse cardiovascular events.

Background Lipoprotein(a) [Lp(a)] is associated with increased risk of myocardial infarction, although the mechanism for this observation remains uncertain. Objectives This study aims to investigate whether Lp(a) is associated with adverse plaque progression. Methods Lp(a) was measured in patients with advanced stable coronary artery disease undergoing coronary computed tomography angiography at baseline and 12 months to assess progression of total, calcific, noncalcific, and low-attenuation plaque (necrotic core) in particular. High Lp(a) was defined as Lp(a) ≥ 70 mg/dL. The relationship of Lp(a) with plaque progression was assessed using linear regression analysis, adjusting for body mass index, segment involvement score, and ASSIGN score (a Scottish cardiovascular risk score comprised of age, sex, smoking, blood pressure, total and high-density lipoprotein [HDL]–cholesterol, diabetes, rheumatoid arthritis, and deprivation index). Results A total of 191 patients (65.9 ± 8.3 years of age; 152 [80%] male) were included in the analysis, with median Lp(a) values of 100 (range: 82 to 115) mg/dL and 10 (range: 5 to 24) mg/dL in the high and low Lp(a) groups, respectively. At baseline, there was no difference in coronary artery disease severity or plaque burden. Patients with high Lp(a) showed accelerated progression of low-attenuation plaque compared with low Lp(a) patients (26.2 ± 88.4 mm3 vs −0.7 ± 50.1 mm3; P = 0.020). Multivariable linear regression analysis confirmed the relation between Lp(a) and low-attenuation plaque volume progression (β = 10.5% increase for each 50 mg/dL Lp(a), 95% CI: 0.7%-20.3%). There was no difference in total, calcific, and noncalcific plaque volume progression. Conclusions Among patients with advanced stable coronary artery disease, Lp(a) is associated with accelerated progression of coronary low-attenuation plaque (necrotic core). This may explain the association between Lp(a) and the high residual risk of myocardial infarction, providing support for Lp(a) as a treatment target in atherosclerosis., Central Illustration

Aortic atherosclerosis represents an important contributor to ischemic stroke risk. Identifying patients with high-risk aortic atheroma could improve preventative treatment strategies for future ischemic stroke.The purpose of this study was to investigate whether thoracicIn a post hoc observational cohort study, we quantified thoracic aortic and coronaryAfter 12.7 ± 2.7 months, progression of thoracic aortic calcium volume correlated with baseline thoracic aorticIn patients with established cardiovascular disease, thoracic aortic

To assess the prognostic implications of standardized reporting systems for coronary computed tomography angiography (CCTA) and coronary artery calcium scores (CACS) in patients with stable chest pain.The Coronary Artery Disease Reporting And Data System (CAD-RADS) and Coronary Artery Calcium - Data and Reporting System (CAC-DRS) aim to improve communication of CACS and CCTA results, but its influence on prognostication is unknown.Images from 1769 patients who underwent CCTA as part of the Scottish Computed Tomography of the HEART (SCOT-HEART) multi-center randomized controlled trial were assessed. CACS were classified as CAC-DRS 0 to 3 based on Agatston scores. CCTA were classified as CAD-RADS 0 to 5 based on the most clinically relevant finding per patient. The primary outcome was the five-year events of fatal and non-fatal myocardial infarction.Patients had a mean age of 58 ± 10 years and 56% were male. CAC-DRS 0, 1, 2 and 3 occurred in 642 (36%), 510 (29%), 239 (14%) and 379 (21%) patients respectively. CAD-RADS 0, 1, 2, 3, 4A, 4B and 5 occurred in 622 (35%), 327 (18%), 211 (12%), 165 (9%), 221 (12%), 42 (2%) and 181 (10%) patients respectively. Patients classified as CAC-DRS 3 were at an increased risk of fatal or non-fatal myocardial infarction compared to CAC-DRS 0 patients (hazard ratio (HR) 9.41; 95% confidence interval (CI) 3.24, 27.31; p 0.001). Patients with higher CAD-RADS categories were at an increased risk of fatal or non-fatal myocardial infarction, with patients classified as CAD-RADS 4B at the highest risk compared to CAD-RADS 0 patients (HR 19.14; 95% CI 4.28, 85.53; p 0.001).Patients with higher CAC-DRS and CAD-RADS scores were at increased risk of subsequent fatal and non-fatal myocardial infarction. This confirms that the classification provides additional prognostic discrimination for future coronary heart disease events.

Left ventricular thrombus formation is a complication of acute myocardial infarction. However, the incidence and risk of systemic thromboembolism in the era of primary angioplasty for ST elevation myocardial infarction (STEMI) is unclear. This study aims to determine clinical outcomes in patients with STEMI treated with primary angioplasty and left ventricular thrombus at 1 year.Patients who underwent primary angioplasty for STEMI and had a transthoracic echocardiogram were recruited. The primary endpoint was a composite of all-cause mortality, stroke, and systemic thromboembolism at 1 year. For the primary endpoint, the difference between the presence and absence of left ventricular thrombus was compared using a logistic regression, adjusting for minimization variables including age, diabetes mellitus, hypertension, and previous stroke.Of 2608 patients who underwent primary angioplasty for STEMI, 1645 (63%) patients had a transthoracic echocardiogram performed during the index hospital admission. Forty patients (2.4%) had evidence of left ventricular thrombus on transthoracic echocardiography. Patients with left ventricular thrombus were more likely to develop atrial fibrillation in the immediate postinfarction period (6 [15%] vs 87 [5.4%], P = 0.025). At 1 year, the primary endpoint occurred in 4 (10%) patients with left ventricular thrombus and 146 (9.1%) who did not (logistic regression hazard ratio 0.79, 95% confidence interval 0.23-2.70).In the contemporary era of mechanical reperfusion for STEMI, echocardiographic detection of left ventricular thrombus was observed in3% patients. The presence of left ventricular thrombus was not associated with an increased risk of systemic thromboembolism.

ObjectiveTroponin and B-type natriuretic peptide (BNP) concentrations are associated with cardiovascular risk in stable patients. Understanding their determinants and identifying modifiable clinical targets may improve outcomes. We aimed to establish clinical and cardiac determinants of these biomarkers.MethodsThis was a prespecified substudy from the randomised Scottish Computed Tomography of the Heart trial, which enrolled patients 18–75 years with suspected stable angina between 2010 and 2014 (NCT01149590). We included patients from six centres in whom high-sensitivity troponin I and BNP were measured (Singulex Erenna). Patients with troponin >99th centile upper reference limit (10.2 ng/L) or BNP ≥400 ng/L were excluded to avoid inclusion of patients with myocardial injury or heart failure. Multivariable linear regression models were constructed with troponin and BNP as dependent variables.ResultsIn total, 885 patients were included; 881 (99%) and 847 (96%) had troponin and BNP concentrations above the limit of detection, respectively. Participants had a slight male preponderance (n=513; 56.1%), and the median age was 59.0 (IQR 51.0–65.0) years. The median troponin and BNP concentrations were 1.4 (IQR 0.90–2.1) ng/L and 29.1 (IQR 14.0–54.0) ng/L, respectively. Age and atherosclerotic burden were independent predictors of both biomarkers. Male sex, left ventricular mass and systolic blood pressure were independent predictors of increased troponin. In contrast, female sex and left ventricular volume were independent predictors of increased BNP.ConclusionsTroponin and BNP are associated with coronary atherosclerosis but have important sex differences and distinct and contrasting associations with CT-determined left ventricular mass and volume.Clinical Trial registrationNCT01149590; Post-results.

ObjectiveAssess the relative incidence and compare characteristics and outcome of unstable angina (UA) and non-ST-elevation myocardial infarction (NSTEMI).DesignTwo independent prospective multicentre diagnostic studies (Advantageous Predictors of Acute Coronary Syndromes Evaluation [APACE] and High-Sensitivity Troponin in the Evaluation of Patients With Acute Coronary Syndrome [High-STEACS]) enrolling patients with acute chest discomfort presenting to the emergency department. Central adjudication of the final diagnosis was done by two independent cardiologists using all clinical information including serial measurements of high-sensitivity cardiac troponin (hs-cTn). All-cause death and future non-fatal MI were assessed at 30 days and 1 year.Results8992 patients were enrolled at 11 centres. UA was adjudicated in 8.9%(95% CI 8.0 to 9.7) and 2.8% (95% CI 2.3 to 3.3) patients in APACE and High-STEACS, respectively, and NSTEMI in 15.1% (95% CI 14.0 to 16.2) and 13.4% (95% CI 12.4 to 14.3). Coronary artery disease was pre-existing in 73% and 76% of patients with UA. At 30 days, all-cause mortality in UA was substantially lower as compared with NSTEMI (0.5% vs 3.7%, p=0.002 in APACE, 0.7% vs 7.4%, p=0.004 in High-STEACS). Similarly, at 1 year in UA all-cause mortality was 3.3% (95% CI 1.2 to 5.3) vs 10.4% (95% CI 7.9 to 12.9) in APACE, and 5.1% (95% CI 0.7 to 9.5) vs 22.9% (95% CI 19.3 to 26.4) in High-STEACS, and similar to non-cardiac chest pain (NCCP). In contrast, future non-fatal MI in APACE was comparable in UA and NSTEMI (11.2%, 95% CI 7.8 to 14.6 and 7.9%, 95% CI 5.7 to 10.2), and higher than in NCCP (0.6%, 95% CI 0.2 to 1.0).ConclusionsThe relative incidence and mortality of UA is substantially lower than that of NSTEMI, while the rate of future non-fatal MI is similar.

The last two decades in New Zealand have seen increased availability of primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI) and early invasive coronary angiography (ICA) for other high-risk acute coronary syndrome (ACS) patients. One metric to assess the clinical appropriateness of these invasive strategies is to examine the false-positive rate for the investigation (ie, the rate of non-ACS diagnoses).All patients presenting to New Zealand public hospitals with suspected ACS who underwent ICA between 2015 and 2019 were recorded prospectively in the All New Zealand Acute Coronary Syndrome Quality Improvement registry. The cohort was divided according to clinical impression at presentation: (1) suspected STEMI24h and (2) other suspected ACS. The final discharge diagnosis for each patient were obtained from the registry.There were 6,059 (20%) patients with suspected STEMI24h and 24,258 (80%) with other suspected ACS. Of the suspected STEMIs24h, 90.6% had a final diagnosis of STEMI, 3.5% non-ST segment elevation ACS (NSTEACS) and only 5.9% had a non-ACS diagnosis. Of those with other suspected ACS, 80.7% had a final ACS diagnosis. Across all New Zealand district health boards (DHBs), the proportion of non-ACS diagnoses was similar for suspected STEMI presentations. However, for other suspected ACS, the proportions were higher in DHBs with rapid access to coronary interventional facilities than in those without (17.6% vs 7.0%, p0.001).False-positive catheter laboratory activations for suspected STEMI patients are low across New Zealand. The differences in the proportion of non-ACS diagnoses according to DHB interventional capability for other suspected ACS requires further investigation.

‘First, do no harm’ are oft misquoted words from Hippocrates’ 2500-year-old work Epidemics . A more complete and accurate translation of his exhortation reads: > The physician must be able to tell the antecedents, know the present, and foretell the future — must mediate these things, and have two special objects in view with regard to disease, namely, to do good or to do no harm.1 This is laudable sentiment but is it realistic for a diagnosis surrounding which much uncertainty remains? Looking back only 20 years, a case report in this publication described spontaneous coronary artery dissection (SCAD) as ‘an extremely rare cause of unstable angina and acute myocardial infarction’.2 That is no longer the case. There has been a surge in the recognition of the condition. One recent study found 33 (2.4%) cases of SCAD among 1375 patients who underwent invasive coronary angiography for acute coronary syndrome in 2019.3 This represents a 10-fold increase in relative diagnostic frequency since an earlier registry (1999–2007) identified only 22 (0.2%) cases from 11 175 patients.4 Presuming that the true incidence is unchanged, this growth reflects a remarkable ‘paradigm shift in clinical appreciation’.5 In contrast to many cardiovascular disorders, SCAD is predominantly a disease affecting middle-aged women with comparatively few traditional atherosclerotic risk factors. The epidemiology, pathophysiology and approach to diagnosis of SCAD have been informed by retrospective observational cohort studies but optimal management remains unclear. Invasive coronary angiography represents the primary imaging modality for identifying the condition, meaning definitive treatment decisions are commonly made in the catheter laboratory and herein lies the challenge. In contrast with atherosclerotic disease, percutaneous coronary intervention (PCI) is associated with less predictable outcomes in …

OBJECTIVES: This study was designed to investigate whether coronary computed tomography angiography assessments of coronary plaque might explain differences in the prognosis of men and women presenting with chest pain. BACKGROUND: Important sex differences exist in coronary artery disease. Women presenting with chest pain have different risk factors, symptoms, prevalence of coronary artery disease and prognosis compared to men. METHODS: Within a multicenter randomized controlled trial, we explored sex differences in stenosis, adverse plaque characteristics (positive remodeling, low-attenuation plaque, spotty calcification, or napkin ring sign) and quantitative assessment of total, calcified, noncalcified and low-attenuation plaque burden. RESULTS: Of the 1,769 participants who underwent coronary computed tomography angiography, 772 (43%) were female. Women were more likely to have normal coronary arteries and less likely to have adverse plaque characteristics (p < 0.001 for all). They had lower total, calcified, noncalcified, and low-attenuation plaque burdens (p < 0.001 for all) and were less likely to have a low-attenuation plaque burden >4% (41% vs. 59%; p < 0.001). Over a median follow-up of 4.7 years, myocardial infarction (MI) occurred in 11 women (1.4%) and 30 men (3%). In those who had MI, women had similar total, noncalcified, and low-attenuation plaque burdens as men, but men had higher calcified plaque burden. Low-attenuation plaque burden predicted MI (hazard ratio: 1.60; 95% confidence interval: 1.10 to 2.34; p = 0.015), independent of calcium score, obstructive disease, cardiovascular risk score, and sex. CONCLUSIONS: Women presenting with stable chest pain have less atherosclerotic plaque of all subtypes compared to men and a lower risk of subsequent MI. However, quantitative low-attenuation plaque is as strong a predictor of subsequent MI in women as in men. (Scottish Computed Tomography of the HEART Trial [SCOT-HEART]; NCT01149590).

Despite significant advances in the treatment of ST elevation myocardial infarction (STEMI), there remains a significant short-term and long-term increased mortality risk. Risk stratification to target those who may benefit from more intensive therapy postrevascularisation therefore remains an important goal. Risk stratification models in acute coronary syndrome (ACS) have been researched for many years, but few risk scores have been developed and validated specifically for the STEMI population. Only 27% of the cohort for the Global Registry of Acute Coronary Events (GRACE) score was derived from those undergoing percutaneous intervention (PCI), and the GRACE score performs less accurately in those undergoing PCI compared with medical therapy. Nevertheless European1 (but not American2) guidelines recommend its use for clinical risk stratification in the STEMI cohort. Risk scores derived specifically for STEMI include the Global Utilization of Streptokinase and Tissue plasminogen activator to treat Occluded arteries (GUSTO) risk score, which was developed in the era of thrombolysis, while risk scores assessing mortality in primary PCI patients include the Primary Angioplasty in Myocardial Infarction (PAMI) risk score, Controlled Abciximab and Device Investigation to Lower Late Angioplasty Complications (CADILLAC) risk score, Assessment of Pexelizumab in Acute Myocardial Infarction (APEX-AMI) score, Soroka Acute Myocardial Infarction (SAMI) score, and the Zwolle risk score. Coelho-Lima and colleagues3 examine the prognostic value of troponin specifically in the STEMI population, a group where troponin is not used to guide initial treatment. Their major findings are that admission troponin, but not troponin measured 12 hours post-reperfusion, was a significant independent predictor of both inpatient or overall mortality, with a median follow-up time of over 4 years. The authors are to be commended for this large retrospective study—in particular, the clinical …

Preterm birth affects 1 in 10 pregnancies worldwide, with increasing survival rates over the last 30 years. However, as this new generation of long-term survivors approaches middle age, recent studies have revealed increased cardiovascular risk factors and higher rates of ischaemic heart disease and heart failure. Cardiovascular imaging has identified smaller cardiac chamber size, changes in myocardial mass and impaired ventricular function, particularly under physiological stress. Accordingly, this population should be recognised as having a higher risk of heart failure as they age. In this review, we present current evidence for increased rates of heart failure and evidence of alterations in cardiac structure and function in those born preterm. We discuss potential mechanisms to explain this risk including greater frequency of co-morbidities known to be associated with heart failure. We also explore potential mechanistic links specific to the preterm-born population, including the impact of premature birth on myocardial and vascular development and the effects of perinatal haemodynamic changes and chronic lung disease on the developing heart. We highlight gaps in our knowledge and consider implications for patient management relevant to the adult physician.

ObjectivesNon-contrast CT aortic valve calcium scoring ignores the contribution of valvular fibrosis in aortic stenosis. We assessed aortic valve calcific and non-calcific disease using contrast-enhanced CT.MethodsThis was a post hoc analysis of 164 patients (median age 71 (IQR 66–77) years, 78% male) with aortic stenosis (41 mild, 89 moderate, 34 severe; 7% bicuspid) who underwent echocardiography and contrast-enhanced CT as part of imaging studies. Calcific and non-calcific (fibrosis) valve tissue volumes were quantified and indexed to annulus area, using Hounsfield unit thresholds calibrated against blood pool radiodensity. The fibrocalcific ratio assessed the relative contributions of valve fibrosis and calcification. The fibrocalcific volume (sum of indexed non-calcific and calcific volumes) was compared with aortic valve peak velocity and, in a subgroup, histology and valve weight.ResultsContrast-enhanced CT calcium volumes correlated with CT calcium score (r=0.80, p3/cm2). Fibrocalcific volume correlated with ex vivo valve weight (r=0.72, pConclusionsContrast-enhanced CT assessment of aortic valve calcific and non-calcific volumes correlates with aortic stenosis severity and may be preferable to non-contrast CT when fibrosis is a significant contributor to valve obstruction.

Background The ability to characterize and to quantify the extent of coronary artery disease has the potential to improve the prognostic capability of coronary computed tomography angiography. Although reproducible techniques have been described in those with mild coronary disease, this has yet to be assessed in patients with advanced disease. Methods Twenty patients with known multivessel disease underwent repeated computed tomography coronary angiography, 2 weeks apart. Coronary artery segments were analysed using semi-automated software by two trained observers to determine intraobserver, interobserver and interscan reproducibility. Results Overall, 149 coronary arterial segments were analysed. There was excellent intraobserver and interobserver agreement for all plaque volume measurements (Lin’s coefficient 0.95 to 1.0). There were no substantial interscan differences (P ​> ​0.05 for all) for total (2063 ​± ​1246 ​mm3, mean of differences −35.6 ​mm3), non-calcified (1795 ​± ​910 ​mm3, mean of differences −4.3 ​mm3), calcified (298 ​± ​425 ​mm3, mean of differences −31.3 ​mm3) and low-attenuation (13 ​± ​13 ​mm3, mean of differences −2.6 ​mm3) plaque volumes. Interscan agreement was highest for total and noncalcified plaque volumes. Calcified and low-attenuation plaque (−236.6 to 174 ​mm3 and -15.8 to 10.5 ​mm3 respectively) had relatively wider 95% limits of agreement reflecting the lower absolute plaque volumes. Conclusion In the presence of advanced coronary disease, semi-automated plaque quantification provides excellent reproducibility, particularly for total and non-calcified plaque volumes. This approach has major potential to assess change in disease over time and optimize risk stratification in patients with established coronary artery disease.

Background Positron emission tomography (PET) using

Early microcalcification is a feature of coronary plaques with an increased propensity to rupture and to cause acute coronary syndromes. In this ex vivo imaging study of coronary artery specimens, the non-invasive imaging radiotracer, 18F-fluoride, was highly selective for hydroxyapatite deposition in atherosclerotic coronary plaque. Specifically, coronary 18F-fluoride uptake had a high signal to noise ratio compared with surrounding myocardium that makes it feasible to identify coronary mineralisation activity. Areas of 18F-fluoride uptake are associated with osteopontin, an inflammation-associated glycophosphoprotein that mediates tissue mineralisation, and Runt-related transcription factor 2, a nuclear protein involved in osteoblastic differentiation. These results suggest that 18F-fluoride is a non-invasive imaging biomarker of active coronary atherosclerotic mineralisation.

BackgroundBalloon aortic valvuloplasty (BAV) remains a treatment option for the selected patients with severe aortic stenosis. We examined clinical outcomes and predictors of prognosis in patients undergoing BAV for severe aortic stenosis.MethodsWe identified all patients undergoing BAV from January 2010 to March 2018 (n=167) at a single transcatheter aortic valve implantation (TAVI) centre. Patient demographics, investigations, subsequent interventions and clinical outcomes were obtained from electronic health records.ResultsPatients undergoing BAV were elderly (median age 80, IQR 73–86 years) and half (n=87, 52%) were male. All-cause mortality at 30 days and 12 months was 11% and 43%, respectively. Reduce ejection fraction (EF 30%–50%: HR 1.76, 95% CI 1.05 to 2.94; EF ConclusionBAV as a bridge to definitive aortic valve intervention in carefully selected patients offers acceptable outcomes. These contemporary observational findings demonstrate the ongoing potential utility of BAV in the TAVI era.

Aims Valvular heart disease can be identified by calcification on coronary computed tomography angiography (CCTA) and has been associated with adverse clinical outcomes. We assessed aortic and mitral valve calcification in patients presenting with stable chest pain and their association with cardiovascular risk factors, coronary artery disease, and cardiovascular outcomes. Methods and results In 1769 patients (58 ± 9 years, 56% male) undergoing CCTA for stable chest pain, aortic and mitral valve calcification were quantified using Agatston score. Aortic valve calcification was present in 241 (14%) and mitral calcification in 64 (4%). Independent predictors of aortic valve calcification were age, male sex, hypertension, diabetes mellitus, and cerebrovascular disease, whereas the only predictor of mitral valve calcification was age. Patients with aortic and mitral valve calcification had higher coronary artery calcium scores and more obstructive coronary artery disease. The composite endpoint of cardiovascular mortality, non-fatal myocardial infarction, or non-fatal stroke was higher in those with aortic [hazard ratio (HR) 2.87; 95% confidence interval (CI) 1.60–5.17; P Conclusion Aortic and mitral valve calcification occurs in one in six patients with stable chest pain undergoing CCTA and is associated with concomitant coronary atherosclerosis. Whilst valvular calcification is associated with a higher risk of cardiovascular events, this was not independent of the burden of coronary artery disease.

Aims Treatment advances have improved cancer-related outcomes and shifted interest towards minimising long-term iatrogenic complications, particularly chemotherapy-related cardiotoxicity. High-sensitivity cardiac troponin I (hs-cTnI) assays accurately quantify very low concentrations of plasma troponin and enable early detection of cardiomyocyte injury prior to the development of myocardial dysfunction. The profile of hs-cTnI in response to anthracycline-based treatment has not previously been described. Materials and methods This was a multicentre prospective observational cohort study. Female patients with newly diagnosed invasive breast cancer scheduled to receive anthracycline-based (epirubicin) chemotherapy were recruited. Blood sampling was carried out before and 24 h after each cycle. Hs-cTnI concentrations were measured using the Abbott ARCHITECTSTAT assay. Results We recruited 78 women with a median (interquartile range) age of 52 (49–61) years. The median baseline troponin concentration was 1 (1–4) ng/l and the median cumulative epirubicin dose was 394 (300–405) mg/m2. Following an initial 33% fall 24 h after anthracycline dosing (P, Highlights • Plasma hs-cTnI concentrations showed an anthracycline dose-dependent increase. • Hs-cTnI could act as an early and sensitive anthracycline cardiotoxicity prediction tool. • Hs-cTnI measurement should happen before rather than after each cycle.

Background Within the SCOT-HEART (Scottish COmputed Tomography of the HEART Trial) trial of patients with stable chest pain, the use of coronary computed tomography angiography (CTA) reduced the rate of death from coronary heart disease or nonfatal myocardial infarction (primary endpoint). Objectives This study sought to assess the consistency and mechanisms of the 5-year reduction in this endpoint. Methods In this open-label trial, 4,146 participants were randomized to standard care alone or standard care plus coronary CTA. This study explored the primary endpoint by symptoms, diagnosis, coronary revascularizations, and preventative therapies. Results Event reductions were consistent across symptom and risk categories (p = NS for interactions). In patients who were not diagnosed with angina due to coronary heart disease, coronary CTA was associated with a lower primary endpoint incidence rate (0.23; 95% confidence interval [CI]: 0.13 to 0.35 vs. 0.59; 95% CI: 0.42 to 0.80 per 100 patient-years; p, Central Illustration

The Authors’ reply: We thank the author for their interest in our report documenting the long-term prognostic importance of convalescent cardiac troponin concentrations.1 First, we agree that when used for risk stratification low cardiac troponin concentrations miss fewer events than applying the sex-specific 99th centile upper reference limit as a single threshold, and indeed we identified the lower troponin threshold of 5 ng/L to be associated with a 5-year negative predictive value for cardiovascular death of 97.1% (95% CI 95.5 to …

Objectives This study sought to compare the performance of major guidelines for the assessment of stable chest pain including risk-based (American College of Cardiology/American Heart Association and European Society of Cardiology) and symptom-focused (National Institute for Health and Care Excellence) strategies. Background Although noninvasive testing is not recommended in low-risk individuals with stable chest pain, guidelines recommend differing approaches to defining low-risk patients. Methods Patient-level data were obtained from the PROMISE (Prospective Multicenter Imaging Study for Evaluation of Chest Pain) and SCOT-HEART (Scottish Computed Tomography of the Heart) trials. Pre-test probability was determined and patients dichotomized into low-risk and intermediate-high–risk groups according to each guideline’s definitions. The primary endpoint was obstructive coronary artery disease on coronary computed tomography angiography. Secondary endpoints were coronary revascularization at 90 days and cardiovascular death or nonfatal myocardial infarction up to 3 years. Results In total, 13,773 patients were included of whom 6,160 had coronary computed tomography angiography. The proportions of patients identified as low risk by the American College of Cardiology/American Heart Association, European Society of Cardiology, and National Institute for Health and Care Excellence guidelines, respectively, were 2.5%, 2.5%, and 10.0% within PROMISE, and 14.0%, 19.8%, and 38.4% within SCOT-HEART. All guidelines identified lower rates of obstructive coronary artery disease in low- versus intermediate-high–risk patients with a negative predictive value of ≥0.90. Compared with low-risk groups, all intermediate-high–risk groups had greater risks of coronary revascularization (odds ratio [OR]: 2.2 to 24.1) and clinical outcomes (OR: 1.84 to 5.8). Conclusions Compared with risk-based guidelines, symptom-focused assessment identifies a larger group of low-risk chest pain patients potentially deriving limited benefit from noninvasive testing. (Scottish Computed Tomography of the Heart Trial [SCOT-HEART]; NCT01149590; Prospective Multicenter Imaging Study for Evaluation of Chest Pain [PROMISE]; NCT01174550), Graphical abstract

Background: Patients with chronic obstructive pulmonary disease (COPD) have increased risk of cardiovascular events.Objectives: This study evaluated the association between high-sensitivity cardiac troponin I concentration and cardiovascular events in patients with COPD and heightened cardiovascular risk.Methods: In a double-blind randomized controlled trial, 16,485 patients with COPD and cardiovascular disease or risk factors were randomized to once daily inhaled placebo, fluticasone furoate (100 μg), vilanterol (25 μg), or their combination. Plasma high-sensitivity cardiac troponin I concentrations were measured in a subgroup of 1,599 patients. Outcomes were on-treatment cardiovascular events and COPD exacerbations over a median of 18 months, and cardiovascular death over a median of 27 months.Results: Baseline plasma cardiac troponin I concentrations were above the limit of detection (1.2 ng/l) in 1,542 (96%) patients. Concentrations were unaffected by inhaled therapies at 3 months (p > 0.05). Compared with the lowest quintile (cardiac troponin Conclusions: In patients with COPD and heightened cardiovascular risk, plasma cardiac troponin I concentrations are a specific and major indicator of future cardiovascular events and cardiovascular death. Inhaled therapies did not affect cardiac troponin I concentrations consistent with their neutral effect on mortality and cardiovascular outcomes. (Study to Evaluate the Effect of Fluticasone Furoate/Vilanterol on Survival in Subjects With Chronic Obstructive Pulmonary Disease [SUMMIT]; NCT01313676)

Aims To assess contemporary pre-test probability estimates for obstructive coronary artery disease in patients with stable chest pain. Methods and results In this substudy of a multicentre randomized controlled trial, we compared 2019 European Society of Cardiology (ESC)-endorsed pre-test probabilities with observed prevalence of obstructive coronary artery disease on computed tomography coronary angiography (CTCA). We assessed associations between pre-test probability, 5-year coronary heart disease death or non-fatal myocardial infarction and study intervention (standard care vs. CTCA). The study population consisted of 3755 patients (30–75 years, 46% women) with a median pre-test probability of 11% of whom 1622 (43%) had a pre-test probability of >15%. In those who underwent CTCA (n = 1613), the prevalence of obstructive disease was 22%. When divided into deciles of pre-test probability, the observed disease prevalence was similar but higher than the corresponding median pre-test probability [median difference 2.3 (1.3–5.6)%]. There were more clinical events in patients with a pre-test probability >15% compared to those at 5–15% and 15% (2.8% vs. 5.3%, log rank P = 0.01), although this interaction was not statistically significant on multivariable modelling. Conclusion The updated 2019 ESC guideline pre-test probability recommendations tended to slightly underestimate disease prevalence in our cohort. Pre-test probability is a powerful predictor of future coronary events and helps select those who may derive the greatest absolute benefit from CTCA.

Supplemental Digital Content is available in the text., Background: The introduction of more sensitive cardiac troponin assays has led to increased recognition of myocardial injury in acute illnesses other than acute coronary syndrome. The Universal Definition of Myocardial Infarction recommends high-sensitivity cardiac troponin testing and classification of patients with myocardial injury based on pathogenesis, but the clinical implications of implementing this guideline are not well understood. Methods: In a stepped-wedge cluster randomized, controlled trial, we implemented a high-sensitivity cardiac troponin assay and the recommendations of the Universal Definition in 48 282 consecutive patients with suspected acute coronary syndrome. In a prespecified secondary analysis, we compared the primary outcome of myocardial infarction or cardiovascular death and secondary outcome of noncardiovascular death at 1 year across diagnostic categories. Results: Implementation increased the diagnosis of type 1 myocardial infarction by 11% (510/4471), type 2 myocardial infarction by 22% (205/916), and acute and chronic myocardial injury by 36% (443/1233) and 43% (389/898), respectively. Compared with those without myocardial injury, the rate of the primary outcome was highest in those with type 1 myocardial infarction (cause-specific hazard ratio [HR] 5.64 [95% CI, 5.12–6.22]), but was similar across diagnostic categories, whereas noncardiovascular deaths were highest in those with acute myocardial injury (cause specific HR 2.65 [95% CI, 2.33–3.01]). Despite modest increases in antiplatelet therapy and coronary revascularization after implementation in patients with type 1 myocardial infarction, the primary outcome was unchanged (cause specific HR 1.00 [95% CI, 0.82–1.21]). Increased recognition of type 2 myocardial infarction and myocardial injury did not lead to changes in investigation, treatment or outcomes. Conclusions: Implementation of high-sensitivity cardiac troponin assays and the recommendations of the Universal Definition of Myocardial Infarction identified patients at high-risk of cardiovascular and noncardiovascular events but was not associated with consistent increases in treatment or improved outcomes. Trials of secondary prevention are urgently required to determine whether this risk is modifiable in patients without type 1 myocardial infarction. Clinical Trial Registration: https://www.clinicaltrials.gov. Unique identifier: NCT01852123.

Despite recent advances, cardiovascular disease remains the leading cause of death globally. As such, there is a need to optimise our current diagnostic and risk stratification pathways in order to better deliver individualised preventative therapies. Non-invasive imaging of coronary artery plaque can interrogate multiple aspects of coronary atherosclerotic disease, including plaque morphology, anatomy and flow. More recently, disease activity is being assessed to provide mechanistic insights into in vivo atherosclerosis biology. Molecular imaging using positron emission tomography is unique in this field, with the potential to identify specific biological processes using either bespoke or re-purposed radiotracers. This review provides an overview of non-invasive vulnerable plaque detection and molecular imaging of coronary atherosclerosis.

Background Major disparities between women and men in the diagnosis, management, and outcomes of acute coronary syndrome are well recognized. Objectives The aim of this study was to evaluate the impact of implementing a high-sensitivity cardiac troponin I assay with sex-specific diagnostic thresholds for myocardial infarction in women and men with suspected acute coronary syndrome. Methods Consecutive patients with suspected acute coronary syndrome were enrolled in a stepped-wedge, cluster-randomized controlled trial across 10 hospitals. Myocardial injury was defined as high-sensitivity cardiac troponin I concentration >99th centile of 16 ng/l in women and 34 ng/l in men. The primary outcome was recurrent myocardial infarction or cardiovascular death at 1 year. Results A total of 48,282 patients (47% women) were included. Use of the high-sensitivity cardiac troponin I assay with sex-specific thresholds increased myocardial injury in women by 42% and in men by 6%. Following implementation, women with myocardial injury remained less likely than men to undergo coronary revascularization (15% vs. 34%) and to receive dual antiplatelet (26% vs. 43%), statin (16% vs. 26%), or other preventive therapies (p, Central Illustration

Background 18F-Fluoride uptake denotes calcification activity in aortic stenosis and atherosclerosis. While PET/MR has several advantages over PET/CT, attenuation correction of PET/MR data is challenging, limiting cardiovascular application. We compared PET/MR and PET/CT assessments of 18F-fluoride uptake in the aortic valve and coronary arteries. Methods and results 18 patients with aortic stenosis or recent myocardial infarction underwent 18F-fluoride PET/CT followed immediately by PET/MR. Valve and coronary 18F-fluoride uptake were evaluated independently. Both standard (Dixon) and novel radial GRE) MR attenuation correction (AC) maps were validated against PET/CT with results expressed as tissue-to-background ratios (TBRs). Visually, aortic valve 18F-fluoride uptake was similar on PET/CT and PET/MR. TBRMAX values were comparable with radial GRE AC (PET/CT 1.55±0.33 vs. PET/MR 1.58 ± 0.34, P = 0.66; 95% limits of agreement − 27% to + 25%) but performed less well with Dixon AC (1.38 ± 0.44, P = 0.06; bias (−)14%; 95% limits of agreement − 25% to + 53%). In native coronaries, 18F-fluoride uptake was similar on PET/MR to PET/CT regardless of AC approach. PET/MR identified 28/29 plaques identified on PET/CT; however, stents caused artifact on PET/MR making assessment of 18F-fluoride uptake challenging. Conclusion Cardiovascular PET/MR demonstrates good visual and quantitative agreement with PET/CT. However, PET/MR is hampered by stent-related artifacts currently limiting clinical application. Electronic supplementary material The online version of this article (10.1007/s12350-019-01962-y) contains supplementary material, which is available to authorized users.

CoronaryIn a prospective observational study, patients with multi-vessel coronary artery disease underwent serialThirty patients (90% male, 20 patients with stable coronary artery disease, and 10 with recent type 1 myocardial infarction) underwent paired serial positron emission tomography-coronary computed tomography angiography imaging within an interval of 12±5 days. A mean of 3.7±1.8CoronaryURL: http://www.clinicaltrials.gov. Unique identifiers: NCT02110303 and NCT02278211.

Objectives The goal of this study was to determine whether ticagrelor reduces high-sensitivity troponin I concentrations in patients with established coronary artery disease and high-risk coronary plaque. Background High-risk coronary atherosclerotic plaque is associated with higher plasma troponin concentrations suggesting ongoing myocardial injury that may be a target for dual antiplatelet therapy. Methods In a randomized, double-blind, placebo-controlled trial, patients with multivessel coronary artery disease underwent coronary 18F-fluoride positron emission tomography/coronary computed tomography scanning and measurement of high-sensitivity cardiac troponin I. Patients were randomized (1:1) to receive ticagrelor 90 mg twice daily or matched placebo. The primary endpoint was troponin I concentration at 30 days in patients with increased coronary 18F-fluoride uptake. Results In total, 202 patients were randomized to treatment, and 191 met the pre-specified criteria for inclusion in the primary analysis. In patients with increased coronary 18F-fluoride uptake (120 of 191), there was no evidence that ticagrelor had an effect on plasma troponin concentrations at 30 days (ratio of geometric means for ticagrelor vs. placebo: 1.11; 95% confidence interval: 0.90 to 1.36; p = 0.32). Over 1 year, ticagrelor had no effect on troponin concentrations in patients with increased coronary 18F-fluoride uptake (ratio of geometric means: 0.86; 95% confidence interval: 0.63 to 1.17; p = 0.33). Conclusions Dual antiplatelet therapy with ticagrelor did not reduce plasma troponin concentrations in patients with high-risk coronary plaque, suggesting that subclinical plaque thrombosis does not contribute to ongoing myocardial injury in this setting. (Dual Antiplatelet Therapy to Reduce Myocardial Injury [DIAMOND]; NCT02110303), Central Illustration

Aims The relative benefits of computed tomography coronary angiography (CTCA)-guided management in women and men with suspected angina due to coronary heart disease (CHD) are uncertain. Methods and results In this post hoc analysis of an open-label parallel-group multicentre trial, we recruited 4146 patients referred for assessment of suspected angina from 12 cardiology clinics across the UK. We randomly assigned (1:1) participants to standard care alone or standard care plus CTCA. Fewer women had typical chest pain symptoms (n = 582, 32.0%) when compared with men (n = 880, 37.9%; P Conclusion Following the addition of CTCA, women were more likely to be found to have normal coronary arteries than men. This led to more women being reclassified as not having CHD, resulting in more downstream tests and treatments being cancelled. There were similar prognostic benefits of CTCA for women and men.

We assessed the feasibility of utilizing previously acquired computed tomography angiography (CTA) with subsequent positron-emission tomography (PET)-only scan for the quantitative evaluation ofForty-five patients (age 67.1±6.9 years; 76% males) underwent CTA (CTA1) and combinedCoronary CTA/PET protocol with CTA first followed by PET-only allows for reliable and reproducible quantification of

BACKGROUND: High-sensitivity cardiac troponin assays permit use of lower thresholds for the diagnosis of myocardial infarction, but whether this improves clinical outcomes is unknown. We aimed to determine whether the introduction of a high-sensitivity cardiac troponin I (hs-cTnI) assay with a sex-specific 99th centile diagnostic threshold would reduce subsequent myocardial infarction or cardiovascular death in patients with suspected acute coronary syndrome. METHODS: In this stepped-wedge, cluster-randomised controlled trial across ten secondary or tertiary care hospitals in Scotland, we evaluated the implementation of an hs-cTnI assay in consecutive patients who had been admitted to the hospitals' emergency departments with suspected acute coronary syndrome. Patients were eligible for inclusion if they presented with suspected acute coronary syndrome and had paired cardiac troponin measurements from the standard care and trial assays. During a validation phase of 6-12 months, results from the hs-cTnI assay were concealed from the attending clinician, and a contemporary cardiac troponin I (cTnI) assay was used to guide care. Hospitals were randomly allocated to early (n=5 hospitals) or late (n=5 hospitals) implementation, in which the high-sensitivity assay and sex-specific 99th centile diagnostic threshold was introduced immediately after the 6-month validation phase or was deferred for a further 6 months. Patients reclassified by the high-sensitivity assay were defined as those with an increased hs-cTnI concentration in whom cTnI concentrations were below the diagnostic threshold on the contemporary assay. The primary outcome was subsequent myocardial infarction or death from cardiovascular causes at 1 year after initial presentation. Outcomes were compared in patients reclassified by the high-sensitivity assay before and after its implementation by use of an adjusted generalised linear mixed model. This trial is registered with ClinicalTrials.gov, number NCT01852123. FINDINGS: Between June 10, 2013, and March 3, 2016, we enrolled 48 282 consecutive patients (61 [SD 17] years, 47% women) of whom 10 360 (21%) patients had cTnI concentrations greater than those of the 99th centile of the normal range of values, who were identified by the contemporary assay or the high-sensitivity assay. The high-sensitivity assay reclassified 1771 (17%) of 10 360 patients with myocardial injury or infarction who were not identified by the contemporary assay. In those reclassified, subsequent myocardial infarction or cardiovascular death within 1 year occurred in 105 (15%) of 720 patients in the validation phase and 131 (12%) of 1051 patients in the implementation phase (adjusted odds ratio for implementation vs validation phase 1·10, 95% CI 0·75 to 1·61; p=0·620). INTERPRETATION: Use of a high-sensitivity assay prompted reclassification of 1771 (17%) of 10 360 patients with myocardial injury or infarction, but was not associated with a lower subsequent incidence of myocardial infarction or cardiovascular death at 1 year. Our findings question whether the diagnostic threshold for myocardial infarction should be based on the 99th centile derived from a normal reference population. FUNDING: The British Heart Foundation.

Suspected stable angina is a common presenting complaint, and the process of establishing the etiology of these symptoms consumes substantial diagnostic resources. Perhaps the greatest challenge relates to individuals with low to intermediate pretest probability for obstructive coronary artery disease. In these patients, additional noninvasive testing—either functional or anatomic—is frequently required to provide patients and clinicians alike with sufficient reassurance that invasive coronary angiography can be deferred. Demand for further investigation continues to grow despite falling baseline risk, and as a consequence, there has been a marked reduction in the prevalence of functionally significant coronary artery disease in patients undergoing stress imaging in recent years (1). Clearly then, there is a need to improve the selection of patients for whom further testing is necessary, and cardiac troponin appears a suitable candidate for such an indication. High-sensitivity assays allow accurate quantification of plasma or serum troponin concentrations in the majority of adults, and numerous studies have demonstrated the prognostic importance of troponin in primary prevention populations (2, 3) and among patients with a variety of stable (4, 5) and acute (6) cardiac disorders. Furthermore, when compared to the reference standard of obstructive disease identified on coronary computed tomography angiography, high-sensitivity troponin I assays have been shown to improve the accuracy of existing risk models for the estimation of pretest probability (7, 8). Within this context, Mueller et al. report in this issue of Clinical Chemistry on a large, well-conducted investigation that reinforces the potential diagnostic value of troponin in the setting of suspected inducible myocardial ischemia (9). An important strength is the use of the most widely available high-sensitivity troponin (hs-cTn) I and T assays with blinded classification of functionally relevant coronary artery disease (fCAD)4, determined from myocardial perfusion imaging with single-photon emission computed …

Non-invasive imaging of the coronary arteries is an enterprise in rapid development. From the research perspective, there is great demand for in vivo techniques that can reliably identify features of high-risk plaque that may offer insight into pathophysiological processes and act as surrogate indicators of response to therapeutic intervention. Meanwhile, there is clear clinical need for greater accuracy in diagnosis and prognostic stratification. Fortunately, ongoing technological improvements and emerging data from randomized clinical trials are helping make these elusive goals a reality. This review provides an update on the current status of non-invasive coronary imaging with computed tomography, magnetic resonance, and positron emission tomography with a focus on current clinical applications and future research directions.

Learning objectives Worldwide more than 17 million people die every year from cardiovascular disease (CVD) with this number projected to increase to over 23 million by 2030.1 Within Europe, CVD results in four million deaths annually, accounting for 47% of all-cause mortality. Between them, heart attacks and strokes are responsible for around 80% of this mortality.2 The vast majority of acute ischaemic vascular events occur in relation to an underlying atherosclerotic plaque. Plaque rupture is the dominant initiating event, responsible for 60–70% of acute coronary syndromes (ACS), while plaque erosion is responsible for most of the remainder.3 ,4 Irrespective of the mechanism, the consequence is exposure of a thrombogenic substrate to circulating blood. This in turn triggers platelet aggregation and the coagulation cascade which compromises vascular blood flow resulting in downstream end-organ ischaemia and infarction. These events occur abruptly and often without warning. Despite intensive therapies, they recur in as many as 25% of patients. Until recently, the high-risk plaque has only been identified by retrospective analysis, predominantly from pathological examination of autopsy specimens. This has limited our ability to appreciate the dynamic nature of plaque vulnerability and rupture, and has placed a heavy reliance on invasive angiography to describe the anatomical luminal stenosis severity rather than plaque biology. Prospective identification of plaque rupture events has suggested that the majority of culprit lesions is non-flow limiting, and often overlooked by angiographic and traditional functional investigations. Novel imaging techniques now have the potential to identify the pathological structures and processes associated with plaque rupture. This in turn has raised hopes for strategies …

This study sought to compare the performance of history-based risk scores in predicting obstructive coronary artery disease (CAD) among patients with stable chest pain from the SCOT-HEART study.Risk scores for estimating pre-test probability of CAD are derived from referral-based populations with a high prevalence of disease. The generalizability of these scores to lower prevalence populations in the initial patient encounter for chest pain is uncertain.We compared 3 scores among patients with suspected CAD in the coronary computed tomographic angiography (CTA) randomized arm of the SCOT-HEART study for the outcome of obstructive CAD by coronary CTA: the updated Diamond-Forrester score (UDF), CAD Consortium clinical score (CAD2), and CONFIRM risk score (CRS). We tested calibration with goodness-of-fit, discrimination with area under the receiver-operating curve (AUC), and reclassification with net reclassification improvement (NRI) to identify low-risk patients.In 1,738 patients (age 58 ± 10 years and 44.0% women), overall calibration was best for UDF, with underestimation by CRS and CAD2. Discrimination by AUC was highest for CAD2 at 0.79 (95% confidence interval [CI]: 0.77 to 0.81) than for UDF (0.77 [95% CI: 0.74 to 0.79]) or CRS (0.75 [95% CI: 0.73 to 0.77]) (p 0.001 for both comparisons). Reclassification of low-risk patients at the 10% probability threshold was best for CAD2 (NRI 0.31, 95% CI: 0.27 to 0.35) followed by CRS (NRI 0.21, 95% CI: 0.17 to 0.25) compared with UDF (p 0.001 for all comparisons), with a consistent trend at the 15% threshold.In this multicenter clinic-based cohort of patients with suspected CAD and uniform CAD evaluation by coronary CTA, CAD2 provided the best discrimination and classification, despite overestimation of obstructive CAD as evaluated by coronary CTA. CRS exhibited intermediate performance followed by UDF for discrimination and reclassification.

Background: Suspected acute coronary syndrome is the commonest reason for emergency admission to hospital and is a large burden on health-care resources. Strategies to identify low-risk patients suitable for immediate discharge would have major benefits.Methods: We did a prospective cohort study of 6304 consecutively enrolled patients with suspected acute coronary syndrome presenting to four secondary and tertiary care hospitals in Scotland. We measured plasma troponin concentrations at presentation using a high-sensitivity cardiac troponin I assay. In derivation and validation cohorts, we evaluated the negative predictive value of a range of troponin concentrations for the primary outcome of index myocardial infarction, or subsequent myocardial infarction or cardiac death at 30 days. This trial is registered with ClinicalTrials.gov (number NCT01852123).Findings: 782 (16%) of 4870 patients in the derivation cohort had index myocardial infarction, with a further 32 (1%) re-presenting with myocardial infarction and 75 (2%) cardiac deaths at 30 days. In patients without myocardial infarction at presentation, troponin concentrations were less than 5 ng/L in 2311 (61%) of 3799 patients, with a negative predictive value of 99·6% (95% CI 99·3-99·8) for the primary outcome. The negative predictive value was consistent across groups stratified by age, sex, risk factors, and previous cardiovascular disease. In two independent validation cohorts, troponin concentrations were less than 5 ng/L in 594 (56%) of 1061 patients, with an overall negative predictive value of 99·4% (98·8-99·9). At 1 year, these patients had a lower risk of myocardial infarction and cardiac death than did those with a troponin concentration of 5 ng/L or more (0·6% vs 3·3%; adjusted hazard ratio 0·41, 95% CI 0·21-0·80; pInterpretation: Low plasma troponin concentrations identify two-thirds of patients at very low risk of cardiac events who could be discharged from hospital. Implementation of this approach could substantially reduce hospital admissions and have major benefits for both patients and health-care providers.Funding: British Heart Foundation and Chief Scientist Office (Scotland).

Importance: High-sensitivity cardiac troponin I testing is widely used to evaluate patients with suspected acute coronary syndrome. A cardiac troponin concentration of less than 5 ng/L identifies patients at presentation as low risk, but the optimal threshold is uncertain.Objective: To evaluate the performance of a cardiac troponin I threshold of 5 ng/L at presentation as a risk stratification tool in patients with suspected acute coronary syndrome.Data Sources: Systematic search of MEDLINE, EMBASE, Cochrane, and Web of Science databases from January 1, 2006, to March 18, 2017.Study Selection: Prospective studies measuring high-sensitivity cardiac troponin I concentrations in patients with suspected acute coronary syndrome in which the diagnosis was adjudicated according to the universal definition of myocardial infarction.Data Extraction and Synthesis: The systematic review identified 19 cohorts. Individual patient-level data were obtained from the corresponding authors of 17 cohorts, with aggregate data from 2 cohorts. Meta-estimates for primary and secondary outcomes were derived using a binomial-normal random-effects model.Main Outcomes and Measures: The primary outcome was myocardial infarction or cardiac death at 30 days. Performance was evaluated in subgroups and across a range of troponin concentrations (2-16 ng/L) using individual patient data.Results: Of 11 845 articles identified, 104 underwent full-text review, and 19 cohorts from 9 countries were included. Among 22 457 patients included in the meta-analysis (mean age, 62 [SD, 15.5] years; n = 9329 women [41.5%]), the primary outcome occurred in 2786 (12.4%). Cardiac troponin I concentrations were less than 5 ng/L at presentation in 11 012 patients (49%), in whom there were 60 missed index or 30-day events (59 index myocardial infarctions, 1 myocardial infarction at 30 days, and no cardiac deaths at 30 days). This resulted in a negative predictive value of 99.5% (95% CI, 99.3%-99.6%) for the primary outcome. There were no cardiac deaths at 30 days and 7 (0.1%) at 1 year, with a negative predictive value of 99.9% (95% CI, 99.7%-99.9%) for cardiac death.Conclusions and Relevance: Among patients with suspected acute coronary syndrome, a high-sensitivity cardiac troponin I concentration of less than 5 ng/L identified those at low risk of myocardial infarction or cardiac death within 30 days. Further research is needed to understand the clinical utility and cost-effectiveness of this approach to risk stratification.

Objective To evaluate how selection of patients for high sensitivity cardiac troponin testing affects the diagnosis of myocardial infarction across different healthcare settings. Design Prospective study of three independent consecutive patient populations presenting to emergency departments. Setting Secondary and tertiary care hospitals in the United Kingdom and United States. Participants High sensitivity cardiac troponin I concentrations were measured in 8500 consecutive patients presenting to emergency departments: unselected patients in the UK (n=1054) and two selected populations of patients in whom troponin testing was requested by the attending clinician in the UK (n=5815) and the US (n=1631). The final diagnosis of type 1 or type 2 myocardial infarction or myocardial injury was independently adjudicated. Main outcome measures Positive predictive value of an elevated cardiac troponin concentration for a diagnosis of type 1 myocardial infarction. Results Cardiac troponin concentrations were elevated in 13.7% (144/1054) of unselected patients, with a prevalence of 1.6% (17/1054) for type 1 myocardial infarction and a positive predictive value of 11.8% (95% confidence interval 7.0% to 18.2%). In selected patients, in whom troponin testing was guided by the attending clinician, the prevalence and positive predictive value were 14.5% (843/5815) and 59.7% (57.0% to 62.2%) in the UK and 4.2% (68/1631) and 16.4% (13.0% to 20.3%) in the US. Across both selected patient populations, the positive predictive value was highest in patients with chest pain, with ischaemia on the electrocardiogram, and with a history of ischaemic heart disease. Conclusions When high sensitivity cardiac troponin testing is performed widely or without previous clinical assessment, elevated troponin concentrations are common and predominantly reflect myocardial injury rather than myocardial infarction. These observations highlight how selection of patients for cardiac troponin testing varies across healthcare settings and markedly influences the positive predictive value for a diagnosis of myocardial infarction.

ObjectivesTo evaluate the diagnostic and prognostic benefits of CT coronary angiography (CTCA) using the 2016 National Institute for Health and Care Excellence (NICE) guidelines for the assessment of suspected stable angina.MethodsPost hoc analysis of the Scottish COmputed Tomography of the HEART (SCOT-HEART) trial of 4146 participants with suspected angina randomised to CTCA. Patients were dichotomised into NICE guideline-defined possible angina and non-anginal presentations. Primary (diagnostic) endpoint was diagnostic certainty of angina at 6 weeks and prognostic endpoint comprised fatal and non-fatal myocardial infarction (MI).ResultsIn 3770 eligible participants, CTCA increased diagnostic certainty more in those with possible angina (relative risk (RR) 2.22 (95% CI 1.91 to 2.60), pinteraction ConclusionsNICE-guided patient selection maximises the benefits of CTCA on diagnostic certainty, use of invasive coronary angiography and reductions in fatal and non-fatal myocardial infarction. Patients with non-anginal chest pain derive minimal benefit from CTCA and increase the rates of invasive investigation.Trial registration numberClinicalTrials.gov: NCT01149590;post results.