High-sensitivity Troponin T in relation to coronary plaque characteristics in patients with stable coronary artery disease; results of the ATHEROREMO-IVUS study

High-Sensitivity Troponins and Subclinical Coronary Atherosclerosis Evaluated by Coronary Calcium Score Among Older Asians Living With Well-Controlled Human Immunodeficiency Virus

Background

Elevated levels of high-sensitivity cardiac troponin (hs-cTn) are suggestive of myocardial cell injury and coronary artery disease. We explored the association between hs-cTn and subclinical arteriosclerosis using coronary artery calcification (CAC) scoring among 337 virally suppressed patients with human immunodeficiency virus (HIV) who were ≥50 years old and without evidence of known coronary artery disease.

Methods

Noncontrast cardiac computed tomography and blood sampling for hs-cTn, both subunit I (hs-cTnI) and subunit T (hs-cTnT), were performed. The relationship between CAC (Agatston score) and serum hs-cTn levels was analyzed using Spearman correlation and logistic regression models.

Results

The patients, of whom 62% were male, had a median age of 54 years and had been on antiretroviral therapy for a median of 16 years; the CAC score was >0 in 50% of patients and ≥100 in 16%. Both hs-cTn concentrations were positively correlated with the Agatston score, with correlation coefficients of 0.28 and 0.27 (P < .001) for hs-cTnI and hs-cTnT, respectively. hs-cTnI and hs-cTnT concentrations of ≥4 and ≥5.3 pg/mL, respectively, provided the best performance for discriminating patients with Agatston scores ≥100, with a sensitivity and specificity of 76% and 60%, respectively, for hs-cTnI and 70% and 50% for hs-cTnT. In multivariable logistic regression analysis, each log unit increase in hs-cTnI level was independently associated with increased odds of having an Agatston score ≥100 (odds ratio, 2.83 [95% confidence interval, 1.69-4.75]; P <.001). Although not an independent predictor, hs-cTnT was also associated with an increased odds of having an Agatston score ≥100 (odds ratio, 1.58 [95% confidence interval, .92-2.73]; P = .10).

Conclusions

Among Asians aged ≥50 years with well-controlled HIV infection and without established cardiovascular disease, 50% had subclinical arteriosclerosis. Increasing hs-cTnI and hs-cTnT concentrations were associated with an increased risk of severe subclinical arteriosclerosis, and hs-cTn may be a potential biomarker to detect severe subclinical arteriosclerosis.

Biomarkers to monitor the prognosis, disease severity, and treatment efficacy in coronary artery disease

INTRODUCTION

Coronary Artery Disease (CAD) is a prevalent condition characterized by the presence of atherosclerotic plaques in the coronary arteries of the heart. The global burden of CAD has increased significantly over the years, resulting in millions of deaths annually and making it the leading health-care expenditure and cause of mortality in developed countries. The lack of cost-effective strategies for monitoring the prognosis of CAD warrants a pressing need for accurate and efficient markers to assess disease severity and progression for both reducing health-care costs and improving patient outcomes.

AREA COVERED

To effectively monitor CAD, prognostic biomarkers and imaging techniques play a vital role in risk-stratified patients during acute treatment and over time. However, with over 1,000 potential markers of interest, it is crucial to identify the key markers with substantial utility in monitoring CAD progression and evaluating therapeutic interventions. This review focuses on identifying and highlighting the most relevant markers for monitoring CAD prognosis and disease severity. We searched for relevant literature using PubMed and Google Scholar.

EXPERT OPINION

By utilizing the markers discussed, health-care providers can improve patient care, optimize treatment plans, and ultimately reduce health-care costs associated with CAD management.

Rapid diagnostic strategies using high sensitivity troponin assays: what is the evidence and how should they be implemented?

The introduction of high sensitivity measurement of cardiac troponin T (hs cTnT) and cardiac troponin I (hs cTnI) has given the laboratory the ability to measure very low levels of cardiac troponin. The limit of detection of these assays is well below the 99th percentile. These low levels can also be measured with small values of imprecision. A range of algorithms combining presentation measurement with repeat sample intervals of as little as one to 2 hours have been developed. These are able to predict with acceptable accuracy the diagnosis that would be achieved with continued repeat sampling out to six to 12 hours from presentation. In this article, we review the evidence for the diagnostic accuracy of these approaches and the practical aspects of implementation into routine clinical practice.

Pathophysiology and Outcomes of Endothelium Function in Coronary Microvascular Diseases: A Systematic Review of Randomized Controlled Trials and Multicenter Study

BACKGROUND

Coronary macrovascular disease is a concept that has been well-studied within the literature and has long been the subject of debates surrounding coronary artery bypass grafting (CABG) vs. Percutaneous Coronary Intervention (PCI). ISCHEMIA trial reported no statistical difference in the primary clinical endpoint between initial invasive management and initial conservative management, while in the ORBITA trial PCI did not improve angina frequency score significantly more than placebo, albeit PCI resulted in more patient-reported freedom from angina than placebo. However, these results did not prove the superiority of the PCI against OMT, therefore do not indicate the benefit of PCI vs. the OMT. Please rephrase the sentence. We reviewed the role of different factors responsible for endothelial dysfunction from recent randomized clinical trials (RCTs) and multicentre studies.

METHODS

A detailed search strategy was performed using a dataset that has previously been published. Data of pooled analysis include research articles (human and animal models), CABG, and PCI randomized controlled trials (RCTs). Details of the search strategy and the methods used for data pooling have been published previously and registered with Open-Source Framework.

RESULTS

The roles of nitric oxide (NO), endothelium-derived contracting factors (EDCFs), and vasodilator prostaglandins (e.g., prostacyclin), as well as endothelium-dependent hyperpolarization (EDH) factors, are crucial for the maintenance of vasomotor tone within the coronary vasculature. These homeostatic mechanisms are affected by sheer forces and other several factors that are currently being studied, such as vaping. The role of intracoronary testing is crucial when determining the effects of therapeutic medications with further studies on the horizon.

CONCLUSION

The true impact of coronary microvascular dysfunction (CMD) is perhaps underappreciated, which supports the role of medical therapy in determining outcomes. Ongoing trials are underway to further investigate the role of therapeutic agents in secondary prevention.

Biomarker Prediction of Complex Coronary Revascularization Procedures in the FOURIER Trial

BACKGROUND

Biomarkers are known to predict major adverse cardiovascular events. However, the association of biomarkers with complex coronary revascularization procedures or high-risk coronary anatomy at the time of revascularization is not understood.

OBJECTIVES

We examined the associations between baseline biomarkers and major coronary events (MCE) and complex revascularization procedures.

METHODS

FOURIER was a randomized trial of the proprotein convertase subtilisin-kexin type 9 inhibitor evolocumab vs placebo in 27,564 patients with stable atherosclerosis. We analyzed adjusted associations among the biomarkers, MCE (coronary death, myocardial infarction, or revascularization), and complex revascularization (coronary artery bypass graft or complex percutaneous coronary intervention) using a multimarker score with 1 point assigned for each elevated biomarker (high-sensitivity C-reactive protein ≥2 mg/L; N-terminal pro-B-type natriuretic peptide ≥450 pg/mL; high-sensitivity troponin I ≥6 ng/L; growth-differentiation factor-15 ≥1,800 pg/mL).

RESULTS

When patients were grouped by the number of elevated biomarkers (0 biomarkers, n = 6,444; 1-2 biomarkers, n = 12,439; ≥3 biomarkers, n = 2,761), there was a significant graded association between biomarker score and the risk of MCE (intermediate score: HR_adj: 1.57 [95% CI: 1.38-1.78]; high score: HR_adj: 2.90 [95% CI: 2.47-3.40]), and for complex revascularization (intermediate: HR_adj: 1.33 [95% CI: 1.06-1.67]; high score: HR_adj: 2.07 [95% CI: 1.52-2.83]) and its components (P_trend <0.05 for each). The number of elevated biomarkers also correlated with the presence of left main disease, multivessel disease, or chronic total occlusion at the time of revascularization (P < 0.05 for each).

CONCLUSIONS

A biomarker-based strategy identifies stable patients at risk for coronary events, including coronary artery bypass graft surgery and complex percutaneous coronary intervention, and predicts high-risk coronary anatomy at the time of revascularization. These findings provide insight into the relationships between cardiovascular biomarkers, coronary anatomical complexity, and incident clinical events. (Further Cardiovascular Outcomes Research With PCSK9 Inhibition in Subjects With Elevated Risk [FOURIER]; NCT01764633).

Myocardial injury in stress echocardiography: Comparison of dobutamine, dipyridamole and dynamic stressors-single center study

OBJECTIVES

In stress echocardiography (SE), dipyridamole (DIP) and dynamic stress (ExSE) are reported as being safer than dobutamine stress echocardiography (DSE). We investigated whether these commonly used stressors cause myocardial injury, measured by high sensitivity troponin T (hsTnT).

METHODS

One hundred and thirty five patients (DSE n = 46, ExsE n = 46, DIP n = 43) with negative result of SE were studied. The exclusion criteria were known ischaemic heart disease (IHD), baseline wall motion abnormalities, left ventricle systolic dysfunction/regional wall motion abnormalities, septum/posterior wall ≥13 mm, diabetes/pre-diabetes, baseline hsTnT level ≥14 ng/L, baseline blood pressure ≥160/100 mmHg, peak pulmonary pressure ≥45mmHg, eGFR <1ml/s/1.73m² , more than mild to moderate valvular disease and dobutamine side effects. HsTnT was measured before and 180 minutes after the test.

RESULTS

All patients had low pre-test probabilities of having obstructive IHD. HsTnT increased in DSE, less so in ExSE, and was unchanged in the DIP group (∆hsTnT 9.4 [1.5-58.6], 1.1 [-0.9-15.7], -0.1 [-1.4-2.1] ng/L, respectively, p<0.001). In DSE, the ∆hsTnT was associated with peak dobutamine dose (r = 0.30, p = 0.045), test length (r = 0.43, p = 0.003) and atropine use (p<0.001). In ExSE, the hsTnT increase was more likely in females (p = 0.012) and the elderly (>65 years) (r = 0.32, p = 0.03); no association was found between atropine use (p = 0.786) or test length and ∆hsTnT (r = 0.10, p = 0.530).

CONCLUSIONS

DSE is associated with myocardial injury in patients with negative SE, no injury was observed in DIP and only mild case in ExSE. Whether myocardial injury is causative of the higher reported adverse event rates in DSE remains to be determined.

Machine learning models of clinically relevant biomarkers for the prediction of stable obstructive coronary artery disease

Background

In patients with suspected obstructive coronary artery disease (CAD), evaluation using a pre-test probability model is the key element for diagnosis; however, its accuracy is controversial. This study aimed to develop machine learning (ML) models using clinically relevant biomarkers to predict the presence of stable obstructive CAD and to compare ML models with an established pre-test probability of CAD models.

Methods

Eight machine learning models for prediction of obstructive CAD were trained on a cohort of 1,312 patients [randomly split into the training (80%) and internal validation sets (20%)]. Twelve clinical and blood biomarker features assessed on admission were used to inform the models. We compared the best-performing ML model and established the pre-test probability of CAD (updated Diamond-Forrester and CAD consortium) models.

Results

The CatBoost algorithm model showed the best performance (area under the receiver operating characteristics, AUROC, 0.796, and 95% confidence interval, CI, 0.740-0.853; Matthews correlation coefficient, MCC, 0.448) compared to the seven other algorithms. The CatBoost algorithm model improved risk prediction compared with the CAD consortium clinical model (AUROC 0.727; 95% CI 0.664-0.789; MCC 0.313). The accuracy of the ML model was 74.6%. Age, sex, hypertension, high-sensitivity cardiac troponin T, hemoglobin A1c, triglyceride, and high-density lipoprotein cholesterol levels contributed most to obstructive CAD prediction.

Conclusion

The ML models using clinically relevant biomarkers provided high accuracy for stable obstructive CAD prediction. In real-world practice, employing such an approach could improve discrimination of patients with suspected obstructive CAD and help select appropriate non-invasive testing for ischemia.

Association of GDF-15, hs-cTnT and NT-proBNP with coronary artery disease in patients undergoing elective angiography

Aim: This study investigated the association between plasma levels of GDF-15, hs-cTnT and NT-proBNP and the presence of coronary artery disease (CAD) in stable patients referred for elective coronary angiography. Methods: The outcome of CAD was defined as an ordinal variable with 3 levels. The association between each biomarker and the outcome was tested using the Winell and Lindbäck method. Results: In unadjusted analysis of 252 patients, GDF-15 and hs-cTnT were associated with the presence and extent of CAD. In multivariate regression analysis including traditional risk factors, this association was no longer significant. Conclusion: NT-proBNP, GDF-15 and hs-cTnT plasma levels do not seem to improve the predictive ability of traditional risk factors for CAD in stable patients referred for coronary angiography.

Association of serum cardiac troponin I and severity of coronary stenosis in patients with varied renal functions: a retrospective cohort study

BACKGROUND AND OBJECTIVE

Recent studies showed cardiac troponin I (cTnI) might be a non-invasive biomarker to estimate the severity of coronary stenosis. However, serum cTnI is also found associated with renal function. The study objective is to analyse the association of serum cTnI and severity of coronary stenosis in patients with varied renal functions.

DESIGN

A retrospective cohort study.

SETTING

The First Affiliated Hospital, College of Medicine, Zhejiang University in Hangzhou, China.

POPULATION

A total of 6487 subjects who underwent elective coronary angiography between January 2017 to June 2020 were involved in this study.

PRIMARY OUTCOMES

Severity of coronary stenosis was divided into three degrees based on Gensini score, mild coronary stenosis, moderate coronary stenosis and severe coronary stenosis.

RESULTS

By using ordinal logistic regression, serum cTnI was associated with severity of coronary stenosis (OR=1.14, p<0.05). By construction and comparison of two models for predicting severity of coronary stenosis, the addition of cTnI significantly improved the predictive ability of the model. Differences between areas under the curves were 0.03, 0.03, 0.03, 0.12 (all p<0.05). Net reclassification improvements were 0.08, 0.05, 0.05, 0.35, respectively, in varied renal functions. Compared with the participants with normal renal function and without hypertroponinaemia, groups of participants with hypertroponinaemia showed higher ORs. ORs were 3.52, 4.20, 4.45, 6.00, respectively, as renal function decreased (all p<0.05).

CONCLUSIONS

In this cohort of patients with stable coronary artery disease and varied renal functions, cTnI was intensely associated with severity of coronary stenosis which based on Gensini score. The presentation of hypertroponinaemia in patients with impaired renal function always indicates a higher risk of severe coronary stenosis.

Relation Between Plasma Proteomics Analysis and Major Adverse Cardiovascular Events in Patients With Stable Coronary Artery Disease

Objective

Despite the advances in the control of traditional risk factors, coronary artery disease (CAD) remains the greatest cause of morbidity and mortality. Our aim was to establish the relation between plasma proteomics analysis and the risk of cardiovascular events in patients with stable CAD.

Materials and Methods

Patients with stable CAD and documented coronary atherosclerosis were screened for inclusion. Using proximity extension assays, 177 plasma proteins were simultaneously measured. The endpoint consisted of the first major adverse cardiovascular event (MACE) and was the composite of cardiovascular death, acute coronary syndrome, stroke, transient ischemic attack, or acute limb ischemia at 18 months follow-up. Cox proportional-hazards regression with adjustment for multiple comparisons was used to identify biomarkers for the outcomes of interest.

Results

The cohort consisted of 229 patients. Six mediators were associated with MACE (p < 0.001). For these markers, the risk of MACE was calculated: tumor necrosis factor receptor superfamily member 13B (HR = 1.65; 95% CI: 1.30–2.10), C-C motif chemokine-3 (HR = 1.57; 95% CI: 1.23–1.98), decorin (HR = 1.65; 95% CI: 1.26–2.16), fibroblast growth factor-23 (HR = 1.56; 95% CI: 1.23–1.99), tumor necrosis factor-related apoptosis-inducing ligand-receptor 2 (TRAIL-R2) (HR = 1.61; 95% CI: 1.23–2.11), and tumor necrosis factor receptor superfamily member 10A (HR = 1.69; 95% CI: 1.25–2.29). Except for TRAIL-R2, the other proteins were associated with MACE independent of age, sex, diabetes mellitus, or estimated glomerular filtration rate.

Conclusions

In patients with stable CAD, five novel biomarkers were identified as independent risk factors for adverse outcomes. Novel biomarkers could represent pharmacological targets for the prevention of adverse cardiovascular events.

Troponin-Guided Coronary Computed Tomographic Angiography After Exclusion of Myocardial Infarction

BACKGROUND

Patients with suspected acute coronary syndrome in whom myocardial infarction has been excluded are at risk of future adverse cardiac events.

OBJECTIVES

This study evaluated the usefulness of high-sensitivity cardiac troponin I (hs-cTnI) to select patients for further investigation after myocardial infarction has been excluded.

METHODS

This is a prospective cohort study of patients presenting to the emergency department with suspected acute coronary syndrome and hs-cTnI concentrations below the sex-specific 99th percentile. Patients were recruited in a 2:1 fashion, stratified by peak hs-cTnI concentration above and below the risk stratification threshold of 5 ng/L. All patients underwent coronary computed tomography angiography (CCTA) after hospital discharge.

RESULTS

Overall, 250 patients were recruited (61.4 ± 12.2 years 31% women) in whom 62.4% (156 of 250 patients) had coronary artery disease (CAD). Patients with intermediate hs-cTnI concentrations (between 5 ng/L and the sex-specific 99th percentile) were more likely to have CAD than those with hs-cTnI concentrations <5 ng/L (71.9% [120 of 167 patients] vs 43.4% [36 of 83 patients]; odds ratio: 3.33; 95% CI: 1.92-5.78). Conversely, there was no association between anginal symptoms and CAD (63.2% [67 of 106 patients] vs 61.8% [89 of 144 patients]; odds ratio: 0.92; 95% CI: 0.48-1.76). Most patients with CAD did not have a previous diagnosis (53.2%; 83 of 156 patients) and were not on antiplatelet and statin therapies (63.5%; 99 of 156 patients) before they underwent CCTA.

CONCLUSIONS

In patients who had myocardial infarction excluded, CAD was 3× more likely in those with intermediate hs-cTnI concentrations compared with low hs-cTnI concentrations. In such patients, CCTA could help to identify those with occult CAD and to target preventative treatments, thereby improving clinical outcomes.

Cardiac troponin and defining myocardial infarction

The 4th Universal Definition of Myocardial Infarction has stimulated considerable debate since its publication in 2018. The intention was to define the types of myocardial injury through the lens of their underpinning pathophysiology. In this review, we discuss how the 4th Universal Definition of Myocardial Infarction defines infarction and injury and the necessary pragmatic adjustments that appear in clinical guidelines to maximize triage of real-world patients.

Ticagrelor to Reduce Myocardial Injury in Patients With High-Risk Coronary Artery Plaque

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).

Use of Troponin as a predictor for cardiovascular diseases in patients with type 2 Diabetes Mellitus

People with type 2 diabetes mellitus (T2DM) have two- to four-fold increased cardiovascular mortality in comparison to the general population. With the identification of new therapeutic targets and hypoglycemic drugs for T2DM, the need for a better stratification of CVD risk has emerged to select patients who may need intensive or specific treatment. At present, risk stratification is based on clinical, demographic, and biochemical factors. High sensitivity cardiac troponin (hs-cTn) increases after several ischemic and non-ischemic insults and it is considered a marker of myocardial injury. This review summarizes the main findings about hs-cTn utilization for risk stratification in people with T2DM and no clinical CVD. Several large observational studies have documented the association between hs-cTn and adverse cardiovascular outcomes in both the general population and in patients with T2DM. Lifestyle interventions, and particularly promotion of physical activity and adoption of healthy nutritional habits, have been associated to a significant benefit on hs-cTn release in the general population. Randomized controlled trials suggested that hypoglycemic, anti-hypertensive and lipid-lowering therapy may influence the degree of T2DM-induced cardiac injury. Besides these promising findings, the efficacy of an hs-cTn-based approach for CVD prevention in T2DM patients still requires more investigations.

Association of High-Sensitivity Troponin with Cardiac CT Angiography Evidence of Myocardial and Coronary Disease in a Primary Prevention Cohort of Men: Results from MACS

BACKGROUND

High-sensitivity cardiac troponin (hs-cTn) elevations are associated with incident cardiovascular disease events in primary prevention samples. However, the mechanisms underlying this association remain unclear.

METHODS

We studied 458 men without known cardiovascular disease who participated in the cardiovascular disease substudy of the Multicenter AIDS Cohort Study and had cardiac CT angiography. We used multivariable linear and logistic regression models to examine the cross-sectional associations between coronary artery stenosis, coronary artery plaque, indexed left ventricular mass (LVMi), and the outcome of hs-cTnI. We also evaluated the associations between HIV serostatus or use of highly active antiretroviral therapy (HAART) and hs-cTnI.

RESULTS

The mean age was 54 years, 54% were white, and 61% were HIV infected. In multivariable-adjusted logistic models, comparing the highest quartile of LVMi with the lowest quartile, the odds ratio (OR) of hs-cTnI ≥75th percentile was 2.59 (95% CI, 1.20-5.75). There was no significant association between coronary stenosis severity or plaque type and hs-cTnI in linear models; however, in logistic regression models, coronary artery stenosis ≥70% (8% of sample) was marginally associated with a higher likelihood (OR, 2.75 [95% CI, 1.03, 7.27]) of having hs-cTnI ≥75th percentile. There were no associations between HIV serostatus or HAART use and hs-cTnI in either linear or logistic models.

CONCLUSION

Among primary prevention men with or at risk for HIV, hs-cTnI concentrations were strongly associated with LVMi but were not associated with HIV infection or treatment status or with coronary plaque type or stenosis until the extremes of severity (≥70% stenosis).

Variability in High-Sensitivity Cardiac Troponin T Testing in Stable Patients With and Without Coronary Artery Disease

BACKGROUND

High-sensitivity cardiac troponin T (hs-cTnT) is used to diagnosis acute myocardial infarction, often based on values exceeding the 99th percentile threshold (14 ng/L) of normal populations. The short- and long-term variability of hs-cTnT in stable patients with or without coronary artery disease (CAD) is unknown.

METHODS

Prospective cohort study of 75 stable patients with CAD and 3 differing clinical profiles (stable angina [SA]; remote myocardial infarction [MI]; repetitive acute coronary syndrome [ACS]) and 25 controls without angiographic CAD, each with 15 hs-cTnT measurements over 1 year.

RESULTS

Individual results (1491 measurements) did not vary over within-day, daily, weekly, monthly, seasonal, or yearly time windows. The overall median was 2.8 ng/L (interquartile range [IQR] 5.2 ng/L) with the highest median (6.3 ng/L) and variability (IQR 6. 9 ng/L) in the repetitive ACS group. Diabetes, impaired renal function, and raised C-reactive protein were independent predictors of higher hs-cTnT values (average increase by 8.5 ng/L [95% CI, 5.0-11.9], 5.0 ng/L [95% CI, 2.0-8.1] and 4.0 ng/L (95% CI, 1.0-7.0), respectively). The 99th percentile value of all hs-cTnT measurements in the combined stable patients with CAD was 39 ng/L compared with 14 ng/L in the non-CAD patients.

CONCLUSIONS

Individual hs-cTnT readings in both patients with and without CAD were stable over hours, days, weeks, and months. Diabetes, poor renal function, and elevated C-reactive protein were independent predictors of higher median and IQR hs-cTnT values, often exceeding conventional thresholds. These findings highlight the need for caution and clinical contextualization in the interpretation of hs-cTnT results.

Impact of High-Sensitivity Cardiac Troponin Elevation in Relation to Diagnostic Invasive Intravascular Imaging for the Assessment of Coronary Artery Disease

Recent studies reported that cardiac troponin elevation after percutaneous coronary intervention is related to adverse cardiac events. Intravascular ultrasound (IVUS) and optical coherence tomography (OCT) are often used to assess lesion characteristics in the coronary arteries. However, little is known about the trend of cardiac troponin elevation after diagnostic invasive intracoronary examination and the prognostic influence. We assessed the relationship between myocardial injury manifested by the high-sensitivity cardiac troponin T (hs-cTnT) level after invasive intracoronary examination and future adverse cardiac outcomes. We evaluated 115 patients with stable coronary artery disease who underwent IVUS or OCT for detailed coronary assessment during coronary angiography (CAG). Baseline and post-procedural (within 24 hours after examination) hs-cTnT were measured. In consequence, post-procedural hs-cTnT level and percentage increase were higher in patients with IVUS or OCT during CAG than in those without. Periprocedural myocardial injury (PMI, defined as post-procedural hs-cTnT with upper reference limit greater than five-fold) occurred in 10 (8.6%) patients. There were no significant differences in baseline characteristics between patients with and without PMI, except for left-ventricular diastolic dimension. Only two major adverse cardiac events (MACE, defined as cardiovascular death, nonfatal myocardial infarction, and target lesion revascularization) occurred in non-PMI during a mean observation period of 32 ± 18 months. On Kaplan-Meier analysis, MACE-free survival rate was similar between PMI and non-PMI. In conclusion, a few imperceptible PMI derived by hs-cTnT assay occurred after diagnostic invasive intracoronary examination. However, it was not associated with subsequent poor cardiac outcome.

Cardiac Troponin T and Troponin I in the General Population

BACKGROUND

There is great interest in widening the use of high-sensitivity cardiac troponins for population cardiovascular disease (CVD) and heart failure screening. However, it is not clear whether cardiac troponin T (cTnT) and troponin I (cTnI) are equivalent measures of risk in this setting. We aimed to compare and contrast (1) the association of cTnT and cTnI with CVD and non-CVD outcomes, and (2) their determinants in a genome-wide association study.

METHODS

High-sensitivity cTnT and cTnI were measured in serum from 19 501 individuals in Generation Scotland Scottish Family Health Study. Median follow-up was 7.8 years (quartile 1 to quartile 3, 7.1-9.2). Associations of each troponin with a composite CVD outcome (1177 events), CVD death (n=266), non-CVD death (n=374), and heart failure (n=216) were determined by using Cox models. A genome-wide association study was conducted using a standard approach developed for the cohort.

RESULTS

Both cTnI and cTnT were strongly associated with CVD risk in unadjusted models. After adjusting for classical risk factors, the hazard ratio for a 1 SD increase in log transformed troponin was 1.24 (95% CI, 1.17-1.32) and 1.11 (1.04-1.19) for cTnI and cTnT, respectively; ratio of hazard ratios 1.12 (1.04-1.21). cTnI, but not cTnT, was associated with myocardial infarction and coronary heart disease. Both cTnI and cTnT had strong associations with CVD death and heart failure. By contrast, cTnT, but not cTnI, was associated with non-CVD death; ratio of hazard ratios 0.77 (0.67-0.88). We identified 5 loci (53 individual single-nucleotide polymorphisms) that had genome-wide significant associations with cTnI, and a different set of 4 loci (4 single-nucleotide polymorphisms) for cTnT.

CONCLUSIONS

The upstream genetic causes of low-grade elevations in cTnI and cTnT appear distinct, and their associations with outcomes also differ. Elevations in cTnI are more strongly associated with some CVD outcomes, whereas cTnT is more strongly associated with the risk of non-CVD death. These findings help inform the selection of an optimal troponin assay for future clinical care and research in this setting.

Predictive value of targeted proteomics for coronary plaque morphology in patients with suspected coronary artery disease

Background

Risk stratification is crucial to improve tailored therapy in patients with suspected coronary artery disease (CAD). This study investigated the ability of targeted proteomics to predict presence of high-risk plaque or absence of coronary atherosclerosis in patients with suspected CAD, defined by coronary computed tomography angiography (CCTA).

Methods

Patients with suspected CAD (n = 203) underwent CCTA. Plasma levels of 358 proteins were used to generate machine learning models for the presence of CCTA-defined high-risk plaques or complete absence of coronary atherosclerosis. Performance was tested against a clinical model containing generally available clinical characteristics and conventional biomarkers.

Findings

A total of 196 patients with analyzable protein levels (n = 332) was included for analysis. A subset of 35 proteins was identified predicting the presence of high-risk plaques. The developed machine learning model had fair diagnostic performance with an area under the curve (AUC) of 0·79 ± 0·01, outperforming prediction with generally available clinical characteristics (AUC = 0·65 ± 0·04, p < 0·05). Conversely, a different subset of 34 proteins was predictive for the absence of CAD (AUC = 0·85 ± 0·05), again outperforming prediction with generally available characteristics (AUC = 0·70 ± 0·04, p < 0·05).

Interpretation

Using machine learning models, trained on targeted proteomics, we defined two complementary protein signatures: one for identification of patients with high-risk plaques and one for identification of patients with absence of CAD. Both biomarker subsets were superior to generally available clinical characteristics and conventional biomarkers in predicting presence of high-risk plaque or absence of coronary atherosclerosis. These promising findings warrant external validation of the value of targeted proteomics to identify cardiovascular risk in outcome studies.

Fund

This study was supported by an unrestricted research grant from HeartFlow Inc. and partly supported by a European Research Area Network on Cardiovascular Diseases (ERA-CVD) grant (ERA CVD JTC2017, OPERATION). Funders had no influence on trial design, data evaluation, and interpretation.

Use of High-Sensitivity Cardiac Troponin for the Exclusion of Inducible Myocardial Ischemia: A Cohort Study

BACKGROUND

Many patients with coronary artery disease (CAD) are routinely referred for surveillance stress testing despite recommendations against it.

OBJECTIVE

To determine whether low levels of resting high-sensitivity cardiac troponin I (hs-cTnI) can identify persons without inducible myocardial ischemia.

DESIGN

Observational study.

SETTING

A university-affiliated hospital network.

PATIENTS

Persons with stable CAD: 589 in the derivation group and 118 in the validation cohort.

MEASUREMENTS

Presence of inducible myocardial ischemia was determined by myocardial perfusion imaging with technetium-99m single-photon emission computed tomography during either treadmill or pharmacologic stress testing. Resting plasma hs-cTnI was measured within 1 week of the stress test, and the negative predictive value (NPV) for inducible ischemia was calculated. The derivation cohort was followed for 3 years for incident cardiovascular death and myocardial infarction.

RESULTS

In the derivation cohort, 10 of 101 patients with an hs-cTnI level below 2.5 pg/mL had inducible myocardial ischemia (NPV, 90% [95% CI, 83% to 95%]) and 3 of 101 had inducible ischemia involving at least 10% of the myocardium (NPV, 97% [CI, 92% to 99%]). In the validation cohort, 4 of 32 patients with an hs-cTnI level below 2.5 pg/mL had inducible ischemia (NPV, 88% [CI, 71% to 96%]) and 2 of 32 had ischemia of 10% or greater (NPV, 94% [CI, 79% to 99%]). After a median follow-up of 3 years in the derivation cohort, no adverse events occurred in patients with an hs-cTnI level below 2.5 pg/mL, compared with 33 (7%) cardiovascular deaths or incident myocardial infarctions among those with an hs-cTnI level of 2.5 pg/mL or greater.

LIMITATION

The data may not be applicable to a population without known CAD or to persons with unstable angina, and the modest sample sizes warrant further validation in a larger cohort.

CONCLUSION

Very low hs-cTnI levels may be useful in excluding inducible myocardial ischemia in patients with stable CAD.

PRIMARY FUNDING SOURCE

National Institutes of Health.

Cardiac Troponin - diagnostic problems and impact on cardiovascular disease

The definition of a high-sensitivity cardiac Troponin (cTn) assay describes the ability to quantify a cardiac biomarker level in at least 50% of healthy individuals. This advance in analytic sensitivity has come with a perceived loss of specificity in the most classic application - chest pain triage and the diagnosis of acute myocardial infarction (AMI). As cardiac Troponin can no longer be used as a dichotomous test, the medical field is increasingly moving towards a more granular interpretation. However, rapid rule-out/rule-in algorithms for AMI still rely on concrete thresholds for efficient triage, irrespective of the patient's comorbidities. Owing to a slightly elevated cTn value, evermore patients appear to fall into an indeterminate risk zone of diagnostic uncertainty. The reasons are manifold, spanning biological variation, analytical issues, increased plasma membrane permeability and the potential cytosolic release of cTn. This review provides a contemporary overview of the literature concerning the use of cardiac Troponin in chronic and acute cardiovascular care. Key messages High-sensitivity cardiac Troponin assays have transformed the assessment of cardiovascular disease. Rapid rule-out algorithms for chest pain triage have become increasingly complicated, but enable safe rule-out. Cardiac Troponin tracks mid- to long-term risk in patients with hyperlipidaemia, heart failure and renal dysfunction.

Circulating levels of cardiac troponin T are associated with coronary noncalcified plaque burden in HIV-infected adults: a pilot study

HIV infection and/or antiretroviral therapy may increase the risk of subclinical coronary atherosclerosis. However, patients with chronic kidney disease (CKD) and those without IV access cannot undergo contrast-enhanced coronary CT angiography (CCTA). This study was to explore the relationship between cardiac troponin T (cTnT) levels and the extent of coronary plaque burden, as assessed by CCTA in those with HIV infection. Between June and September 2017, 58 HIV-infected participants were recruited and underwent contrast-enhanced CCTA. cTnT was measured with the Elecsys Troponin T Gen 5 STAT assay, and noncalcified plaque burden was quantified using coronary plaque analysis. Robust regression model was employed to perform primary statistical analysis. Univariate robust regression analysis indicated that male gender, cardiovascular risk score defined by the 2013 ACC/AHA cardiovascular risk score algorithm, and cTnT levels were significantly associated with noncalcified plaque volume index (NCPI). Final robust regression analyses showed that only cTnT (log scale) was independently associated with the NCPI (regression coefficient: 0.0453 with 95% CI: 0.0151, 0.0755, p = 0.003). These results of this study suggest that cTnT may be a promising marker for coronary plaque burden, especially in patients with HIV-associated CKD or without IV access.

Three-Year Impact of Immediate Invasive Strategy in Patients With Non-ST-Segment Elevation Myocardial Infarction (from the RIDDLE-NSTEMI Study)

Previous studies compared clinical outcomes of early versus delayed invasive strategy in patients with non-ST-elevation acute coronary syndrome up to 1-year follow-up, but long-term data remain scarce. Our aim was to evaluate the long-term effects of immediate invasive intervention in patients with Non-ST-Segment Elevation Myocardial Infarction (NSTEMI). The Randomized Study of Immediate Versus Delayed Invasive Intervention in Patients With Non-ST-Segment Elevation Myocardial Infarction (RIDDLE-NSTEMI) was a randomized, investigator-initiated, parallel-group trial that assigned 323 patients with NSTEMI (1:1) to either immediate (median time to intervention 1.4 hours) or delayed invasive strategy (61.0 hours). The primary end point was the composite of death or new myocardial infarction (MI). At 3 years, immediate invasive intervention was associated with a lower rate of death or new MI, compared with a delayed invasive strategy (12.3% vs 22.5%, hazard ratio 0.50, 95% confidence interval 0.29 to 0.87, p = 0.014). The observed benefit of immediate intervention was mainly driven by an increased early reinfarction risk in delayed strategy, with similar new MI rates beyond 30 days (4.4% in the immediate and 5.6% in the delayed group, p = 0.61). Three-year mortality was 9.3% in the immediate invasive strategy, and 10.0% in the delayed strategy (p = 0.83). High baseline Global Registry of Acute Coronary Events score (>140) was associated with a significant increase in long-term mortality, regardless of the timing of invasive intervention. In conclusion, whereas immediate invasive intervention significantly reduced the early risk of new MI, the timing of invasive intervention appears to have no significant impact on clinical outcomes beyond 30 days, which seem to mostly be related to the baseline clinical risk profile.

Biomarkers in stable coronary artery disease

Coronary artery disease (CAD) remains a significant cause of morbidity and mortality around the world. Patients with stable CAD can have an unpredictable clinical trajectory; thus, additional tools to prognosticate risk in this cohort are warranted. In recent years, a wide range of biomarkers has been recognized for their diagnostic capabilities in patients with stable CAD, identifying those with obstructive disease who may require more intensive preventive therapies or even consideration of percutaneous coronary intervention in some circumstances. In addition, a multiple-biomarker approach may identify stable CAD patients at highest risk for future major adverse cardiac events. Thus, randomized controlled trials to assess biomarker-guided preventive therapy in this cohort appear warranted.

High Sensitivity Troponins Discriminate Different Morphologies of Coronary Artery Plaques Being Assessed by Coronary Computed Tomography Angiography

BACKGROUND

This study evaluates the association between high sensitivity troponin I (hsTnI) and T (hsTnT) and the morphology of coronary artery plaques detected by coronary computed tomography angiography (CCTA) in patients with suspected coronary artery disease (CAD).

METHODS

Patients undergoing CCTA were prospectively enrolled. CCTA was indicated by a low to intermediate pretest probability for CAD during routine clinical care. Within 24 hours of CCTA examination, peripheral blood samples were taken to measure hsTnI, hsTnT, and N-terminal probrain natriuretic peptide (NT-proBNP).

RESULTS

A total of 99 patients were enrolled with 43% without CAD, 9% with noncalcified plaques, 28% with calcified plaques, and 19% with mixed type plaque lesions. Both hsTnI and hsTnT levels were able to discriminate significantly between the groups, especially in the presence of mixed coronary plaques (AUC range: 0.741-0.752; p = 0.0001). In multivariate logistic regression models, hsTnT, but not hsTnI, was still significantly associated with mixed coronary plaque morphology (odds ratio = 8.968; 95% CI 1.999-40.241; p = 0.004).

CONCLUSIONS

Both hsTnI and hsTnT are able to discriminate between different coronary artery plaques morphologies, whereas hsTnT was significantly associated with mixed coronary plaques in patients with suspected CAD. This trial is registered with NCT03074253.

Association of high-sensitivity cardiac troponin T with mortality and cardiovascular events in a community-based prospective study in Beijing

OBJECTIVE

The prognostic value of cardiac troponins in apparently healthy populations is not well established. The aim of this study was to investigate the prognostic properties of high-sensitivity cardiac troponin T (hs-cTnT) for long-term adverse outcomes.

SETTING

A community-dwelling prospective survey of residents from two communities in Beijing.

PARTICIPANTS

From September 2007 to January 2009, 1680 participants were initially enrolled. Of these, 1499 (870 females, mean age: 61.4 years) participants completed the survey and were followed up for a median of 4.8 years (IQR: 4.5-5.2).

OUTCOME MEASURES

The primary outcome was the occurrence of all-cause mortality and major cardiovascular events.

RESULTS

Overall, 820 individuals (54.7%) had detectable hs-cTnT levels. During the follow-up, 52 participants (3.5%) died, 154 (10.3%) had major cardiovascular events and 99 (6.6%) experienced new-onset coronary events. Compared with those with undetectable hs-cTnT levels, participants with hs-cTnT levels in the highest category (≥14 ng/L) had a significantly increased risk for all-cause mortality (adjusted HR (aHR): 2.07, 95% CI 1.05 to 3.01), major cardiovascular events (aHR: 3.27, 95% CI 1.88 to 5.70) and coronary events (aHR: 4.50, 95% CI 2.26 to 9.02) in covariate-adjusted analyses. No differences in stroke incidence were found (aHR: 1.27, 95% CI 0.69 to 2.62). Also, significant associations were presented when hs-cTnT levels were modelled as a continuous variable and when analysing changes in hs-cTnT levels over time with adverse outcomes. The addition of troponin T levels to clinical variables led to significant increases in risk prediction with a marked improvement in the C-statistics (p=0.003 or lower).

CONCLUSIONS

In this cohort of individuals from a community-based population, cTnT levels measured with a highly sensitive assay were associated with increases in the subsequent risk for all-cause mortality and major cardiovascular events. These results might support screening for at-risk individuals.

Association Between High-Sensitivity Cardiac Troponin Levels and Myocardial Ischemia During Mental Stress and Conventional Stress

OBJECTIVES

This study sought to investigate whether patients with mental stress-induced myocardial ischemia will have high resting and post-mental stress high-sensitivity cardiac troponin I (hs-cTnI).

BACKGROUND

Hs-cTnI is a marker of myocardial necrosis, and its elevated levels are associated with adverse outcomes. Hs-cTnI levels may increase with exercise in patients with coronary artery disease. Mental stress-induced myocardial ischemia is also linked to adverse outcomes.

METHODS

In this study, 587 patients with stable coronary artery disease underwent technetium Tc 99m sestamibi-single-photon emission tomography myocardial perfusion imaging during mental stress testing using a public speaking task and during conventional (pharmacological/exercise) stress testing as a control condition. Ischemia was defined as new/worsening impairment in myocardial perfusion using a 17-segment model.

RESULTS

The median hs-cTnI resting level was 4.3 (interquartile range [IQR]: 2.9 to 7.3) pg/ml. Overall, 16% and 34.8% of patients developed myocardial ischemia during mental and conventional stress, respectively. Compared with those without ischemia, median resting hs-cTnI levels were higher in patients who developed ischemia either during mental stress (5.9 [IQR: 3.9 to 8.3] pg/ml vs. 4.1 [IQR: 2.7 to 7.0] pg/ml; p < 0.001) or during conventional stress (5.4 [IQR: 3.9 to 9.3] pg/ml vs. 3.9 [IQR: 2.5 to 6.5] pg/ml; p < 0.001). Patients with high hs-cTnI (cutoff of 4.6 pg/ml for men and 3.9 pg/ml for women) had greater odds of developing mental (odds ratio [OR]: 2.4; 95% confidence interval [CI]: 1.5 to 3.9; p < 0.001) and conventional (OR: 2.4; 95% CI: 1.7 to 3.4; p < 0.001) stress-induced ischemia. Although there was a significant increase in 45-min post-treadmill exercise hs-cTnI levels in those who developed ischemia, there was no significant increase after mental or pharmacological stress test.

CONCLUSIONS

In patients with coronary artery disease, myocardial ischemia during either mental stress or conventional stress is associated with higher resting levels of hs-cTnI. This suggests that hs-cTnI elevation is an indicator of chronic ischemic burden experienced during everyday life. Whether elevated hs-cTnI levels are an indicator of adverse prognosis beyond inducible ischemia or whether it is amenable to intervention requires further investigation.

Cohort profile of BIOMArCS: the BIOMarker study to identify the Acute risk of a Coronary Syndrome-a prospective multicentre biomarker study conducted in the Netherlands

PURPOSE

Progression of stable coronary artery disease (CAD) towards acute coronary syndrome (ACS) is a dynamic and heterogeneous process with many intertwined constituents, in which a plaque destabilising sequence could lead to ACS within short time frames. Current CAD risk assessment models, however, are not designed to identify increased vulnerability for the occurrence of coronary events within a precise, short time frame at the individual patient level. The BIOMarker study to identify the Acute risk of a Coronary Syndrome (BIOMArCS) was designed to evaluate whether repeated measurements of multiple biomarkers can predict such 'vulnerable periods'.

PARTICIPANTS

BIOMArCS is a multicentre, prospective, observational study of 844 patients presenting with ACS, either with or without ST-elevation and at least one additional cardiovascular risk factor.

METHODS AND ANALYSIS

We hypothesised that patterns of circulating biomarkers that reflect the various pathophysiological components of CAD, such as distorted lipid metabolism, vascular inflammation, endothelial dysfunction, increased thrombogenicity and ischaemia, diverge in the days to weeks before a coronary event. Divergent biomarker patterns, identified by serial biomarker measurements during 1-year follow-up might then indicate 'vulnerable periods' during which patients with CAD are at high short-term risk of developing an ACS. Venepuncture was performed every fortnight during the first half-year and monthly thereafter. As prespecified, patient enrolment was terminated after the primary end point of cardiovascular death or hospital admission for non-fatal ACS had occurred in 50 patients. A case-cohort design will explore differences in temporal patterns of circulating biomarkers prior to the repeat ACS.

FUTURE PLANS AND DISSEMINATION

Follow-up and event adjudication have been completed. Prespecified biomarker analyses are currently being performed and dissemination through peer-reviewed publications and conference presentations is expected from the third quarter of 2016. Should identification of a 'vulnerable period' prove to be feasible, then future research could focus on event reduction through pharmacological or mechanical intervention during such periods of high risk for ACS.

TRIAL REGISTRATION NUMBER

NTR1698 and NTR1106.

Prognostic Value of Cardiac Troponin T and Sex in Patients Undergoing Elective Percutaneous Coronary Intervention

BACKGROUND

In patients with stable coronary artery disease undergoing elective percutaneous coronary intervention, the prognostic value of high-sensitivity cardiac troponin T (hs-cTnT) and the influence of sex remain poorly defined.

METHODS AND RESULTS

Consecutive patients with stable coronary artery disease who underwent elective percutaneous coronary intervention were included. Primary endpoint was all-cause mortality. Unadjusted hazard ratio (HR) in overall and sex-specific population and multivariable adjusted HR were calculated by using Cox proportional hazard models. In a total of 5626 patients, elevated hs-cTnT levels, more than the sex-specific 99th percentile upper reference limit of normal (URL), were observed in 2221 patients (39%) at baseline. During follow-up (median, 14.5 months; 25th-75th percentiles, 6.4-27.2 months), 265 patients died. Mortality was higher in patients with the sex-specific 99th percentile URL compared to those with normal hs-cTnT (17.3% vs 3.4%; HR=6.10; 95% CI, 4.58-8.14; P<0.001). hs-cTnT was an independent predictor of mortality in multivariable adjusted models. The C-statistic was significantly increased by adding hs-cTnT to the basic prediction model for mortality (0.793-0.815; P<0.001). There was a significant interaction between hs-cTnT and sex on mortality. Differences in all-cause mortality between patients with more than the sex-specific 99th percentile URL and those with normal hs-cTnT were numerically larger in male than female patients (male, HR=6.45; 95% CI, 4.68-8.87, P<0.001; female, HR=4.29, 95% CI, 2.36-9.03; P<0.001).

CONCLUSIONS

In patients with stable coronary artery disease undergoing elective percutaneous coronary intervention, preprocedural hs-cTnT was a strong predictor of mortality in both men and women.

State of the Art: Blood Biomarkers for Risk Stratification in Patients with Stable Ischemic Heart Disease

BACKGROUND

Multiple circulating biomarkers have been associated with the incidence of cardiovascular events and proposed as potential tools for risk stratification in stable ischemic heart disease (IHD), yet current guidelines do not make any firm recommendations concerning the use of biomarkers for risk stratification in this setting. This state-of-the-art review provides an overview of biomarkers for risk stratification in stable IHD.

CONTENT

Circulating biomarkers associated with the risk of cardiovascular events in patients with stable IHD reflect different pathophysiological processes, including myocardial injury, myocardial stress and remodeling, metabolic status, vascular inflammation, and oxidative stress. Compared to the primary prevention setting, biomarkers reflecting end-organ damage and future risk of heart failure development and cardiovascular death may play more important roles in the stable IHD setting. Accordingly, biomarkers that reflect chronic, low-grade myocardial injury, and stress, i.e., high-sensitivity cardiac troponins and natriuretic peptides, provide graded and incremental prognostic information to conventional risk markers. In contrast, in stable IHD patients the prognostic value of traditional metabolic biomarkers, including serum lipids, is limited. Among several novel biomarkers, growth-differentiation factor-15 may provide the most robust prognostic information, whereas most inflammatory markers provide limited incremental prognostic information to risk factor models that include conventional risk factors, natriuretic peptides, and high-sensitivity troponins.

SUMMARY

Circulating biomarkers hold promise as useful tools for risk stratification in stable IHD, but their future incorporation into clinically useful risk scores will depend on prospective, rigorously performed clinical trials that document enhanced risk prediction.