Cardiac troponin T concentrations above the 99th percentile value as measured by a new high-sensitivity assay predict long-term prognosis in patients with acute coronary syndromes undergoing routine early invasive strategy

Contrasting the potential benefits of early invasive coronary angiography in acute and chronic myocardial injury patterns

BACKGROUND

In cases of evolving myocardial injury not definitively attributed to coronary ischaemia precipitated by plaque rupture, referral for invasive coronary angiography (ICA) may be influenced by observed troponin profiles. We sought to explore association between early ICA and elevated high-sensitivity troponin T (hs-cTnT) concentrations with and without dynamic changes, to examine if there may be a hs-cTnT threshold associated with benefit from an initial ICA strategy.

METHODS

Using published studies (hs-cTnT study n = 1937, RAPID-TnT study n = 3270) and the Fourth Universal Definition of Myocardial Infarction (MI), index presentations of patients with hs-cTnT concentrations 5-14ng/L were classified as 'non-elevated' (NE). Hs-cTnT greater than upper reference limit (14ng/L) were classified as 'elevated hs-cTnT with dynamic change' (encompassing acute myocardial injury, Type 1 MI, and Type 2 MI), or 'non-dynamic hs-cTnT elevation' (chronic myocardial injury). Patients with hs-cTnT <5ng/L and/or eGFR<15mmol/L/1.73m2 were excluded. ICA was performed within 30 days of admission. Primary outcome was defined as composite endpoint of death, MI, or unstable angina at 12 months.

RESULTS

Altogether, 3620 patients comprising 837 (23.1%) with non-dynamic hs-cTnT elevations and 332 (9.2%) with dynamic hs-cTnT elevations were included. Primary outcome was significantly higher with dynamic and non-dynamic hs-cTnT elevations (Dynamic: HR: 4.13 95%CI:2.92-5.82; p<0.001 Non-dynamic: HR: 2.39 95% confidence interval [CI]:1.74-3.28, p<0.001). Hs-cTnT thresholds where benefit from initial ICA strategy appeared to emerge was observed at 110ng/L and 50ng/L in dynamic and non-dynamic elevations, respectively.

CONCLUSION

Early ICA appears to portend benefit in hs-cTnT elevations with and without dynamic changes, and at lower hs-cTnT threshold in non-dynamic hs-cTnT elevation. Differences compel further investigation.

Association of Troponin T measurements with long-term outcomes in patients with coronary artery disease participating in a secondary prevention trial

BACKGROUND AND AIMS

Identification of high-risk patients in secondary cardiovascular prevention may be challenging, although risk stratification tools are available. Cardiac troponins might have predictive value in identification of high-risk patients. The aim of this study was to investigate the association between cardiac Troponin T (cTnT) levels following a coronary event and long-term outcomes.

METHODS

This study was carried out as a subanalysis from a randomized controlled trial conducted at Sørlandet Hospital, Norway, where patients hospitalized with myocardial infarction (MI) or scheduled percutaneous coronary intervention (PCI)/coronary artery bypass grafting (CABG) were included between 2007 and 2017. Participants were followed-up for up to 10 years after the index event through out-patient consultations. cTnT was assessed at each consultation as well as information regarding new cardiovascular events or death.

RESULTS

A total of 1278 patients (18-80 years) with complete measurements of cTnT were included. cTnT was elevated (≥ 14 ng/L) one year after the primary event in 241 (19%) of participants. Median follow-up was 5.7 [SD 2.7] years. Cox regression analyses showed reduced survival (adjusted HR 0.37, 95% CI 0.19-0.72; p = 0.003) and composite endpoint-free survival (adjusted HR 0.73, 95% CI 0.55-0.98; p = 0.04) in participants with elevated cTnT versus participants with low cTnT after adjustment for risk factors at inclusion and randomization assignment.

CONCLUSIONS

Assessment of cTnT after coronary heart events may help identify patients at high risk of poor outcomes and might contribute to more focused secondary preventive treatment.

TRIAL REGISTRATION

The study is registered in ClinicalTrials.gov (NCT00679237).

Coronary artery disease, left ventricular function and cardiac biomarkers determine all-cause mortality in cancer patients-a large monocenter cohort study

Cancer patients are at risk of suffering from cardiovascular diseases (CVD). Nevertheless, the impact of cardiovascular comorbidity on all-cause mortality (ACM) in large clinical cohorts is not well investigated. In this retrospective cohort study, we collected data from 40,329 patients who were subjected to cardiac catherization from 01/2006 to 12/2017 at University Hospital Heidelberg. The study population included 3666 patients with a diagnosis of cancer prior to catherization and 3666 propensity-score matched non-cancer patients according to age, gender, diabetes and hypertension. 5-year ACM in cancer patients was higher with a reduced left ventricular function (LVEF < 50%; 68.0% vs 50.9%) or cardiac biomarker elevation (high-sensitivity cardiac troponin T (hs-cTnT; 64.6% vs 44.6%) and N-terminal brain natriuretic peptide (NT-proBNP; 62.9% vs 41.4%) compared to cancer patients without cardiac risk. Compared to non-cancer patients, NT-proBNP was found to be significantly higher (median NT-proBNP cancer: 881 ng/L, IQR [254; 3983 ng/L] vs non-cancer: 668 ng/L, IQR [179; 2704 ng/L]; p < 0.001, Wilcoxon-rank sum test) and turned out to predict ACM more accurately than hs-cTnT (NT-proBNP: AUC: 0.74; hs-cTnT: AUC: 0.63; p < 0.001, DeLong's test) in cancer patients. Risk factors for atherosclerosis, such as diabetes and age (> 65 years) were significant predictors for increased ACM in cancer patients in a multivariate analysis (OR diabetes: 1.96 (1.39-2.75); p < 0.001; OR age > 65 years: 2.95 (1.68-5.4); p < 0.001, logistic regression). Our data support the notion, that overall outcome in cancer patients who underwent cardiac catherization depends on cardiovascular comorbidities. Therefore, particularly cancer patients may benefit from standardized cardiac care.

The Predictive Power of the 14-51 Ng/L High Sensitive Troponin T (hsTnT) Values for Predicting Cardiac Revascularization in a Clinical Setting

Background: high sensitive Troponin T (hsTnT) values between 14−50 ng/L represent a challenge in diagnosing acute coronary syndrome (ACS) at the Emergency Department (ED). The European Society for Cardiology (ESC) recommends a second hsTnT measurement 3 h later to distinguish between ACS and other causes depending on the Δ hsTnT. Our study aims to evaluate the predictive power this approach in a clinical setting by following patients presenting at the ED with hsTnT values 14−51 ng/L. Materials and methods: patients presenting with chest pain or dyspnea and a hsTnT value between 14 and 50 ng/L at the Erasmus MC ED in 2012−2013 were included and retrospectively monitored for 90 days after initial presentation for the occurrence of a cardiac revascularization. Patient records were reviewed according to the standing protocol, which depended on the Δ hsTnT. The “event-group” consists of patients receiving cardiac revascularization within 90 days after the ED visit, whereas the “no event-group” consisted of patients without revascularization. Results: a total of 889 patients patient records were reviewed. After excluding out-of-hospital-cardia-arrests (60), non-cardiological chest pain (373) and incomplete follow-up (100), 356 patients remained for final analysis. In 207 patients, a second hsTnT was actually performed (58%). From these 207 patients, 68 (33%) had a Δ hsTnT ≥7 ng/L. In these patients, 37 (54%) experienced an event within 90 days. In the 139 patients with a Δ hsTnT < 7 ng/L, 23 (17%) presented with an event within 90 days. Conclusion: our study demonstrated a sensitivity of 62%, a specificity of 79%, a positive predicted value (PPV) of 54% and a negative predictive value (NPV) of 83% for using a 3-h Δ hsTnT ≥7 ng/L cut-off, related to risk of an event in 90 days following ED presentation.

Biomarkers-in-Cardiology 8 RE-VISITED-Consistent Safety of Early Discharge with a Dual Marker Strategy Combining a Normal hs-cTnT with a Normal Copeptin in Low-to-Intermediate Risk Patients with Suspected Acute Coronary Syndrome-A Secondary Analysis of the Randomized Biomarkers-in-Cardiology 8 Trial

Regarding the management of suspected Non-ST-segment-elevation acute coronary syndrome (ACS), the main Biomarker-in-Cardiology (BIC)-8 randomized controlled trial study had reported non-inferiority for the incidence of major adverse cardiac events at 30 days in the Copeptin group (dual marker strategy of copeptin and hs-cTnT at presentation) compared to the standard process (serial hs-cTnT testing). However, in 349 (38.7%) of the 902 patients, high-sensitivity cardiac troponin was not available for the treating physicians. High sensitivity cardiac troponin T was re-measured from thawed blood samples collected at baseline. This cohort qualified for a re-analysis of the 30-day incidence rate of MACE (death, survived cardiac death, acute myocardial infarction, re-hospitalization for acute coronary syndrome, acute unplanned percutaneous coronary intervention, coronary bypass grafting, or documented life-threatening arrhythmias), or components of the primary endpoint including death or death/MI. After re-measurement of troponin and exclusion of 9 patients with insufficient blood sample volume, 893 patients qualified for re-analysis. A total of 57 cases were detected with high sensitivity cardiac troponin T ≥ 14 ng/L who had been classified as “troponin negative” based on a conventional cardiac troponin T or I < 99th percentile upper limit of normal. Major adverse cardiac events rates after exclusion were non-inferior in the Copeptin group compared to the standard group (4.34% (95% confidence intervals 2.60–6.78%) vs. 4.27% (2.55–6.66%)). Rates were 53% lower in the per-protocol analysis (HR 0.47, 95% CI: 0.18–1.15, p = 0.09). No deaths occurred within 30 days in the discharged low risk patients of the Copeptin group. Copeptin combined with high sensitivity cardiac troponin is useful for risk stratification and allows early discharge of low-to-intermediate risk patients with suspected acute coronary syndrome is as safe as a re-testing strategy at 3 h or later.

Prognostic value of changes in high-sensitivity cardiac troponin T beyond biological variation in stable outpatients with cardiovascular disease: a validation study

Objective

To evaluate the prognostic implications of longitudinal long-term changes beyond the biological variation of high-sensitivity cardiac troponin T (hs-cTnT) in outpatients with stable or asymptomatic cardiovascular disease (CV) and to assess possible differences in the prognostic value while using reference change value (RCV) and minimal important differences (MID) as metric for biological variation.

Methods

Hs-cTnT was measured at index visit and after 12 months in outpatients presenting for routine follow-up. The prognostic relevance of a concentration change of hs-cTnT values exceeding the biological variation defined by RCV and MID of a healthy population within the next 12 months following the stable initial period was determined regarding three endpoints: all-cause mortality (EP1), a composite of all-cause mortality, non-fatal myocardial infarction and stroke (EP2), and a composite of all-cause mortality, non-fatal myocardial infarction, stroke, hospitalization for acute coronary syndrome (ACS) or decompensated heart failure, and planned and unplanned percutaneous coronary interventions (PCI, EP3).

Results

Change in hs-cTnT values exceeding the biovariability defined by MID but not by RCV discriminated a group with a higher cardiovascular risk profile. Changes within MID were associated with uneventful course (NPV 91.6–99.7%) while changes exceeding MID were associated with a higher occurrence of all endpoints within the next 365 days indicating a 5.5-fold increased risk for EP 1 (p = 0.041) a 2.4-fold increased risk for EP 2 (p = 0.049) and a 1.9-fold increased risk for EP 3 (p < 0.0001).

Conclusions

In stable outpatients MID calculated from hs-cTnT changes measured 365 ± 120 days apart are helpful to predict an uneventful clinical course.

Clinical trials identifier

NCT01954303.

Graphic abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s00392-021-01952-6.

High-sensitivity cardiac troponin T determines all-cause mortality in cancer patients: a single-centre cohort study

Aims

Cardio‐oncology is a growing interdisciplinary field which aims to improve cardiological care for cancer patients in order to reduce morbidity and mortality. The impact of cardiac biomarkers, echocardiographic parameters, and cardiological assessment regarding risk stratification is still unclear. We aimed to identify potential parameters that allow an early risk stratification of cancer patients.

Methods and results

In this cohort study, we evaluated 930 patients that were admitted to the cardio‐oncology outpatient clinic of the University Hospital Heidelberg from January 2016 to January 2019. We performed echocardiography, including Global Longitudinal Strain (GLS) analysis and measured cardiac biomarkers including N‐terminal pro brain‐type natriuretic peptide (NT‐proBNP) and high‐sensitivity cardiac troponin T levels (hs‐cTnT). Most patients were suffering from breast cancer (n = 450, 48.4%), upper gastrointestinal carcinoma (n = 99, 10.6%) or multiple myeloma (n = 51, 5.5%). At the initial visit, we observed 86.7% of patients having a preserved left ventricular ejection fraction (LVEF >50%). At the second follow up, still 78.9% of patients showed a preserved LVEF. Echocardiographic parameters or elevation of NT‐proBNP did not significantly correlate with all‐cause mortality (ACM) (logistic regression LVEF <50%: P = 0.46, NT‐proBNP: P = 0.16) and failed to identify high‐risk patients. In contrast, hs‐cTnT above the median (≥7 ng/L) was an independent marker to determine ACM (multivariant logistic regression, OR: 2.21, P = 0.0038) among all included patients. In particular, hs‐cTnT levels before start of a chemotherapy were predictive for ACM.

Conclusions

Based on our non‐selected cohort of cardio‐oncological patients, hs‐cTnT was able to identify patients with high mortality by using a low cutoff of 7 ng/L. We conclude that measurement of hs‐cTnT is an important tool to stratify the risk for mortality of cancer patients before starting chemotherapy.

State of the Art-High-Sensitivity Troponins in Acute Coronary Syndromes

In cases of suspected acute coronary syndrome (ACS), rapid and accurate diagnosis is essential to establish effective evidence-based medical treatment. Patients' history, clinical examination, 12-lead electrocardiogram, and cardiac biomarkers are cornerstones in initial management. Since high-sensitivity cardiac troponins were established, they have markedly expedited and revolutionized rule-in and rule-out pathways of patients with ACS and changed our everyday clinical practice. Thus, they have become an indispensable tool in daily routine in emergency units. This review focuses on historical and contemporary standards in laboratory biomarkers of myocardial injury and discusses their implication in the context of the updated universal definition of myocardial infarction.

Value of Blood-Based microRNAs in the Diagnosis of Acute Myocardial Infarction: A Systematic Review and Meta-Analysis

Background: Recent studies have shown that blood-based miRNAs are dysregulated in patients with acute myocardial infarction (AMI) and are therefore a potential tool for the diagnosis of AMI. Therefore, this study summarized and evaluated studies focused on microRNAs as novel biomarkers for the diagnosis of AMI from the last ten years. Methods: MEDLINE, the Cochrane Central database, and EMBASE were searched between January 2010 and December 2019. Studies that assessed the diagnostic accuracy of circulating microRNAs in AMI were chosen. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and area under the curve (AUC) were used to assess the test performance of miRNAs. Results: A total of 58 studies that included 8,206 participants assessed the diagnostic accuracy of circulating miRNAs in AMI. The main results of the meta-analyses are as follows: (1) Total miRNAs: the overall pooled sensitivity and specificity were 0.82 (95% CI: 0.79-0.85) and 0.87 (95% CI: 0.84-0.90), respectively. The AUC value was 0.91 (95% CI: 0.88-0.93) in the overall summary receiver operator characteristic (SROC) curve. (2) The panel of two miRNAs: sensitivity: 0.88 (95% CI: 0.77-0.94), specificity: 0.84 (95% CI: 0.72-0.91), AUC: 0.92 (95% CI: 0.90-0.94). (3) The panel of three miRNAs: sensitivity: 0.91 (95% CI: 0.85-0.94), specificity: 0.87 (95% CI: 0.77-0.92), AUC: 0.92 (95% CI: 0.89-0.94). (4) Results by types of miRNAs: miRNA-1: sensitivity: 0.78 (95% CI: 0.71-0.84), specificity: 0.86 (95% CI: 0.77-0.91), AUC: 0.88 (95% CI: 0.85-0.90); miRNA-133a: sensitivity: 0.85 (95% CI: 0.69-0.94), specificity: 0.92 (95% CI: 0.61-0.99), AUC: 0.93 (95% CI: 0.91-0.95); miRNA-208b: sensitivity: 0.80 (95% CI: 0.69-0.88), specificity: 0.96 (95% CI: 0.77-0.99), AUC: 0.91 (95% CI: 0.88-0.93); miRNA-499: sensitivity: 0.85 (95% CI: 0.77-0.91), specificity: 0.95 (95% CI: 0.89-0.98), AUC: 0.96 (95% CI: 0.94-0.97). Conclusion: miRNAs may be used as potential biomarkers for the detection of AMI. For single, stand-alone miRNAs, miRNA-499 may have better diagnostic accuracy compared to other miRNAs. We propose that a panel of multiple miRNAs with high sensitivity and specificity should be tested.

Circulating MicroRNA-499 as a Diagnostic Biomarker for Acute Myocardial Infarction: A Meta-analysis

Background

Recent studies have shown that circulating microRNA-499 could be a powerful biomarker of acute myocardial infarction (AMI). Interest in circulating microRNA-499 for detecting AMI is increasing rapidly. To evaluate the diagnosis of circulating microRNA-499 for AMI, this study was performed.

Methods

We searched PubMed, Embase, and the Cochrane Library for studies published up to December 31, 2018, as well as the reference lists of relevant studies. Studies were included if they assessed the accuracy of blood circulating microRNA-499 or cardiac troponin T (cTnT) for AMI and provided sufficient data to construct a 2 × 2 contingency table. Extracted data were analysed for sensitivity, specificity, diagnostic odds ratio (DOR), and summary receiver operator curve (SROC) analyses. Prespecified subgroup analysis and metaregression were also performed.

Results

Fourteen studies including 3816 participants were included in this meta-analysis. The overall pooled sensitivity and specificity were 0.84 (95% CI: 0.64-0.94) and 0.97 (95% CI: 0.90-0.99), respectively. The area under the SROC curve (AUC) was 0.98 (95% CI: 0.96-0.99). The studies had substantial heterogeneity (I² = 98.74%). Seven studies also used cTnT as a marker for the diagnosis of AMI. The overall pooled sensitivity and specificity of cTnT were 0.95 (95% CI: 0.87-0.98) and 0.96 (95% CI: 0.85-0.99), respectively. The area under the SROC curve (AUC) was 0.99 (95% CI: 0.97-0.99). The DOR of circulating miR-499 and cTnT were 188 (95% CI: 19-1815) and 420 (95% CI: 86-2038), respectively. Metaregression analysis suggested that specimen and healthy controls were the main sources of heterogeneity. No publication bias was suggested by Deeks' regression test of asymmetrical funnel plot (t = 0.85; p value = 0.41).

Conclusion

The results showed that circulating microRNA-499 is a reliable biomarker for diagnosing AMI patients.

Prognostic Value of High-Sensitivity Cardiac Troponin T Compared with Risk Scores in Stable Cardiovascular Disease

BACKGROUND

Risk stratification of patients with cardiovascular disease remains challenging despite consideration of risk scores.

METHODS

We aimed to evaluate the prognostic performance of high-sensitivity cardiac troponin T in a low-risk outpatient population presenting for nonsecondary and secondary prevention. All-cause mortality, a composite of all-cause mortality, acute myocardial infarction, and stroke (end point 2), and a composite of all-cause mortality, acute myocardial infarction, stroke and rehospitalization for acute coronary syndrome, and decompensated heart failure (end point 3) were defined. The prognostic performance of high-sensitivity cardiac troponin T on index visit was compared with the PROCAM score and 3 FRAMINGHAM subscores.

RESULTS

In 693 patients with a median follow-up of 796 days, we observed 16 deaths, 32 patients with end point 2, and 83 patients with end point 3. All risk scores performed better in the prediction of all-cause mortality in nonsecondary prevention (area under the curve [AUC]: PROCAM: 0.922 vs 0.523, P = .001, consistent for all other scores). In secondary prevention, high-sensitivity cardiac troponin T outperformed all risk scores in the prediction of all-cause mortality (ΔAUC: PROCAM: 0.319, P <.001, consistent for all other scores) and performed superiorly in the prediction of end point 2 compared with the PROCAM, FRAMINGHAM-Coronary Heart Disease, and FRAMINGHAM-Hard Coronary Heart Disease scores (ΔAUC: PROCAM: 0.176, P = .047, consistent for FRAMINGHAM-Coronary Heart Disease and FRAMINGHAM-Hard Coronary Heart Disease). In nonsecondary prevention, we observed a comparable prognostic performance of high-sensitivity cardiac troponin T and multivariable risk scores. Our findings on the prediction of all-cause mortality compared with the FRAMINGHAM-Hard Coronary Heart Disease score were confirmed in an independent validation cohort on 2046 patients.

CONCLUSIONS

High-sensitivity troponin T provides excellent risk stratification regarding all-cause mortality and all-cause mortality, acute myocardial infarction, and stroke in a secondary prevention cohort in whom risk scores perform poorly.

Implications of Introducing High-Sensitivity Cardiac Troponin T Into Clinical Practice: Data From the SWEDEHEART Registry

BACKGROUND

Cardiac troponin is the preferred biomarker for diagnosing myocardial infarction (MI).

OBJECTIVES

The aim of this study was to examine the implications of introducing high-sensitivity cardiac troponin T (hs-cTnT) into clinical practice and to define at what hs-cTnT level risk starts to increase.

METHODS

We analyzed data from 48,594 patients admitted because of symptoms suggesting an acute coronary syndrome and who were entered into a large national registry. Patients were divided into Group 1, those with hs-cTnT<6 ng/l; Group 2, those with hs-cTnT 6 to 13 ng/l; Group 3, those with hs-cTnT 14 to 49 ng/l (i.e., a group in which most patients would have had a negative cardiac troponin T with older assays); and Group 4, those with hs-cTnT≥50 ng/l.

RESULTS

There were 5,790 (11.9%), 6,491 (13.4%), 10,476 (21.6%), and 25,837 (53.2%) patients in Groups 1, 2, 3, and 4, respectively. In Groups 1 to 4, the proportions with MI were 2.2%, 2.6%, 18.2%, and 81.2%. There was a stepwise increase in the proportion of patients with significant coronary stenoses, left ventricular systolic dysfunction, and death during follow-up. When dividing patients into 20 groups according to hs-cTnT level, the adjusted mortality started to increase at an hs-cTnT level of 14 ng/l.

CONCLUSIONS

Introducing hs-cTnT into clinical practice has led to the recognition of a large proportion of patients with minor cardiac troponin increases (14 to 49 ng/l), the majority of whom do not have MI. Although a heterogeneous group, these patients remain at high risk, and the adjusted mortality rate started to increase at the level of the 99th percentile in healthy controls.

"Troponin elevation in coronary ischemia and necrosis"

Detection of a rise and/or fall of cardiac troponin (cTn) is the cornerstone in the diagnosis of myocardial infarction (MI). For the acute risk, it is hypothesized that cTn mirrors activated coagulation and platelet reactivity and indicates the presence of a ruptured plaque, which may help to identify patients at high risk who benefit particularly from aggressive pharmacological treatment and early invasive strategy. High-sensitivity assays using the 99th percentile as the threshold for positivity can achieve sensitivity at presentation of 90 % or more, and performance further improves with subsequent measurements within 3 to 6 h. By 3 h, negative predictive values of almost 100 % have been reported. However, use of assays with higher sensitivity lead ultimately to a loss of clinical specificity. Thus, other conditions than MI, such as stroke, pulmonary embolism, sepsis, acute perimyocarditis, Takotsubo, acute heart failure and tachycardia also can go with elevated troponin levels. The detection of brief rise and subsequent fall of troponin concentration in marathon runners, and even in healthy subjects, after a standardized exercise test has cast doubts on the hypothesis that troponin is released only upon irreversible damage. This kind of troponin leakage may originate from a cytosolic compartment of the cells and not from the necrosis of thin filaments.

[Essential cardiac biomarkers in myocardial infarction and heart failure]

With the discovery of novel biomarkers in cardiovascular diseases, over the past decades considerable improvements in diagnosis, risk stratification and patient care could be achieved; however, despite extensive research, only few biomarkers have met the requirements of significantly improving diagnostic or prognostic approaches. Among the most established markers are cardiac troponins and natriuretic peptides, which are recommended in current guidelines for myocardial infarction or heart failure and are routinely used in clinical practice. Cardiac troponins T and I are the preferred biomarkers of choice for definition of myocardial infarction and proved to be prognostically relevant not only in acute coronary syndrome but also in non-cardiac diseases. The natriuretic peptides B-type natriuretic peptide (BNP) and amino-terminal pro-B-type natriuretic peptide (NT-proBNP) aid in diagnosis, risk stratification and monitoring of heart failure. In recent years several new promising markers have been proposed which might add incremental clinical information, most notably copeptin and growth differentiation factor (GDF) 15; however, larger studies are still required before recommendations for routine clinical use can be made.

Prognostic performance of high-sensitivity cardiac troponin T kinetic changes adjusted for elevated admission values and the GRACE score in an unselected emergency department population

PURPOSE

The aim of this study was to test the prognostic performance of rising and falling kinetic changes of high-sensitivity cardiac troponin T (hs-cTnT) and the GRACE score.

METHODS

Rising and falling hs-cTnT changes in an unselected emergency department population were compared.

RESULTS

635 patients with a hs-cTnT >99th percentile admission value were enrolled. Of these, 572 patients qualified for evaluation with rising patterns (n=254, 44.4%), falling patterns (n=224, 39.2%), or falling patterns following an initial rise (n=94, 16.4%). During 407days of follow-up, we observed 74 deaths, 17 recurrent AMI, and 79 subjects with a composite of death/AMI. Admission values >14ng/L were associated with a higher rate of adverse outcomes (OR, 95%CI:death:12.6, 1.8-92.1, p=0.01, death/AMI:6.7, 1.6-27.9, p=0.01). Neither rising nor falling changes increased the AUC of baseline values (AUC: rising 0.562 vs. 0.561, p=ns, falling: 0.533 vs. 0.575, p=ns). A GRACE score ≥140 points indicated a higher risk of death (OR, 95%CI: 3.14, 1.84-5.36), AMI (OR, 95%CI: 1.56, 0.59-4.17), or death/AMI (OR, 95%CI: 2.49, 1.51-4.11). Hs-cTnT changes did not improve the prognostic performance of a GRACE score ≥140 points (AUC, 95%CI: death: 0.635, 0.570-0.701 vs. 0.560, 0.470-0.649 p=ns, AMI: 0.555, 0.418-0.693 vs. 0.603, 0.424-0.782, p=ns, death/AMI: 0.610, 0.545-0.676 vs. 0.538, 0.454-0.622, p=ns). Coronary angiography was performed earlier in patients with rising than with falling kinetics (median, IQR [hours]:13.7, 5.5-28.0 vs. 20.8, 6.3-59.0, p=0.01).

CONCLUSION

Neither rising nor falling hs-cTnT changes improve the prognostic performance of elevated hs-cTnT admission values or the GRACE score. However, rising values are more likely associated with the decision for earlier invasive strategy.

Long-term outcomes of minor troponin elevations in the intensive care unit

The aim of our study is to determine the short-term and long-term outcomes of intensive care unit (ICU) patients with minor troponin elevations. The retrospective study compared ICU patients with peak troponin elevation less than 0.1 ng/ml to those with only negative tests during their hospital stay. Data were gathered from ICUs at Beth Israel Deaconess Medical Center between 2001 and 2008. A total of 4224 patients (2547 controls and 1677 positives) were analysed. The primary outcome was mortality at one year. Secondary outcomes were 30-day mortality and hospital and ICU lengths of stay. After adjusting for age, sex, Simplified Acute Physiology Score, Sequential Organ Failure Assessment and combined Elixhauser score, we found that minor troponin elevations (peak troponin elevation between 0.01 and 0.09 ng/ml) were associated with a higher one-year mortality (Hazard Ratio 1.22, P <0.001 for binary troponin presence; Hazard Ratio 1.03, P <0.001 for each 0.01 ng/ml troponin increment). This relationship held for the subgroup of seven-day post-discharge survivors (Hazard Ratio 1.26, P <0.001). Minor elevations of troponin also significantly increased the net reclassification index over traditional risk markers for mortality prediction (net reclassification score 0.12, P <0.001). Minor troponin elevation was also associated with 30-day mortality (odds ratio 1.33, P=0.003). Importantly, troponin testing did not increase the adjusted mortality odds (P=0.9). Minor elevations in troponin substantially increase one-year, all-cause mortality in a stepwise fashion; it was also independently associated with 30-day mortality. We propose that minor elevations in troponin should not be regarded as clinically unimportant, but rather be included as a prognostic element if measured. We recommend prospective ICU studies to assess prognostic value of routine troponin determination.

A comparison of markers of myocardial injury and their relation to nutritional parameters in hemodialysis patients

BACKGROUND

Serum cardiac troponin T (cTnT) is a valuable marker of ischemic heart disease (IHD) and left ventricular hypertrophy, as well as a mortality predictor in hemodialysis populations. We compared the value of cTnT, creatinine kinase (CK)-MB mass and myoglobin as mortality predictors in our hemodialysis patients and evaluated their relation to nutritional status.

METHODS

A total of 118 hemodialysis patients were prospectively studied from January 2004 to April 2013. Clinical and laboratory evaluations during the 12-month baseline period included the history of IHD, signs of left ventricular hypertrophy (LVH), Kt/V and serum cardiac markers together with the percentage of body fat (%fat), mid-arm circumference (MAC), mid-arm muscle circumference (MAMC), triceps skinfold (TSF) and BMI.

RESULTS

Underweight patients had significantly higher cTnT values (Mann-Whitney, p<0.05). Correlation analysis (Spearman) showed an inverse association between cTnT and TSF (ρ=-0.22, p<0.05), as well as between CK-MB mass and TSF (ρ=-0.26, p<0.01). In men cTnT also correlated inversely with %fat (ρ=-0.27, p<0.05) and BMI (ρ=-0.33, p<0.05). In addition, myoglobin was correlated significantly with MAC, MAMC and albumin. Among cardiac markers cTnT was the only independent variable predicting mortality (Multivariate Cox regression, HR=1.04 CI (1.01-1.07); p<0.01; measurement units 0.01 μg/L).

CONCLUSION

Troponin T and CK-MB mass were significantly elevated in the underweight patient group. Troponin T was the only independent cardiac marker predictor of all cause mortality in our hemodialysis patients.

[Effect of diabetes on the relation between troponin T and inflammatory markers in patients on hemodialysis]

INTRODUCTION

Cardiac troponin T in renal failure is used for the assessment of cardiovascular risk and mortality. Elevated cardiac troponin T levels correlate with subclinical myocardial necrosis, coronary heart disease, several echocardiographic parameters, metastatic calcification, as well as the presence of diabetes and uremic toxins.

AIM

The aim of the authors was to examine the impact of factors, mainly the independent effects of inflammatory laboratory parameters, which may influence hypersensitive troponin T levels in hemodialysed patient groups with and without diabetes.

METHOD

Hemodialysed patient groups with (n = 44) and without diabetes (n = 76) were studied. Difference in serum hypersensitive troponin T values before and after dialysis were analysed by paired Wilcoxon test. Factors possibly affecting the level of hypersensitive troponin T (especially inflammatory markers) were evaluated by multiregression analysis.

RESULTS

Hypersensitive troponin T levels in patients without diabetes (p = 0.0003) and those with diabetes (p = 0.0032) significantly increased during hemodialysis. In patients without diabetes several factors had significant effect on hypersensitive troponin T including age (p = 0.025), duration of hemodialysis (p = 0.0002), presence of cardiovascular complications (p = 0.0002), high sensitivity C-reactive protein (p = 0.0021), white blood cell count (p = 0.038), and the monocyte ratio (p = 0.0202). However, in patients with diabetes only high sensitivity C-reactive protein (p = 0.0024) showed association with hypersensitive troponin T levels.

CONCLUSIONS

In hemodyalised patients with and without diabetes the hypersensitive troponin T levels are differently influenced by clinical and inflammatory laboratory parameters, which should be taken into consideration during clinical judgement.

High sensitivity troponin T in acute medicine; more questions than answers?

BACKGROUND

Troponin testing in acute medicine is routine. The introduction of a high sensitivity assay (hs Tn T) has created uncertainty regarding the clinical significance of 'abnormal' troponin T levels. The previous assay could not detect troponin levels <30 ng/l.

AIMS AND METHODS

To characterize those with a hs Tn T ≥14 ng/l. Prospective cohort study of consecutive admissions to an acute medical unit.

RESULTS

Troponin was measured in 564 consecutive patients (∼50% of all admissions) over 1 month; was ≥14 ng/l in 224 (40%) of which 220 patients had demographic data for this analysis. Median (inter-quartile range) peak troponin was 47.5 ng/l (24-130) and 36% had a Tn T between 14 and 30 ng/l. Mean [standard deviation (SD)] age was 72 (12) years and 57% were male. Only 44 patients (20%) had an acute myocardial infarction, reflecting the increased sensitivity but reduced specificity of the assay. Prognosis was poor with 31% mortality at 1 year. Over a mean (SD) follow-up of 648 (61) days, there were 87 deaths (40%). Those with a primary non-cardiac diagnosis (n = 126) had poorer survival than those with a primary cardiac diagnosis (n = 94). Troponin elevation related to sepsis conferred a very poor prognosis with 24 deaths (70%) over the follow-up period.

CONCLUSION

Elevated hs Tn T is very common in acute medicine, but myocardial infarction as an explanation is uncommon. Overall, the prognosis is poor with a tendency to worse outcomes in those with a primary 'non-cardiac' diagnosis.

Association of high-sensitivity assayed troponin I with cardiovascular phenotypes in the general population: the population-based Gutenberg health study

BACKGROUND

Aim of the study was to analyze the correlation of high-sensitivity assayed troponin I with cardiac and vascular structure and function in a large population-based cohort.

METHODS

In a sample of 4,139 subjects (2,099 men, 2,040 women, age 35-74 years) from the population-based Gutenberg Health Study, troponin I was measured with a high-sensitivity assay that had a limit of detection of 1.9 pg/mL.

RESULTS

In the study cohort, 3,405 subjects had detectable troponin I concentrations [82.3% overall, 89.9% men (N = 1,888), 74.4% women (N = 1,517)]. All analyses were adjusted for age. The strongest correlate between detectable troponin I and measures of cardiac phenotypes was observed for left ventricular mass (p < 0.001) and left ventricular end-diastolic diameter (p < 0.001) for both, women and men. Left ventricular ejection fraction was inversely correlated with troponin I (p value <0.001 in men and 0.0013 in women), also measures of diastolic dysfunction as represented by Tei index and E/E' correlated with detectable troponin I concentrations (p < 0.001 for both gender). With respect to vascular structure and function, troponin I correlated with mean intima-media thickness of the carotid artery (p < 0.001 in men and p = 0.013 in women) but showed only borderline correlation with measures of vascular function represented by flow-mediated dilation (p = 0.05 in women and p = 0.018 in men) and arterial stiffness.

CONCLUSIONS

Troponin I assessed by a high-sensitivity assay correlated with measures of left ventricular hypertrophy and systolic and diastolic function, whereas its correlation with vascular phenotypes was only of weak magnitude.

Short-term outcome of patients with ST-segment elevation myocardial infarction (STEMI) treated with an everolimus-eluting bioresorbable vascular scaffold

OBJECTIVES

To evaluate safety and efficacy of the everolimus-eluting bioresorbable scaffold (BVS) in patients with ST-segment elevation myocardial infarction (STEMI).

BACKGROUND

According to the current guidelines, drug-eluting stents are the treatment of choice in patients with STEMI. BVS represents a new technology capable to restore the native vessel vasomotion and potentially avoiding long-term limitations such as stent thrombosis.

METHODS

From October 2012 to May 2013, patients with evidence of STEMI eligible for BVS implantation were included in this study. Exclusion criteria were not defined.

RESULTS

A total of 25 patients, respectively 31 lesions, were treated. Procedural success was achieved in 97%. Two major adverse cardiac events occurred during hospitalization and follow-up: one patient with cardiogenic shock at the index procedure subsequently died. One patient suffered from instable angina with need for interventional revascularization of a previously untreated vessel. One target vessel failure as a consequence of an intra-procedural dissection was seen. However, no target lesion failure was noted. During 132.7 ± 68.7 days of follow-up none of the patients died.

CONCLUSION

Our findings suggest that implantation of BVS in STEMI patients is feasible in this small cohort of highly selected patients. Further evaluation in randomized-controlled trials is needed.

Use of high-sensitivity troponin assays predicts mortality in patients with normal conventional troponin assays on admission-insights from a meta-analysis

BACKGROUND

Use of high-sensitivity troponin (hs-Tn) assays can detect small levels of myocardial damage previously undetectable with conventional troponin (c-Tn) assays. However, prognostic utility of these hs-Tn assays in prediction of mortality remains unclear in the presence of nonelevated c-Tn levels on admission. A systematic review and meta-analysis was performed to assess mortality risk of patients with hs-Tn elevations in the setting of normal c-Tn levels.

HYPOTHESIS

Patients with hs-Tn elevations with normal c-Tn levels on admission blood samples, drawn to rule out acute coronary syndrome (ACS), have a higher mortality risk than those without hs-Tn or c-Tn elevations.

METHODS

A search was made of the PubMed, CENTRAL, EMBASE, CINAHL, EBSCO, and Web of Science databases. Studies evaluating patients with suspected ACS that reported mortality rates for those with elevated hs-Tn levels but normal c-Tn levels on admission were included. A random-effects model was used to pool event rates, and data were reported in odds ratios (95% confidence interval).

RESULTS

Four studies (N = 2033, mean age 64-75 years, 49%-70% male) revealed that nearly 32% of suspected ACS patients with normal c-Tn levels on admission had elevated hs-Tn levels. Elevated hs-Tn levels conferred a significantly higher risk of all-cause mortality vs normal hs-Tn levels (odds ratio: 4.35, 95% confidence interval: 2.81-6.73, P < 0.01), with negligible heterogeneity (I(2) = 0%).

CONCLUSIONS

Elevation of hs-Tn levels predicted a higher risk of mortality in patients with suspected ACS and may aid in the early identification of higher-risk patients in this setting. Future studies are needed to investigate further optimal management strategies.

Sensitive troponin assays and N-terminal pro-B-type natriuretic peptide in acute coronary syndrome: prediction of significant coronary lesions and long-term prognosis

BACKGROUND

Sensitive troponin assays have substantially improved early diagnosis of myocardial infarction. However, the role of sensitive cardiac troponin (cTn) assays in prediction of significant coronary lesions and long-term prognosis in non-ST-elevation acute coronary syndrome (NSTE-ACS) remains unresolved.

METHODS

This prospective study includes 458 consecutive patients with NSTE-ACS admitted for coronary angiography. Serum levels of 4 commercial available sensitive troponin assays were analyzed (Roche high-sensitive cTnT [hs-cTnT; Roche Diagnostics, Basel, Switzerland], Siemens cTnI Ultra [Siemens, Munich, Germany], Abbott-Architect cTnI [Abbott, Abbott Park, IL], Access Accu-cTnI [Beckman Coulter, Nyon, Switzerland]), as well as a standard assay (Roche cTnT) and N-terminal pro-B-type natriuretic peptide (NT-proBNP), before coronary angiography.

RESULTS

The relationship between the analyzed biomarkers and significant coronary lesions on coronary angiography, as quantified by area under the receiver operating characteristic curve, was significantly higher with Roche hs-cTnT, Siemens cTnI Ultra, and Access Accu-cTnI as compared with standard troponin T assay (P < .001 for all comparisons). This difference was mainly caused by increased sensitivity below the 99th percentile. Also, NT-proBNP was associated with the presence of significant coronary lesions. Cardiac troponin values were correlated with cardiac death (primary end point) during 1373 (1257-1478) days of follow-up. In both univariate and multivariate Cox regression analyses, NT-proBNP was superior to both hs-cTnT and cTnI in prediction of cardiovascular mortality. Troponin values with all assays were correlated with the need for repeated revascularization (secondary end point) during follow-up.

CONCLUSIONS

Sensitive cTn assays are superior to standard cTnT assay in prediction of significant coronary lesions in patients with NSTE-ACS. However, this improvement is primary caused by increased sensitivity below the 99th percentile. N-terminal pro-B-type natriuretic peptide is superior to cTns in prediction of long-term mortality.

Sensible use of high-sensitivity troponin assays

The first intracellular Ca(2+)-sensor protein to be described was the troponin complex. Only later it was -discovered that cardiac-specific isoforms of troponin I (cTnI) and troponin T (cTnT) exist, and nowadays, measurement of cardiac troponins is a corner stone in the diagnosis of patients with acute coronary syndrome (ACS). High-sensitivity (hs-) assays have been developed that can record slightly elevated plasma concentrations of cardiac troponins as early as 3 h after onset of clinical symptoms. International guidelines defined a diagnostic cut-off at cardiac troponin levels corresponding to the 99th percentile of a healthy reference population and require that hs-assays measure this concentration with an interassay coefficient of variation ≤10%. This review provides an overview of the diagnostic and prognostic use of cardiac troponins.

Comparison of a 3-hour versus a 6-hour sampling-protocol using high-sensitivity cardiac troponin T for rule-out and rule-in of non-STEMI in an unselected emergency department population

BACKGROUND

Current European guidelines recommend the use of sensitive or high-sensitivity cardiac troponin assays to reduce the minimal sampling interval from 6 to 3h.

METHODS

We compared a 3-hour versus a 6-hour protocol for diagnosis of non-STEMI and used the 99th percentile for rule-out, and relative and absolute concentration changes for rule-in of non-STEMI.

RESULTS

459 patients with either an NSTE-ACS or elevated hs-cTnT not due to MI and hs-cTnT measurements at 0, 3 and 6h were enrolled. Among the 404 patients excluded due to an incomplete sampling protocol performance was comparable to the 459 patients with a complete sampling protocol (AUC 0.79 vs 0.80, p=ns). In the study group, non-STEMI was diagnosed in 111 cases (24.2%) and elevated hs-cTnT not due to MI was observed in 215 cases (46.8%). For rule-out of non-STEMI, NPVs were 94.9%, 98.7% and 100% on admission, at 3 and 6h with comparable performance at 3 and 6h (AUC 0.782 vs 0.790, p=ns). For rule-in a 3-hour protocol performed as well as a 6-hour protocol, with a significantly (p<0.0001) better performance of absolute (AUC 0.851 vs. 0.845, p=0.740) as compared to relative concentration changes (AUC 0.771 vs. 0.739, p=0.169).

CONCLUSIONS

Rule-in and rule-out of non-STEMI may be accomplished comparably effective at 3 or 6h. For rule-in, absolute kinetic changes perform better than relative changes at all time points. ROC-optimal absolute δ-change was 6.95 ng/L at 3h and 8.9 ng/L at 6h.

Cardiogoniometry as a diagnostic tool in patients with acute coronary syndromes: results of the CGM@ACS trial

BACKGROUND

Cardiogoniometry (CGM) is a novel electrocardiac method utilising computer-assisted three-dimensional information on cardiac potentials.

OBJECTIVE

To investigate the potential of CGM in discriminating non-ST-segment elevation acute coronary syndrome (NSTE-ACS) and relevant coronary stenosis upon hospital admission by prospectively comparing its sensitivity, specificity and accuracy against those of a single troponin test and a 12-lead ECG performed on admission

DESIGN

A multicenter prospective observational trial.

SETTING

Eight interventional cardiac centres in Germany.

PATIENTS

A cohort of 216 patients (mean age 67 years, 34.7 % female) who presented with acute chest pain or dyspnoea without ST-segment elevation and were scheduled for coronary angiography within 72 h of admission.

INTERVENTION

Pre-angiography screening by CGM, troponin test, 12-lead ECG MAIN OUTCOME MEASURES: ECG, troponin and CGM on admission compared with final diagnosis of NSTE-ACS or relevant diameter stenosis ≥70 % verified by an independent review board and an angiographic core laboratory.

RESULTS

NSTE-ACS was finally confirmed in 162 cases, whereas the remaining 54 cases without proof of NSTE-ACS served as controls. Diagnostic sensitivity for NSTE-ACS was 28, 50 and 69 % and specificity 78, 96 and 54 % for first ECG, serial troponin and first CGM, respectively. Accuracy was 40, 62 and 65 %. The sensitivity of the tests to detect relevant coronary stenosis (n = 126) was 32, 53 and 74 %, respectively. The sensitivity of CGM to detect NSTE-ACS (65 %) or relevant stenosis (71 %) was high even in patients with normal troponin and ECG.

CONCLUSIONS

CGM can detect NSTE-ACS at first medical contact. CGM in conjunction with traditional markers, 12-lead ECG and troponin may effectively aid early decision making in patients presenting with acute chest pain.

Pre- and early in-hospital procedures in patients with acute coronary syndromes: first results of the "German chest pain unit registry"

BACKGROUND

In an attempt to improve the treatment of patients with acute coronary syndromes (ACS), a network of certified chest pain units (CPUs) has been recently established in Germany.

METHODS

Data from patients admitted between December 2008 and September 2011 for ACS in 40 certified CPUs participating in the registry were prospectively collected.

RESULTS

A total of 5,457 patients was admitted for ACS; 798 patients (14.6 %) were diagnosed with an ST-elevation myocardial infarction (STEMI), 2,244 (41.1 %) with a non-ST-elevation myocardial infarction (NSTEMI), and 2,415 (44.3 %) with unstable angina. The mean time to first medical contact was 2:08 h for STEMI patients. A pre-hospital ECG was available in 23.8 % of all ACS patients. Importantly, evidence of ST-segment elevation was present in 79.7 % of the STEMI patients already in this pre-hospital ECG. As many as 76.6 % of the patients, independently of their symptoms and final diagnosis, received an ECG within 10 min of reaching the CPU. 98.2 % of STEMI patients underwent invasive diagnostics, with an in-hospital delay as little as 31 (11-75) min.

CONCLUSION

The establishment of a nation-wide network of certified CPUs optimizes the medical treatment of patients with ACS while providing an ideal infrastructure to evaluate and improve, both on a nation-wide and a single center scale, the adherence to guidelines. The median delay between symptom onset and first medical contact remains high. Although performed relatively rarely, a pre-hospital ECG facilitates earlier diagnosis of a STEMI in a large majority of patients. The introduction of CPUs minimizes in-hospital delays and exploits the benefit of invasive diagnostics and treatment.

Clinical Use and Measurement of Cardiac Troponin (cTn)

Cardiac troponins are cardio-specific and are widely used for the early diagnosis and triage of patients with acute coronary syndromes in conjunction with clinical history, electrocardiographic changes and imaging. Troponin is also useful for the prediction of outcomes in acute coronary syndromes, renal failure, sepsis, and critically ill patients. New developments in assay technology, designated as high sensitivity troponins, permit detection of lower levels of troponin in most healthy individuals, earlier diagnosis of myocardial infarction, and prognosis of stable coronary disease in the community.