Diagnostic accuracy of single baseline measurement of Elecsys Troponin T high-sensitive assay for diagnosis of acute myocardial infarction in emergency department: systematic review and meta-analysis

Analytical assays and bootstrap resampling method to validate performance of the Roche Elecsys STAT highly sensitive troponin T assay and its application for the 'rule-out' part of ESC guidelines for NTSTEMI

BACKGROUND

The European Society of Cardiology (ESC) guidelines recommend a dynamic (0-1h) cardiac troponin (cTn) determination for non-ST elevation myocardial infarction diagnosis. For patients with low cTn levels, a discharge from emergency can be considered. Nevertheless, cTn cutoffs for discharge are lower than the limits of quantification proposed by laboratory reagent suppliers.

AIM

Validate cTn assay on the Elecsys STAT kit.

MATERIALS AND METHODS

Precision, trueness, repeatability and within-laboratory variability were calculated from internal quality control and plasma pooled at 5.78 and 10.73 ng/L. Accuracy was calculated from external quality control. Uncertainty of measurement was calculated from (i) the uncertainty of the standard and control values and (ii) by precision from pooled plasma. Distribution of precision results from pooled plasma has been evaluated by bootstrap simulations. Dilution linearity tests with patient plasma were performed to evaluate the method for values near 5 ng/L.

RESULTS

Precision and trueness ranged from 1.35 to 4.45% and from 0.14 to -3.74%, respectively. Accuracy results ranged from 101.40 to 104.90%. Within laboratory variability was 2.91%. Uncertainty ranged from 3.66% to 19.90% for higher (2188) to lower values (5.78 ng/L). Bootstrap simulations allowed utilization of precision data from pooled plasma to evaluate cTn assay. The method was linear from 4.48 to 39.80 ng/L. A linear regression model best described the data.

CONCLUSION

Elecsys STAT method provides accurate cTn results, including patients with cTn results categorizing them as 'rule-out' in the ESC guidelines.

Establishing optimal cutoff values for high-sensitivity cardiac troponin algorithms in risk stratification of acute myocardial infarction

Acute myocardial infarction (AMI) is a leading cause of mortality globally, highlighting the need for timely and accurate diagnostic strategies. Cardiac troponin has been the biomarker of choice for detecting myocardial injury. A dynamic change in concentrations supports the diagnosis of AMI in the setting of evidence of acute myocardial ischemia. The new generation of high-sensitivity cardiac troponin (hs-cTn) assays has significantly improved analytical sensitivity but at the expense of decreased clinical specificity. As a result, sophisticated algorithms are required to differentiate AMI from non-AMI patients. Establishing optimal hs-cTn cutoffs for these algorithms to rule out and rule in AMI has been the subject of intensive investigations. These efforts have evolved from examining the utility of the hs-cTn 99th percentile upper reference limit, comparing the percentage versus absolute delta thresholds, and evaluating the performance of an early European Society of Cardiology-recommended 3 h algorithm, to the development of accelerated 1 h and 2 h algorithms that combine the admission hs-cTn concentrations and absolute delta cutoffs to rule out and rule in AMI. Specific cutoffs for individual confounding factors such as sex, age, and renal insufficiency have also been investigated. At the same time, concerns such as whether the small delta thresholds exceed the analytical and biological variations of hs-cTn assays and whether the algorithms developed in European study populations fit all other patient cohorts have been raised. In addition, the accelerated algorithms leave a substantial number of patients in a non-diagnostic observation zone. How to properly diagnose patients falling in this zone and those presenting with elevated baseline hs-cTn concentrations due to the presence of confounding factors or comorbidities remain open questions. Here we discuss the developments described above, focusing on criteria and underlying considerations for establishing optimal cutoffs. In-depth analyses are provided on the influence of biological variation, analytical imprecision, local AMI rate, and the timing of presentation on the performance metrics of the accelerated hs-cTn algorithms. Developing diagnostic strategies for patients who remain in the observation zone and those presenting with confounding factors are also reviewed.

Diagnostic performance of a device for acoustic heart sound analysis in patients with suspected myocardial infarction

BACKGROUND

As only a small proportion of patients with chest pain suffers from myocardial infarction (MI), safe rule-out of MI is of immense importance. Recently an ultrasensitive microphone performing diastolic heart sound analysis (CADScorSystem) for rule-out of coronary artery disease (CAD) has emerged. In this explorational study, we aimed to evaluate the feasibility of the CADScorSystem for diagnosis of MI in the setting of a large emergency department.

METHODS

Patients presenting to the emergency department with suspected MI were included. Acoustic heart sound analysis was performed in all patients and automated CAD-score values were calculated via a device-embedded algorithm, which also requires inclusion of three clinical variables: age, sex and presence of hypertension. Patients additionally received serial high-sensitive troponin T measurement measurements to assess the final diagnosis according to third Universal Definition of Myocardial Infarction applying the European Society of Cardiology 0 hour/3 hours algorithm. Diagnostic parameters for MI, considering different CAD-score cut-offs, were computed.

RESULTS

Of 167 patients, CAD-scores were available in 61.1%. A total of eight patients were diagnosed with MI. At a cut-off value of <20, CAD-score had a negative predictive value (NPV) of 90.7 (78.4-96.3). The corresponding positive predictive value (PPV) was 6.8 (2.7-16.2). For the adjusted CAD-score (age, sex, hypertension), at a cut-off value of <20, NPV was 90.0 (59.6-99.5) with a PPV of 10.8 (5.3-20.6).

CONCLUSION

In this explorative analysis, a transcutaneous ultrasensitive microphone for heart sound analysis resulted in a high NPV analogous to the findings in rule-out of stable CAD in elective patients yet inferior to serial high-sensitivity cardiac troponin measurements and does not seem feasible for application in an emergency setting for rule-out of MI.

TRIAL REGISTRATION NUMBER

NCT02355457.

Copeptin with high-sensitivity cardiac troponin to rule out non-ST-elevation myocardial infarction early on: A systematic review and meta-analysis

High-sensitivity cardiac troponin (hs-cTn) with copeptin in rapidly ruling out non-ST-elevation myocardial infarction (NSTEMI) remains controversial. We aimed to evaluate the diagnostic accuracy of this combination compared to hs-cTn alone. A literature search of electronic databases was performed from inception to 26 March 2022. Primary studies that evaluated the diagnostic accuracy of hs-cTn with and without copeptin in patients with NSTEMI were eligible. The reference standard consisted of all available medical results, including a significant rise or fall of cTn with at least one value above the 99th percentile of the reference population. The QUality Assessment of Diagnostic Accuracy Studies (QUADAS-2) was used to assess the quality of the included studies. Thirteen studies involving 8,966 patients, 1,405 of whom were diagnosed with NSTEMI (prevalence, 15.67 %), were included. Combining copeptin with hs-cTn (99th percentile of the healthy population as the threshold) at admission improved the sensitivity from 0.89 to 0.96 (95 % confidence interval [CI] 0.84-0.93 vs 0.93-0.98); the specificity reduced from 0.79 to 0.56 (95 % CI 0.71-0.86 vs 0.51-0.60). In five studies with 6,073 participants (900 NSTEMI), the hs-cTn alone (with 'very low' or limit of detection [LoD] threshold) had higher diagnostic sensitivity than the dual-marker strategy (0.98 vs 0.96). Combining copeptin with hs-cTn (99th percentile of the population as the threshold) at admission improved sensitivity in NSTEMI identification at the expense of specificity. However, with the LoD threshold for hs-cTn, copeptin had no additional value, deterring the widespread use of copeptin if the hs-cTn assay is clinically available.

Clinical Features of the Aslanger Pattern to Compensate for the Limitation of ST-Elevation Myocardial Infarction (STEMI) Criteria

BACKGROUND

ST-elevation is one of the most valuable electrocardiogram findings to diagnose acute myocardial infarction. However, more than a quarter of acute coronary occlusions are missed by this criterion, causing a delay in revascularization. Therefore, there should be awareness of the limitations of the current criteria and new electrocardiographic findings are required as a diagnostic tool to compensate for them. The Aslanger pattern is a specific electrocardiographic finding in acute inferior myocardial infarction with multivessel disease and allows the detection of inferior myocardial infarction that does not show ST-elevation, leading to rapid revascularization. However, in patients with the Aslanger pattern, the hemodynamic characteristics, such as the rate of shock and the use of mechanical circulatory support, as well as prognostic characteristics such as the in-hospital mortality rate, have not yet been clarified.

METHODS

In this study, we retrospectively surveyed the current practice on the basis of ST-elevation myocardial infarction (STEMI) criteria in patients with acute coronary artery occlusion presenting with inferior myocardial infarction. We examined the clinical characteristics of the Aslanger pattern.

RESULTS

Based on the STEMI criteria, 71.8% (51/72) of patients were diagnosed with STEMI from an acute electrocardiogram, and 28.2% (21/78) were diagnosed with non-STEMI. As expected, ruling out in all acute coronary artery occlusions using STEMI criteria alone was difficult. A total of 48% of patients with non-STEMI had the Aslanger pattern. In addition, 80% of patients with the Aslanger pattern had multivessel disease, 30% had the use of the mechanical circulatory support, and 20% had in-hospital mortality.

CONCLUSION

This study suggests that the Aslanger pattern is useful not only for diagnosis, but also for predicting hemodynamic collapse and a poor prognosis. Therefore, we should share information on Aslanger pattern with other physicians and use this pattern in daily practice.

Meta-analysis of diagnostic test accuracy studies with multiple thresholds for data integration

OBJECTIVES

The objective of this study is to introduce methods to use all of the information without omission when individual studies provide multiple effect sizes according to multiple cut-off values (thresholds) during diagnostic test accuracy (DTA) for data integration. For diagnostic test meta-analysis, a general performance method for synthesizing data according to one cut value in one study and a performance method for synthesizing data according to two or more cut values in one study were compared and analyzed.

METHODS

As sample data for meta-analysis of DTA studies, 13 DTA studies on prostate cancer (34 effect sizes including total cut-offs) were collected. The summary statistics were calculated and the summary line was analyzed using the "meta", "mada", and "diagmeta" packagesof the R software.

RESULTS

The summary statistics of the random effect model univariate analysis of the "meta" package with a single cut-off corresponding to the highest Youden index in a single study and those of the bivariate analysis of the "mada" package were highly similar. However, in the bivariate analysis of the "diagmeta" package including all cut-off values, the sensitivity decreased and the specificity increased as the amount of data increased.

CONCLUSIONS

Considering the heterogeneity of the summary receiver op erating characteristic curve and the use of all given cut-offs, the use of the bivariate analysis model of the "diagmeta" package is recommended. This study focused on practical methods of DTA rather than theoretical concepts for use by researchers whose fields of study are non-statistics related. By performing this study, we hope that many researchers will use R software to determine the DTA more easily, and that there will be greater interest in related research.

The performance of HEAR score for identification of low-risk chest pain: a systematic review and meta-analysis

Chest pain is one of the most common presentations to the emergency department (ED) and HEART score (history, ECG, age, risk factors, and cardiac troponin) is recommended for risk stratification. It has been proposed that the sum of four items with no troponin (HEAR score) below 2 can be used safely to lower testing and reduce length of stay. To assess the performance of the HEAR score in hospital and prehospital settings, we performed a systematic review and meta-analysis. English studies on the performance of the HEAR score in patients with acute chest pain were included. They were excluded if data are inaccessible. MEDLINE, Embase, Evidence-Based Medicine Reviews, Scopus, and web of science were searched from 1946 to July 2021. The quality of studies was assessed using Quality Assessment of Diagnostic Accuracy Studies version 2. Acute coronary syndrome or major adverse cardiac events prediction were outcomes of interest. The performance indices with 95% confidence intervals (CIs) were extracted. Inverse variance and the random-effects model were used to report the results. Of the 692 articles on the HEAR score, 10 studies were included in the analysis with 33 843 patients. Studies were at low to moderate risk of bias. Three studies were in prehospital and three were retrospective. The pooling of data on the HEAR score showed that the sensitivity at the HEAR<2, <3, and <4 cutoffs in the ED were 99.03% (95% CI, 98.29-99.77), 97.54% (95% CI, 94.50-100), and 91.80% (95% CI, 84.62-98.98), respectively. The negative predictive values (NPVs) for the above cutoffs were 99.84% (95% CI, 99.72-99.95), 99.75% (95% CI, 99.65-99.85), and 99.57% (95% CI, 99.11-100), respectively. Of note, for the HEAR<2, negative likelihood ratio was 0.07 (95% CI, 0.02-0.12). In the prehospital, at the HEAR<4 cutoff, the pooled sensitivity and NPV were 85.01% (95% CI, 80.56-89.47) and 91.48% (95% CI, 87.10-95.87), respectively. This study showed that in the ED, the HEAR score<2 can be used for an early discharge strategy. Currently, this score cannot be recommended in prehospital setting. Prospero (CRD42021273710).

Performance of the European Society of Cardiology 0/1-Hour, 0/2-Hour, and 0/3-Hour Algorithms for Rapid Triage of Acute Myocardial Infarction : An International Collaborative Meta-analysis

BACKGROUND

The 2020 European Society of Cardiology (ESC) guidelines recommend using the 0/1-hour and 0/2-hour algorithms over the 0/3-hour algorithm as the first and second choices of high-sensitivity cardiac troponin (hs-cTn)-based strategies for triage of patients with suspected acute myocardial infarction (AMI).

PURPOSE

To evaluate the diagnostic accuracies of the ESC 0/1-hour, 0/2-hour, and 0/3-hour algorithms.

DATA SOURCES

PubMed, Embase, Cochrane Central Register of Controlled Trials, Web of Science, and Scopus from 1 January 2011 to 31 December 2020. (PROSPERO: CRD42020216479).

STUDY SELECTION

Prospective studies that evaluated the ESC 0/1-hour, 0/2-hour, or 0/3-hour algorithms in adult patients presenting with suspected AMI.

DATA EXTRACTION

The primary outcome was index AMI. Twenty unique cohorts were identified. Primary data were obtained from investigators of 16 cohorts and aggregate data were extracted from 4 cohorts. Two independent authors assessed each study for methodological quality.

DATA SYNTHESIS

A total of 32 studies (20 cohorts) with 30 066 patients were analyzed. The 0/1-hour algorithm had a pooled sensitivity of 99.1% (95% CI, 98.5% to 99.5%) and negative predictive value (NPV) of 99.8% (CI, 99.6% to 99.9%) for ruling out AMI. The 0/2-hour algorithm had a pooled sensitivity of 98.6% (CI, 97.2% to 99.3%) and NPV of 99.6% (CI, 99.4% to 99.8%). The 0/3-hour algorithm had a pooled sensitivity of 93.7% (CI, 87.4% to 97.0%) and NPV of 98.7% (CI, 97.7% to 99.3%). Sensitivity of the 0/3-hour algorithm was attenuated in studies that did not use clinical criteria (GRACE score <140 and pain-free) compared with studies that used clinical criteria (90.2% [CI, 82.9 to 94.6] vs. 98.4% [CI, 88.6 to 99.8]). All 3 algorithms had similar specificities and positive predictive values for ruling in AMI, but heterogeneity across studies was substantial. Diagnostic performance was similar across the hs-cTnT (Elecsys; Roche), hs-cTnI (Architect; Abbott), and hs-cTnI (Centaur/Atellica; Siemens) assays.

LIMITATION

Diagnostic accuracy, inclusion and exclusion criteria, and cardiac troponin sampling time varied among studies.

CONCLUSION

The ESC 0/1-hour and 0/2-hour algorithms have higher sensitivities and NPVs than the 0/3-hour algorithm for index AMI.

PRIMARY FUNDING SOURCE

National Taiwan University Hospital.

2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This clinical practice guideline for the evaluation and diagnosis of chest pain provides recommendations and algorithms for clinicians to assess and diagnose chest pain in adult patients.

METHODS

A comprehensive literature search was conducted from November 11, 2017, to May 1, 2020, encompassing randomized and nonrandomized trials, observational studies, registries, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, Agency for Healthcare Research and Quality reports, and other relevant databases. Additional relevant studies, published through April 2021, were also considered.

STRUCTURE

Chest pain is a frequent cause for emergency department visits in the United States. The "2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain" provides recommendations based on contemporary evidence on the assessment and evaluation of chest pain. This guideline presents an evidence-based approach to risk stratification and the diagnostic workup for the evaluation of chest pain. Cost-value considerations in diagnostic testing have been incorporated, and shared decision-making with patients is recommended.

2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This clinical practice guideline for the evaluation and diagnosis of chest pain provides recommendations and algorithms for clinicians to assess and diagnose chest pain in adult patients.

METHODS

A comprehensive literature search was conducted from November 11, 2017, to May 1, 2020, encompassing randomized and nonrandomized trials, observational studies, registries, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, Agency for Healthcare Research and Quality reports, and other relevant databases. Additional relevant studies, published through April 2021, were also considered.

STRUCTURE

Chest pain is a frequent cause for emergency department visits in the United States. The "2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain" provides recommendations based on contemporary evidence on the assessment and evaluation of chest pain. This guideline presents an evidence-based approach to risk stratification and the diagnostic workup for the evaluation of chest pain. Cost-value considerations in diagnostic testing have been incorporated, and shared decision-making with patients is recommended.

2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain: Executive Summary: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This executive summary of the clinical practice guideline for the evaluation and diagnosis of chest pain provides recommendations and algorithms for clinicians to assess and diagnose chest pain in adult patients.

METHODS

A comprehensive literature search was conducted from November 11, 2017, to May 1, 2020, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, Agency for Healthcare Research and Quality reports, and other relevant databases. Additional relevant studies, published through April 2021, were also considered.

STRUCTURE

Chest pain is a frequent cause for emergency department visits in the United States. The "2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain" provides recommendations based on contemporary evidence on the assessment and evaluation of chest pain. These guidelines present an evidence-based approach to risk stratification and the diagnostic workup for the evaluation of chest pain. Cost-value considerations in diagnostic testing have been incorporated and shared decision-making with patients is recommended.

2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This clinical practice guideline for the evaluation and diagnosis of chest pain provides recommendations and algorithms for clinicians to assess and diagnose chest pain in adult patients.

METHODS

A comprehensive literature search was conducted from November 11, 2017, to May 1, 2020, encompassing randomized and nonrandomized trials, observational studies, registries, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, Agency for Healthcare Research and Quality reports, and other relevant databases. Additional relevant studies, published through April 2021, were also considered. Structure: Chest pain is a frequent cause for emergency department visits in the United States. The "2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain" provides recommendations based on contemporary evidence on the assessment and evaluation of chest pain. This guideline presents an evidence-based approach to risk stratification and the diagnostic workup for the evaluation of chest pain. Cost-value considerations in diagnostic testing have been incorporated, and shared decision-making with patients is recommended.

2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain: Executive Summary: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This executive summary of the clinical practice guideline for the evaluation and diagnosis of chest pain provides recommendations and algorithms for clinicians to assess and diagnose chest pain in adult patients.

METHODS

A comprehensive literature search was conducted from November 11, 2017, to May 1, 2020, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, Agency for Healthcare Research and Quality reports, and other relevant databases. Additional relevant studies, published through April 2021, were also considered. Structure: Chest pain is a frequent cause for emergency department visits in the United States. The "2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain" provides recommendations based on contemporary evidence on the assessment and evaluation of chest pain. These guidelines present an evidence-based approach to risk stratification and the diagnostic workup for the evaluation of chest pain. Cost-value considerations in diagnostic testing have been incorporated and shared decision-making with patients is recommended.

Implementation of an early rule-out pathway for myocardial infarction using a high-sensitivity cardiac troponin T assay

OBJECTIVES

Patients with suspected acute coronary syndrome and high-sensitivity cardiac troponin (hs-cTn) concentrations below the limit of detection at presentation are low risk. We aim to determine whether implementing this approach facilitates the safe early discharge of patients.

METHODS

In a prospective single-centre cohort study, consecutive patients with suspected acute coronary syndrome were included before (standard care) and after (intervention) implementation of an early rule-out pathway. During standard care, myocardial infarction was ruled out if hs-cTnT concentrations were <99th centile (14 ng/L) at presentation and at 6-12 hours after symptom onset. In the intervention, patients were ruled out if hs-cTnT concentrations were <5 ng/L at presentation and symptoms present for ≥3 hours or were ≥5 ng/L and unchanged within the reference range at 3 hours. We compared duration of stay (efficacy) and all-cause death at 1 year (safety) before and after implementation.

RESULTS

We included 10 315 consecutive patients (64±16 years, 46% women) with 6642 (64%) and 3673 (36%) in the standard care and intervention groups, respectively. Duration of stay was reduced from 534 (IQR, 220-2279) to 390 (IQR, 218-1910) min (p<0.001) after implementation. At 1 year, all-cause death occurred in 10.9% (721 of 6642) and 10.4% (381 of 3673) of patients in the standard care group (referent) and intervention group, respectively (adjusted OR 1.02, 95% CI 0.88 to 1.18).

CONCLUSION

In patients with suspected acute coronary syndrome, implementing an early rule-out pathway using hs-cTnT concentrations <5 ng/L at presentation reduced the duration of stay in hospital without compromising safety.

MicroRNAs as Biomarkers for the Diagnosis of Ankylosing Spondylitis: A Systematic Review and Meta-Analysis

Background: Abnormal expression levels of microRNAs (miRNAs) were observed in ankylosing spondylitis (AS) in recent articles, suggesting that miRNAs may be used as biomarkers for AS diagnoses. In this paper, we conducted a meta-analysis to identify the overall diagnostic accuracy of miRNA biomarkers in AS patients. Methods: An extensive search was undertaken in PubMed, Embase, Cochrane databases, and Wan Fang database up to 30 December 2020 using the following key words: ("microRNAs" or "microRNA" or "miRNA" or "miR" or "RNA, Micro" or "Primary MicroRNA") and ("Spondylitis Ankylosing" or "Spondyloarthritis Ankylopoietica" or "Ankylosing Spondylarthritis" or "Ankylosing Spondylarthritides" or "Spondylarthritides Ankylosing" or "Ankylosing Spondylitis") and ("blood" or "serum" or "plasma"). Statistical evaluation of dysregulated miRNAs using the sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and the area under the curve (AUC). Results: Twenty-nine articles reporting on the miRNAs of AS were included. A total of 42 miRNAs were observed to be up-regulated and 45 miRNAs were down-regulated in the AS cases compared with the controls. Besides, 29 studies from nine articles were included in our meta-analysis. The pooled sensitivity, specificity, PLR, NLR, DOR, and AUC were 0. 76 (95% CI, 0.70-0.81), 0.80 (95% CI, 0.74-0.85), 3.75 (95% CI, 2.82-5.01), 0.30 (95% CI, 0.24-0.39), 12.32 (95% CI, 7.65-19.83), 0.85 (95% CI, 0.81-0.88), respectively, suggesting a good diagnostic accuracy of miRNAs for AS. Conclusions: Circulating miRNAs are deregulated in AS patients. miRNAs may be used as a relatively non-invasive biomarkers for the detection of AS.

The change in high-sensitivity troponin-T as a risk factor for significant coronary stenosis in patients with acute coronary syndrome

BACKGROUND/AIMS

High-sensitivity cardiac troponin (hs-TnT) assays detect very low levels of cardiac troponin. This study examined the interval change between initial and subsequent hs-TnT levels and evaluated its ability to predict significant coronary stenosis.

METHODS

The study analyzed 163 patients who presented with acute coronary syndrome (ACS) and underwent coronary angiography (CAG) between April 2014 and May 2018. The 0 and 3-hour hs-TnT were checked. The patients were subdivided into positive (n = 32) and negative (n = 131) interval change groups. The presence of significant coronary artery stenosis on CAG in the two groups was compared.

RESULTS

The positive interval change group was older and had higher 0 and 3-hour hs-TnT and blood glucose levels than the negative interval change group. Significant coronary stenosis was more common in the positive interval change group than in the negative interval change group (68.8% vs. 23.7%, p = 0.001). However, vasospasm was more common in the negative interval change group (6.3% vs. 31.3%, p = 0.003). The positive interval change group had higher rates of bifurcation lesions and received more percutaneous coronary intervention. In multivariate analysis, age, interval change of serial hs-TnT and diabetes mellitus were independent predictors of significant coronary artery stenosis.

CONCLUSION

This study identified a relationship between the serial change in cardiac biomarkers and the presence of significant coronary stenosis in patients with ACS. Serial hs-TnT change was associated with real angiographic stenosis in patients with ACS.

Do age-adjusted sex-specific cut-off values improve the agreement between high sensitivity cardiac troponins I and T? A retrospective study

BACKGROUND

Many reports noted a disagreement between High sensitivity cardiac Troponin (hs-cTn) assays on the diagnosis of Acute Coronary Syndrome (ACS).

METHODS

We conducted a retrospective study aiming to assess the agreement between hs-cTn T (Roche) and hs-cTn I (Abbott) in patients presenting with a suspected ACS to the emergency department at Hotel-Dieu hospital between September 2017 and October 2019 using overall, sex-specific, and age-adjusted sex-specific cut-off values. This was measured using Cohen's Kappa. We explored whether renal function, circadian rhythm, age and sex influenced the discordance. And we analyzed the trend of agreement between baseline and repeated measurements.

RESULTS

4856 patients who had simultaneous hs-cTn I and T values were retained for the analysis. 53.5% had a hs-cTn T above the overall 99th percentile, compared to 19.9% for hs-cTn I. The numbers were significantly reduced when applying age-adjusted sex-specific 99th percentile. A disagreement was seen in 34% of cases using overall 99th percentile. Using sex-specific cut off values did not impact this discordance; however, age-adjusted sex-specific cut-off values reduced the percentage of discrepancies to 15.8%. The decreased renal function had a negative effect on the agreement while the circadian rhythm had minimal effect. This initial discordance was carried forward into repeated measurements.

CONCLUSION

The disagreement between hs-cTn T and I assays could be imputed to the choice of cut-off values. The use of age-adjusted sex specific 99th percentile reduced majorly these discordances. Further studies are needed in order to evaluate their clinical utility in patients presenting with ACS.

Baseline High Sensitivity Cardiac Troponin I Level Below Limit of Quantitation Rules Out Acute Myocardial Infarction in the Emergency Department

The objective of our study was to determine the utility of a baseline high sensitivity cardiac troponin (hs-cTnI) value below the limit of quantitation to rule-out acute myocardial infarction (AMI) in patients presenting to the emergency department (ED) with any suspicious symptoms of a cardiac etiology. We enrolled subjects presenting to the ED with symptoms suspicious for AMI. Blood specimens were collected within 1 hour after a triage electrocardiogram. Cardiac troponin I was measured using the Beckman Coulter Access hs-cTnI assay. The diagnosis of AMI was adjudicated by 2 cardiologists using the Third Universal Definition of AMI and Roche Diagnostics Troponin T Generation 5 assay with all available clinical data at 30 days after presentation. A total of 567 subjects had all data required for data analyses. AMI was diagnosed in 46 (8.1%) patients. Two hundred thirty-two (40.9%) individuals had presentation hs-cTnI results <4.0 ng/L. None of the patients with baseline hs-cTnI <4.0 ng/L had an AMI, yielding a negative predictive value of 100.0% and a sensitivity of 100%, and a good prognosis (no AMIs or cardiac-related deaths at 30 days). In this single-center ED study, a baseline presenting novel hs-cTnI value of <4.0 ng/L effectively ruled out AMI in 40.9% of all patients presenting to the ED and having any symptoms suspicious for AMI. Importantly all patients, not only those with chest pain, and those having symptoms for any duration or those with end-stage renal disease requiring dialysis were included.

Comparison of a single high-sensitivity cardiac troponin T measurement with the HEART score for rapid rule-out of acute myocardial infarction in a primary care emergency setting: a cohort study

OBJECTIVE

This study aims to compare the rule-out safety of a single high-sensitivity cardiac troponin T (hs-cTnT) with the History, ECG, Age, Risk factors and Troponin (HEART) score in a low-prevalence primary care setting of acute myocardial infarction (AMI).

PARTICIPANTS

Patients with non-specific symptoms suggestive of AMI were consecutively enroled at a primary care emergency clinic in Oslo, Norway from November 2016 to October 2018.

METHODS

After initial assessment by a general practitioner, hs-cTnT samples were drawn. AMI was ruled-out by a single hs-cTnT <5 ng/L measured ≥3 hours after symptom onset. The HEART score was calculated retrospectively; a score ≤3 of 10 points was considered low risk. We also calculated a modified HEART score using more sensitive hs-cTnT thresholds. The primary outcome was the diagnostic performance for the rule-out of AMI at the index event; the secondary the composite of AMI or all-cause death at 90 days.

RESULTS

Among 1711 patients, 61 (3.6%) were diagnosed with AMI, and 569 (33.3%) patients were assigned to single rule-out (<5 ng/L). With no AMIs in this group, the negative predictive value (NPV) and sensitivity were both 100.0% (95% CI 99.4% to 100.0% and 94.1% to 100.0%, respectively), and the specificity 34.5% (32.2% to 36.8%). The original HEART score triaged more patients as low risk (n=871), but missed five AMIs (NPV 99.4% (98.7% to 99.8%); sensitivity 91.8% (81.9% to 97.3%) and specificity 52.5% (50.0% to 54.9%)). The modified HEART score increased the low-risk sensitivity to 98.4% (91.2% to 100.0%), with specificity 38.7% (36.3% to 41.1%). The 90-day incidence of AMI or death in the single rule-out and the original and modified low-risk HEART groups were 0.0%, 0.7%, and 0.2%, respectively.

CONCLUSION

In a primary care emergency setting, a single hs-cTnT strategy was superior to the HEART score in ruling out AMI. This rapid and safe approach may enhance the assessment of patients with chest pain outside of hospitals.

TRIAL REGISTRATION NUMBER

NCT02983123.

Development of a Novel Sensor System Based on Magnetic Microspheres to Detect Cardiac Troponin T

Acute myocardial infarction (AMI) causes irreversible injury to cardiomyocytes in a short time and may result in various complications, severely threatening patient safety. Therefore, it is necessary to predict the possibility of AMI in the prophase. Prognostic detection of biomarkers that specifically reflect myocardial damage in a patient’s blood has become an essential mediating measure to prevent the serious occurrence of AMI. The present study is aimed at exploring a novel sensing system with high specificity and precision based on magnetic microspheres developed to detect cardiac troponin T (cTnT), which is the most specific diagnostic marker for AMI in cardiovascular diseases. Naive human cTnT protein in serum samples and antigens on functional magnetic microspheres will competitively bind with limited specific antibodies. After rapid removal of heterogeneous elements in the sera using a magnetic separator, fluorescein isothiocyanate-labeled immunoglobulin G is added to react with specific antibodies on the magnetic microspheres. Then, a flow cytometer is used to collect signals of different fluorescence intensities. The results show that the method is characterized by economy, high accuracy, and novelty. It can be used for the detection of cTnT in blood at 1.7–106.1 ng/mL, with a detection limit of 0.5 ng/mL. Thus, the proposed sensor improves the accuracy and efficiency of diagnosis before clinical deterioration of AMI.

Elevated FURIN levels in predicting mortality and cardiovascular events in patients with acute myocardial infarction

OBJECTIVES

Proprotein convertase subtilisin/kexin (PCSK) family member 3 (FURIN) has been suggested to be involved in the development of atherosclerosis. The aim of this study was to investigate the prognostic implication of FURIN in patients after acute myocardial infarction (AMI).

METHODS

This prospective study analyzed data from a total of 1312 consecutive patients hospitalized with ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation myocardial infarction from August 2013 to June 2016. FURIN levels were analyzed in plasma obtained from AMI patients.

RESULTS

The study included 1312 AMI patients. The patient population was predominantly male (63%) with a median age of 66 years (IQR: 19 years), and 59% were STEMI patients. During a follow-up of 2 years, 117 patients died, and 377 patients reached the combined endpoints of major adverse cardiac events (MACE). Patients with elevated FURIN levels had increased risk of MACE, all-cause mortality, recurrent MI and hospitalization for HF (log-rank test, p < 0.0001). After adjusting for clinical risk factors and established markers, the association of FURIN concentrations with the risk of MACE and its individual components and cardiovascular death was statistically significant in the higher tertile of FURIN concentrations. After the addition of FURIN to the models, FURIN showed additive prognostic significance for 2-year clinical outcomes. Variable importance plots of the models showed that FURIN was of high importance to predict both occurrence of MACE and all-cause mortality.

CONCLUSIONS

We found that FURIN was associated with all-cause mortality and recurrent cardiovascular events in AMI patients independent of conventional risk factors and established markers.

Impact of the Introduction of High-Sensitive Troponin Assay in the Emergency Department: A Retrospective Study

BACKGROUND

Compared with troponin T/I test, the introduction of a high-sensitive (hs) troponin test may result in a higher proportion of positive test results in patients with chest pain and over-testing in patients without acute coronary syndrome. We assessed the impact of the introduction of the hs-troponin assay on the discharge diagnoses and the number of diagnostic tests in patients presenting with chest pain in a real-life setting in an emergency department.

METHODS

Retrospective chart review of patients presenting with chest pain to one of the largest hospitals in Switzerland. We compared the standard troponin period (December 2009 to November 2010) with the hs-troponin period (December 2010 to December 2011).

RESULTS

Data from 1274 patients (standard 597 [46.9%], hs-troponin 677 [53.1%]) were analyzed. The proportion of patients with non-ST-segment elevation myocardial infarction increased (hs-troponin 14.9%, compared with 9.7%); the proportion in unstable angina (1.5% to 4.0%) and other cardiac illnesses (8.1% to 11.7%) decreased. Although the proportion of noncardiac chest pain illnesses (67%) remained unchanged, the proportion of positive hs-troponin was higher (6.1% vs 2.0%). The average number of additional tests/person decreased in troponin-positive patients (2.0 to 1.7 test per patient; P = .02) and troponin-negative patients (3.1 to 2.8 tests; P < .0001).

CONCLUSION

Although the introduction of the hs-troponin test resulted in a higher proportion of positive hs-troponin tests in patients with noncardiac chest pain, the average number of diagnostic tests decreased in patients with chest pain presenting to an emergency department, indicating an increased confidence of clinicians in their diagnosis.

Association of trimethylamine N-oxide with coronary atherosclerotic burden in patients with non-ST-segment elevation myocardial infarction

BACKGROUND

Recently, trimethylamine N-oxide (TMAO) unexplained gut microbe has been proposed as a promising risk factor for atherosclerotic cardiovascular disease (CVD) pathogenesis and adverse events. The relationship of TMAO with coronary atherosclerotic burden has been evaluated in patients with stable coronary artery disease and ST-segment elevation myocardial infarction, but still needs to be explored in newly diagnosed non-ST-segment elevation myocardial infarction (NSTEMI) patients.

MATERIAL AND METHODS

A prospective, single-center, SZ-NSTEMI trial (ChiCTR1900022366) is underway to investigate the relationship of TMAO with the severity and prognosis of coronary atherosclerosis in newly diagnosed NSTEMI patients who will undergo coronary angiography with primary percutaneous coronary intervention (pPCI). The primary endpoint of the study will be assessed the association of TMAO with coronary atherosclerotic severity quantify by the number of diseased coronary arteries and SYNTAX score after the coronary angiography. The secondary endpoints will be identified the TMAO as a prognostic biomarker for the short (1 month) and long-term (12 months) major cardiovascular and cerebrovascular events (MACCEs) rate including myocardial infarction, target vessel revascularization, stroke, heart failure, all-cause rehospitalization, and all-cause mortality after the pPCI. The blood samples will be collected from each patient before the procedure to measure the TMAO by isotope dilution high-performance liquid chromatography. In conclusion, SZ-NSTEMI will be the first cohort that will be investigated the association of TMAO with the severity and prognosis of coronary atherosclerotic burden in NSTEMI patients, aiming to identify TMAO as a predictor and a prognostic biomarker.

Extreme occupational heat exposure is associated with elevated haematological and inflammatory markers in Fire Service Instructors

NEW FINDINGS

What is the central question of this study? Fire service instructors are frequently exposed to live fire scenarios, representing the most extreme chronic occupational heat exposure. These individuals report a series of unique health issues. We sought to identify whether the number of exposures completed was associated with inflammatory and immunological markers and symptoms of ill health. What is the main finding and its importance? Fire service instructors exhibit greater levels of inflammatory markers in comparison to firefighters. The number of exposures to fire is positively related to the prevalence of ill health and inflammation. Implementation of a proposed limit of nine exposures per month might be appropriate to minimize health issues.

ABSTRACT

Fire Service Instructors (FSIs) experience ∼10 times more fire exposures than firefighters (FFs), and the increased physiological stress from this potentially puts them at risk of ill health and future cardiac events. The aim of the study was to establish whether FSIs exhibit elevated biomarkers associated with cardiac event risk, identify whether FSIs experience systemic inflammation linked to the frequency of fire exposure and evaluate a proposed exposure limit of nine exposures per month. Blood samples were collected from 110 Fire Service personnel (mean ± SD, age,44 ± 7 years; height, 178.1 ± 7.1 cm; and body mass, 84.3 ± 12.0 kg; FSIs n = 53 and FFs n = 57) for biomarker analysis. Work history details were collected from all participants. Participants with biomarker concentrations above healthy reference ranges were classified as being 'at risk'. The neutrophil-to-lymphocyte ratio, platelet count, cardiac troponin T, interleukin (IL)-6, IL-1β, C-reactive protein and immunoglobulin G were greater in FSIs than in FFs (P < 0.05). Multiple regression analysis revealed that 18.8% of IL-6, 24.9% of IL-1β, 29.2% of C-reactive protein and 10.9% of immunoglobulin G variance could be explained by the number of exposures to heat per month. Odds ratios revealed that those FSIs above the nine per month exposure limit were six to 12 times more likely to be classified as 'at risk' and were 16 times more likely to experience symptoms of ill health. Increased cytokine levels suggest that FSIs experience systemic inflammation, which is related to symptoms of ill health. We propose that an exposure limit could reduce the prevalence of these biomarker risk factors and ill health.

Short-term prognosis of unstable angina in the era of high-sensitivity cardiac troponin: insights for early rule-out strategies

BACKGROUND

It is unclear if strategies to rule-out myocardial infarction (MI) based on a single high-sensitivity troponin T (hsTnT) measurement at the emergency department (ED) presentation may also exclude unstable angina.

METHODS

We measured hsTnT ex-post on the admission frozen blood sample of 644 subjects with Braunwald IIIB CK-MB-negative unstable angina. This analysis included the 240 patients with hsTnT value ≤99th percentile reference limit (UA). We evaluated the clinical outcome of UA patients and the applicability of two rule-out strategies based on the combination of a non-ischemic ECG with (1) a single hsTnT value below the Limit-of-Detection (LoD), (2) a TIMI risk score ≤1.

RESULTS

UA patients with hsTnT ≤99th percentile reference limit had a favorable 30-day outcome [0.8% MI, 0% cardiovascular death (CVD)], but the rate of CVD/MI at 180-day was 4.7%. Sensitivities for UA were 94.6% according to the 'TIMI ≤1-strategy' and 75.4% according to 'hsTnT-below-LoD-strategy', accounting for 5.4 and 24.6% missed diagnoses, respectively. A prognostic risk stratification to guide appropriate outpatient assessment in potential discharged unrecognized UA patients was developed: a risk score based on the combination of age >60 years and C-reactive protein >4.5 mg/L effectively stratified the 180-day CVD/MI occurrence: 0, 2.5 and 12.7% for score 0, 1 and 2 (log-rank = 0.001, C-statistic = 0.776).

CONCLUSION

Single measurement hsTnT strategies, successfully tested to rule-out MI, may allow safe ED discharge of patients with a suspected acute coronary syndrome: even if UA may not be excluded, its short-term prognosis is favorable. UA patients with a C-reactive protein >4.5 mg/L and older than 60 years have a substantial medium-term cardiovascular risk and may benefit from a timely outpatient diagnostic assessment.

Limit of detection of troponin discharge strategy versus usual care: randomised controlled trial

Introduction

The clinical effectiveness of a ‘rule-out’ acute coronary syndrome (ACS) strategy for emergency department patients with chest pain, incorporating a single undetectable high-sensitivity cardiac troponin (hs-cTn) taken at presentation, together with a non-ischaemic ECG, remains unknown.

Methods

A randomised controlled trial, across eight hospitals in the UK, aimed to establish the clinical effectiveness of an undetectable hs-cTn and ECG (limit of detection and ECG discharge (LoDED)) discharge strategy. Eligible adult patients presented with chest pain; the treating clinician intended to perform investigations to rule out an ACS; the initial ECG was non-ischaemic; and peak symptoms occurred <6 hours previously. Participants were randomised 1:1 to either the LoDED strategy or the usual rule-out strategy. The primary outcome was discharge from the hospital within 4 hours of arrival, without a major adverse cardiac event (MACE) within 30 days.

Results

Between June 2018 and March 2019, 632 patients were randomised; 3 were later withdrawn. Of 629 patients (age 53.8 (SD 16.1) years, 41% women), 7% had a MACE within 30 days. For the LoDED strategy, 141 of 309 (46%) patients were discharged within 4 hours, without MACE within 30 days, and for usual care, 114 of 311 (37%); pooled adjusted OR 1.58 (95% CI 0.84 to 2.98). No patient with an initial undetectable hs-cTn had a MACE within 30 days.

Conclusion

The LoDED strategy facilitates safe early discharge in >40% of patients with chest pain. Clinical effectiveness is variable when compared with existing rule-out strategies and influenced by wider system factors.

Trial registration number

ISRCTN86184521.

SERS-based immunoassay using gold-patterned array chips for rapid and sensitive detection of dual cardiac biomarkers

Cardiac troponin I (cTnI) and creatine kinase-MB (CK-MB) are important diagnostic biomarkers for acute myocardial infarction (AMI). Many efforts have been undertaken to develop highly sensitive detection methods for the quantitative analysis of these dual targets. However, current immunoassay methods are inadequate for accurate measurement of cTnI and CK-MB, due to their limited detection sensitivity. Thus, there is still an urgent demand for a new technique that will enable ultrahigh sensitive detection of these biomarkers. In this study, we developed a surface-enhanced Raman scattering (SERS)-based sandwich immunoassay platform for the ultrasensitive detection of cTnI and CK-MB. In this study, a monoclonal-antibody-immobilized gold-patterned chip was used as a SERS active template. Target samples and polyclonal-antibody-conjugated Au@Ag core-shell nanoparticles were then added. Using this SERS platform, the concentration of biomarkers could be quantified by monitoring the characteristic Raman peak intensity of Raman reporter molecules. Under optimized conditions, the limits of detection (LODs) were estimated to be 8.9 pg mL-1 and 9.7 pg mL-1 for cTnI and CK-MB, respectively. Thus, the proposed SERS-based immunoassay has great potential to be an effective diagnostic tool for the rapid and accurate detection of cTnI and CK-MB.

Safety and efficacy of the European Society of Cardiology 0/1-hour algorithm for diagnosis of myocardial infarction: systematic review and meta-analysis

OBJECTIVE

The European Society of Cardiology (ESC) 0/1 hour algorithm has been primarily validated in Europe, America and Australasia with less knowledge of its performance outside of these settings. We aim to evaluate the performance of the ESC 0/1 hour algorithm across different contexts.

METHODS

We searched PubMed, Embase, Scopus, Web of Science and the Cochrane Central Register of Controlled Trials for relevant studies published between 1 January 2008 and 31 May 2019. The primary outcome was index myocardial infarction and the secondary outcome was major adverse cardiac event or mortality. A bivariate random-effects meta-analysis was used to derive the pooled estimate of each outcome.

RESULTS

A total of 11 014 patients from 10 cohorts were analysed for the primary outcome. The algorithm based on high-sensitivity cardiac troponin (hs-cTn)T (Roche), hs-cTnI (Abbott) and hs-cTnI (Siemens) had pooled sensitivity of 98.4% (95% CI=95.1% to 99.5%), 98.1% (95% CI=94.6% to 99.3%) and 98.7% (95% CI=97.3% to 99.3%), respectively. The algorithm based on hs-cTnT (Roche) and hs-cTnI (Siemens) had pooled specificity of 91.2% (95% CI=86.0% to 94.6%) and 95.9% (95% CI=94.1% to 97.2%), respectively. Among patients in the rule-out category, the pooled mortality rate at 30 days and at 1 year was 0.1% (95% CI=0.0% to 0.4%) and 0.8% (95% CI=0.5% to 1.2%), respectively. Among patients in the observation zone, the pooled mortality rate was 0.7% (95% CI=0.3% to 1.2%) at 30 days but increased to 8.1% (95% CI=6.1% to 10.4%) at 1 year, comparable to the mortality rate in the rule-in group.

CONCLUSION

The ESC 0/1 hour algorithm has high diagnostic accuracy but may not be sufficiently safe if the 1% miss-rate for myocardial infarction is desired.

PROSPERO REGISTRATION NUMBER

CRD42019142280.

Undetectable high-sensitivity troponin in combination with clinical assessment for risk stratification of patients with chest pain and normal troponin at hospital arrival

BACKGROUND

Undetectable high-sensitivity cardiac troponin (hs-cTn) in a single determination upon admission may rule out acute coronary syndrome. We investigated undetectable hs-cTnT (<detection limit; <5 ng/l) together with clinical risk scores (GRACE, TIMI, HEART and a previously published simple score), for one-year outcomes in patients with chest pain and normal hs-cTnT (<99th percentile; <14 ng/l) upon admission.

METHODS

This study was a retrospective design involving 2254 consecutive patients (July 2016-November 2017). The primary endpoint was one-year death or acute myocardial infarction; the secondary endpoint added unstable angina requiring revascularization. Early (<90 minutes since pain onset, n = 661) and late (n = 1593) presenters were separately considered.

RESULTS

A total of 56 (2.5%) patients reached the primary endpoint and 91 (4%) the secondary endpoint. Undetectable hs-cTnT had a poor C-statistic in early and late presenters (0.648 and 0.703, respectively). Adding hs-cTnT measurable concentrations above the detection limit (as continuous variable) significantly enhanced the C-statistics (0.754 and 0.847, respectively). Addition of the HEART (0.809, p = 0.005) or simple clinical scores (0.804, p = 0.02) further improved the model and significantly reclassified patient risk, in early presenters. The results were similar for the secondary endpoint. The TIMI risk score performed worse and the GRACE score did not give additional information. In late presenters, no clinical score provided significant additional information over hs-cTnT.

CONCLUSIONS

Diagnostic algorithms should consider not only whether hs-cTnT is above or below the detection limit but also its concentration if above, for risk stratification over one year in patients with initial normal hs-cTnT. The clinical scores provide valuable additional information in early presenters.

High-sensitivity-cardiac troponin for accelerated diagnosis of acute myocardial infarction: A systematic review and meta-analysis

OBJECTIVES

Cardiovascular disease is the leading cause of mortality and morbidity. Serial troponin tests have been endorsed as essential diagnostic steps to rule out/-in acute myocardial infarction (AMI), and hs-cTn assays have shown promise in enhancing the accuracy and efficiency of AMI diagnosis in the emergency department (ED).

METHODS

A systematic review and meta-analysis of diagnostic test accuracy studies were conducted to compare the diagnostic performance of various accelerated diagnostic algorithms of hs-cTn assays for patients with symptoms of AMI. Random-effects bivariate meta-analysis was conducted to estimate the summary sensitivity, specificity, likelihood ratios, and area under receiver operating characteristic curve.

RESULTS

In the systematic review consisting of 56 studies and 67,945 patients, both hs-cTnT and hs-cTnI-based 0-, 1-, 2- and 0-1 h algorithms showed a pooled sensitivity >90%. The hs-cTnI-based algorithm showed a pooled specificity >80%. The hs-cTnT-based algorithms had a specificity of 68% for the 0-h algorithm and of around 80% for the 1-, 2-, and 0-1 h algorithms. The heterogeneities of all diagnostic algorithms were mild (I² < 50%).

CONCLUSION

Both hs-cTnI- and hs-cTnT-based accelerated diagnostic algorithms have high sensitivities but moderate specificities for early diagnosis of AMI. Overall, hs-cTnI-based algorithms have slightly higher specificities in early diagnosis of AMI. For patients presenting ED with typical symptoms, the use of hs-cTnT or hs-cTnI assays at the 99th percentile may help identify patients with low risk for AMI and promote early discharge from the ED.

Early Recovery of Left Ventricular Function After Revascularization in Acute Coronary Syndrome

The aim of this study was to assess the accuracy of echocardiographic techniques in detecting the early recovery of left ventricular (LV) function after revascularization in acute coronary syndrome (ACS). In 80 consecutive patients with ACS (age 55.7 ± 9.4 years, 77% male, 15% with CCS Angina III), an echocardiographic examination of left ventricle regional wall motion abnormalities (LV RWMA), peak systolic strain rate (PSSR), peak systolic strain (PSS) and end systolic strain (ESS) was performed before and after percutaneous intervention (PCI). Of the 80 patients, one vessel stenosis (>70%) was present in 53 (66%), two vessel disease in 12 (15%) and multivessel disease in 15 patients (19%). In total, 51% of patients had hypertension, 40% diabetes and 23% dyslipidemia. After PCI, regional PSS, ESS and PSSR of their segments subtended by the culprit vessel improved; left anterior descending-LAD, circumflex-LCx and right coronary-RCA (p<0.05 for all) as well as global S and SR (p < 0.05 for all). In univariate analysis, hypertension (HTN) (β = -0.294 (-0.313-0.047), p = 0.009, smoking β = -0.244 (-0.289-0.015) =0.03, WMA β = -0.317 (-0.284-0.014), p = 0.004 and the number of diseased vessels β = -0.256 (-0.188- 0.054) p=0.03 were predictors of delta global SR. In multivariate analysis, only HTN β = 0.263 (0.005-3.159) and the number of diseased vessels β =0.263 (0.005 - 3.159), p=0.04) predicted delta global SR. In ACS, the echocardiographic regional myocardial deformation is accurate in detecting early recovery of LV myocardial function after culprit lesion revascularization. Also, the findings of this study support the current practice regarding the crucial importance of proximal epicardial vessel PCI treatment on LV function compared to more distal lesions.

The Asia-Pacific Society of Cardiology (APSC) Expert Committee Consensus Recommendations for Assessment of Suspected Acute Coronary Syndrome Using High-Sensitivity Cardiac Troponin T in the Emergency Department

The Asia-Pacific Society of Cardiology (APSC) high-sensitivity troponin T (hs-TnT) consensus recommendations and rapid algorithm were developed to provide guidance for healthcare professionals in the Asia-Pacific region on assessing patients with suspected acute coronary syndrome (ACS) using a hs-TnT assay. Experts from Asia-Pacific convened in 2 meetings to develop evidence-based consensus recommendations and an algorithm for appropriate use of the hs-TnT assay. The Expert Committee defined a cardiac troponin assay as a high-sensitivity assay if the total imprecision is ≤10% at the 99th percentile of the upper reference limit and measurable concentrations below the 99th percentile are attainable with an assay at a concentration value above the assay's limit of detection for at least 50% of healthy individuals. Recommendations for single-measurement rule-out/rule-in cutoff values, as well as for serial measurements, were also developed. The Expert Committee also adopted similar hs-TnT cutoff values for men and women, recommended serial hs-TnT measurements for special populations, and provided guidance on the use of point-of-care troponin T devices in individuals suspected of ACS. These recommendations should be used in conjunction with all available clinical evidence when making the diagnosis of ACS.

Paper-based cascade cationic isotachophoresis: Multiplex detection of cardiac markers

Paper-based analytical devices (PADs) are widely used in point-of-care testing (POCT) as they are cost-effective, simple and straightforward. However, poor sensitivity hinders their use in detecting diseases with low abundance biomarkers. The poor detection limit of PADs is mainly attributed to the low concentration of analytes, and the complexity of biological fluid, leading to insufficient interactions between analytes and capture antibodies. This study aims to overcome these difficulties by developing a paper-based cationic isotachophoresis (ITP) approach for simultaneously detecting pico-molar levels of two essential cardiac protein markers: acidic troponin T (cTnT) and basic troponin I (cTnI) spiked into human serum samples. The approach utilizes 3-aminopropyltrimethoxysilane (APTMS) treated glass fiber papers with decreasing cross-sectional area assembled on a 3D printed cartridge device. Our results showed that in the presence of cTnT monoclonal antibody (mAb), fluorescently labeled cTnI and cTnT could be effectively enriched in cationic ITP. Each individual target was captured subsequently by a test line in the detection zone where the capture mAb was immobilized. Detailed analysis suggests that the technology is capable of simultaneous on-board depletion of abundant plasma proteins and enrichment of cTnI/cTnT by ~1300-fold with a sensitivity of 0.6 pmol/L for cTnT and a sensitivity of 1.5 pmol/L for cTnI in less than 6 min. The results demonstrate the potential of this technology for rapid, ultra-sensitive and cost-effective analysis of multiplex protein markers in clinical serum samples at point of care.

Impact of statin use on high sensitive troponin T levels with moderate exercise

Background: High-sensitive cardiac troponin (hsTn) levels can be elevated due to non-pathological events such as strenuous exercise. However, the effect of statins on circulating hsTnT levels with moderate exercise is uncertain. Therefore, we evaluated the impact of statins on hsTnT level with moderate exercise. Methods: We enrolled a total of 56 patients: 26 statin users and 30 non-users. All patients were shown to have no coronary artery disease before participating in the study. Participants performed a fixed-protocol moderate level exercise. HsTnT levels were measured before and 4 h after the exercise. Participants were also grouped based on their hsTnT levels, as proposed in the recent European Society of Cardiology guideline (0-1 hour algorithm) for acute coronary syndromes without persistent ST-segment elevation. Results: Statin users showed a significant increase in serum hsTnT levels with moderate exercise (p = .004), whereas the control group showed a modest increase without statistical significance (p = .664). The percentage of patients whose hsTnT levels exceeded the rule-out limits for non-ST-segment myocardial infarction diagnosis (according to the 0-1 algorithm) after moderate exercise varied significantly between groups (p = .024). Conclusions: Statin therapy can cause a significant increase in hsTnT levels after moderate exercise. This increase can jeopardise the accuracy of clinical diagnoses based on the newly implemented algorithms. The awareness of these adverse effects of statins, mainly used by patients with high risk of coronary events, can prevent misdiagnosis or unnecessary hospitalisations.

Reduced regional strain rate is the most accurate dysfunction in predicting culprit lesions in patients with acute coronary syndrome

BACKGROUND AND AIM

Predicting culprit lesions in acute coronary syndrome (ACS) could be a challenge. The aim of this study was to assess the accuracy of regional wall motion abnormalities (RWMA) using various echocardiographic techniques and ECG changes in predicting the culprit coronary lesion in a group of patients with ACS.

METHODS

In 80 consecutive patients with ACS (age 55·7 ± 9·4 years, 77% male, 15% with CCS Angina III), an echocardiographic examination of left ventricle (LV) RWMA, tissue Doppler imaging (TDI) and speckle tracking myocardial strain and strain rate (SR) were performed before intervention.

RESULTS

Of the 80 patients, one-vessel stenosis (>70%) was present in 53 (66%), two-vessel disease in 12 (15%) and multivessel disease in 15 patients (19%). About 51% of patients had hypertension, 40% diabetes and 23% dyslipidaemia. There was no relationship between individual segmental RWMA and SR. Mean regional SR, but not peak strain, correlated with culprit lesion branch: left anterior descending - LAD (r = 0·35, P = 0·005), circumflex LCx (r = 0·32, P = 0·03) and right coronary RCA (r = 0·37, P = 0·01). Only ECG changes in the LAD territory (r = 0·26, P = 0·04) correlated with the culprit lesion. SR of LAD territories ≤-0·74 was 71% sensitive and 70% specific (AUC = 0·70, CI = 0·67-0·93, P = 0·01), SR of LCx territories of ≤-0·67 was 75% sensitive and 63% specific (AUC = 0·72, CI = 0·58-0·87, P = 0·02) and SR of RCA territories ≤-0·83 was 73% sensitive and 71% specific (AUC = 0·80, CI = 0·66-0·93, P = 0·001) in predicting significant stenosis. SR was more accurate than all other techniques in predicting the culprit lesion.

CONCLUSION

In ACS, mean regional speckle tracking SR is more sensitive than peak strain, TDI, ECG changes and wall motion abnormalities in detecting significant coronary artery stenosis.

Efficacy of High-Sensitivity Troponin T in Identifying Very-Low-Risk Patients With Possible Acute Coronary Syndrome

Importance

Physicians need information on how to use the first available high-sensitivity troponin (hsTnT) assay in the United States to identify patients at very low risk for 30-day adverse cardiac events (ACE).

Objective

To determine whether a negative hsTnT assay at 0 and 3 hours following emergency department presentation could identify patients at less than 1% risk of a 30-day ACE.

Design, Setting, and Participants

A prospective, observational study at 15 emergency departments in the United States between 2011 and 2015 that included individuals 21 years and older, presenting to the emergency department with suspected acute coronary syndrome. Of 1690 eligible individuals, 15 (no cardiac troponin T measurement) and 320 (missing a 0-hour or 3-hour sample) were excluded from the analyses.

Exposures

Serial hsTnT measurements (fifth-generation Roche Elecsys hsTnT assay).

Main Outcomes and Measures

Serial blood samples from each patient were collected after emergency department presentation (once identified as a potential patient with acute coronary syndrome) and 3 hours, 6 to 9 hours, and 12 to 24 hours later. Adverse cardiac events were defined as myocardial infarction, urgent revascularization, or death. The upper reference level for the hsTnT assay, defined as the 99th percentile, was established as 19 ng/L in a separate healthy US cohort. Patients were considered ruled out for acute myocardial infarction if their hsTnT level at 0 hours and 3 hours was less than the upper reference level. Gold standard diagnoses were determined by a clinical end point committee. Evaluation of assay clinical performance for acute myocardial infarction rule-out was prespecified; the hypothesis regarding 30-day ACE was formulated after data collection.

Results

In 1301 healthy volunteers (50.4% women; median age, 48 years), the upper reference level was 19 ng/L. In 1600 patients with suspected acute coronary syndrome (48.4% women; median age, 55 years), a single hsTnTlevel less than 6 ng/L at baseline had a negative predictive value for AMI of 99.4%. In 974 patients (77.1%) with both 0-hour and 3-hour hsTnT levels of 19 ng/L or less, the negative predictive value for 30-day ACE was 99.3% (95% CI, 99.1-99.6). Using sex-specific cutpoints, C statistics for women (0.952) and men (0.962) were similar for acute myocardial infarction.

Conclusions and Relevance

A single hsTnT level less than 6 ng/L was associated with a markedly decreased risk of AMI, while serial levels at 19 ng/L or less identified patients at less than 1% risk of 30-day ACE.

Low High-Sensitivity Troponin Thresholds Identify Low-Risk Patients With Chest Pain Unlikely to Benefit From Further Risk Stratification

Background

Very low high-sensitivity cardiac troponin T (hs-cTnT) thresholds on presentation can rule out acute myocardial infarction (AMI), but the ability to identify patients at low risk of 30-day major adverse cardiac events (MACE) is less clear. This study examines the sensitivity of low concentrations of hs-cTnT on presentation to rule out 30-day MACE.

Methods

This prospective cohort study enrolled patients with chest pain presenting to the emergency department with nonischemic electrocardiograms who underwent AMI rule-out with an hs-cTnT assay. The primary outcome was 30-day MACE; secondary outcomes were individual MACE components. Because guidelines recommend using a single hs-cTnT strategy only for patients with more than 3 hours since symptom onset, a subgroup analysis was performed for this population. Outcomes were adjudicated on the basis of review of medical records and telephone follow-up.

Results

Of 1167 patients enrolled, 125 (10.7%) experienced 30-day MACE and 97 (8.3%) had AMI on the index visit. More than one-third of patients (35.6%) had presenting hs-cTnT concentrations below the limit of detection (5 ng/L), which was 94.4% (95% confidence interval [CI], 88.8-97.7) sensitive for 30-day MACE and 99.0% (95% CI, 94.5-100) sensitive for index AMI. Of 292 patients (25.0%) with hs-cTnT < 5 ng/L and at least 3 hours since symptom onset, only 3 experienced 30-day MACE (sensitivity 97.6%; 95% CI, 93.2-100) and none had AMI within 30 days (sensitivity 100%; 95% CI, 96.3-100).

Conclusions

Among patients with nonischemic electrocardiograms and > 3 hours since symptom onset, low hs-cTnT thresholds on presentation confer a very low risk of 30-day MACE. In the absence of a high-risk clinical presentation, further risk stratification is likely to be low yield.

Trimethyllysine, a trimethylamine N-oxide precursor, provides near- and long-term prognostic value in patients presenting with acute coronary syndromes

AIMS

Trimethyllysine (TML) serves as a nutrient precursor of the gut microbiota-derived metabolite trimethylamine N-oxide (TMAO) and is associated with incident cardiovascular (CV) events in stable subjects. We examined the relationship between plasma TML levels and incident CV events in patients presenting with acute coronary syndromes (ACS).

METHODS AND RESULTS

Plasma levels of TML were quantified in two independent cohorts using mass spectrometry, and its relationship with CV events was investigated. In a Cleveland Cohort (N = 530), comprised of patients presenting to the emergency department with chest pain and suspected ACS, TML was associated with major adverse cardiac events (MACE, myocardial infarction, stroke, need for revascularization, or all-cause mortality) over both 30 days [3rd tertile (T3), adjusted odds ratio (OR) 1.77, 95% confidence interval (CI) 1.04-3.01; P < 0.05] and 6 months (T3, adjusted OR 1.95, 95% CI 1.15-3.32; P < 0.05) of follow-up independent of traditional CV risk factors and indices of renal function. Elevated TML levels were also associated with incident long-term (7-year) all-cause mortality [T3, adjusted hazard ratio (HR) 2.52, 95% CI 1.50-4.24; P < 0.001], and MACE even amongst patients persistently negative for cardiac Troponin T at presentation (e.g. 30-day MACE, T3, adjusted OR 4.49, 95% CI 2.06-9.79; P < 0.001). Trimethyllysine in combination with TMAO showed additive significance for near- and long-term CV events, including patients with 'negative' high-sensitivity Troponin T levels. In a multicentre Swiss Cohort (N = 1683) comprised of ACS patients, similar associations between TML and incident 1-year adverse cardiac risks were observed (e.g. mortality, adjusted T3 HR 2.74, 95% CI 1.28-5.85; P < 0.05; and MACE, adjusted T3 HR 1.55, 95% CI 1.04-2.31; P < 0.05).

CONCLUSION

Plasma TML levels, alone and together with TMAO, are associated with both near- and long-term CV events in patients with chest pain and ACS.

Ethnicity-Specific Changes in Cardiac Troponin T in Response to Acute Mental Stress and Ethnicity-Specific Cutpoints for the R Wave of the aVL Lead

Acute mental stressor-induced cardiac stress responses might contribute to excessive myocardial strain and resultant cardiovascular episode risk. We assessed ethnicity-specific acute cardiac stress (by measuring cardiac troponin T (cTnT) and N-terminal prohormone of brain natriuretic peptide) related to hemodynamic activity. The prospective Sympathetic Activity and Ambulatory Blood Pressure in Africans (SABPA) study was conducted during 2007-2008 in South Africa. In the cross-sectional phase of the SABPA study, 388 black and white participants underwent a 1-minute acute mental stressor, during which blood pressure was continuously measured. Fasting blood samples for cardiac stress markers were obtained before and 10 minutes after stress (% change). Resting 10-lead electrocardiogram measured the R wave of the aVL lead (RaVL). Black participants exhibited greater cardiac stress responses (P < 0.001), diastolic blood pressure, total peripheral resistance, and stroke volume compared with white participants, who displayed decreases in cardiac stress and increases in cardiac output. Prestress and stressor cTnT cutpoints of 4.2 pg/mL predicted 24-hour, daytime, and nighttime diastolic hypertension in black participants (P < 0.001). These cTnT cutpoints were associated with an ethnicity-specific RaVL cutpoint of 0.28 mV (odds ratio = 3.49, 95% confidence interval: 2.18, 5.83; P = 0.021). Acute mental stress elicited an α-adrenergic activation pattern and cardiac stress hyperreactivity only in black participants. Mental stress might increase the black population's risk for ischemic episodes and heart disease.

Experiences of a One-hour Algorithm in Chest Pain Patients With a Nonelevated Troponin T at Presentation

Supplemental Digital Content is available in the text.

Background:

We aimed to evaluate the use of a 1-hour measurement of high-sensitivity cardiac troponin T (hs-cTnT) in an emergency department (ED) population of chest pain patients with a nonelevated baseline hs-cTnT and to examine the prevalence of early dynamic changes in hs-cTnT and the association with admission rate, diagnosis, and outcome.

Methods:

All patients with a chief complaint of chest pain presenting to the ED of Karolinska University Hospital, Solna, Sweden, from December 2014 to September 2015 who had a baseline hs-cTnT of ≤14 ng/L and a second value obtained within >30 to ≤90 minutes were followed for 30 days regarding admission, readmission, myocardial infarction (MI), and death.

Results:

A total of 1091 patients were included. Dynamic 1-hour changes in hs-cTnT defined as an increase or decrease of ≥3 ng/L occurred in 23 patients (2.1%). Fifteen patients (65.2%) in the dynamic group were admitted, compared with 148 patients (13.9%) in the nondynamic group (P < 0.001). Four of the admitted patients (26.7%) in the dynamic and 1 (0.7%) in the nondynamic group were diagnosed with an MI (P < 0.001). No death or MI occurred within 30 days among those discharged from the ED.

Conclusions:

Dynamic 1-hour changes in hs-cTnT were uncommon but associated with a higher rate of admission and of MI in an unselected population of chest pain patients with a nonelevated hs-cTnT at presentation. Lack of dynamic changes makes MI highly unlikely, and a 1-hour measurement may facilitate an early rule out of MI but should be used together with clinical assessment.

Susceptibility of Cardiac Troponin Assays to Biotin Interference

OBJECTIVES

To investigate biotin interference on three cardiac troponin (cTn) assays and demonstrate a method to overcome biotin interference.

METHODS

cTn levels were measured in (1) plasma from healthy volunteers on 10-mg daily biotin supplementation mixed with a plasma with known elevated troponin, (2) plasmas with known elevated cTn after mixing in reagent biotin to simulate supplementation, and (3) biotin-spiked plasma specimens pretreated with streptavidin-agarose beads.

RESULTS

Daily biotin ingestion (10 mg) and studies simulating daily biotin use resulted in significant interference in the Gen5 cardiac troponin T (cTnT) assay; the contemporary Gen 4 cTnT and high-sensitivity cardiac troponin I (hs-cTnI) assays were unaffected. The biotin interference threshold was 31, 315, and more than 2,000 ng/mL for Gen5 cTnT, cTnT, and hs-cTnI assays, respectively. Streptavidin pretreatment blocked biotin interference in cTn assays.

CONCLUSIONS

Biotin interference is possible at plasma concentrations achievable by ingestion of over-the-counter supplements that may lead to delayed or missed diagnosis of myocardial injury with the Gen5 cTnT assay.