Clinical Use of High-Sensitivity Cardiac Troponin in Patients With Suspected Myocardial Infarction

Therapy-naïve malignancy causes cardiovascular disease: a state-of-the-art cardio-oncology perspective

Cardiovascular disease (CVD) and cancer are the leading causes of mortality worldwide. Although generally thought of as distinct diseases, the intersectional overlap between CVD and cancer is increasingly evident in both causal and mechanistic relationships. The field of cardio-oncology is largely focused on the cardiotoxic effects of cancer therapies (e.g., chemotherapy, radiation). Furthermore, the cumulative effects of cardiotoxic therapy exposure and the prevalence of CVD risk factors in patients with cancer lead to long-term morbidity and poor quality of life in this patient population, even when patients are cancer-free. Evidence from patients with cancer and animal models demonstrates that the presence of malignancy itself, independent of cardiotoxic therapy exposure or CVD risk factors, negatively impacts cardiac structure and function. As such, the primary focus of this review is the cardiac pathophysiological and molecular features of therapy-naïve cancer. We also summarize the strengths and limitations of preclinical cancer models for cardio-oncology research and discuss therapeutic strategies that have been tested experimentally for the treatment of cancer-induced cardiac atrophy and dysfunction. Finally, we explore an adjacent area of interest, called "reverse cardio-oncology," where the sequelae of heart failure augment cancer progression. Here, we emphasize the cross-disease communication between malignancy and the injured heart and discuss the importance of chronic low-grade inflammation and endocrine factors in the progression of both diseases.

Low-level elevations in high-sensitivity cardiac troponin predict obstructive coronary artery disease and revascularisation in rural patients with non-ST-elevation myocardial infarction referred for coronary angiography

Rural patients with non-ST-elevation myocardial infarction (NSTEMI) are transferred to metropolitan hospitals for invasive coronary angiography (ICA). Yet, many do not have obstructive coronary artery disease (CAD). In this analysis of rural Western Australian patients transferred for ICA for NSTEMI, low-level elevations in high-sensitivity cardiac troponin (≤5× upper reference limit) were associated with less obstructive CAD and revascularisation. Along with other factors, this may help identify rural patients not requiring transfer for ICA.

The molecular interaction of six single-stranded DNA aptamers to cardiac troponin I revealed by docking and molecular dynamics simulation

Cardiac troponin I (cTnI) is a cardiac biomarker for diagnosing ischemic heart disease and acute myocardial infarction. Current biochemical assays use antibodies (Abs) due to their high specificity and sensitivity. However, there are some limitations, such as the high-cost production of Abs due to complex instruments, reagents, and steps; the variability of Abs quality from batch to batch; the low stability at high temperatures; and the difficulty of chemical modification. Aptamer overcomes the limitations of antibodies, such as relatively lower cost, high reproducibility, high stability, and ease of being chemically modified. Aptamers are three-dimensional architectures of single-stranded RNA or DNA that bind to targets such as proteins. Six aptamers (Tro1-Tro6) with higher binding affinity than an antibody have been identified, but the molecular interaction has not been studied. In this study, six DNA aptamers were modeled and docked to cTnI protein. Molecular docking revealed that the interaction between all aptamer and cTnI happened in the similar cTnI region. The interaction between aptamer and cTnI involved hydrophobic interaction, hydrogen bonds, π-cation interactions, π-stack interactions, and salt-bridge formation. The calculated binding energy of all complexes was negative, which means that the complex formation was thermodynamically favorable. The electrostatic energy term was the main driving force of the interaction between all aptamer and cTnI. This study could be used to predict the behavior of further modified aptamer to improve aptamer performance.

Characterization of myocardial injury phenotype by thermal liquid biopsy

Background and aims

With the advent and implementation of high-sensitivity cardiac troponin assays, differentiation of patients with distinct types of myocardial injuries, including acute thrombotic myocardial infarction (TMI), acute non-thrombotic myocardial injury (nTMi), and chronic coronary atherosclerotic disease (cCAD), is of pressing clinical importance. Thermal liquid biopsy (TLB) emerges as a valuable diagnostic tool, relying on identifying thermally induced conformational changes of biomolecules in blood plasma. While TLB has proven useful in detecting and monitoring several cancers and autoimmune diseases, its application in cardiovascular diseases remains unexplored. In this proof-of-concept study, we sought to determine and characterize TLB profiles in patients with TMI, nTMi, and cCAD at multiple acute-phase time points (T 0 h, T 2 h, T 4 h, T 24 h, T 48 h) as well as a follow-up time point (Tfu) when the patient was in a stable state.

Methods

TLB profiles were collected for 115 patients (60 with TMI, 35 with nTMi, and 20 with cCAD) who underwent coronary angiography at the event presentation and had subsequent follow-up. Medical history, physical, electrocardiographic, histological, biochemical, and angiographic data were gathered through medical records, standardized patient interviews, and core laboratory measurements.

Results

Distinctive signatures were noted in the median TLB profiles across the three patient types. TLB profiles for TMI and nTMi patients exhibited gradual changes from T0 to Tfu, with significant differences during the acute and quiescent phases. During the quiescent phase, all three patient types demonstrated similar TLB signatures. An unsupervised clustering analysis revealed a unique TLB signature for the patients with TMI. TLB metrics generated from specific features of TLB profiles were tested for differences between patient groups. The first moment temperature (TFM) metric distinguished all three groups at time of presentation (T0). In addition, 13 other TLB-derived metrics were shown to have distinct distributions between patients with TMI and those with cCAD.

Conclusion

Our findings demonstrated the use of TLB as a sensitive and data-rich technique to be explored in cardiovascular diseases, thus providing valuable insight into acute myocardial injury events.

Safety and Effectiveness of the High-Sensitivity Cardiac Troponin HEART Pathway in Patients With Possible Acute Coronary Syndrome

BACKGROUND

The HEART Pathway (History, Electrocardiogram, Age, Risk factors, Troponin) can be used with high-sensitivity cardiac troponin to risk stratify emergency department patients with possible acute coronary syndrome. However, data on whether a high-sensitivity HEART Pathway (hs-HP) are safe and effective is lacking.

METHODS

An interrupted time series study was conducted at 5 North Carolina sites in 26 126 adult emergency department patients being investigated for possible acute coronary syndrome and without ST-segment-elevation myocardial infarction. Patients were accrued into 16-month preimplementation and postimplementation cohorts with a 6-month wash-in phase. Preimplementation (January 2019 to April 2020), the traditional HEART Pathway was used with 0- and 3-hour contemporary troponin measures (Siemens). In the postimplementation period (November 2020 to February 2022), a modified hs-HP was used with 0- and 2-hour high-sensitivity cardiac troponin (Beckman Coulter) measures. The primary safety and effectiveness outcomes were 30-day all-cause death or myocardial infarction and 30-day hospitalizations. These outcomes and early discharge rate (emergency department discharge without stress testing or coronary angiography) were determined from health records and death index data. Outcomes were compared preimplementation versus postimplementation using χ2 tests and multivariable logistic regression to adjust for potential confounders.

RESULTS

Preimplementation and postimplementation cohorts included 12 317 and 13 809 patients, respectively, of them 52.7% (13 767/26 126) were female with a median age of 54 years (interquartile range, 42-66). Rates of 30-day death or MI were 6.8% (945/13 809) postimplementation and 7.7% (948/12 317) preimplementation (adjusted odds ratio, 1.00 [95% CI, 0.90-1.11]). hs-HP implementation was associated with 19.9% (95% CI, 18.7%-21.1%) higher early discharges (post versus pre: 63.6% versus 43.7%; adjusted odds ratio, 2.22 [95% CI, 2.10-2.35]). The hs-HP was also associated with 16.1% (95% CI, 14.9%-17.3%) lower 30-day hospitalizations (postimplementation versus preimplementation, 31.4% versus 47.5%; adjusted odds ratio, 0.51 [95% CI, 0.48-0.54]). Among early discharge patients, death or myocardial infarction occurred in 0.5% (41/8780) postimplementation versus 0.4% (22/5383) preimplementation (P=0.61).

CONCLUSIONS

hs-HP implementation is associated with increased early discharges without increasing adverse events. These findings support the use of a modified hs-HP to improve chest pain care.

External validation of the 0/1h-algorithm and derivation of a 0/2h-algorithm using a new point-of-care Hs-cTnI assay

BACKGROUND

The high-sensitivity cardiac troponin (hs-cTn) I point-of-care (POC) hs-cTnI-PATHFAST assay has recently become clinically available.

METHODS

We aimed to externally validate the hs-cTnI-PATHFAST 0/1h-algorithm recently developed for the early diagnosis of non-ST-segment-elevation myocardial infarction (NSTEMI) and derive and validate a 0/2-algorithm in patients presenting to the emergency department with acute chest discomfort included in a multicenter diagnostic study. Two independent cardiologists centrally adjudicated the final diagnoses using all the clinical and study-specific information available including serial measurements of hs-cTnI-Architect.

RESULTS

Among 1,532 patients (median age 60 years, 33% [n = 501] women), NSTEMI was the final diagnosis in 13%. External validation of the hs-cTnI-PATHFAST 0/1h-algorithm showed very high negative predictive value (NPV; 100% [95%CI, 99.5%-100%]) and sensitivity 100% (95%CI, 98.2%-100%) for rule-out of NSTEMI. Positive predictive value (PPV) and specificity for rule-in of NSTEMI were high (74.9% [95%CI, 68.3%-80.5%] and 96.4% [95%CI, 95.2%-97.3%], respectively). Among 1,207 patients (median age 61 years, 32% [n = 391] women) available for the derivation (n = 848) and validation (n = 359) of the hs-cTnI-PATHFAST 0/2h-algorithm, a 0h-concentration <3 ng/L or a 0h-concentration <4 ng/L with a 2h-delta <4ng/L ruled-out NSTEMI in 52% of patients with a NPV of 100% (95%CI, 98-100) and sensitivity of 100% (95%CI, 92.9%-100%) in the validation cohort. A 0h-concentration ≥90ng/L or a 2h-delta ≥ 55ng/L ruled-in 38 patients (11%): PPV 81.6% (95%CI, 66.6-90.8), specificity 97.7% (95%CI, 95.4-98.9%).

CONCLUSIONS

The POC hs-cTnI-PATHFAST assay allows rapid and effective rule-out and rule-in of NSTEMI using both a 0/1h- and a 0/2h-algorithm with high NPV/sensitivity for rule-out and high PPV/specificity for rule-in.

CLINICAL TRIAL REGISTRATION

NCT00470587.

Introduction of a high sensitivity troponin reduces ED length of stay

BACKGROUND

High sensitivity cardiac troponins (hs-cTn) allow earlier identification and exclusion of acute myocardial infarction. We determined if transitioning from contemporary to high sensitivity troponin T (hs-cTnT) would reduce ED length of stay in chest pain (CP) patients.

METHODS

We conducted a pragmatic, prospective, before and after study of implementing a hs-cTnT by reviewing the electronic health records in all adult ED patients presenting to a large, suburban academic medical center during the 3 months before and after transitioning from a 4th generation troponin to a 5th generation hs-cTnT (Elecsys® Troponin T-high sensitive, Roche Diagnostics, Indianapolis, IN).

RESULTS

There were 1431 and 1437 CP patients before and after the intervention. Mean (SD) age was 51.5 (18) yrs. and 54.3% were female. The median (IQR) ED LOS for chest pain patients directly discharged to home was 6.2 (4.7-8.4) and 5.3 (4.0-7.2) hours before and after introducing hs-cTn respectively; difference 47 min (95%CI, 35-59); P < 0.001. The median (IQR) ED LOS for chest pain patients admitted to the hospital was 9.5 (6.6-13.8) and 8.1 (5.7-11.2) hours before and after introducing hs-cTn respectively; difference 77 min (95%CI, 35-121); P < 0.001. Overall admission rates (22 vs 21% both before and after) did not change during the study. The rates of computed tomography coronary angiography before and after the intervention were 21 and 20.4% respectively. The rates of invasive coronary angiography before and after the intervention were 5.8 and 5.6% respectively.

CONCLUSIONS

Transitioning to a hs-cTnT is associated with a clinically relevant and statistically significant reduction in ED LOS for both discharged and admitted patients with and without CP with no increase in admission or coronary angiography rates.

Diagnostic value of high sensitivity cardiac troponin T (hs-cTnT) in dialysis patients with myocardial infarction

Background

As a sensitive diagnostic marker for myocardial infarction (MI) in people with normal renal function, elevated high sensitivity cardiac troponin T (hs-cTnT) was often found in chronic kidney disease (CKD) patients requiring dialysis. However, the accuracy of baseline hs-cTnT in the diagnosis of MI (including Type 1 MI (T1MI) and Type 2 MI (T2MI)) in dialysis patients is still controversial. The aim of this study was to retrospectively explore whether there were any clinical indices that could increase the predictive value of hs-cTnT on admission for MI occurrence in dialysis patients.

Methods

Here, 136 patients with uremia who underwent regular dialysis with coronary angiography in the First Affiliated Hospital of Nanjing Medical University from August 2017 to October 2021 were enrolled. According to the coronary angiography results and the presence of clinical symptoms, the patients were divided into: (1). AMI group (n = 69; angiography positive) and Control group (n = 67; angiography negative); (2). T1MI group (n = 69; angiography positive), T2MI group (n = 7; angiography negative & symptomatic), and Control group (n = 60; angiography negative & asymptomatic).

Results

Here, we found the mean hs-cTnT on admission in the Control group was much lower than that in the AMI group. Hs-cTnT alone had a mediocre predictive performance, with an AUROC of 0.7958 (95% CI: 0.7220, 0.8696). Moreover, the ROC curve of hs-cTnT combined with the Triglyceride (TG), Time of dialysis, and Albumin (Alb) showed a higher sensitivity area [0.9343 (95% CI: 0.8901, 0.9786)] than that of single hs-cTnT. Next, hs-cTnT combined with the TG, Time of dialysis, and Alb also presented a better performance in predicting T1MI [0.9150 (95% CI: 0.8678, 0.9621)] or T2MI (0.9167 [0.9167 (95% CI: 0.8427, 0.9906)] occurrences. Last, these combined variables could better distinguish patient between T1MI and T2MI group than hs-cTnT alone.

Conclusions

On admission, a combination of hs-cTnT, TG, Time of dialysis, and Alb presented a higher sensitivity than hs-cTnT alone in predicting MI occurrence in dialysis patients, suggesting a better diagnostic approach for future clinical applications.

Impacts of high sensitivity troponin T reporting on care and outcomes in clinical practice: Interactions between low troponin concentrations and participant sex within two randomized clinical trials

BACKGROUND

The impacts of high sensitivity cardiac troponin (hs-cTn) reporting on downstream interventions amongst suspected acute coronary syndrome (ACS) in the emergency department (ED), especially amongst those with newly identified hs-cTn elevations and in consideration of well-established sex-related disparities, has not been critically evaluated to date. This investigation explores the impact of hs-cTnT reporting on care and outcomes, particularly by participant sex.

METHODS

Two similarly ED-based randomized controlled trials conducted between July 2011 to March 2013 (n = 1988) and August 2015 to April 2019 (n = 3378) were comparatively evaluated. Clinical outcomes were adjudicated to the Fourth Universal Definition of MI. Changes in practice were assessed at 30 days, and death or MI were explored to 12 months.

RESULTS

The HS-Troponin study demonstrated no difference in death or MI with unmasking amongst those with hs-cTnT <30 ng/L, whereas the RAPID TnT study demonstrated a significantly higher rate. In RAPID TnT, there was significant increase in death or MI associated with unmasking for females with hs-cTnT <30 ng/L (masked: 11[1.5%], unmasked: 25[3.4%],HR: 2.27,95%C.I.:1.87-2.77,P < 0.001). Less cardiac stress testing with unmasking amongst those <30 ng/L was observed in males in both studies, which was significant in RAPID TnT (masked: 92[12.0%], unmasked: 55[7.0%], P = 0.008). In RAPID TnT, significantly higher rates of angiography in males were observed with unmasking, with no such changes amongst females <30 ng/L (masked: 28[3.7%], unmasked: 51[6.5%],P = 0.01).

CONCLUSION

Compared with males, there were no evident impacts on downstream practices for females with unmasking in RAPID TnT, likely representing missed opportunities to reduce late death or MI.

Lead activates neutrophil degranulation to induce early myocardial injury in mice

Lead (Pb) is a pervasive toxic metal contaminant associated with a high risk of myocardial injury. However, the precise mechanism underlying Pb-induced myocardial injury has yet to be fully elucidated. In this study, a murine model of Pb exposure (0, 1, 5, and 10 mg/kg) was employed to investigate the involvement of neutrophil degranulation in the induction of myocardial injury. Notably, serum levels of cardiac troponin I (cTnI) and creatine kinase-MB (CK-MB) increased significantly in Pb-exposed mice, whereas cTnI levels in cardiomyocytes decreased, suggesting that Pb exposure may cause early myocardial injury. Moreover, Pb exposure was found to promote neutrophil degranulation, as evidenced by elevated myeloperoxidase (MPO) and neutrophil elastase (NE) concentrations in both the serum of Pb-exposed workers and Pb-exposed mice, as well as the extracellular supernatant of neutrophils following exposure. However, we found that serum level of cTnI enhanced by Pb exposure is associated with increased NE levels in the serum, but not with MPO levels. Upon treatment with NE inhibitor (sivelestat), the serum level of cTnI markedly reduced in Pb-exposed mice, we found that early myocardial injury is associated with NE levels in the serum. At the molecular level, western blotting analysis revealed an upregulation of ERK1/2 expression in vitro following Pb exposure, suggesting that the activation of the ERK1/2 signaling pathway may underlie the participation of neutrophil degranulation in Pb-induced myocardial injury. In summary, our findings demonstrate that Pb exposure can initiate early myocardial injury by promoting the neutrophil degranulation process, thereby highlighting the potential role of this process in the pathogenesis of Pb-associated myocardial injury.

Impact of a high sensitivity troponin accelerated diagnostic protocol on the safety and emergency department length of stay of chest pain in an academic tertiary hospital: a quality improvement study

PURPOSE

High-sensitivity troponin (hsTn) accelerated diagnostic protocols are highly recommended for evaluating acute coronary syndromes. Our goal was to improve care for chest pain patients through the safe adoption of an accelerated diagnostic protocol in our academic Emergency Department (ED) with an aim to reduce mean ED length of stay for chest pain patients by 1 h over 1.5 years. Pre-accelerated diagnostic protocol, our mean ED length of stay for chest pain patients was 9.0 h.

METHODS

Using the Model for Improvement, we implemented a two-hour accelerated diagnostic protocol and conducted two Plan-Do-Study-Act cycles and education efforts to improve accelerated diagnostic protocol compliance and decrease ED length of stay. Using control charts, we measured the mean monthly ED length of stay for chest pain patients to look for special cause evidence of improvement. Process measures measured compliance with the accelerated diagnostic protocol. Balancing measures included the ED length of stay for abdominal pain patients and the number of admissions and deaths at 7 days for chest pain patients.

RESULTS

Mean ED length of stay for chest pain patients decreased from 9.0 to 8.2 h post-accelerated diagnostic protocol. The mean time between troponins decreased from 3.9 to 3.0 h, and the percentage of second troponins repeated at < 2.75 h increased from 22.3% to 58.6%. For abdominal pain patients, ED length of stay decreased from 10.8 to 10.5 h. No chest pain patients died within 7 days pre- or post-accelerated diagnostic protocol. Pre-accelerated diagnostic protocol, 0.84% (41/4,905) were admitted within 7 days. Post-accelerated diagnostic protocol and accelerated diagnostic protocol compliant, 0.70% (13/1,844) were admitted. Post-accelerated diagnostic protocol and accelerated diagnostic protocol non-compliant, 1.1% (13/1,183) were admitted.

CONCLUSION

We safely introduced a hsTn accelerated diagnostic protocol in an academic ED. ED length of stay decreased for chest pain patients but did not meet our 1-h goal.

Comparing the utility of clinical risk scores and integrated clinical judgement in patients with suspected acute coronary syndrome

AIMS

The utility of clinical risk scores regarding the prediction of major adverse cardiac events (MACE) is uncertain. We aimed to directly compare the prognostic performance of five established clinical risk scores as well as an unstructured integrated clinical judgement (ICJ) of the treating emergency department (ED) physician.

METHODS AND RESULTS

Thirty-day MACE including all-cause death, life-threatening arrhythmia, cardiogenic shock, acute myocardial infarction (including the index event), and unstable angina requiring urgent coronary revascularization were centrally adjudicated by two independent cardiologists in patients presenting to the ED with acute chest discomfort in an international multicentre study. We compared the prognostic performance of the HEART score, GRACE score, T-MACS, TIMI score, and EDACS, as well as the unstructured ICJ of the treating ED physician (visual analogue scale to estimate the probability of acute coronary syndrome, ranging from 0 to 100). Among 4551 eligible patients, 1110/4551 patients (24.4%) had at least one MACE within 30 days. Prognostic accuracy was high and comparable for the HEART score, GRACE score, T-MACS, and ICJ [area under the receiver operating characteristic curve (AUC) 0.85-0.87] but significantly lower and only moderate for the TIMI score (AUC 0.79, P < 0.001) and EDACS (AUC 0.74, P < 0.001), resulting in sensitivities for the rule-out of 30-day MACE of 93-96, 87 (P < 0.001), and 72% (P < 0.001), respectively.

CONCLUSION

The HEART score, GRACE score, T-MACS, and unstructured ICJ of the treating physician, not the TIMI score or EDACS, performed well for the prediction of 30-day MACE and may be considered for routine clinical use.

TRIAL REGISTRATION

ClinicalTrials.gov number NCT00470587.

Use of the HEAR Score for 30-Day Risk-Stratification in Emergency Department Patients

BACKGROUND

The 2021 American College of Cardiology/American Heart Association chest pain guidelines recommend risk scores such as HEAR (History, Electrocardiogram, Age, Risk factors) for short-term risk stratification, yet limited data exist integrating them with high-sensitivity cardiac troponin T (hs-cTnT).

METHODS

Retrospective, multicenter (n = 2), observational, US cohort study of consecutive emergency department patients without ST-elevation myocardial infarction who had at least one hs-cTnT (limit of quantitation [LoQ] <6 ng/L, and sex-specific 99th percentiles of 10 ng/L for women and 15 ng/L for men) measurement on clinical indications in whom HEAR scores (0-8) were calculated. The composite major adverse cardiovascular event (MACE) outcome was 30-day prognosis.

RESULTS

Among 1979 emergency department patients undergoing hs-cTnT measurement, 1045 (53%) were low risk (0-3), 914 (46%) intermediate risk (4-6), and 20 (1%) high risk (7-8) based on HEAR scores. HEAR scores were not associated with increased risk of 30-day MACE in adjusted analyses. Patients with quantifiable hs-cTnT (LoQ-99th) had an increased risk for 30-day MACE (3.4%) irrespective of HEAR scores. Those with serial hs-cTnT <99th percentile remained at low risk (range 0%-1.2%) across all HEAR score strata. Higher scores were not associated with long-term (2-year) events.

CONCLUSIONS

HEAR scores are of limited value in those with baseline hs-cTnT 99th percentile to define short-term prognosis. In those with baseline quantifiable hs-cTnT within the reference range (<99th percentile), a higher risk (>1%) for 30-day MACE exists even in those with low HEAR scores. With serial hs-cTnT measurements, HEAR scores overestimate risk when hs-cTnT remains <99th percentile.

Novel Biomarkers and the Multiple-Marker Approach in Early Detection, Prognosis, and Risk Stratification of Cardiac Diseases: A Narrative Review

Cardiac diseases are a primary cause of mortality worldwide, underscoring the importance of early identification and risk stratification to enhance patient outcomes. Biomarkers have become important tools for the risk assessment of cardiovascular disease and monitoring disease progression. This narrative review focuses on the multiple-marker approach, which involves simultaneously evaluating several biomarkers for the early detection and risk stratification of heart diseases. The review covers the clinical applications of novel biomarkers, such as high-sensitivity troponin, galectin-3, source of tumorigenicity 2, B-type natriuretic peptide and N-terminal pro-B-type natriuretic peptide, growth differentiation factor 15, myeloperoxidase, fatty acid-binding protein, C-reactive protein, lipoprotein-associated phospholipase A2, microRNAs, circulating endothelial cells, and ischemia-modified albumin. These biomarkers have demonstrated potential in identifying people who are at high risk for developing heart disease and in providing prognostic data. Given the complexity of cardiac illnesses, the multiple-marker approach to risk assessment is extremely beneficial. Implementing the multiple-marker strategy can improve risk stratification, diagnostic accuracy, and patient care in heart disease patients.

Frequencies of Anti-Troponin I vs Anti-Troponin T Autoantibodies and Degrees of Interference on Troponin Assays

OBJECTIVE

Presence of autoantibodies against troponin I (cTnI) or T (cTnT) has been reported to interfere with troponin assays. However, the extent of the interference with the measurement has not been explored sufficiently. The aims of this study were to examine the frequencies of autoantibodies against troponin I and troponin T and how much these antibodies would affect the measurement.

METHODS

The study comprised 52 subjects who visited Hokkaido University Hospital with suspected ischemic heart diseases. To evaluate the presence of autoantibodies, we calculated the recoveries of cTnI or cTnT after immunoglobulin G depletion, and the distributions of peaks reactive with cTnI or cTnT by high-performance liquid chromatography were examined.

RESULTS

Autoantibodies against cTnI and cTnT were identified in 8 subjects (15.4%) and 1 subject (1.9%), respectively. Although the greatest difference between cTnI and cTnT was 32-fold, the distributions of cTnI-to-cTnT ratios in groups with and without anti-cTnI were not statistically different.

CONCLUSION

Autoantibodies against cTnI were more frequent by several fold than those against cTnT. Their presence did not significantly expand the discrepancy between cTnI and cTnT assays.

New scoring system for acute chest pain risk stratification: Is it worth SVEAT-ing it?

The emergency room is a very potent environment in the hospital. With the growing demands of the population, improved accessibility to health resources, and the onslaught of the triple pandemic, it is extremely crucial to triage patients at presentation. In the spectrum of complaints, chest pain is the commonest. Despite it being a daily ailment, chest pain brings concern to every physician at first. Chest pain could span from acute coronary syndrome, pulmonary embolism, and aortic dissection (all potentially fatal) to reflux, zoster, or musculoskeletal causes that do not need rapid interventions. We often employ scoring systems such as GRACE/PURSUIT/TIMI to assist in clinical decision-making. Over the years, the HEART score became a popular and effective tool for predicting the risk of 30-d major adverse cardiovascular events. Recently, a new scoring system called SVEAT was developed and compared to the HEART score. We have attempted to summarize how these scoring systems differ and their generalizability. With an increasing number of scoring systems being introduced, one must also prevent anchorage bias; i.e., tools such as these are only diagnosis-specific and not organ-specific, and other emergent differential diagnoses must also be kept in mind before discharging the patient home without additional workup.

Management and outcomes of patients with chest pain and psychiatric disorders in the era of high-sensitivity cardiac troponins

BACKGROUND

The management of patients with psychiatric disease and chest pain in the emergency department (ED) in the era of high-sensitivity cardiac troponin assays is unexplored.

OBJECTIVES

To investigate differences in management and outcomes comparing patients with versus without psychiatric disorders who present with chest pain in the ED.

METHODS

All visits to seven different EDs in Sweden from 9 December 2010 to 31 December 2016 by patients with chest pain were included. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to estimate differences in clinical management. Hazard ratios with 95% CIs were used for comparisons of all-cause mortality and risk of cardiovascular events.

RESULTS

Altogether, 216,653 visits were identified, of which 40,054 (18%) occurred in patients with psychiatric disorders. The risk of a myocardial infarction (MI) was reduced almost by half in patients with an affective (OR 0.63; 95% CI: 0.59-0.68) or psychotic disorder (OR 0.57; 95% CI: 0.47-0.70). These patients were less likely to be treated with any cardiovascular medication or to undergo percutaneous coronary intervention. Contrastingly, patients with psychiatric disease had a 1.8- to 2.6-fold increased risk of being diagnosed with an MI registered after the index visit but within 30 days.

CONCLUSIONS

Patients with psychiatric disease and chest pain undergo less intense investigation and are less likely to receive cardiovascular medications compared with patients without psychiatric disease, even in the presence of myocardial injury. In addition, they experience a higher risk of being diagnosed with an MI within 30 days after a visit with no MI.

2022 use of coronary computed tomographic angiography for patients presenting with acute chest pain to the emergency department: An expert consensus document of the Society of cardiovascular computed tomography (SCCT): Endorsed by the American College of Radiology (ACR) and North American Society for cardiovascular Imaging (NASCI)

Coronary computed tomography angiography (CTA) improves the quality of care for patients presenting with acute chest pain (ACP) to the emergency department (ED), particularly in patients with low to intermediate likelihood of acute coronary syndrome (ACS). The Society of Cardiovascular Computed Tomography Guidelines Committee was formed to develop recommendations for acquiring, interpreting, and reporting of coronary CTA to ensure appropriate, safe, and efficient use of this modality. Because of the increasing use of coronary CTA testing for the evaluation of ACP patients, the Committee has been charged with the development of the present document to assist physicians and technologists. These recommendations were produced as an educational tool for practitioners evaluating acute chest pain patients in the ED, in the interest of developing systematic standards of practice for coronary CTA based on the best available data or broad expert consensus. Due to the highly variable nature of medical care, approaches to patient selection, preparation, protocol selection, interpretation or reporting that differs from these guidelines may represent an appropriate variation based on a legitimate assessment of an individual patient's needs.

Implementation of the ESC 0 h/1 h high-sensitivity troponin algorithm for decision-making in the emergency department

Diagnosis of non-ST-segment elevation acute coronary syndromes (NSTEACS) is based on 3 cornerstones: clinical presentation, 12-lead electrocardiogram, and cardiac troponin measurement. Advances in the development of high-sensitivity cardiac troponin (hs-cTn) assays have substantially improved the detection of cardiomyocyte injury in a shorter time period, and hs-cTn has consequently been established as the gold-standard biomarker for the assessment of patients with suspected NSTEACS. The implementation of these assays in clinical practice allows a faster "rule-out", especially among low-risk patients, as well as a safer and more rapid "rule-in", with its therapeutic consequences. Current guidelines for the diagnosis of NSTEACS recommend the use of hs-cTn applied in rapid diagnostic algorithms based on serial hs-cTn sampling within the first few hours. The current work provides an overview of the use of hs-cTn for the early detection of NSTEACS.

Diagnostic discrimination of a novel high-sensitivity cardiac troponin I assay and derivation/validation of an assay-specific 0/1h-algorithm

BACKGROUND

We aimed to assess the diagnostic utility of the Dimension EXL LOCI High-Sensitivity Troponin I (hs-cTnI-EXL) assay.

METHODS

This multicenter study included patients with chest discomfort presenting to the emergency department. Diagnoses were centrally and independently adjudicated by two cardiologists using all available clinical information. Adjudication was performed twice including serial measurements of high-sensitivity cardiac troponin (hs-cTn) I-Architect (primary analysis) and serial measurements of hs-cTnT-Elecsys (secondary analysis) in addition to the clinically used (hs)-cTn. The primary objective was to assess and compare the discriminatory performance of hs-cTnI-EXL, hs-cTnI-Architect and hs-cTnT-Elecsys for acute myocardial infarction (MI). Furthermore, we derived and validated a hs-cTnI-EXL-specific 0/1h-algorithm.

RESULTS

Adjudicated MI was the diagnosis in 204/1454 (14%) patients. The area under the receiver operating characteristics curve for hs-cTnI-EXL was 0.94 (95%CI, 0.93-0.96), and comparable to hs-cTnI-Architect (0.95; 95%CI, 0.93-0.96) and hs-cTnT-Elecsys (0.93; 95%CI, 0.91-0.95). In the derivation cohort (n = 813), optimal criteria for rule-out of MI were <9ng/L at presentation (if chest pain onset >3h) or <9ng/L and 0h-1h-change <5ng/L, and for rule-in ≥160ng/L at presentation or 0h-1h-change ≥100ng/L. In the validation cohort (n = 345), these cut-offs ruled-out 56% of patients (negative predictive value 99.5% (95%CI, 97.1-99.9), sensitivity 97.8% (95%CI, 88.7-99.6)), and ruled-in 9% (positive predictive value 83.3% (95%CI, 66.4-92.7), specificity 98.3% (95%CI, 96.1-99.3)). Secondary analyses using adjudication based on hs-cTnT measurements confirmed the findings.

CONCLUSIONS

The overall performance of the hs-cTnI-EXL was comparable to best-validated hs-cTnT/I assays and an assay-specific 0/1h-algorithm safely rules out and accurately rules in acute MI.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov number, NCT00470587.

The Characteristic of Resident Macrophages and their Therapeutic Potential for Myocardial Infarction

Resident macrophages (R-mac) are a subset of macrophages with self-renewal functions, which play a pivotal role in the homeostasis, inflammation, injury, and repair of the heart. In this paper, we summarize the knowledge related to cardiac R-mac and describe their dominating functions in myocardial infarction, such as inhibiting fibrosis and adverse remodeling, promoting revascularization and improving arrhythmia, etc. In the last, we sketch out the extended application of R-mac in tissue engineering, providing a novel direction of research and application for the therapy in the future.

Evaluation of the Practice Guideline Used for Rule-Out of Myocardial Infarction at a Tertiary Cardiology Center

INTRODUCTION

With the current high burden on the healthcare system and limited resources, the efficient utilization of facilities is of utmost importance. We sought to present the practice guideline used at a high prevalence tertiary cardiology center and compare its safety and efficacy performance with the single high-sensitivity cardiac troponin T strategy, conventional and modified HEART score.

METHODS

In this prospective cohort study, consecutive patients presenting to the emergency department with chest pain or an angina equivalent were recruited. The primary endpoints consisted of major adverse cardiac events at index visits and 30-day follow-up. Patients were managed according to the practice guideline, and sensitivity and negative predictive values were compared.

RESULTS

Of the total 1548 patients, the mean age was 50.4 ± 15.7 years. Ninety-nine (10.9%) patients were admitted at the index visit, and 89 patients were consequently diagnosed with acute coronary symptoms. Six (0.007%) patients experienced major adverse cardiac events within the 30-day follow-up among discharged patients. Among 911 patients with at least 1 troponin, using single high-sensitivity cardiac troponin T, HEART score, and modified HEART score would have further admitted 805, 450, and 609 patients, respectively. The negative predictive value for all 4 algorithms did not significantly differ (99.2% vs. 100% vs. 99.3% vs. 99.6%, respectively).

CONCLUSIONS

The Tehran Herat Center protocol was a relatively safe protocol with high efficacy. Despite the high safety of the other diagnostic pathways, the high volume of patients needing additional evaluation could impose a high burden on the health care system.

Extending the no objective testing rules to patients triaged by the European Society of Cardiology 0/1-hour algorithms

AIMS

After rule-out of non-ST elevation myocardial infarction (NSTEMI) with the European Society of Cardiology (ESC) 0/1 h-algorithms, it is unclear which patients require further anatomical or functional cardiac testing. To test the safety and efficacy of the no-objective-testing (NOT)-rules after NSTEMI rule-out by the ESC 0/1 h-algorithms.

METHODS AND RESULTS

International, prospective, diagnostic multicentre study enrolling adult patients presenting with chest pain to the emergency department. Central adjudication of final diagnosis by two independent cardiologists using information including cardiac imaging. Primary endpoints were the safety and efficacy of the NOT-rules for the rule-out of major adverse cardiovascular events (MACE). Secondary endpoints included 365-day and 2-year MACE. Among 4804 and 4569 patients with available 0/1 h high-sensitivity cardiac troponin (hs-cTn)T-Elecsys or hs-cTnI-Architect concentrations, 2783 (58%) and 2252 (49%) were eligible for application of the NOT-rules after rule-out of NSTEMI by the ESC hs-cTnT/I-0/1h-algorithm. The first rule identified 26% of patients with a sensitivity of 100% (95%CI 98.3-100%) and a negative predictive value (NPV) of 100% (95% CI, n.c.). The second and third rules both identified 31% of patients with a sensitivity of 99.5% (95% CI 97.4-99.9%) and a NPV of 99.9% (95% CI 99.2-99.9%). Similar findings emerged for hs-cTnI. High safety was confirmed for rule-out of 365-day and 2-year MACE and proven to be superior to the HEART Score.

CONCLUSION

All three NOT-rules performed very well for rule-out of MACE. The third NOT-rule best balanced feasibility, safety, and efficacy by identifying nearly one out of three patients as low-risk and may not require further cardiac testing. https://clinicaltrials.gov/ct2/show/NCT00470587.

A Review on Aptamers Selection and Application in Heart Diseases Diagnosis

Biomarkers detection and quantification in biological fluids play a key role in the screening, diagnosing and treating several diseases. Recently, a large number of aptamers have been selected and applied for the sensing of different biomarkers. Combined with different transducers, aptamers provide simple and rapid tools that allow highly sensitive and selective detection. Cardiology requires an accurate assessment of cardiac biomarkers for a complete diagnosis of cardiovascular diseases. The analysis is generally performed by immunoassays using antibodies as biorecognition elements. This review paper focuses on using aptamers as a promising alternative for antibodies in cardiac biomarkers biosensing. First, the different aptamers specific to the most important cardiac biomarkers are Troponin I, the peptide of B-type natriuretic peptide and myoglobin. Then, in the second part, we overview the electrochemical aptasensors principle and characteristics reported in the literature in the last five years.

Contemporary Risk Stratification of Acute Coronary Syndrome

Chest pain is one of the most common presenting concerns of patients seeking care in the emergency department, and the underlying etiology can range from acute coronary syndrome to various other non-cardiac causes. Initial evaluation should focus on characterizing symptoms and identifying risk factors, but further risk stratification using clinical decision pathways and biomarkers (cardiac troponin) is essential. The 2021 American Heart Association/American College of Cardiology guidelines for the evaluation and diagnosis of chest pain represent the first ever guidelines for the evaluation of patients with acute chest pain. The contemporary risk stratification methods described in these guidelines allow for the identification of patient subgroups: patients who do not require further testing, patients who should proceed directly to the cath lab, and patients who will benefit from further anatomic or functional testing. In this review, we describe contemporary risk stratification methods for acute coronary syndrome and summarize the recommendations put forth by the guidelines.

High sensitivity troponin - Six hours is the magic number

BACKGROUND

High sensitivity troponin assays have become widespread for emergency department evaluation of acute chest pain. We assessed if a high sensitivity troponin under the 99th percentile upper reference limit drawn at 6 h or greater from symptom onset could safely rule out acute coronary syndrome in patients who did not meet the rapid rule-out strategy.

METHODS

We conducted a multicenter retrospective study examining emergency department patients with chest pain who did not meet rapid-rule out criteria and were admitted for further evaluation. Among these admitted patients, we assessed the rate of clinically relevant adverse cardiac events (death, cardiac or respiratory arrest, STEMI, or life-threatening arrhythmia) and NSTEMI in patients with high sensitivity troponin less than the 99th percentile value obtained after at least 6 h of chest pain.

RESULTS

Out of 1187 patients admitted, we found 30 clinically relevant adverse cardiac events, all of which occurred in patients admitted for another compelling reason or ischemic ECG. 36 patients had an NSTEMI, of which 33 were identified with high sensitivity troponin greater than 99th percentile upper reference limit within 6 h of chest pain onset. This left 0 clinically relevant adverse cardiac events and 3 NSTEMI among the 429 patients with high sensitivity troponin less than the 99th percentile at 6 h and nonischemic ECG and no other compelling reason for admission.

CONCLUSION

This study assessed patients with chest pain with high sensitivity troponin values between 3 ng/L and the 99th percentile upper reference limit after 6 h of chest pain and found that they have a low rate of clinically relevant adverse cardiac events and NSTEMI.

High-sensitivity troponin I with or without ultra-sensitive copeptin for the instant rule-out of acute myocardial infarction

Background

The instant, single-sampling rule-out of acute myocardial infarction (AMI) is still an unmet clinical need. We aimed at testing and comparing diagnostic performance and prognostic value of two different single-sampling biomarker strategies for the instant rule-out of AMI.

Methods

From the Biomarkers in Acute Cardiac Care (BACC) cohort, we recruited consecutive patients with acute chest pain and suspected AMI presenting to the Emergency Department of the University Medical Center Hamburg-Eppendorf, Hamburg, Germany. We compared safety, effectiveness and 12-month incidence of the composite endpoint of all-cause death and myocardial infarction between (i) a single-sampling, dual-marker pathway combining high-sensitivity cardiac troponin I (hs-cTnI) and ultra-sensitive copeptin (us-Cop) at presentation (hs-cTnI ≤ 27 ng/L, us-Cop < 10 pmol/L and low-risk ECG) and (ii) a single-sampling pathway based on one-off hs-cTnI determination at presentation (hs-cTnI < 5 ng/L and low-risk ECG). As a comparator, we used the European Society of Cardiology (ESC) 0/1-h dual-sampling algorithm.

Results

We enrolled 1,136 patients (male gender 65%) with median age of 64 years (interquartile range, 51–75). Overall, 228 (20%) patients received a final diagnosis of AMI. The two single-sampling instant rule-out pathways yielded similar negative predictive value (NPV): 97.4% (95%CI: 95.4–98.7) and 98.7% (95%CI: 96.9–99.6) for dual-marker and single hs-cTnI algorithms, respectively (P = 0.11). Both strategies were comparably safe as the ESC 0/1-h dual-sampling algorithm and this was consistent across subgroups of early-comers, low-intermediate risk (GRACE-score < 140) and renal dysfunction. Despite a numerically higher rate of false-negative results, the dual-marker strategy ruled-out a slightly but significantly higher percentage of patients compared with single hs-cTnI determination (37.4% versus 32.9%; P < 0.001). There were no significant between-group differences in 12-month composite outcome.

Conclusions

Instant rule-out pathways based on one-off determination of hs-cTnI alone or in combination with us-Cop are comparably safe as the ESC 0/1 h algorithm for the instant rule-out of AMI, yielding similar prognostic information. Instant rule-out strategies are safe alternatives to the ESC 0/1 h algorithm and allow the rapid and effective triage of suspected AMI in patients with low-risk ECG. However, adding copeptin to hs-cTn does not improve the safety of instant rule-out compared with the single rule-out hs-cTn at very low cut-off concentrations.

Trending Cardiac Biomarkers During Pregnancy in Women With Cardiovascular Disease

BACKGROUND

Clinical utility of cardiac biomarker testing during pregnancy in women with preexisting cardiac disease is not well known. We studied the levels and temporal trends of NT-proBNP (N-terminal pro-B-type natriuretic peptide) and hs-cTnI (high-sensitivity cardiac troponin I) throughout pregnancy in women with preexisting cardiac disease and sought to assess the association between NT-proBNP and hs-cTnI and pregnancy outcomes.

METHODS

Three hundred seven pregnant women with preexisting cardiac disease were prospectively recruited. Mixed-effects linear regression analysis was used to compare the NT-proBNP and hs-cTnI levels between time periods and subgroups. Logistic regression analysis adjusted for maternal age and CARPREG II (Cardiac Disease in Pregnancy) risk score assessed the association between NT-proBNP levels and adverse events.

RESULTS

Geometric mean NT-proBNP (95% CI) was stable through pregnancy with a transient significant increase with labor and delivery (101.4 pg/mL [87.1-118.1], 90.2 pg/mL [78.5-103.6], 153.6 pg/mL [126.8-186.1], and 112.2 pg/mL [94.2-133.7] for first/second trimester, third trimester, labor/delivery and postpartum, respectively). We observed a statistically significant difference in the NT-proBNP between women with preserved versus decreased systemic ventricular function, structurally normal versus abnormal heart, modified World Health Organization class 1, 2 versus modified World Health Organization class 3, 4 and no congenital heart disease versus congenital heart disease. Compared to those without events, median (interquartile range) NT-proBNP levels were significantly higher in those who had heart failure (204 pg/mL [51-450] versus 55 pg/mL [31-97]; P=0.001) and preeclampsia (98 pg/mL [40-319] versus 55 pg/mL [31-99]; P=0.027). NT-proBNP, adjusted for age and CARPREG II risk score, was significantly associated with combined heart failure and preeclampsia (adjusted odds ratio, 2.14 [95% CI, 1.48-3.10] per log NT-proBNP increase; P<0.001). NT-proBNP <200 pg/mL had a specificity of 91% and negative predictive value of 95% in predicting combined heart failure and preeclampsia.

CONCLUSIONS

NT-proBNP remains steady over the course of pregnancy with a transient increase during labor and delivery with higher levels in subgroups of stable cardiac patients. NT-proBNP level of 200 pg/mL can be used in the diagnosis of heart failure/preeclampsia in the pregnant cardiac population.

Effects of perilipin-5 on lipid metabolism and high-sensitivity cardiac troponin I

OBJECTIVE:

Heart attack is one of the most common causes of sudden death in adults. Therefore, early detection of heart attack and investigation of potential new biomarkers are of great importance. We investigated whether perilipin-5 is a potential biomarker by examining changes in perilipin-5 serum levels along with high-sensitivity cardiac troponin I during a heart attack.

METHODS:

The subjects were divided into two groups: (1) control group and (2) patients with heart attack, with 150 people in each group. High-sensitivity cardiac troponin I, perilipin-5, total oxidant status, malondialdehyde, reduced glutathione, and superoxide dismutase levels in serum samples were measured. In addition, perilipin-5 mRNA expressions and protein levels were analyzed.

RESULTS:

There was no overall statistical difference between the demographic characteristics of the groups. However, high-density lipoprotein, creatine kinase, Creatine kinase myocardial band, aspartate amino transferase, lactate dehydrogenase, and calcium levels were higher in the heart attack group compared to the control group. We found that the high-sensitivity cardiac troponin I and perilipin-5 levels increased in the patients with heart attack (p<0.0001) compared to control. Although there was an insignificant increase in malondialdehyde levels in the heart attack group (p>0.05), there was a 35.9% increase in total oxidant status levels and a 33.5 and 24.1% decrease in glutathione and superoxide dismutase levels, respectively (p<0.01), compared to control. Perilipin-5 mRNA and protein levels in heart attack patients increased by 48.2 and 23.6%, respectively, compared to the control group (p<0.01).

CONCLUSION:

Our results showed that perilipin-5 together with high-sensitivity cardiac troponin I could be a promising biomarker in heart attack.

Association of Chest Pain Protocol-Discordant Discharge With Outcomes Among Emergency Department Patients With Modest Elevations of High-Sensitivity Troponin

IMPORTANCE

Accelerated diagnostic protocols (ADPs) for chest pain using high-sensitivity troponin (hsTn) levels have excellent sensitivity and negative predictive value for rapid risk stratification of patients with chest pain. However, little is known about the outcomes of patients who are discharged despite abnormal ADP results, ie, after "ruling-in" with a modest elevation of hsTn.

OBJECTIVE

To determine outcomes of patients discharged following ADP, including those who were ruled in with modestly elevated levels of hsTnT but discharged nonetheless.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study included patients with chest pain who presented to the emergency departments (EDs) of a large multisite health system ED between January 2017 to September 2019. Patients were assessed using an ADP, had a peak hsTnT level measured between the limit of quantitation and 52 ng/L, were discharged, and had follow-up in the electronic medical record. Data analysis was conducted from January 2017 to September 2019.

EXPOSURES

Application of an hsTnT ADP.

MAIN OUTCOMES AND MEASURES

Thirty-day major adverse cardiac events (MACE), including myocardial infarction, urgent coronary revascularization, and all-cause death, comparing patients who were discharged following ADP-concordant vs ADP-discordant results.

RESULTS

Of 10 342 patients with chest pain (mean [SD] age 51 [17] years; 5902 [57%] women) discharged following ADP, 29 (0.28%) had MACE. Patients with MACE were older (median [IQR] age, 66 [53-75] years vs 50 [38-62] years; P < .001) and more likely to have prior CAD (12 [41.4%] vs 1805 [17.5%]; P = .002) and hyperlipidemia (13 [44.8%] vs 2248 [21.8%]; P = .006). Additionally, patients with MACE were 5-fold more likely to have been discharged despite ADP discordance (16 [55.2%] vs 1145 [11.1%]; P < .001). A multivariable logistic regression analysis revealed only ADP discordance was independently associated with MACE (odds ratio, 6.42 [95% CI, 2.94-14.0]; P < .001). When stratified by peak hsTnT level, there were no differences in MACE between ADP-concordant and -discordant discharges provided the peak hsTnT measured was less than 12 ng/L. In contrast, patients with peak hsTnT level between 12 and 51 ng/L were significantly more likely to have MACE if they were discharged after ADP-discordant vs -concordant hsTnT series (14 of 609 [2.30%] vs 5 of 1047 [0.48%]; P < .002). Notably, a HEART (history, electrocardiogram, age, risk factors, troponin) score of 4 or greater retrospectively identified the most ADP-discordant discharges (13 of 16 [81.3%]) who had MACE.

CONCLUSIONS AND RELEVANCE

In this cohort study, an hsTnT ADP identified patients who could be discharged from the ED with low 30-day risk of MACE, provided the discharge was based on ADP-concordant "rule-out." Conversely, the rate of MACE was significantly higher among patients discharged despite ADP discordance. Most patients with ADP-discordant discharges who experienced MACE had a HEART score of 4 or greater, suggesting that application of this score may augment discharge decisions of patients despite ADP-discordant troponin series.

Cardiac Troponin Biosensor Designs: Current Developments and Remaining Challenges

Acute myocardial infarction (AMI) is considered as one of the main causes of death, threating human lives for decades. Currently, its diagnosis relies on electrocardiography (ECG), which has been proven to be insufficient. In this context, the efficient detection of cardiac biomarkers was proposed to overcome the limitations of ECG. In particular, the measurement of troponins, specifically cardiac troponin I (cTnI) and cardiac troponin T (cTnT), has proven to be superior in terms of sensitivity and specificity in the diagnosis of myocardial damage. As one of the most life-threatening conditions, specific and sensitive investigation methods that are fast, universally available, and cost-efficient to allow for early initiation of evidence-based, living-saving treatment are desired. In this review, we aim to present and discuss the major breakthroughs made in the development of cTnI and cTnT specific biosensor designs and analytical tools, highlighting the achieved progress as well as the remaining challenges to reach the technological goal of simple, specific, cheap, and portable testing chips for the rapid and efficient on-site detection of cardiac cTnI/cTnT biomarkers in order to diagnose and treat cardiovascular diseases at an incipient stage.

Emergency Department Management of Chest Pain With a High-Sensitivity Troponin-Enabled 0/1-Hour Rule-Out Algorithm

OBJECTIVES

The analytical sensitivity of high-sensitivity cardiac troponin T (hsTnT) assays has enabled rapid myocardial infarction rule-out algorithms for emergency department (ED) presentations. Few studies have analyzed the real-world impact of hsTnT algorithms on outcomes and operations.

METHODS

Comparison of ED length of stay (LOS) and 30-day outcomes (return to ED, inpatient admission, and mortality) for patients presenting with chest pain during 2 separate 208-day periods using a 0/1-hour hsTnT-enabled algorithm or fourth-generation TnT.

RESULTS

Discharge, 30-day readmission, and 30-day mortality rates were not significantly different with fourth-generation TnT vs hsTnT. Thirty-day return rates were significantly decreased with hsTnT (17.4% vs 14.9%; P < .01). For encounters with TnT measured at least twice and resulting in discharge, median ED LOS decreased by 61 minutes with the use of hsTnT (488 vs 427 minutes; P < .0001). Median time between first and second TnT results decreased by 82 minutes with hsTnT (202 vs 120 minutes; P < .0001), suggesting that the 0/1-hour algorithm was incompletely adopted.

CONCLUSIONS

Implementation of the hsTnT algorithm was associated with decreased 30-day return rates and decreased ED LOS for a subset of patients, despite incomplete adoption of the 0/1-hour algorithm.

Mountain Ultra-Marathon (UTMB) Impact on Usual and Emerging Cardiac Biomarkers

The number of participants in ultra-marathons is increasing. However, the data regarding the impact of this type of exercise on the cardiovascular system are contradictory. In our study, 28 ultra-trail runners were enrolled. Blood samples were collected at three time points: immediately before, immediately after, and 7 days after the ultra-marathon. Different biomarkers were measured. Immediately after the race, the blood concentrations of the different cardiac and inflammatory biomarkers increased significantly. Interestingly, some biomarkers remained high even after 7 days of recovery.

Factors associated with late presentation to the emergency department in patients complaining of chest pain

OBJECTIVE

We investigated which factors predict late presentation (LP) to the emergency department (ED) in patients with non-traumatic chest pain (CP).

METHODS

All CP cases attended at a single ED (2008-2017) were included. LP was considered if time from CP onset to ED arrival was>6 h. We analyzed associations between 42 patient/CP-related characteristics and LP in the whole cohort and in patients with CP due to acute coronary syndrome (ACS).

RESULTS

The cohort included 25,693 cases (LP=50.6%; ACS=19.0%). Twenty factors were associated with LP, and 8 were also found in patients with ACS: CP of short-duration, aggravated by exertion or breathing/movement, undulating or recurrent CP increased the risk of LP, whereas CP accompanied by diaphoresis, irradiated to the throat, and chronic treatment with nitrates decreased the risk of LP. Exertional and recurrent CP were associated with both, LP and ACS.

CONCLUSION

Some characteristics, mainly CP-related, may lead to LP to the ED. CP aggravated by exercise and recurrent CP were associated with both LP and a final diagnosis of ACS.

PRACTICE IMPLICATIONS

Patient educational initiatives should consider these two features as potential warnings for ACS and thereby encourage patients to seek early medical consultation.

[The AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR guidelines 2021 on thoracic pain]

The AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR guidelines 2021 on thoracic pain focusses on chest pain as a single but important symptom. The guidelines fall back on many guidelines on cardiac disease entities, such as myocardial infarction with (STEMI) or without ST segment elevation (NSTEMI), chronic coronary artery disease (CAD), pericarditis and aortic dissection. They also refer to guidelines on cardiac syndromes, such as acute coronary syndrome (ACS) or ACS without persisting ST segment elevation (NSTE-ACS), in which angina pectoris is an integral component. The guideline separates acute from stable angina pectoris. It gives a comprehensive overview on risk stratification and clinical work-up of chest pain. It stretches the main theme to angina equivalents, such as dyspnoe. They meticulously weigh up the noninvasive against the invasive diagnostic methods under the aspects of a cost-benefit analysis. In this context, a clear trend towards evidence-based, cost-effective noninvasive methods in recent years is unmistakable.

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.

Initial experience regarding the safety and yield of rest-stress myocardial perfusion imaging in emergency department patients with mildly abnormal high-sensitivity cardiac troponins

BACKGROUND

With high-sensitivity troponin testing, approximately a third of patients presenting to emergency departments (EDs) with suspected acute coronary syndromes will have mildly abnormal values. However, data regarding rest-stress myocardial perfusion imaging (MPI) in these patients are limited. We hypothesize that stress testing is safe and that the yield for detecting myocardial ischemia is associated with risk stratification by the HEART score.

METHODS AND RESULTS

We conducted a retrospective cohort study of consecutive patients referred for rest-stress MPI with mildly abnormal high-sensitivity troponin T (hs-cTn) values. Outcomes were adverse events related to stress MPI, defined as myocardial infarction or ventricular tachyarrhythmia, and the presence of ischemia, defined as a reversible perfusion defect. Among 213 patients, the median age was 67, most were male (61.5%, n = 131), and prior CAD was common (53.5%, n = 114). Myocardial ischemia was present in 13.6% (n = 29), and there were no adverse events attributable to stress MPI. A higher HEART score was associated with myocardial ischemia (Odds Ratio [OR] 1.50, 95% Confidence Interval [CI] 1.08 to 2.08, P = .002).

CONCLUSION

Rest-stress MPI appears safe in patients with mildly abnormal hs-cTn values, and the yield for detecting ischemia is associated with the HEART score, though further validation studies are needed.

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.

0/2 h-Algorithm for Rapid Triage of Suspected Myocardial Infarction Using a Novel High-Sensitivity Cardiac Troponin I Assay

Background

We aimed to derive and validate a 0/2 h-algorithm using the new high-sensitivity cardiac troponin I (hs-cTnI)-VITROS assay (VITROS® Immunodiagnostic Products hs-Troponin I Reagent Pack, Ortho Clinical Diagnostics) for rapid rule-out/in of non-ST-segment elevation myocardial infarction (NSTEMI).

Methods

The final diagnosis was centrally adjudicated by 2 independent cardiologists according to the fourth universal definition of myocardial infarction (MI) among 1888 patients presenting to the emergency department with acute chest pain. hs-cTnI-VITROS concentrations were measured at presentation and at 2 h in a blinded fashion. The optimal assay-specific thresholds for the hs-cTnI-VITROS 0/2 h-algorithm were derived in a randomly selected 70% of the cohort and validated in the remaining 30%.

Results

NSTEMI was the final diagnosis in 216/1322 (16.3%) patients of the derivation cohort. Rule-out was defined as baseline hs-cTnI concentrations of &lt;1 ng/L in patients presenting with chest pain onset &gt;3 h or a baseline hs-cTnI concentration of &lt;2 ng/L and an absolute change of &lt;3 ng/L within 2 h. Thresholds for rule-in were either ≥40 ng/L at presentation or an absolute change within 2 h of ≥ 5ng/L. In the derivation cohort, these thresholds ruled-out 50.8% of patients with a negative predictive value (NPV) and sensitivity of 99.7% (95% Confidence Interval (CI), 98.8–99.9%) and 99.1% (95% CI, 96.7–99.9%), and ruled-in 17.9% with a positive predictive value (PPV) of 79.2% (95% CI, 74.3–83.5%). In the validation cohort, NSTEMI was the final diagnosis in 91/566 (16.1%) patients. The derived 0/2 h-algorithm ruled-out 46.3% of patients with a NPV and sensitivity of 100% (95% CI, 95.6–100%) and 100% (95% CI, 96.0–100%), and ruled-in 18.9% with a PPV of 73.8% (95% CI, 66.1–80.3%) in the validation cohort.

Conclusion

hs-cTnI-VITROS concentrations at presentation combined with absolute changes within the first 2 h allowed safe rule-out and accurate rule-in of NSTEMI in two-thirds of unselected patients presenting with acute chest pain to the emergency department.

Trial registration

www.clinicaltrials.gov: NCT0047058

Accounting for frailty and multimorbidity when interpreting high-sensitivity troponin I tests in oldest old

Background

Older patients evaluated in Emergency Departments (ED) for suspect Myocardial Infarction (MI) frequently exhibit unspecific elevations of serum high‐sensitivity troponin I (hs‐TnI), making interpretation particularly challenging for emergency physicians. The aim of this longitudinal study was to identify the interaction of multimorbidity and frailty with hs‐TnI levels in older patients seeking emergency care.

Methods

A group of patients aged≥75 with suspected MI was enrolled in our acute geriatric ward immediately after ED visit. Multimorbidity and frailty were measured with Cumulative Illness Rating Scale (CIRS) and Clinical Frailty Scale (CFS), respectively. The association of hs‐TnI with MI (main endpoint) was assessed by calculation of the Area Under the Receiver‐Operating Characteristic Curve (AUROC), deriving population‐specific cut‐offs with Youden test. The factors associated with hs‐TnI categories, including MI, CFS and CIRS, were determined with stepwise multinomial logistic regression. The association of hs‐TnI with 3‐month mortality (secondary endpoint) was also investigated with stepwise logistic regression.

Results

Among 268 participants (147 F, median age 85, IQR 80–89), hs‐TnI elevation was found in 191 cases (71%, median 23 ng/L, IQR 11–65), but MI was present in only 12 cases (4.5%). hs‐TnI was significantly associated with MI (AUROC 0.751, 95% CI 0.580–0.922, p = 0.003), with an optimal cut‐off of 141 ng/L. hs‐TnI levels ≥141 ng/L were significantly associated with CFS (OR 1.58, 95% CI 1.15–2.18, p = 0.005), while levels <141 ng/L were associated with the cardiac subscore of CIRS (OR 1.36, 95% CI 1.07–1.71, p = 0.011). CFS, but not hs‐TnI levels, predicted 3‐month mortality.

Conclusions

In geriatric patients with suspected MI, frailty and cardiovascular multimorbidity should be carefully considered when interpreting emergency hs‐TnI testing.

Establishment of the reference interval for high-sensitivity cardiac troponin T in healthy children of Chongqing Nan'an district

OBJECTIVE

To detect the concentration of high-sensitivity cardiac troponin T (hs-cTnT) in healthy children aged 0-14 years by electrochemiluminescence immunoassay (ECLIA), so as to explore the differences in different ages and genders. The aim of this study is to establish the reference interval for hs-cTnT in healthy children aged 0-14 years.

METHODS

After screening, 3463 healthy children, including 1924 boys and 1539 girls, were selected from 4617 children aged 0-14 years. They were divided into nine groups: one day (umbilical cord blood; 'UCB'), one day (venous blood; 'VB'), 2-28 days, 29 days-<3 months, 3-<6 months, 6 months-<1 year old, 1-< 3 years old, 3-< 6 years old and 6-14 years old. A nonparametric test was used to detect the hs-cTnT concentration. The upper limit of the reference interval is the mean of the 99th percentile after bootstrap sampling.

RESULTS

Hs-cTnT levels conformed to a non-Gaussian distribution. There was no significant difference in the concentration of hs-cTnT between boys and girls in the general data, but there were differences between boys and girls in the 3-<6 years old and 6-14 years old age groups. Except for UCB and 2-28 days, the concentration of hs-cTnT was significantly different in other age groups. The level of hs-cTnT in neonatal serum (2-28 days) was the highest. In other groups, it decreased gradually with age and dropped to the reference range of adults (0-14ng/L) at one-year old. The upper limit of reference interval of hs-cTnT concentration in each group was, respectively, 60.8, 78.8, 96.6, 58.6, 34.2, 16.2, 11.4, 8.0 (7.8 female), and 7.9 (7.3 female) ng/L.

CONCLUSIONS

Referring to WS/T 402-2012 establishment of reference intervals for clinical laboratory testing projects and CLSI (Clinical and Laboratory Standards Institute) C28-A3 documents and the joint expert consensus of ESC (European Society of Cardiology) and ACC (American College of Cardiology) in 2007, we established the reference interval of hs-cTnT concentration in children aged 0-14 years in Chongqing Nan'an district of China which can provide certain reference value for clinical diagnosis and treatment of myocarditis and myocardial (micro) injury in children.