True 99th centile of high sensitivity cardiac troponin for hospital patients: prospective, observational cohort study

Impact of Elevated Troponin Level at the Time of Sepsis Recognition on the Clinical Outcomes: A Propensity Score-Matched Cohort Study

BACKGROUND

Sepsis-induced cardiac dysfunction, known as septic cardiomyopathy, is a common complication associated with increased mortality. Cardiac troponins serve as markers for myocardial injury and are frequently elevated in patients with sepsis. However, the role of troponin elevation at sepsis recognition in risk stratification remains controversial.

METHODS AND RESULTS

This nationwide multicenter prospective cohort study analyzed 2141 adult patients with sepsis without prior cardiovascular disease from the Korean Sepsis Alliance registry. These patients were classified as having either elevated troponin levels or troponin levels in the normal range at the time of sepsis recognition, according to the reference ranges specific to each participating institution. The primary outcome was hospital mortality, and propensity score matching was used to control for confounding factors. In the propensity score-matched cohort (523 pairs), there were no significant differences in hospital mortality (35.2% versus 32.7%, odds ratio [OR], 1.12 [95% CI, 0.86-1.44], P=0.396), hospital length of stay (13.0 versus 15.0 days, OR, 1.00 [95% CI, 0.99-1.00], P=0.128), intensive care unit mortality (24.7% versus 25.0%, OR, 0.98 [95% CI, 0.74-1.30], P=0.886), or intensive care unit length of stay between the elevated troponin and control groups. However, landmark analysis revealed that the elevated troponin group had a lower survival probability after 1 week (log-rank P=0.033) and significantly higher kidney Sequential Organ Failure Assessment scores from intensive care unit admission to day 7 (P=0.003).

CONCLUSIONS

Troponin elevation at sepsis recognition was not significantly associated with increased hospital mortality or worse clinical outcomes in patients with sepsis.

Enhancing lateral flow immunoassay performance for cardiac troponin I detection with pore-size tailored silica nanoparticles and smartphone-based "AdaptiScan" analysis

The accurate and rapid detection of cardiac troponin I (cTnI) at the point of care is crucial for the timely diagnosis of myocardial infarction (MI). This study introduces an advanced lateral flow immunoassay (LFIA) platform for cTnI detection. We employed small-sized, large-pore dendritic mesoporous silica nanoparticles (DMSN-2) to encapsulate quantum dots (QDs), achieving an enhanced QD loading capacity of 1.427 g QD/g silica, compared to 0.881 g QD/g silica for smaller pore counterparts (DMSN-1). This nano-LFIA was further integrated with "AdaptiScan", a smartphone-based detection system that uses adaptive detection algorithms to automatically extract and analyze fluorescence signals from LFIA strips. This integration of pore-size tailored DMSNs and "AdaptiScan" resulted in a limit of detection for cTnI of 42.6 ng/L, which meets clinical diagnostic requirements. The platform offers a sensitive, cost-effective, and portable solution for rapid detection of MI, potentially transforming point-of-care testing in resource-limited settings.

Type 2 myocardial infarction: challenges in diagnosis and treatment

The Fourth Universal Definition of Myocardial Infarction recommends a classification based on aetiology, in recognition that the underlying pathophysiology of myocardial infarction influences the approach to investigation and treatment. Type 1 myocardial infarction occurs due to atherosclerotic plaque rupture with thrombosis, whereas type 2 myocardial infarction occurs due to an imbalance in myocardial oxygen supply or unmet need in myocardial oxygen demand, without atherothrombosis, usually in the context of another acute illness. In this state-of-the-art review, the diagnosis, investigation, and treatment of patients with type 2 myocardial infarction are considered, with general advice for clinical practice and a consideration of future research directions.

Sex and Population-Specific 99th Percentiles of Troponin for Myocardial Infarction in the Danish Population (DANSPOT)

BACKGROUND

Sex- and population-specific 99th percentiles of high-sensitivity cardiac troponin (hs-cTn) are recommended in guidelines although the evidence for a clinical utility is sparse. The DANSPOT trial will investigate the clinical effect of sex- and population-specific 99th percentiles of cTn. We report the 99th percentiles derived from this trial and their dependency on kidney function.

METHODS

We used samples from healthy Danish blood donors and measured hemoglobin A1c, N-terminal pro-brain natriuretic peptide and creatinine, and calculated an estimated glomerular filtration rate (eGFR). We compared 2 cutoffs for the eGFR of healthy participants (60 vs 90 mL/min/1.73 m2). The cTn assays investigated were Siemens Atellica and Dimension Vista hs-cTnI, Abbott hs-cTnI, and Roche hs-cTnT.

RESULTS

A total of 2287 participants were sampled, of which 71 (3.1%) were excluded due to a history of heart disease (n = 4), insufficient material (n = 7), or a screening biomarker (n = 60). Of the remaining 2216 participants, 1325 (59.8%) had an eGFR ≥90 mL/min/1.73 m2. Compared to a cutoff of 60 mL/min/1.73 m2 for eGFR, using 90 mL/min/1.73 m2 resulted in lower 99th percentiles for females; Siemens Vista (46 vs 70 ng/L), Abbott (14 vs 18 ng/L), and Roche cTnT (10 vs 13 ng/L), and decreased the number of measurements above the manufacturers' 99th percentiles for all assays.

CONCLUSIONS

We present reference values for 4 cTn assays for eGFR cutoffs of 60 and 90 mL/min/1.73 m2. These cutoffs differ based on the eGFR threshold for inclusion indicating that any chosen cutoff is also valuable with moderately reduced kidney function.

Relevance of surveillance manual for the early detection of immune checkpoint inhibitor-induced myocarditis: A case series

Objective

The European Cardio-Oncology Guidelines recommend regular electrocardiography and troponin testing during immune checkpoint inhibitors (ICIs) treatment, but their efficacy for monitoring ICI treatment remains unclear. This study aimed to evaluate the effectiveness of a surveillance protocol for early detection of ICI-induced myocarditis.

Methods

Between May 2014 and May 2024, patients who began treatment with ICIs at our hospital and developed ICI-induced myocarditis were included in this study. We created a straightforward management flowchart for myocarditis. The protocol was based on monitoring troponin T levels. We confirmed the efficacy of our surveillance protocol using a case series of ICI-induced myocarditis.

Results

During the observation period, 3481 patients were newly started on ICIs at our hospital. Five patients were previously diagnosed with myocarditis, and five patients were diagnosed with myocarditis after the implementation of the surveillance protocol. The manual enabled the early detection of myocarditis, and the mortality rate for myocarditis at our hospital improved from 60% to 0%. The incidence of conduction system disorders significantly reduced from 100% to 0% (P < 0.01). After the surveillance protocol was initiated, there were no cases of myocarditis requiring immunosuppressive drugs beyond steroids.

Conclusions

This study confirmed the relevance of a troponin-based surveillance protocol for the early detection of ICI-induced myocarditis. The implementation of the surveillance protocol reduced mortality from myocarditis and significantly reduced serious complications of conduction system disorders. Although this study is a small case series of patients who developed myocarditis, we confirm the effectiveness of surveillance for myocarditis.

Management of Acute Coronary Syndrome in Elderly Patients: A Narrative Review through Decisional Crossroads

Diagnosis and treatment of acute coronary syndrome (ACS) pose particular challenges in elderly patients. When high troponin levels are detected, the distinction between non-ischemic myocardial injury (NIMI), type 1, and type 2 myocardial infarction (MI) is the necessary first step to guide further care. However, the assessment of signs of ischemia is hindered in older patients, and no simple clinical or laboratory tool proved useful in this discrimination task. Current evidence suggests a benefit of an invasive vs. conservative approach in terms of recurrence of MI, with no significant impact on mortality. In patients with multivessel disease in which the culprit lesion has been treated, a physiology-guided complete percutaneous revascularization significantly reduced major events. The management of ACS in elderly patients is an example of the actual need for a multimodal, thorough clinical approach, coupled with shared decision-making, in order to ensure the best treatment and avoid futility. Such a need will likely grow throughout the next decades, with the aging of the world population. In this narrative review, we address pivotal yet common questions arising in clinical practice while caring for elderly patients with ACS.

Acute Myocardial Infarction in the Setting of Pulmonary Hypertension due to a Patent Foramen Ovale and Paradoxical Embolism

A 67-year-old woman with pulmonary hypertension (PH) presented with a 1-day history of worsening shortness of breath and pleuritic chest pain and was found to have a troponin T level of 3755 ng/L (ref. range 0-19 ng/L). An initial diagnostic workup in the emergency department (ED) led to an urgent left heart catheterization which revealed a 90% occlusive right coronary artery blood clot, even though a recent heart catheterization less than a month prior was completely unremarkable. Further workup led to the discovery of a patent foramen ovale (PFO) and an aneurysmal interatrial septum, suggesting the presence of a paradoxical embolism. While typically asymptomatic, a PFO is an important clinical entity that can lead to irreversible cardiac damage. Suspicion should be high for this finding in the case of an acute myocardial infarction (MI) with no clear cause, especially in a patient with elevated right heart pressures.

High-Sensitivity Cardiac Troponin Assays: Ready for Prime Time!

Rapid and accurate triage of patients presenting with chest pain to an emergency department (ED) is critical to prevent ED overcrowding and unnecessary resource use in individuals at low risk of acute myocardial infarction (AMI) and to efficiently and effectively guide patients at high risk to definite therapy. The use of biomarkers for rule-out or rule-in of suspected AMI has evolved substantially over the last several decades. Previously well-established biomarkers have been replaced by cardiac troponin (cTn). High-sensitivity cTn (hs-cTn) assays represent the newest generation of cTn assays and offer tremendous advantages, including improved sensitivity and precision. Still, implementation of these assays in the United States lags behind several other areas of the world. Within this educational review, we discuss the evolution of biomarker testing for detection of myocardial injury, address the specifics of hs-cTn assays and their recommended use within triage algorithms, and highlight potential challenges in their use. Ultimately, we focus on implementation strategies for hs-cTn assays, as they are now clearly ready for prime time.

High-Sensitivity Troponin I and Cardiovascular Events in Stable Coronary Artery Disease: Insights from a Longitudinal Outpatient Study

Numerous studies have been published suggesting that troponin levels are related to adverse outcomes in chronic cardiac and non-cardiac conditions. Our study investigated whether troponin levels gathered from unselected blood samples taken during outpatient care are associated with adverse outcomes in a population with stable coronary artery disease. In a cohort of 949 patients with stable coronary artery disease, an average age of 67.5 ± 9.5 years, 69.5% male, 52.1% diabetics, 51.6% with previous myocardial infarction, and 57.9% with triple-vessel disease, 21.7% of patients encountered new events during an average period of monitoring of 2.07 ± 0.81 years. Troponin I/99th percentile categorized into tertiles emerged as an independent predictor of death and combined events risk (hazard ratio: 2.02 (1.13-3.60), p = 0.017; 2.30 (1.37-3.88, p = 0.002, respectively). A troponin ratio > 0.24 was able to identify 53.3% of patients at risk of death and heart failure hospitalization. In patients with stable coronary artery disease who are adherent to treatment, troponin levels are independently associated with death and heart failure hospitalization in a medium-term follow-up.

Association between troponin level and medium-term mortality in 20 000 hospital patients

INTRODUCTION

Cardiac troponin (cTn) concentrations above the manufacturer recommended upper limit of normal (ULN) are frequently seen in hospital patients without a clinical presentation consistent with type 1 myocardial infarction, and the significance of this is uncertain. The aim of this study was to assess the relationship between medium-term mortality and cTn concentration in a large consecutive hospital population, regardless of whether there was a clinical indication for performing the test.

METHOD

This prospective observational study included 20 000 consecutive in-hospital and outpatient patients who had a blood test for any reason at a large teaching hospital, and in whom a hs-cTnI assay was measured, regardless of the original clinical indication. Mortality was obtained via NHS Digital.

RESULTS

A total of 20 000 patients were included in the analysis and 18 282 of these (91.4%) did not have a clinical indication for cardiac troponin I (cTnI) testing. Overall, 2825 (14.1%) patients died at a median of 809 days. The mortality was significantly higher if the cTnI concentration was above the ULN (45.3% vs 12.3% p<0.001 log rank). Multivariable Cox analysis demonstrated that the log10 cTnI concentration was independently associated with mortality (HR 1.76 (95% CI 1.65 to 1.88)). Landmark analysis, excluding deaths within 30 days, showed the relationship between cTnI concentration and mortality persisted.

CONCLUSION

In a large, unselected hospital population, in 91.4% of whom there was no clinical indication for testing, cTnI concentration was independently associated with medium-term cardiovascular and non-cardiovascular mortality in the statistical model tested.

The Relationship Between Cardiac Troponin in People Hospitalised for Exacerbation of COPD and Major Adverse Cardiac Events (MACE) and COPD Readmissions

Background

No single biomarker currently risk stratifies chronic obstructive pulmonary disease (COPD) patients at the time of an exacerbation, though previous studies have suggested that patients with elevated troponin at exacerbation have worse outcomes. This study evaluated the relationship between peak cardiac troponin and subsequent major adverse cardiac events (MACE) including all-cause mortality and COPD hospital readmission, among patients admitted with COPD exacerbation.

Methods

Data from five cross-regional hospitals in England were analysed using the National Institute of Health Research Health Informatics Collaborative (NIHR-HIC) acute coronary syndrome database (2008-2017). People hospitalised with a COPD exacerbation were included, and peak troponin levels were standardised relative to the 99th percentile (upper limit of normal). We used Cox Proportional Hazard models adjusting for age, sex, laboratory results and clinical risk factors, and implemented logarithmic transformation (base-10 logarithm). The primary outcome was risk of MACE within 90 days from peak troponin measurement. Secondary outcome was risk of COPD readmission within 90 days from peak troponin measurement.

Results

There were 2487 patients included. Of these, 377 (15.2%) patients had a MACE event and 203 (8.2%) were readmitted within 90 days from peak troponin measurement. A total of 1107 (44.5%) patients had an elevated troponin level. Of 1107 patients with elevated troponin at exacerbation, 256 (22.8%) had a MACE event and 101 (9.0%) a COPD readmission within 90 days from peak troponin measurement. Patients with troponin above the upper limit of normal had a higher risk of MACE (adjusted HR 2.20, 95% CI 1.75-2.77) and COPD hospital readmission (adjusted HR 1.37, 95% CI 1.02-1.83) when compared with patients without elevated troponin.

Conclusion

An elevated troponin level at the time of COPD exacerbation may be a useful tool for predicting MACE in COPD patients. The relationship between degree of troponin elevation and risk of future events is complex and requires further investigation.

Is high sensitivity troponin, taken regardless of a clinical indication, associated with 1 year mortality in critical care patients?

The aim of this study was to assess whether high sensitivity troponin (hs-cTnI) is associated with 1 year mortality in critical care (CC). One year mortality data were obtained from NHS Digital for a consecutive cohort of patients admitted to general CC unit (GCCU) and neuroscience CC unit (NCCU) who had hs-cTnI tests performed throughout their CC admission, regardless of whether the test was clinically indicated. Cox proportional hazards were used to estimate the risk of 1-year mortality. A landmark analysis was undertaken to assess whether any relationship at 1 year was driven by mortality within the first 30 days. A total of 1033 consecutive patients were included. At 1 year 254 (24.6%) patients had died. The admission log(10)hs-cTnI concentration in the entire cohort (HR 1.35 (95% CI 1.05-1.75) p = 0.009 with a bootstrap of 1000 samples) was independently associated with 1 year mortality. On landmark analysis the association with 1 year mortality was driven by 30 day mortality. These results indicate that admission hs-cTnI concentration is independently associated with 1 year mortality in CC and this relationship may be driven by differences in mortality at 30 days.

A pipeline to further enhance quality, integrity and reusability of the NCCID clinical data

The National COVID-19 Chest Imaging Database (NCCID) is a centralized UK database of thoracic imaging and corresponding clinical data. It is made available by the National Health Service Artificial Intelligence (NHS AI) Lab to support the development of machine learning tools focused on Coronavirus Disease 2019 (COVID-19). A bespoke cleaning pipeline for NCCID, developed by the NHSx, was introduced in 2021. We present an extension to the original cleaning pipeline for the clinical data of the database. It has been adjusted to correct additional systematic inconsistencies in the raw data such as patient sex, oxygen levels and date values. The most important changes will be discussed in this paper, whilst the code and further explanations are made publicly available on GitLab. The suggested cleaning will allow global users to work with more consistent data for the development of machine learning tools without being an expert. In addition, it highlights some of the challenges when working with clinical multi-center data and includes recommendations for similar future initiatives.

Myocardial injury defined as elevated high-sensitivity cardiac troponin T is associated with higher mortality in patients seeking care at emergency departments with acute dyspnea

BACKGROUND

Elevated levels of cardiac troponin T has been observed in patients seeking care at the emergency department (ED) presenting with chest pain but without myocardial infarction (MI). The clinical importance of this observation remains, however, still unclear. Our main aim was to study the role of cardiac troponin T in patients admitted to the emergency department with acute dyspnea, a group of patients with a high cardiovascular comorbidity, but no primary acute MI.

POPULATION AND METHODS

Patients from the age of 18 seeking care at the ED for dyspnea, without an acute cardiac syndrome, and with a recorded assessment of high-sensitivity cardiac troponin T (hs-cTnT), were included (n = 1001). Patients were categorized into 3 groups by hs-cTnT level, i.e. <15, 15-100 and > 100 µg/l. Cox regression with Hazard Ratios (HRs) and 95% Confidence Intervals (CI) for 3-months mortality was performed, with adjustment for sex, age, respiratory frequency, saturation, CHF, renal disease, and BMI.

RESULTS

Fully adjusted HRs (95% CI) for 3-month mortality, with hs-cTnT < 15 µg/l as reference level, showed for hs-cTnT 15-100 a HR of 3.682 (1.729-7.844), and for hs-cTnT > 100 a HR of 10.523 (4.465-24.803).

CONCLUSION

Elevated hs-cTnT seems to be a relevant marker of poor prognosis in patients with acute dyspnea without MI and warrants further validation and clinical testing.

Death rates following emergency department chest pain assessment

OBJECTIVES

We sought to define the rate of unexpected death from acute coronary syndrome or arrhythmia in chest pain patients directly discharged from the ED.

METHODS

Retrospective audit of all chest pain patients at a tertiary ED for 7 years. Medical and post-mortem records of the deceased were reviewed with independent cardiologist adjudication to determine outcomes. Primary outcome measure was 28-day unexpected death secondary to acute coronary syndrome or arrhythmia.

RESULTS

During the study period, 25 924 patients presented with chest pain, 292 (1.1%, 95% confidence interval [CI] 0.99-1.01%) died within 28 days. Of these, 16 680(64%, 95% CI 63.88-64.12%) were discharged by ED, two (0.01%, 95% CI 0-0.011%) of this group died from the primary outcome.

CONCLUSION

Unexpected death is very uncommon after ED discharge of chest pain patients.

Influence of Age on the Diagnosis of Myocardial Infarction

BACKGROUND

The 99th centile of cardiac troponin, derived from a healthy reference population, is recommended as the diagnostic threshold for myocardial infarction, but troponin concentrations are strongly influenced by age. Our aim was to assess the diagnostic performance of cardiac troponin in older patients presenting with suspected myocardial infarction.

METHODS

In a secondary analysis of a multicenter trial of consecutive patients with suspected myocardial infarction, we assessed the diagnostic accuracy of high-sensitivity cardiac troponin I at presentation for the diagnosis of type 1, type 2, or type 4b myocardial infarction across 3 age groups (<50, 50-74, and ≥75 years) using guideline-recommended sex-specific and age-adjusted 99th centile thresholds.

RESULTS

In 46 435 consecutive patients aged 18 to 108 years (mean, 61±17 years), 5216 (11%) had a diagnosis of myocardial infarction. In patients <50 (n=12 379), 50 to 74 (n=22 380), and ≥75 (n=11 676) years, the sensitivity of the guideline-recommended threshold was similar at 79.2% (95% CI, 75.5-82.9), 80.6% (95% CI, 79.2-82.1), and 81.6% (95% CI, 79.8-83.2), respectively. The specificity decreased with advancing age from 98.3% (95% CI, 98.1-98.5) to 95.5% (95% CI, 95.2-95.8), and 82.6% (95% CI, 81.9-83.4). The use of age-adjusted 99th centile thresholds improved the specificity (91.3% [90.8%-91.9%] versus 82.6% [95% CI, 81.9%-83.4%]) and positive predictive value (59.3% [57.0%-61.5%] versus 51.5% [49.9%-53.3%]) for myocardial infarction in patients ≥75 years but failed to prevent the decrease in either parameter with increasing age and resulted in a marked reduction in sensitivity compared with the use of the guideline-recommended threshold (55.9% [53.6%-57.9%] versus 81.6% [79.8%-83.3%].

CONCLUSIONS

Age alters the diagnostic performance of cardiac troponin, with reduced specificity and positive predictive value in older patients when applying the guideline-recommended or age-adjusted 99th centiles. Individualized diagnostic approaches rather than the adjustment of binary thresholds are needed in an aging population.

Presentation cardiac troponin and early computed tomography coronary angiography in patients with suspected acute coronary syndrome: a pre-specified secondary analysis of the RAPID-CTCA trial

Aims

To evaluate the potential associations between presentation cardiac troponin and the clinical impact of early computed tomography coronary angiography (CTCA) in intermediate-risk patients with suspected acute coronary syndrome.

Methods and results

In a large multicentre randomized controlled trial of patients with intermediate-risk chest pain due to suspected acute coronary syndrome, early CTCA had no effect on the primary outcome—death or subsequent Type 1 or 4b myocardial infarction—but reduced the rate of invasive coronary angiography. In this pre-specified secondary analysis, cardiovascular testing and clinical outcomes were compared between those with or without cardiac troponin elevation at presentation. Of 1748 patients, 1004 (57%) had an elevated cardiac troponin concentration and 744 (43%) had a normal concentration. Patients with cardiac troponin elevation had a higher Global Registry of Acute Coronary Events score (132 vs. 91; P < 0.001) and were more likely to have obstructive coronary artery disease (59 vs. 33%; P < 0.001), non-invasive (72 vs. 52%; P < 0.001) and invasive (72 vs. 38%; P < 0.001) testing, coronary revascularization (47 vs. 15%; P < 0.001), and the primary outcome (8 vs. 3%; P = 0.007) at 1 year. However, there was no evidence that presentation cardiac troponin was associated with the relative effects of early CTCA on rates of non-invasive (P_interaction = 0.33) and invasive (P_interaction = 0.99) testing, coronary revascularization (P_interaction = 0.57), or the primary outcome (P_interaction = 0.41).

Conclusion

Presentation cardiac troponin had no demonstrable associations between the effects of early CTCA on reductions in non-invasive and invasive testing, or the lack of effect on coronary revascularization or the primary outcome in intermediate-risk patients with suspected acute coronary syndrome.

Assessment of Oxygen Supply-Demand Imbalance and Outcomes Among Patients With Type 2 Myocardial Infarction: A Secondary Analysis of the High-STEACS Cluster Randomized Clinical Trial

Importance

Type 2 myocardial infarction occurs owing to multiple factors associated with myocardial oxygen supply-demand imbalance, which may confer different risks of adverse outcomes.

Objective

To evaluate the prevalence and outcomes of different factors associated with oxygen supply-demand imbalance among patients with type 2 myocardial infarction.

Design, Setting, and Participants

In this secondary analysis of a stepped-wedge, cluster randomized clinical trial conducted at 10 secondary and tertiary care hospitals in Scotland, 6096 patients with an adjudicated diagnosis of type 1 or type 2 myocardial infarction from June 10, 2013, to March 3, 2016, were identified, and the findings were reported on August 28, 2018. The trial enrolled consecutive patients with suspected acute coronary syndrome. The diagnosis of myocardial infarction was adjudicated according to the Fourth Universal Definition of Myocardial Infarction and the primary factor associated with oxygen supply-demand imbalance in type 2 myocardial infarction was defined. This secondary analysis was not prespecified. Statistical analysis was performed from July 7 to 30, 2020.

Intervention

Implementation of a high-sensitivity cardiac troponin I assay.

Main Outcomes and Measures

All-cause death at 1 year according to the factors associated with oxygen supply-demand imbalance among patients with type 2 myocardial infarction.

Results

Of 6096 patients (2602 women [43%]; median age, 70 years [IQR, 58-80 years]), 4981 patients had type 1 myocardial infarction, and 1115 patients had type 2 myocardial infarction. The most common factor associated with oxygen supply-demand imbalance was tachyarrhythmia (616 of 1115 [55%]), followed by hypoxemia (219 of 1115 [20%]), anemia (95 of 1115 [9%]), hypotension (89 of 1115 [8%]), severe hypertension (61 of 1115 [5%]), and coronary mechanisms (35 of 1115 [3%]). At 1 year, all-cause mortality occurred for 15% of patients (720 of 4981) with type 1 myocardial infarction and 23% of patients (285 of 1115) with type 2 myocardial infarction. Compared with patients with type 1 myocardial infarction, those with type 2 myocardial infarction owing to hypoxemia (adjusted odds ratio [aOR], 2.35; 95% CI, 1.72-3.18) and anemia (aOR, 1.83; 95% CI, 1.14-2.88) were at greatest risk of death, whereas those with type 2 myocardial infarction owing to tachyarrhythmia (aOR, 0.83; 95% CI, 0.65-1.06) or coronary mechanisms (aOR, 1.07; 95% CI, 0.17-3.86) were at similar risk of death as patients with type 1 myocardial infarction.

Conclusions and Relevance

In this secondary analysis of a randomized clinical trial, mortality after type 2 myocardial infarction was associated with the underlying etiologic factor associated with oxygen supply-demand imbalance. Most type 2 myocardial infarctions were associated with tachyarrhythmia, with better prognosis, whereas hypoxemia and anemia accounted for one-third of cases, with double the mortality of type 1 myocardial infarction. These differential outcomes should be considered by clinicians when determining which cases need to be managed if patient outcomes are to improve.

Trial Registration

ClinicalTrials.gov Identifier: NCT01852123.

Relation of High-Sensitivity Troponin to 1 Year Mortality in 20,000 Consecutive Hospital Patients Undergoing a Blood Test for Any Reason

This was an observational study of the 1-year outcomes of the 20,000 patients included in the original CHARIOT study. The aim of the study was to assess the association between high sensitivity troponin I (hs-cTnI) concentration and 1 year mortality in this cohort. The original CHARIOT study included a consecutive cohort of in- and out-patients undergoing blood tests for any reason. Hs-cTnI concentrations were measured regardless of whether the clinician requested them. These results were nested and not revealed to the team unless requested for clinical reasons. One year mortality data was obtained from NHS Digital as originally planned. Overall, 1782 (8.9%) patients had died at 1 year. Multivariable Cox regression analysis showed that a hs-cTnI concentration above the upper limit of normal was independently associated with the hazard of mortality (HR 2.23; 95% confidence intervals 1.97 to 2.52). Furthermore, the log (10) hs-cTnI concentration was independently associated with the hazard of 1 year mortality (HR 1.77; 95% confidence intervals 1.64 to 1.91). In conclusion, in a large, unselected hospital population of both in- and out-patients, in 18,282 (91.4%) of whom there was no clinical indication for testing, hs-cTnI concentration was associated with 1 year mortality.

Elderly patients with non-cardiac admissions and elevated high-sensitivity troponin: the prognostic value of renal function

BACKGROUND

High-sensitivity cardiac troponin (hs-cTn) levels are frequently elevated in elderly patients presenting to the emergency department for non-cardiac events. However, most studies on the role of elevated hs-cTn in elderly populations have investigated the prognostic value of hs-cTn in patients with a specific diagnosis or have assessed the relationship between hs-cTn and comorbidities.

AIM

To investigate the in-hospital prognosis of consecutive elderly patients admitted to the Internal Medicine Department with acute non-cardiac events and increased hs-cTnI levels.

METHODS

In this retrospective study, we selected patients who were aged ≥ 65 years and admitted to the Internal Medicine Department of our hospital between January 2019 and December 2019 for non-cardiac reasons. Eligible patients were those who had hs-cTnI concentrations ≥ 100 ng/L. We investigated the independent predictors of in-hospital mortality by multivariable logistic regression analysis.

RESULTS

One hundred and forty-six patients (59% female) were selected with an age range from 65 to 100 (mean ± SD: 85.4 ± 7.61) years. The median hs-cTnI value was 284.2 ng/L. For 72 (49%) patients the diagnosis of hospitalization was an infectious disease. The overall in-hospital mortality was 32% (47 patients). Individuals who died did not have higher hs-cTnI levels compared with those who were discharged alive (median: 314.8 vs 282.5 ng/L; P = 0.565). There was no difference in mortality in patients with infectious vs non-infectious disease (29% vs 35%). Multivariable analysis showed that age (OR 1.062 per 1 year increase, 95%CI: 1.000-1.127; P = 0.048) and creatinine levels (OR 2.065 per 1 mg/dL increase, 95%CI: 1.383-3.085; P < 0.001) were the only independent predictors of death. Mortality was 49% in patients with eGFR < 30 mL/min/1.73 m2.

CONCLUSION

Myocardial injury is a malignant condition in elderly patients admitted to the hospital for non-cardiac reasons. The presence of severe renal impairment is a marker of extremely high in-hospital mortality.

Cardiac troponin and defining myocardial infarction

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

Distribution of High-Sensitivity Troponin Taken Without Conventional Clinical Indications in Critical Care Patients and Its Association With Mortality

OBJECTIVES

To describe the distribution of high-sensitivity troponin in a consecutive cohort of patients in critical care units, regardless of clinical indication, and its association with clinical outcomes.

DESIGN

Prospective observational study.

SETTING

Single-center teaching hospital.

PATIENTS

Consecutive patients admitted to two adult critical care units (general critical care unit and neuroscience critical care unit) over a 6-month period.

INTERVENTIONS

All patients had high-sensitivity troponin tests performed at admission and tracked throughout their critical care stay, regardless of whether the supervising team felt there was a clinical indication. The results were not revealed to patients or clinicians unless clinically requested.

MEASUREMENTS AND MAIN RESULTS

There were 1,033 patients in the study cohort (general critical care unit 750 and neuroscience critical care unit 283). The median high-sensitivity troponin was 21 ng/L (interquartile range, 7-86 ng/L), with 560 patients (54.2%) above the upper limit of normal as defined by the manufacturer. Admission high-sensitivity troponin concentrations above the upper limit of normal in general critical care unit and neuroscience critical care unit were associated with increasing age, comorbidity, markers of illness severity, and the need for organ support. On adjusted analysis, the high-sensitivity troponin concentration remained an independent predictor of critical care mortality in general critical care unit and neuroscience critical care unit.

CONCLUSIONS

High-sensitivity troponin elevation, taken outside the context of conventional clinical indications, was common in the critically ill. Such elevations were associated with increasing age, comorbidity, illness severity, and the need for organ support. Admission high-sensitivity troponin concentration is an independent predictor of critical care mortality and as such may represent a novel prognostic biomarker at admission.

99th Percentile Upper-Reference Limit of Cardiac Troponin and the Diagnosis of Acute Myocardial Infarction

BACKGROUND

Concerns exist regarding how the 99th percentile upper reference limit (URL) of cardiac troponin (cTn) is determined and whether it should be derived from normal healthy individuals.

CONTENT

The 99th percentile URL of cTn is an important criterion to standardize the diagnosis of myocardial infarction (MI) for clinical, research, and regulatory purposes. Statistical heterogeneity in its calculation exists but recommendations have been proposed. Some negativity has resulted from the fact that with some high-sensitivity (hs) cTn assays, a greater number of increases above the 99th percentile are observed when transitioning from a contemporary assay. Increases reflect acute or chronic myocardial injury and provide valuable diagnostic and prognostic information. The etiology of increases can sometimes be difficult to determine, making a specific treatment approach challenging. For those reasons, some advocate higher cutoff concentrations. This approach can contribute to missed diagnoses. Contrary to claims, neither clinical or laboratory guidelines have shifted away from the 99th percentile. To support the diagnosis of acute MI, the 99th percentile URL remains the best-established approach given the absence of cTn assay standardization. Importantly, risk stratification algorithms using hs-cTn assays predict the possibility of MI diagnoses established using the 99th percentile.

SUMMARY

The 99th percentile of cTn remains the best-established criterion for the diagnosis of acute MI. While not perfect, it is analytically and clinically evidence-based. Until there are robust data to suggest some other approach, staying with the 99th percentile, a threshold that has served the field well for the past 20 years, appears prudent.

Distribution of contemporary sensitivity troponin in the emergency department and relationship to 30-day mortality: The CHARIOT-ED substudy

BACKGROUND

Contemporary sensitivity troponin (cs-cTn) concentrations above the upper limit of normal (ULN) are seen in a wide range of clinical conditions and evidence is growing that suggests cs-cTn may be a biomarker of future morbidity and mortality.

OBJECTIVES

Our aim was to test the hypothesis that cs-cTn, measured in the emergency department, may be a biomarker for 30-day mortality, irrespective of the patient's presentation.

METHOD

In all 5,708 consecutive cases, contemporary sensitivity troponin I (cs-cTnI) was measured either as requested by the clinical team or as part of the study, in which case both the clinical team and the patient were unaware of the result. Basic demographics were available from the original study and 30-day mortality was derived from NHS Digital data.

RESULTS

In patients whose cs-cTnI test was requested solely as part of the study, 30-day mortality increased with increasing cs-cTnI concentrations (0% with undetectable concentrations to 14.7% with concentrations above the ULN). Multivariable Cox regression analysis showed that log(10)cs-cTnI concentration was independently associated with 30-day mortality.

CONCLUSION

Increasing cs-cTnI concentrations are associated with higher short-term mortality as well as length of stay. As such, cs-cTnI measurements may provide useful prognostic information.

Is the true clinical value of high-sensitivity troponins as a biomarker of risk? The concept that detection of high-sensitivity troponin 'never means nothing'

INTRODUCTION

High-sensitivity troponin (hs-cTn) assays are central to the diagnosis of myocardial infarction (MI). Their increased sensitivity has facilitated rapid pathways for the exclusion of MI. However, hs-cTn is now more readily detectable in patients without symptoms typical of MI, in whom a degree of myocardial injury is assumed. Recently, the practice of using the 99^th centile of hs-cTn as a working 'upper reference limit' has been challenged. There is increasing evidence that hs-cTn may provide useful prognostic information, regardless of any suspicion of MI, and as such these assays may have potential as a general biomarker for mortality. This raises the concept that detection of hs-cTn 'never means nothing.'

AREAS COVERED

In this review, we will evaluate the evidence for the use of hs-cTn assays outside their common clinical indication to rule out or diagnose acute MI.

EXPERT OPINION

The data presented suggest that hs-cTn testing may in the future have a generalized role as a biomarker of mortality risk and may be used less as a test for ruling in acute MI, but will remain a frontline test to exclude that diagnosis in ED. Further, the data suggest that the detection of hs-cTn 'never means nothing.'

Mildly Elevated Cardiac Troponin below the 99th-Percentile Upper Reference Limit after Noncardiac Surgery

BACKGROUND AND OBJECTIVES

In patients with perioperative cardiac troponin (cTn) I below the 99th-percentile upper range of limit (URL), mortality according to cTn I level has not been fully evaluated. This study evaluated the association between postoperative cTn I level above the lowest limit of detection but within the 99th-percentile URL and 30-day mortality after noncardiac surgery.

METHODS

Patients with cTn I values below the 99th-percentile URL during the perioperative period were divided into a no-elevation group with cTn I at the lowest limit of detection (6 ng/L) and a minor elevation group with cTn I elevation below the 99th percentile URL (6 ng/L < cTn I < 40 ng/L). The primary outcome was 30-day mortality.

RESULTS

Of the 5,312 study participants, 2,582 (48.6%) were included in the no-elevation group and 2,730 (51.4%) were included in the minor elevation group. After propensity score-matching, the minor elevation group showed significantly increased 30-day mortality (0.5% vs. 2.3%; hazard ratio, 4.30; 95% confidence interval, 2.23-8.29; p<0.001). The estimated cutoff value of cTn I to predict 30-day mortality was 6 ng/L with the area under the receiver operating characteristic curve 0.657.

CONCLUSIONS

A mild elevation of cTn I within the 99th-percentile URL after noncardiac surgery was significantly associated with increased 30-day mortality as compared with the lowest limit of detection.

TRIAL REGISTRATION

Clinical Research Information Service Identifier: KCT0004244.

High sensitivity troponin measurement in critical care: Flattering to deceive or 'never means nothing'?

INTRODUCTION

Troponin elevation is central to the diagnosis of acute type 1 myocardial infarction. It is, however, elevated in a range of other conditions, including type 2 myocardial infarction, and this setting is increasingly associated with adverse clinical outcomes. Patients within intensive care frequently have at least one organ failure together with a range of co-morbidities. Interpretation of troponin assay results in this population is challenging. This clinical uncertainty is compounded by the introduction of ever more sensitive troponin assays.

AREAS COVERED

The aims of this review are to (a) describe the currently available literature about the use of troponin assays in intensive care, (b) analyse the challenges presented by the introduction of increasingly sensitive troponin assays and (c) assess whether the role of troponin assays in intensive care may change in the future, dependent upon recent and ongoing research suggesting that they are predictive of outcome regardless of the underlying cause: the 'never means nothing' hypothesis.

Comparative outcome analysis of stable mildly elevated high sensitivity troponin T in patients presenting with chest pain. A single-center retrospective cohort study

Background

The ideal high-sensitivity troponin (hsTn) cutoff for identifying those at low risk of 30 days events is debated; however, the 99th percentile overall or gender-specific upper reference limit (URL) is most commonly used. The magnitude of risk and the best management strategy for those with low-level hsTn elevation hasn't been extensively studied.

Methods

We conducted a retrospective cohort analysis including 4396 chest pain patients (542 with low-level hsTn elevation) who ruled out for myocardial infarction (MI), had a stable high-sensitivity troponin T (hsTnT) levels (defined as < 5 ng/l inter-measurements increase in hsTnT levels), and were discharged from the emergency department without further ischemic testing. The aim of the study was to compare the 30-day incidence of adverse cardiac events (ACE) between patients with undetectable high-sensitivity troponin T (hsTnT) (group 1), patients with hsTnT within the 99th percentile sex-specific URL (group 2), and patients with low-level hsTnT elevation (between the 99th percentile URL and ≤ 50 ng/l) (group 3).

Results

30-day event rates were very low 0.1%, 0.6%, and 0.4% for hsTnT groups 1, 2, and 3 respectively (overall P = 0.041, for groups 2 & 3 interaction P = 0.74). 30-day all-cause mortality, as well as 1-year all-cause and cardiovascular mortalities, occurred more frequently in those with low-level hsTnT elevation as did 1-year composite ACE.

Conclusion

In conclusion, 30-day adverse event rates were very low in those with stable low-level hsTnT elevation who ruled out for MI and were discharged from the emergency department without further inpatient testing.

Mortality at 5 Years Among Very Elderly Patients Undergoing High Sensitivity Troponin T Testing for Suspected Acute Coronary Syndromes

BACKGROUND

Patients aged ≥80 years old often present to Emergency Departments (ED) with symptoms potentially due to an acute coronary syndrome (ACS). This study aimed to evaluate associations between baseline level(s) of high sensitivity troponin T (HsTnT), adjudicated diagnoses and outcomes.

METHODS

Consecutive patients aged ≥80 years were studied, who presented to the ED at Liverpool Hospital, NSW, Australia during the 4 months period March to June 2014 (inclusive) with symptoms suggestive of an ACS, and who had at least one HsTnT assay performed. Diagnoses were based on the fourth universal definition of MI (myocardial infarction) including type-1 MI, type-2 MI, acute myocardial injury, chronic myocardial injury; the rest were termed "other diagnoses". Patients were categorised by baseline HsTnT levels 1) ≤14 ng/L, 2) 15-29 ng/L, 3) 30-49 ng/L and 4) ≥50 ng/L.

RESULTS

Of 2,773 patients screened, 545 were aged ≥80 years (median age 85 [IQR 82-88]); median follow-up was 32 months (IQR 5-56). The respective rates of adjudicated diagnoses were type-I MI 3.1%, type-2 MI 13%, acute myocardial injury 9.5%, chronic myocardial injury 56% and 18.6% had other diagnoses. Mortality rates increased, irrespective of adjudicated diagnoses with increasing HsTnT levels (ng/L): 17% (16/96) for ≤14; 35% (67/194) for 15-29; 51% (65/127) for 30-49; and 64% (82/128) for ≥50 ng/L; log rank p≤0.001. On multi-variable analyses, after adjusting for potential confounding factors including age, hypertension, chronic kidney disease (CKD) and chronic obstructive pulmonary disease (COPD), MI type was not associated with late mortality.

CONCLUSIONS

Among patients aged ≥80 years higher HsTnT levels, irrespective of adjudicated diagnoses, were associated with increased mortality. Most very elderly patients presenting with symptoms suggestive of an ACS undergoing HsTnT testing in EDs had elevated levels most commonly due to chronic myocardial injury. Whether any interventions can modify outcomes require prospective evaluation.

Clinical outcomes for chest pain patients discharged home from emergency departments using high-sensitivity versus conventional cardiac troponin assays

BACKGROUND

High-sensitivity cardiac troponin (hs-cTn) assays enhance detection of lower circulating troponin concentrations, but the impact on outcomes in clinical practice is unclear. Our objective was to compare outcomes of chest pain patients discharged from emergency departments (EDs) using hs-cTn and conventional troponin (cTn) assays.

METHODS

We conducted an observational study of chest pain patients aged 40-105 years who presented to an ED from April 1, 2013, to March 31, 2017, and were discharged home. We compared 30-day and 1-year outcomes of EDs that used hs-cTn versus cTn assays. The primary outcome was a composite of all-cause death, myocardial infarction or unstable angina. Comparisons were conducted with (1) no adjustment; (2) adjustment for demographic, socioeconomic, and hospital characteristics; and (3) full clinical adjustment.

RESULTS

Among the 394,910 patients, 62,138 (15.7%) were evaluated at hs-cTn EDs and 332,772 (84.3%) were evaluated at cTn EDs. Patients discharged from hs-cTn EDs were less likely to have diabetes, hypertension, or prior heart disease. At 30 days, the unadjusted primary outcome rate was lower in hs-cTn EDs (0.9% vs 1.0%, P < .001). The 30-day hazard ratios for the primary outcome were 0.84 (95% CI 0.77-0.92) for no adjustment and 0.98 (95% CI 0.88-1.08) for full adjustment. Over 1 year, patients discharged from hs-cTn EDs had significantly fewer primary outcomes (3.7% vs 4.1%, P < .001) and lower hazard ratio (0.93; 95% CI 0.89-0.98) even after full adjustment.

CONCLUSIONS

Hs-cTn testing was associated with a significantly lower adjusted hazard of myocardial infarction, angina, and all-cause hospitalization at 1 year but not 30 days.

Exploring the association between extra-cardiac troponin elevations and risk of future mortality

Although the measurement of cardiac troponin I (cTnI) and T (cTnT) has now become the cornerstone for diagnosing cardiac injury, both ischemic and non-ischemic, recent evidence has become available that many patients display extra-cardiac causes of cTn elevations and carry a considerably enhanced risk of future mortality. The current literature data suggests that cTn elevations may be equally common in patients with cardiac and extra-cardiac diseases. Among the latter cohort of patients, the leading extra-cardiac diseases which may be responsible for either cTnI or cTnT elevations include infectious diseases/sepsis, pulmonary disorders, renal failure, malignancy, as well as gastrointestinal, neurological and musculoskeletal diseases. What also emerges rather clearly from the current literature data, is that the risk of dying for extra-cardiac diseases is higher (i.e., between two to three-fold) in patients with extra-cardiac cTn elevations than in those with cardiac pathologies, and that the most frequent cause of death would then be infections/sepsis, followed by malignancy, respiratory disorders, myocardial infarction, gastrointestinal and neurological diseases, heart failure, stroke, cardiac arrhythmias, renal failure, psychiatric, metabolic, urogenital and musculoskeletal disorders. These figures would lead to conclude that there is a considerable risk that the underlying pathology causing cardiac injury and cTn elevation would then become the cause of death in these patients. This important evidence shall lead the way to defining appropriate and effective strategies for managing patients with extra-cardiac cTn elevations, so that their risk of future death could be prevented or limited.