Significance of elevated cardiac troponin T levels in critically ill patients with acute respiratory disease

Serial high sensitivity troponin sampling in patients with SARS-CoV-2 infection

INTRODUCTION

Multiple studies have investigated the role of cardiac troponin (cTn) in the risk stratification of patients with COVID-19. Most of these investigations are based on cTn values at presentation and do not consider the prognostic significance of cTn changes over time. This study aimed to investigate the prognostic role of serial cTn measurements in patients hospitalized with COVID-19 with samples that were not obtained for clinical indications.

METHODS

Patients hospitalized between April 2020 and March 2021 with PCR-confirmed SARS-CoV-2 infection were evaluated. Blood samples collected for any reason were stored for subsequent analysis. If clinical high sensitivity hs-cTnT (Roche) was not measured, samples were tested separately in batches. Hs-cTnI (Abbott) was also evaluated.

RESULTS

There were 228 unique patients. There were 21 (9.2 %) deaths. No patient with a low hs-cTnT (<6 ng/L) died and 1 patient with low hs-cTnI (<5 ng/L) died. Myocardial injury was associated with higher odds of death, when defined by hs-cTnT (OR: 7.88, 95 % CI: 2.04-30.40, p = 0.003) or hs-cTnI (OR: 7.46, 95 % CI: 2.68-20.77, p < 0.001). This association remained after propensity weighting. An increasing pattern was associated with higher odds of death compared to a stable pattern for hs-cTnT (OR: 5.45, 95 % CI: 1.81-16.40, p = 0.003) and hs-cTnI (OR: 4.49, 95 % CI: 1.02-19.81, p = 0.048). Among patients with myocardial injury defined by hs-cTnT, an increasing pattern was associated with higher odds of death compared to a decreasing pattern (OR: 4.80, 95 % CI: 1.16-19.97, p = 0.031).

CONCLUSIONS

Patients hospitalized with COVID-19 with myocardial injury have higher odds of death. Serial hs-cTn testing provides additional risk stratification in these patients.

Antithrombotic Therapy in Arterial Thrombosis and Thromboembolism in COVID-19: An American College of Chest Physicians Expert Panel Report

BACKGROUND

Evidence increasingly shows that the risk of thrombotic complications in COVID-19 is associated with a hypercoagulable state. Several organizations have released guidelines for the management of COVID-19-related coagulopathy and prevention of VTE. However, an urgent need exists for practical guidance on the management of arterial thrombosis and thromboembolism in this setting.

RESEARCH QUESTION

What is the current available evidence informing the prevention and management of arterial thrombosis and thromboembolism in patients with COVID-19?

STUDY DESIGN AND METHODS

A group of approved panelists developed key clinical questions by using the Population, Intervention, Comparator, and Outcome (PICO) format that address urgent clinical questions regarding prevention and management of arterial thrombosis and thromboembolism in patients with COVID-19. Using MEDLINE via PubMed, a literature search was conducted and references were screened for inclusion. Data from included studies were summarized and reviewed by the panel. Consensus for the direction and strength of recommendations was achieved using a modified Delphi survey.

RESULTS

The review and analysis of the literature based on 11 PICO questions resulted in 11 recommendations. Overall, a low quality of evidence specific to the population with COVID-19 was found. Consequently, many of the recommendations were based on indirect evidence and prior guidelines in similar populations without COVID-19.

INTERPRETATION

The existing evidence and panel consensus do not suggest a major departure from the management of arterial thrombosis according to recommendations predating the COVID-19 pandemic. Data on the optimal strategies for prevention and management of arterial thrombosis and thromboembolism in patients with COVID-19 are sparse. More high-quality evidence is needed to inform management strategies in these patients.

Use and Prognostic Implications of Cardiac Troponin in COVID-19

Myocardial injury is common in patients with COVID-19 and is associated with an adverse prognosis. Cardiac troponin (cTn) is used to detect myocardial injury and assist with risk stratification in this population. SARS-CoV-2 infection can play a role in the pathogenesis of acute myocardial injury due to both direct and indirect damage to the cardiovascular system. Despite the initial concerns about an increased incidence of acute myocardial infarction (MI), most cTn increases are related to chronic myocardial injury due to comorbidities and/or acute nonischemic myocardial injury. This review will discuss the latest findings on this topic.

The use of cardiac troponins and B-type natriuretic peptide in COVID-19

Coronavirus disease 2019 (COVID-19) is still challenging health care systems worldwide. Over time, it has become clear that respiratory disease is not the only important entity as critically ill patients are also more prone to develop complications, such as acute cardiac injury. Despite extensive research, the mainstay of treatment still relies on supportive care and targeted therapy of these complications. The development of a prognostic model which helps clinicians to diverge patients to an appropriate level of care is thus crucial. As a result, several prognostic markers have been studied in the past few months. Among them are the cardiac biomarkers, especially cardiac troponins T/I and brain natriuretic peptide, which seem to have important prognostic values as several reports have confirmed their strong association with adverse clinical outcomes and death. The use of these biomarkers as part of a prognostic tool could potentially result in more precise risk stratification of COVID-19 patients and divergence to an adequate level of care. However, several caveats persist causing international guidelines to still recommend in favour of a more conservative approach to cardiac biomarker testing for prognostic purposes.

Speech-language pathology approaches to neurorehabilitation in acute care during COVID-19: Capitalizing on neuroplasticity

Neurologic manifestations associated with a coronavirus disease 2019 (COVID‐19) diagnosis are common and often occur in severe and critically ill patients. In these patients, the neurologic symptoms are confounded by critical care conditions, such as acute respiratory distress syndrome (ARDS). Patients with dual diagnoses of COVID‐19 and neurologic changes such as myopathy, polyneuropathy, and stroke are likely at a higher risk of experiencing deficits with swallowing, communication, and/or cognition. Speech‐language pathologists are an integral part of both the critical care and neurologic disorders multi‐disciplinary teams, offering valuable contributions in the evaluation, treatment, and management of these areas. Patients in intensive care units (ICUs) who require mechanical ventilation often experience difficulty with communication and benefit from early speech‐language pathology intervention to identify the most efficient communication methods with the medical team and caregivers. Moreover, patients with neurologic manifestations may present with cognitive‐linguistic impairments such as aphasia, thereby increasing the need for communication‐based interventions. Difficulties with voice and swallowing after extubation are common, often requiring frequent treatment sessions, possibly persisting beyond ICU discharge. After leaving the ICU, patients with COVID‐19 often experience physical, cognitive, and mental health impairments collectively called post‐intensive care syndrome. This is often a lengthy road as they progress toward full recovery, requiring continued speech‐language pathology treatment after hospital discharge, capitalizing on the principles of neuroplasticity.

Cardiovascular implications of the COVID-19 pandemic

The COVID-19 pandemic has rapidly emerged as one of the biggest public health concerns of the 21st century. Although it was initially reported as a cluster of pneumonia cases, it quickly became apparent that COVID-19 is not merely a respiratory tract infection. Its clinical course is often complicated by cardiovascular manifestations including venous and arterial thrombosis, electrical disturbances, and myocardial damage. In addition, the cardiovascular system is involved not only during infection but also preceding the contraction of the virus; having cardiovascular comorbidities indicates significant vulnerability to the pathogen. As longer-term data continue to accumulate, we now have concerns over its lasting cardiovascular effects after recovery. Moreover, there have been substantial collateral effects on the epidemiology of cardiovascular diseases. Reports of adverse cardiovascular events from vaccination have emerged as new hurdles to our efforts to bring an end to the pandemic. As such, the association between COVID-19 and the cardiovascular system and cardiovascular practice in general is expansive. In this review, we provide an overview of the knowledge and considerations in this field, based on the evidence available at the time of this writing.

The prognostic value of cardiac troponin for 60 day mortality and major adverse events in COVID-19 patients

BACKGROUND

The variability of coronavirus disease 2019 (COVID-19) illness severity has puzzled clinicians and has sparked efforts to better predict who would benefit from rapid intervention. One promising biomarker for in-hospital morbidity and mortality is cardiac troponin (cTn).

METHODS

A retrospective study of 1331 adult patients with COVID-19 admitted to the Rush University System in Illinois, USA was performed. Patients without cTn measurement during their admission or a history of end stage renal disease or stage 5 chronic kidney disease were excluded. Using logistic regression adjusted for baseline characteristics, pre-existing comorbidities, and other laboratory markers of inflammation, cTn was assessed as a predictor of 60-day mortality and severe COVID-19 infection, consisting of a composite of 60-day mortality, need for intensive care unit, or requiring non-invasive positive pressure ventilation or intubation.

RESULTS

A total of 772 patients met inclusion criteria. Of these, 69 (8.9%) had mild cTn elevation (> 1 to < 2x upper limit of normal (ULN)) and 46 (6.0%) had severe cTn elevation (≥ 2x ULN). Regardless of baseline characteristics, comorbidities, and initial c-reactive protein, lactate dehydrogenase, and ferritin, when compared to the normal cTn group, mild cTn elevation and severe cTn elevation were predictors of severe COVID-19 infection (adjusted OR [aOR] aOR 3.00 [CI: 1.51 - 6.29], P < 0.01; aOR 9.96 [CI: 2.75 - 64.23], P < 0.01, respectively); severe cTn elevation was a predictor of in-hospital mortality (aOR 2.42 [CI: 1.10 - 5.21], P < 0.05) and 60-day mortality (aOR 2.45 [CI: 1.13 - 5.25], P < 0.05).

CONCLUSION

In our cohort, both mild and severe initial cTn elevation were predictors of severe COVID-19 infection, while only severe cTn elevation was predictive of 60-day mortality. First cTn value on hospitalization is a valuable longitudinal prognosticator for COVID-19 disease severity and mortality.

Cardiovascular biomarkers in patients with COVID-19

The coronavirus disease 2019 (COVID-19) pandemic has increased awareness that severe acute respiratory distress syndrome coronavirus-2 (SARS-CoV-2) may have profound effects on the cardiovascular system. COVID-19 often affects patients with pre-existing cardiac disease, and may trigger acute respiratory distress syndrome (ARDS), venous thromboembolism (VTE), acute myocardial infarction (AMI), and acute heart failure (AHF). However, as COVID-19 is primarily a respiratory infectious disease, there remain substantial uncertainty and controversy whether and how cardiovascular biomarkers should be used in patients with suspected COVID-19. To help clinicians understand the possible value as well as the most appropriate interpretation of cardiovascular biomarkers in COVID-19, it is important to highlight that recent findings regarding the prognostic role of cardiovascular biomarkers in patients hospitalized with COVID-19 are similar to those obtained in studies for pneumonia and ARDS in general. Cardiovascular biomarkers reflecting pathophysiological processes involved in COVID-19/pneumonia and its complications have a role evaluating disease severity, cardiac involvement, and risk of death in COVID-19 as well as in pneumonias caused by other pathogens. First, cardiomyocyte injury, as quantified by cardiac troponin concentrations, and haemodynamic cardiac stress, as quantified by natriuretic peptide concentrations, may occur in COVID-19 as in other pneumonias. The level of those biomarkers correlates with disease severity and mortality. Interpretation of cardiac troponin and natriuretic peptide concentrations as quantitative variables may aid in risk stratification in COVID-19/pneumonia and also will ensure that these biomarkers maintain high diagnostic accuracy for AMI and AHF. Second, activated coagulation as quantified by D-dimers seems more prominent in COVID-19 as in other pneumonias. Due to the central role of endothelitis and VTE in COVID-19, serial measurements of D-dimers may help physicians in the selection of patients for VTE imaging and the intensification of the level of anticoagulation from prophylactic to slightly higher or even therapeutic doses.

How often and to what extent do admitted COVID-19 patients have signs of cardiac injury?

Background

COVID-19 can cause myocardial injury in a significant proportion of patients admitted to the hospital and seems to be associated with worse prognosis. The aim of this review was to study how often and to what extent COVID-19 causes myocardial injury and whether this is an important contributor to outcome with implications for management.

Methods

A literature search was performed in Medline and Embase. Myocardial injury was defined as elevated cardiac troponin (cTn) levels with at least one value > 99th percentile of the upper reference limit. The primary outcome measure was mortality, whereas secondary outcome measures were intensive care unit (ICU) admission and length of hospital stay.

Results

Four studies and one review were included. The presence of myocardial injury varied between 9.6 and 46.3%. Myocardial injury was associated with a higher mortality rate (risk ratio (RR) 5.54, 95% confidence interval (CI) 3.48–8.80) and more ICU admissions (RR 3.78, 95% CI 2.07–6.89). The results regarding length of hospital stay were inconclusive.

Conclusion

Patients with myocardial injury might be classified as high-risk patients, with probably a higher mortality rate and a larger need for ICU admission. cTn levels can be used in risk stratification models and can indicate which patients potentially benefit from early medication administration. We recommend measuring cTn levels in all COVID-19 patients admitted to the hospital or who deteriorate during admission.

Supplementary Information

The online version of this article (10.1007/s12471-021-01571-w) contains supplementary material, which is available to authorized users.

Using high sensitivity cardiac troponin values in patients with SARS-CoV-2 infection (COVID-19): The Padova experience

Background

The spectrum of Coronavirus Disease 2019 (COVID-19) is broad and thus early appropriate risk stratification can be helpful. Our objectives were to define the frequency of myocardial injury using high-sensitivity cardiac troponin I (hs-cTnI) and to understand how to use its prognostic abilities.

Methods

Retrospective study of patients with COVID-19 presenting to an Emergency Department (ED) in Italy in 2020. Hs-cTnI was sampled based on clinical judgment. Myocardial injury was defined as values above the sex-specific 99th percentile upper reference limits (URLs). Most data is from the initial hospital value.

Results

426 unique patients were included. Hs-cTnI was measured in 313 (73.5%) patients; 85 (27.2%) had myocardial injury at baseline. Patients with myocardial injury had higher mortality during hospitalization (hazard ratio = 9 [95% confidence interval (CI) 4.55–17.79], p < 0.0001). Multivariable analysis including clinical and laboratory variables demonstrated an AUC of 0.942 with modest additional value of hs-cTnI. Myocardial injury was associated with mortality in patients with low APACHE II scores (<13) [OR (95% CI): 4.15 (1.40, 14.22), p = 0.014] but not in those with scores > 13 [OR (95% CI): 0.48 (0.08, 2.65), p = 0.40]. Initial hs-cTnI < 5 ng/L identified 33% of patients that were at low risk with 97.8% sensitivity (95% CI 88.7, 99.6) and 99.2% negative predictive value. Type 1 myocardial infarction (MI) and type 2 MI were infrequent.

Conclusions

hs-cTnI at baseline is a significant predictor of mortality in COVID-19 patients. A value < 5 ng/L identified patients at low risk.

Cardiac Troponin for Assessment of Myocardial Injury in COVID-19: JACC Review Topic of the Week

Increases in cardiac troponin indicative of myocardial injury are common in patients with coronavirus disease-2019 (COVID-19) and are associated with adverse outcomes such as arrhythmias and death. These increases are more likely to occur in those with chronic cardiovascular conditions and in those with severe COVID-19 presentations. The increased inflammatory, prothrombotic, and procoagulant responses following severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection increase the risk for acute nonischemic myocardial injury and acute myocardial infarction, particularly type 2 myocardial infarction, because of respiratory failure with hypoxia and hemodynamic instability in critically ill patients. Myocarditis, stress cardiomyopathy, acute heart failure, and direct injury from SARS-CoV-2 are important etiologies, but primary noncardiac conditions, such as pulmonary embolism, critical illness, and sepsis, probably cause more of the myocardial injury. The structured use of serial cardiac troponin has the potential to facilitate risk stratification, help make decisions about when to use imaging, and inform stage categorization and disease phenotyping among hospitalized COVID-19 patients.

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Increases in cardiac troponin indicative of myocardial injury are common and prognostic in COVID-19.

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Increases can be due to chronic injury, acute nonischemic injury, or acute MI.

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Troponin, along with inflammatory and thrombotic markers, may facilitate COVID-19 stage classification and risk stratification.

High-sensitivity troponin T is an important independent predictor in addition to the Simplified Acute Physiology Score for short-term ICU mortality, particularly in patients with sepsis

PURPOSE

Elevated cardiac troponin levels have been shown to be associated with a poor prognosis under some intensive care conditions. This study investigated whether inclusion of high-sensitivity troponin T (hsTnT) increased the prognostic accuracy of the Simplified Acute Physiology Score (SAPS 3) for general intensive care unit (ICU) patients, cardiac arrest patients, or patients with a non-cardiac arrest diagnosis.

MATERIALS AND METHODS

We performed a single-center cohort study of ICU patients with an hsTnT measurement on ICU admission at a tertiary university hospital between February 2010 and June 2017.

RESULTS

Of 4185 first-time admissions, 856 patients (20.5%) had hsTnT evaluated at ICU admission. Factoring in ICU admission hsTnT values increased the ability of SAPS 3 to accurately predict 30-day mortality (odds ratio 1.27, 95% confidence interval: 1.15-1.41, p < 0.001). Elevated hsTnT levels were not independently associated with 30-day mortality in cardiac arrest patients. In sepsis patients, hsTnT evaluation in addition to SAPS 3 evaluation improved the area under the receiver operating characteristic curve by >10%.

CONCLUSION

Addition of hsTnT evaluation to SAPS 3 enhances the predictive capability of this model in relation to mortality. In sepsis, the hsTnT level may be an important prognostic marker.

Progressive myocardial injury is associated with mortality in the acute respiratory distress syndrome

PURPOSE

Myocardial injury connotes worse prognosis in the Acute Respiratory Distress Syndrome (ARDS), however the prognostic connotation of changes in cardiac troponin (cTn) levels in ARDS patients is not known.

METHODS

We performed a study of 908 ARDS patients enrolled in two previously completed ARDS Network trials. We obtained plasma samples via the NIH BIOLINCC repository and measured cTn using the ARCHITECT STAT high sensitivity troponin-I assay (Abbott Laboratories) at trial day 0 and 3. We constructed Cox proportional hazard models to determine the association between 60-day mortality and quintiles of percentage change in high-sensitivity troponin (ΔhsTnI).

RESULTS

The median percent change in hsTnI (%ΔhsTnI) from day 0 to day 3 was -58.2% (IQR -79.0 to 0%). After multivariable adjustment, participants with a 32.1% or greater increase in hsTnI between day 0 and day 3 (highest quintile) had a 2.27 fold increased risk for mortality (95% CI 1.29 - 3.99, p = 0.002) as well as fewer ventilator-free and ICU-free days compared to the lowest quintile.

CONCLUSION

Progressive myocardial injury in ARDS patients is associated with worse outcome, independent of severity of critical illness. Investigation of the mechanisms underlying this relationship is warranted to guide possible strategies to mitigate myocardial injury in ARDS.

Determinants and prognosis of high-sensitivity cardiac troponin T peak plasma concentration in patients hospitalized for non-cardiogenic shock

Purpose:

The aim of this study was to assess the determinants and prognostic value of high-sensitivity cardiac troponin T peak plasma concentration in intensive care unit patients with non-cardiogenic shock.

Material and methods:

A prospective observational cohort study was conducted in a single intensive care unit between November 2014 and December 2015.

Results:

During the study period, 206 patients were hospitalized in the intensive care unit for non-cardiogenic shock and the median peak high-sensitivity cardiac troponin T was 55.1 [24.5–136] pg/mL. A multivariate analysis combining all variables showed that higher body mass index (t = 2.52, P = 0.01), lower left ventricular systolic function (t = −2.73, P = 0.007), higher white blood cell count (t = 3.72, P = 0.0001), lower creatinine clearance (t = −2.84, P = 0.0005), higher lactate level (t = 2.62, P = 0.01) and ST-segment depression (t = 3.98, P = 0.0001) best correlated with log₁₀-transformed high-sensitivity cardiac troponin T peak plasma concentration. After multivariate analysis, the high-sensitivity cardiac troponin T peak was not associated with a significant reduction of in-hospital mortality (adjusted odds ratio = 0.99 (95% confidence interval: 0.93–1.02)).

Conclusion:

High-sensitivity cardiac troponin T elevation was very common in patients hospitalized for non-cardiogenic shock. The factors significantly associated with high-sensitivity cardiac troponin T peak plasma concentration were higher body mass index, decreased left ventricular systolic ejection fraction, higher leucocyte count, decreased renal function, increased lactate level, and ST-segment depression. The high-sensitivity cardiac troponin T peak was not significantly associated with in-hospital mortality in this setting.

24-Hour Kinetics of Cardiac Troponin-T Using a "High-Sensitivity" Assay in Thoroughbred Chuckwagon Racing Geldings after Race and Associated Clinical Sampling Guidelines

Background

A “high‐sensitivity” cardiac troponin‐T (hscTnT) assay recently has been validated for use in horses and is a specific biomarker of myocardial damage. Postexercise release kinetics of cTnT utilizing the hscTnT assay have yet to be established in horses.

Objectives

To determine: (1) cTnT release kinetics in racing Thoroughbreds after a high‐intensity 5/8th mile Chuckwagon race; (2) the effects of age on pre‐ and postrace cTnT concentrations; and (3) sampling guidelines for clinicians evaluating horses presenting after exercise.

Animals

Samples were obtained from 38 Thoroughbred geldings aged 5–16 years before racing and immediately, 2, 3, 4, 6, 12, and 24 hour postrace.

Methods

Prospective, observational study with convenience sampling. A fifth‐generation hscTnT assay was used for plasma sample analysis, and concentrations were compared at all time‐points. Correlations were determined between cTnT concentrations and age. Biochemistry analysis was performed to assess rhabdomyolysis, renal failure, and exercise‐induced dehydration.

Results

All horses with measureable cTnT concentrations had significant postexercise increases in cTnT with a median peak (8.0 ng/L) at 3‐hour postrace. All horses had peak postexercise cTnT concentrations 2‐ to 6‐hour postrace ≤ the 99th percentile upper reference limit of 23.2 ng/L, after which all cTnT concentrations decreased until returning to baseline by 12–24 hours. There was no correlation over time between cTnT concentrations and age.

Conclusions and Clinical Importance

In racing Thoroughbreds completing short‐duration, high‐intensity Chuckwagon races, cTnT concentrations are expected to be increased 2‐ to 6‐hour postrace and to decrease by 12–24 hours while remaining ≤23.2 ng/L throughout. This study contributes to establishing guidelines for clinical use of the hscTnT assay in exercising horses.

Negative predictive value of dobutamine stress echocardiography for perioperative risk stratification in patients with cardiac risk factors and reduced exercise capacity undergoing non-cardiac surgery

BACKGROUND

Guidelines recommend functional testing for myocardial ischaemia in the perioperative setting in patients with greater than one recognised cardiac risk factor and self-reported reduced exercise capacity.

AIM

To determine the clinical utility of dobutamine stress echocardiography (DSE) for perioperative risk stratification in patients undergoing major non-cardiac surgery.

METHODS

Data on 79 consecutive patients undergoing DSE for perioperative risk stratification at a single centre were retrospectively reviewed to determine rates of major adverse cardiac events (MACE) during the index hospitalisation and 30 days post-discharge. Echocardiography and outcome data were obtained through a folder audit and echolab database.

RESULTS

Out of the 79 DSE performed for perioperative risk stratification, 11 (14%) were positive (DSE +ve) and 68 (86%) were negative (DSE -ve). Management in the DSE +ve group included medical optimisation without invasive intervention (n = 7(64%)), diagnostic coronary angiography (n = 3(27%)) and coronary artery bypass graft (n = 1(9%)). None of the patients underwent percutaneous coronary intervention preoperatively. Perioperative MACE in the DSE +ve group was 36% compared to 4% in the DSE-ve group (P = 0.006). DSE +ve was a powerful predictor of perioperative inpatient MACE (OR 12.4, 95% CI 2.3-67, P = 0.003). The positive predictive value of DSE +ve status was 36%, whereas the negative predictive value of DSE-ve status for perioperative MACE was 96%.

CONCLUSION

DSE for perioperative risk stratification had a high clinical utility in patients undergoing major non-cardiac surgery. In particular, a normal DSE had a high negative predictive value for perioperative MACE.

Pattern and consequences of cardiologic medications management for patients with elevated troponin I upon admission into an intensive care unit not linked to type 1 acute myocardial infarction: A prospective observational cohort study

OBJECTIVES

No recommendations are currently available to help the clinician with the pharmacological management of intensive care unit (ICU) patients with elevated cardiac troponin (cTn) not linked to type 1 AMI. The aim of this study was to evaluate the pattern of cardiologic medications for patients with elevated cTnI in ICU not link to type 1 AMI and their effects on in-hospital mortality.

MATERIAL AND METHODS

A prospective observational cohort study conducted in two ICU units. Patients with increased plasma concentration of cTnI at admission not linked to type 1 AMI were consecutively included.

RESULTS

One hundred and ninety of the 835 patients admitted (23%) had an increased plasma concentration of cTnI not related to type 1 AMI. Antiplatelet therapy (AT) and statin were prescribed in 56 (29.5%) and 50 (26.3%) of patients, respectively. Others cardiologic medications were prescribed in less than 5% of all cases and were considered as contraindicated in more than 50% of cases. Antiplatelet therapy was the only cardiologic treatment associated with reduction of in-hospital mortality following uni- and multivariate analysis. The death rate was 23% and 40% in these patients treated with and without AT, respectively (aOR=0.39 [95% CI: 0.15-0.97]).

CONCLUSIONS

Statin and AT were frequently prescribed to patients with a cTnI elevation not linked to type 1 AMI. This study suggests that AT in patients with an increased plasma concentration of cTnI, not related to type 1 AMI in ICU, could reduce in-hospital mortality.

Incident Type 2 Myocardial Infarction in a Cohort of Patients Undergoing Coronary or Peripheral Arterial Angiography

Background:

Despite growing recognition of type 2 myocardial infarction (T2MI; related to supply/demand mismatch), little is known about its risk factors or its association with outcome.

Methods:

A single-center cohort of patients undergoing coronary or peripheral angiography with or without intervention was prospectively enrolled and followed for incident type 1 and T2MI, and major adverse cardiovascular events (MACE, a composite of all-cause death, nonfatal myocardial infarction [MI], heart failure, stroke, transient ischemic attack, peripheral arterial complication, and cardiac arrhythmia), as well. T2MI was adjudicated using criteria from the Third Universal Definition of MI. Baseline characteristics, blood samples, and angiography information were obtained. Major end points subsequent to first MI were assessed using landmark analyses to compare the rates of first events only where everyone with a prior history of any MACE before MI were censored and adjusted for follow-up times. Cox proportional hazard models were used for time-to-event analyses with age and sex forced into all models and additional covariates evaluated by using the stepwise option for the selection.

Results:

One thousand two hundred fifty-one patients were enrolled and followed for a median of 3.4 years. Of these patients, 152 (12.2%) had T2MI during follow-up; T2MI was frequently recurrent. Multivariable predictors of T2MI were older age, lower systolic blood pressure, history of coronary artery disease, heart failure, chronic obstructive pulmonary disease, diabetes mellitus, nitrate use, and elevated concentrations of glucose, N-terminal pro-B type natriuretic peptide, and cystatin C. Patients with T2MI had higher rates of subsequent adverse events than those without T2MI (per 100 person-years: MACE, 53.7 versus 21.1, P <0.001; all-cause death, 23.3 versus 3.3, P <0.001; cardiovascular death, 17.5 versus 2.6, P <0.001; heart failure events, 22.4 versus 7.4, P <0.001); these rates are similar to those seen in patients with type 1 MI. Incident diagnosis of T2MI strongly predicted risk for subsequent MACE (adjusted hazard ratio, 1.90; 95% confidence interval, 1.46–2.48; P <0.001), all-cause death (adjusted hazard ratio, 2.96; 95% confidence interval, 2.01–4.36; P <0.001), and cardiovascular death (adjusted hazard ratio, 2.16; 95% confidence interval, 1.36–3.43; P =0.001).

Conclusions:

T2MI is common and associated with poor prognosis. Studies evaluating treatment strategies for management of T2MI are needed.

Clinical Trial Registration:

URL: http://www.clinicaltrials.gov . Unique identifier: NCT00842868.

Cardiac Troponin Measurement in the Critically Ill: Potential for Guiding Clinical Management

Elevated cardiac troponin (cTn) in the absence of acute coronary syndromes (ACS) is associated with increased mortality in critically ill patients. There are no evidence-based interventions that reduce mortality in this group.

Sex-related differential susceptibility to doxorubicin-induced cardiotoxicity in B6C3F1 mice

Sex is a risk factor for development of cardiotoxicity, induced by the anti-cancer drug, doxorubicin (DOX), in humans. To explore potential mechanisms underlying differential susceptibility to DOX between sexes, 8-week old male and female B6C3F₁ mice were dosed with 3mg/kg body weight DOX or an equivalent volume of saline via tail vein once a week for 6, 7, 8, and 9 consecutive weeks, resulting in 18, 21, 24, and 27mg/kg cumulative DOX doses, respectively. At necropsy, one week after each consecutive final dose, the extent of myocardial injury was greater in male mice compared to females as indicated by higher plasma concentrations of cardiac troponin T at all cumulative DOX doses with statistically significant differences between sexes at the 21 and 24mg/kg cumulative doses. A greater susceptibility to DOX in male mice was further confirmed by the presence of cytoplasmic vacuolization in cardiomyocytes, with left atrium being more vulnerable to DOX cardiotoxicity. The number of TUNEL-positive cardiomyocytes was mostly higher in DOX-treated male mice compared to female counterparts, showing a statistically significant sex-related difference only in left atrium at 21mg/kg cumulative dose. DOX-treated male mice also had an increased number of γ-H2A.X-positive (measure of DNA double-strand breaks) cardiomyocytes compared to female counterparts with a significant sex effect in the ventricle at 27mg/kg cumulative dose and right atrium at 21 and 27mg/kg cumulative doses. This newly established mouse model provides a means to identify biomarkers and access potential mechanisms underlying sex-related differences in DOX-induced cardiotoxicity.

Prognostic Impact of Myocardial Injury Related to Various Cardiac and Noncardiac Conditions

BACKGROUND

Elevated cardiac troponins in clinical conditions other than myocardial infarction are well known. For such occurrences, the term "myocardial injury" has been proposed. The long-term outcome in patients with myocardial injury related to various cardiac and noncardiac clinical disorders is unknown.

METHODS

During January 2010 to January 2011, we prospectively studied hospitalized patients who had cardiac troponin I measured on clinical indication. Patients with cardiac troponin I values >30 ng/L and no evidence of myocardial ischemia were diagnosed as having myocardial injury. Patients were classified into 5 categories of plausible related conditions: cardiac ischemic, cardiac nonischemic, noncardiac, multifactorial, or indeterminate. Follow-up was a minimum of 3 years, with all-cause mortality as the single end-point.

RESULTS

A total of 3762 patients were considered, of whom 1089 (29%) had myocardial injury. The most common associated conditions were noncardiac (n = 346) or multifactorial (n = 359). Cardiac ischemic (n = 183) and cardiac nonischemic (n = 134) conditions occurred less frequently. After a median of 3.2 years, 645 patients (59%) had died. A multivariate Cox regression analysis showed no difference in mortality between patients with cardiac ischemic and cardiac nonischemic conditions (hazard ratio [HR] 0.75; 95% confidence interval [CI], 0.50-1.13; P = .2). Patients with noncardiac or multifactorial disorders, however, had significantly higher mortality than those with associated cardiac ischemic conditions (HR 1.39; 95% CI, 1.06-1.80; P = .02, and HR 1.94; 95% CI, 1.50-2.51; P <.001), respectively.

CONCLUSIONS

In patients with myocardial injury, the most common associated conditions were noncardiac or multifactorial. Of notice, these patients had significantly higher long-term mortality when compared with those with associated cardiac conditions.

Obstructive coronary artery disease in patients hospitalized for severe sepsis or septic shock with concomitant acute myocardial infarction

PURPOSE

It is difficult to differentiate type 1 acute myocardial infarction (AMI) with obstructive coronary artery disease (OCAD) from type 2 AMI in patients admitted for severe sepsis. The aims of this study were to assess the risk factors and prognosis of OCAD in patients admitted to the intensive care unit for severe sepsis with concomitant AMI.

MATERIALS AND METHODS

This is a single-center retrospective cohort study including all consecutive patients who were hospitalized for severe sepsis or septic shock between March 2006 and September 2014 and who underwent coronary angiography in the intensive care unit to identify AMI.

RESULTS

Overall, 78 (5.5%) of 1418 patients hospitalized for severe sepsis underwent coronary angiography to identify concomitant AMI. Thirty-two patients (41%) had OCAD. Following multivariate analysis, the risk factors of OCAD were peripheral vascular disease (odds ratio [OR] =5.7; 95% confidence interval [CI], 1.1-30.4; P = .042) and at least 2 cardiovascular risk factors (OR = 6.7; 95% CI, 1.9-23.8; P = .003). Obstructive coronary artery disease was associated with a significant mortality increase at 60 days (OR = 8.1; 95% CI, 1.9-30.2; P = .004).

CONCLUSIONS

Obstructive coronary artery disease is a poor prognosis factor in patients hospitalized for severe sepsis with concomitant AMI. In this setting, medical treatment should be considered for patients with peripheral vascular disease or with at least 2 cardiovascular risk factors; the need to perform coronary angiography should be considered carefully.

Fundamental concepts of effective troponin use: important principles for internists

Troponin testing is an essential component of our diagnostic approach to patients in acute medical care settings. With the advent of high-sensitivity troponin assays, its importance will extend to patients in chronic disease settings. Although elevated troponin levels provide diagnostic information, inform treatment decisions, and influence patient prognosis, proper interpretation of the values is essential. This requires an understanding of the operating characteristics of troponin testing; the likelihood ratios associated with a positive/negative test result and the pre- and post-test probabilities related to individual clinical settings. These principles will become more important as high-sensitivity assays become introduced over the coming years in the United States. This article reviews the important principles of troponin testing focusing in particular on acute settings and is aimed at internal medicine and hospital specialists.

Making sense of high sensitivity troponin assays and their role in clinical care

Cardiac troponin assays have an established and undisputed role in the diagnosis and risk stratification of patients with acute myocardial infarction. As troponin assays gets more sensitive and more precise, the number of potential uses has rapidly expanded, but the use of this test has also become more complicated and controversial. Highly sensitive troponin assays can now detect troponin levels in most individuals, but accurate interpretation of these levels requires a clear understanding of the assay in the context of the clinical scenario. This paper provides a practical and up-to-date overview of the uses of highly sensitive troponin assays for diagnosis, prognosis, and risk stratification in clinical practice.

Prognostic significance of elevated troponin in non-cardiac hospitalized patients: a systematic review and meta-analysis

Cardiac biomarker troponin can be elevated in patients without a primary cardiac diagnosis and may have prognostic value. We conducted a systematic review to estimate the prevalence and prognostic significance of elevated troponin levels in patients admitted to hospital without a primary cardiac diagnosis. Literature search was done using MEDLINE (1946 to November 2012), EMBASE (1974 to Week 45, 2012), and Cochrane Central Register of Controlled Trials (November 2012). Two independent investigators reviewed full-text studies for final inclusion. We included studies of patients admitted without a primary cardiac diagnosis. Eligible studies compared adverse outcomes in patients with normal versus elevated troponin levels. Twenty-seven studies were included in the meta-analysis. Elevated troponin was associated with increased in-hospital and 30-day mortality (25 studies, 7255 patients, OR 3.88, 95% CI 2.90-5.19, P < 0.0001). Elevated troponin was also associated with increased risk of long-term mortality at 6 months (9 studies, 5368 patients, OR 4.21, 95% CI 1.84-9.64, P < 0.00001). Troponin is an independent predictor of short-term mortality with a pooled adjusted OR of 2.36, 95% CI 1.47-3.76, P < 0.0003. In conclusion, elevated troponin in non-cardiac patients is independently associated with increased mortality.

Prediction of long-term outcome by measurement of serum concentration of cardiac troponins in critically ill dogs with systemic inflammation

BACKGROUND

Myocardial injury, detected by cardiac troponin I and T (cTnI and cTnT), has been associated with long-term death in the noncardiac human intensive care unit (ICU).

HYPOTHESIS

Presence of myocardial injury predicts 1-year case fatality in critically ill dogs with systemic inflammation.

ANIMALS

Thirty-eight dogs with evidence of systemic inflammation and no primary cardiac disease.

METHODS

Prospective cohort study. In dogs admitted to the ICU with evidence of systemic inflammation, blood samples were obtained at ICU admission for measurement of cTnI and cTnT, and cTnI was measured once daily during ICU hospitalization. Receiver operating characteristic (ROC) curves were used to examine prognostic capacity of admission cTnI, admission cTnT, and peak cTnI concentrations.

RESULTS

One-year case fatality rate was 47% (18/38 dogs). Admission cTnI concentrations were (median [range]) 0.48 [0.004-141.50] ng/mL, and peak cTnI concentrations were 1.21 [0.021-141.50] ng/mL. Admission cTnT concentrations were 15 [<13-3744] ng/L. For each marker, non-survivors had significantly higher concentrations than survivors (P = .0082-.038). ROC analyses revealed areas under curves [95% CI] of 0.707 [0.537-0.843] for peak cTnI and 0.739 [0.571-0.867] for admission cTnT, respectively. At the optimal cut-off, concentrations were 1.17 ng/mL (peak cTnI) and 23 ng/L (admission cTnT), sensitivities were 72% and 72%, and specificities were 70% and 80%, respectively.

CONCLUSIONS AND CLINICAL IMPORTANCE

While peak cTnI and admission cTnT are significantly related to 1-year case fatality in critically ill dogs with systemic inflammation, low sensitivities and specificities prevent their prediction of long-term outcome in individual patients. Troponins might play a role in identification of dogs at long-term risk of death.

Diagnostic and therapeutic implications of type 2 myocardial infarction: review and commentary

The Task Force for the Universal Definition of Myocardial Infarction recently published updated guidelines for the clinical and research diagnosis of myocardial infarction under a variety of circumstances and in a variety of categories. A type 1 myocardial infarction (MI) is usually the result of atherosclerotic coronary artery disease with thrombotic coronary arterial obstruction secondary to atherosclerotic plaque rupture, ulceration, fissuring, or dissection, causing coronary arterial obstruction with resultant myocardial ischemia and necrosis. Patients with a type 2 MI do not have atherosclerotic plaque rupture. In this latter group of patients, myocardial necrosis occurs because of an increase in myocardial oxygen demand or a decrease in myocardial blood flow. Type 2 MI has been the subject of considerable clinical discussion and confusion. This review by knowledgeable members of the Task Force seeks to help clinicians resolve the confusion surrounding type 2 MI.

Elevated cardiac troponin T levels in critically ill patients with sepsis

BACKGROUND

It is known that troponin elevations have prognostic importance in critically ill patients. We examined whether cardiac troponin T elevations are independently associated with in-hospital, short-term (30 days), and long-term (3 years) mortality in intensive care unit (ICU) patients admitted with sepsis, severe sepsis, and septic shock after adjusting for the severity of disease with the Acute Physiology, Age and Chronic Health Evaluation III system.

METHODS

We studied the Mayo Clinic's Acute Physiology, Age and Chronic Health Evaluation III database and cardiac troponin T levels from patients admitted consecutively to the medical ICU. Between January 2001 and December 2006, 926 patients with sepsis had cardiac troponin T measured at ICU admission. In-hospital, short-term, and long-term all-cause mortality were determined.

RESULTS

Among study patients, 645 (69.7%) had elevated cardiac troponin T levels and 281 (30.3%) had undetectable cardiac troponin T. During hospitalization, 15% of the patients with troponin T <0.01 ng/mL died compared with 31.9% of those with troponin T ≥ 0.01 ng/mL (P < .0001). At 30 days, mortality was 31% and 17% in patients with and without elevations, respectively (P < .0001). The Kaplan-Meier probability of survival at 1-, 2-, and 3-year follow-ups was 68.1%, 56.3%, and 46.8% with troponin T ≥ 0.01 ng/mL, respectively, and 76.4%, 69.1%, and 62.0% with troponin T <0.01 μg/L, respectively (P < .0001). After adjustment for severity of disease and baseline characteristics, cardiac troponin T levels remained associated with in-hospital and short-term mortality but not with long-term mortality.

CONCLUSIONS

In patients with sepsis who are admitted to an ICU, cardiac troponin T elevations are independently associated with in-hospital and short-term mortality but not long-term mortality.

Qualification of cardiac troponins for nonclinical use: a regulatory perspective

The US Food and Drug Administration (FDA) Biomarker Qualification Review Team presents its perspective on the recent qualification of cardiac troponins for use in nonclinical safety assessment studies. The goal of this manuscript is to provide greater transparency into the qualification process and factors that were considered in reaching a regulatory decision. This manuscript includes an overview of the data that were submitted and a discussion of the strengths and shortcomings of these data supporting the qualification decision. The cardiac troponin submission is the first literature-based biomarker application to be reviewed by the FDA and insights gained from this experience may aid future submissions and help streamline the characterization and qualification of future biomarkers.

Association between troponin T and ICU mortality, a changing trend

Background

Initially elevated levels of troponin predict adverse outcomes in patients admitted to the intensive care unit (ICU). No research team has investigated the changes in concentration of cardiac troponin T (cTnT) during ICU stay and their association with patient outcome.

Objective

We investigated whether the change in cTnT levels during ICU stay could predict outcomes (death or survival).

Methods

In this cohort study, all patients admitted to the medical ICU (10 beds) from January to July 2008 were enrolled. Troponin levels were evaluated within the first 24 hours of ICU admission and on the fourth, seventh and 10th days after admission.

Results

The study population (135 patients) had a mean age of 60.9 ± 21.5 years. The outcome was significantly different with regard to normal or elevated cTnT concentrations on the first and seventh days of follow up (p = 0.03 and 0.023, respectively). This difference was non-significant for cTnT levels on the fourth and 10th days after admission (p = 0.69 and 0.78, respectively). The change in cTnT levels was not significantly different between the deceased and discharged patients (p = 0.4).

Conclusion

Changes in cTnT levels during ICU stay did not show a significant trend (power: 0.26). Patients whose cTnT levels were increased on the first and seventh days of ICU stay had a worse survival, which could be associated with cardiac events on admission or at specific times during the stay in ICU.

Increased blood troponin levels in ICU patients

PURPOSE OF REVIEW

Cardiac troponins in serum have become the biomarkers of choice for the diagnosis of myocardial infarction. Yet, troponin can also be elevated by a multitude of causes in the absence of overt myocardial ischemia. Such nonspecific elevations are particularly common in the critically ill. This article aims to provide information on the significance of troponin elevations in unselected critically ill patients and in patients with sepsis or septic shock.

RECENT FINDINGS

Recent studies reconsider the possible association of troponin elevations with myocardial infarction in unselected critically ill patients. There are also more data on the prognostic significance of troponin in this population. In patients with sepsis, recent studies suggest that troponin may be a reliable index of sepsis-induced myocardial dysfunction, although the implications of this finding in the management of sepsis remain unclear for the time being. Troponin also appears to be a predictor of short and possibly also long-term outcome in septic patients. The advent of newer assays with even higher sensitivity, may lead to further redefinition of the role of troponin in the ICU.

SUMMARY

Troponin is frequently elevated in critically ill patients. More research is needed on the diagnostic and prognostic significance and possible clinical applications of troponin measurements in patients with sepsis and critical illness.