Significance and interpretation of elevated troponin in septic patients

Cardiac Troponin I and Electrocardiographic Evaluation in Hospitalized Cats with Systemic Inflammatory Response Syndrome

Several studies conducted on humans demonstrate the increase in cardiac troponins and the onset of arrhythmias in the course of systemic inflammatory response syndrome (SIRS). The aim of the current study was to assess the blood concentration of cardiac troponin I (cTnI) and electrocardiographic findings in SIRS-affected cats. Seventeen shorthair cats hospitalized with SIRS were enrolled (Group 1). SIRS diagnosis was performed based on the detection of at least two of the four criteria such as abnormal body temperature, abnormal heart rate (i.e., tachycardia or bradycardia), abnormal respiratory rate (i.e., tachypnea or bradypnea), and alterations of white blood cell number (i.e., leukocytes or band neutrophils). Ten cats screened for elective surgery such as neutering or dental procedures were evaluated as a control population (Group 2). They were considered healthy based on history, physical examination, hematological and biochemical profile, urinalysis, coprological exam, thyroxine assay, blood pressure measurement, and echocardiography. A physical examination, complete blood cell count, biochemistry test (including an electrolyte panel), electrocardiographic examination, and cTnI assay were carried out in each cat enrolled. Traumatic events, gastrointestinal, neoplastic, respiratory, and neurological disorders were identified as causes of SIRS in Group 1. In Group 1, a significantly higher concentration of cTnI than that in Group 2 was recorded (p = 0.004). In 37.5% of cats with SIRS, ventricular premature complexes occurring in couplets with multiform configuration were detected. Similarly, to humans, data herein reported would indicate possible cardiac damage present in cats with SIRS diagnosis.

Variation in Troponin I Measurement and the Cardiovascular Management Approach Following Elevated Troponin I Among Critically Ill Patients With Sepsis

Troponin I is frequently elevated in sepsis, but optimal clinical approaches to diagnosis and management of troponin I during sepsis are unclear.

OBJECTIVES

We aimed to describe the variation in troponin I measurement and the cardiovascular diagnostic and therapeutic approach to elevated troponin I among critically ill adults with sepsis.

DESIGN SETTING AND PARTICIPANTS

Observational cohort study of the hospital-level variation in serial troponin I measurement, trending troponin I to peak, echocardiography, cardiac stress test, cardiac catheterization, antiplatelet agents, therapeutic anticoagulation, beta-blockers, and statins quantified using hospital median odds ratios-the median odds of receiving an intervention at randomly selected higher versus lower rate hospitals-derived from multivariable-adjusted random-effects logistic regression models with hospital site as the random effect. The Premier Healthcare Database was used. Patients were adults aged greater than 18 years admitted to the ICU with sepsis from 2016 to 2020.

MAIN OUTCOMES AND MEASURES

The hospital-level median odds ratios of troponin I measurement as well as cardiovascular diagnostics and therapeutics.

RESULTS

Among 85,830 adults with sepsis, 53,058 (61.8%) had a troponin I measured, with a median odds ratio of troponin measurement across hospitals of 5.30 (95% CI, 4.98-5.67). Among 27,665 adults (32.2%) with sepsis and an elevated troponin I level, 84.8% had serial troponin I measurements, 66.0% had troponin trended to peak level, 66.7% had an echocardiogram, 4.1% had a cardiac stress test, 6.6% underwent cardiac catheterization, 48.3% received antiplatelet agents, 8.3% received therapeutic anticoagulation, 50.5% received beta-blockers, and 38.1% received statins. The median odds ratios between hospitals for cardiovascular diagnostics and therapeutics ranged from 1.28 (95% CI, 1.24-1.32) for use of beta-blockers to 7.58 (95% CI, 6.43-8.77) for use of therapeutic anticoagulation.

CONCLUSIONS AND RELEVANCE

Both troponin I measurement and the approach to an elevated troponin I among critically ill adults with sepsis varied widely across hospitals consistent with disparate practice and care efficiency. Prospective studies are needed to guide an informed approach to troponin I measurement and cardiovascular evaluation in sepsis.

Research Progress on the Mechanism of Sepsis Induced Myocardial Injury

Sepsis is an abnormal condition with multiple organ dysfunctions caused by the uncontrolled infection response and one of the major diseases that seriously hang over global human health. Besides, sepsis is characterized by high morbidity and mortality, especially in intensive care unit (ICU). Among the numerous subsequent organ injuries of sepsis, myocardial injury is one of the most common complications and the main cause of death in septic patients. To better manage septic inpatients, it is necessary to understand the specific mechanisms of sepsis induced myocardial injury (SIMI). Therefore, this review will elucidate the pathophysiology of SIMI from the following certain mechanisms: apoptosis, mitochondrial damage, autophagy, excessive inflammatory response, oxidative stress and pyroptosis, and outline current therapeutic strategies and potential approaches in SIMI.

Troponin I Cutoff for Non-ST-Segment Elevation Myocardial Infarction in Sepsis

The diagnostic value and optimal cutoff level of cardiac troponin I in patients with sepsis have not been studied. In this single hospital retrospective study, we assessed the optimal cutoff value of troponin I for diagnosing non-ST-segment elevation myocardial infarction (NSTEMI) with type 1 myocardial infarction (MI) in patients with sepsis who had undergone a percutaneous coronary intervention from 2009 to 2019. In total, 5,341 patients (excluding patients with chronic kidney disease) were included, of whom 277 had sepsis or septic shock. Of the 123 patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS) and sepsis, 77 (62.6%) were diagnosed with NSTEMI with type 1 MI. The receiver-operating characteristic curve showed an area under the curve (AUC) of 0.705 for diagnosis of NSTEMI with type 1 MI with a troponin I cutoff of >300 ng/L (sensitivity: 68.4%, specificity: 70.2%, Youden index: 0.386). Multiple linear regression showed no significant predictors of NSTEMI with type 1 MI. Troponin level and the Global Registry of Acute Coronary Events (GRACE) scores were correlated (R² = 0.0625, p = 0.032) and showed comparable predictive value for 6-month mortality (AUC: 0.637 and 0.611, respectively, p = 0.7651). The optimal troponin I cutoff to effectively diagnose NSTEMI with type 1 MI in patients with sepsis was 300 ng/L.

Metabolites Concentration in Plasma and Heart Tissue in Relation to High Sensitive Cardiac Troponin T Level in Septic Shock Pigs

Elevated circulating cardiac troponin T (cTnT) is frequent in septic shock patients. Signs of myocardial ischemia and myocyte necrosis are not universally present, but the precise mechanism for elevated cTnT is unknown. We investigated plasma and heart tissue metabolites concentration in six septic shock (SS) and three sham swine undergoing a protocol of polymicrobial septic shock and resuscitation, in order to highlight possible pathways and biomarkers involved in troponin release (high sensitive cardiac troponin T, hs-cTnT). The animals were divided into two groups: the high cTnT group (n = 3) were pigs showing a significantly higher concentration of cTnT and lactate after resuscitation; the low cTnT group (n = 6, three sham and three septic shock) characterized by a lower value of cTnT and a lactate level < 2 mmol/L. Spearman correlation was assessed on plasma fold-change of cTnT, cytokines (TNF-α and IL-10), and metabolites. Finally, the fold-change between the end of resuscitation and baseline values (Res./BL) of plasma metabolites was used to perform a partial least square discriminant analysis (PLS-DA) with three latent variables. Before building the model, the number of features was reduced by summing up the metabolites of the same class that resulted similarly correlated to cTnT fold-change. Proline and glycine were significantly higher in the high cTnT group at the end of experiment both in the myocardium and plasma analyses. Moreover, plasma proline fold-change was found to be positively correlated with cTnT and cytokine fold-changes, and trans-4-hydroxyproline (t4-OH-Pro) fold-change was positively correlated with cTnT fold-change. The PLS-DA model was able to separate the two groups and, among the first ranked features based on VIP score, we found sugars, t4-OH-Pro, proline, creatinine, total amount of sphingomyelins, and glycine. Proline, t4-OH-Pro, and glycine are very abundant in collagen, and our results may suggest that collagen degradation could represent a possible mechanism contributing to septic myocardial injury. The common phenotype of septic cardiomyopathy could be associated to dysregulated collagen metabolism and/or degradation, further exacerbated by higher inflammation and oxidative stress.

N-terminal pro-brain natriuretic peptide is an independent predictor of mortality in patients with sepsis

This study aims to evaluate the role of cardiac enzymes N-terminal pro-brain natriuretic peptide (NT-proBNP) and cardiac troponin-I (CTnI) as predictors of outcomes in patients with sepsis.78 cases with a diagnosis of sepsis were enrolled over a 2-year period. Baseline demographic, Acute Physiology and Chronic Health Evaluation-II (APACHE-II), Simplified Acute Physiology Score-II (SAPS-II), hematologic and biochemical parameters were noted. Serum NT-proBNP and CTnI were evaluated at 24 and 72 hours of admission along with echocardiography. Patients were prospectively followed up until death or discharge.Mean APACHE-II score was 19.8±9.6 and SAPS-II was 44.8±17.2. Survival rate in the study was 47.5% (36 of 78 patients). NT-proBNP was significantly higher in non-survivors with values over 4300 pg/mL at 24 hours and 5229 pg/mL at 72 hours associated with poor outcomes (p<0.05). CTnI was higher among non-survivors than in survivors, but the difference was not significant. APACHE-II score combined with NT-proBNP predicted a poor outcome in 51.2% cases compared with 14.6% cases with APACHE-II alone (p<0.05), while SAPS-II combined with NT-proBNP predicted a poor outcome in 53.6% cases as compared with 9.6% cases with SAPS-II alone (p<0.05). SAPS-II greater than 45 and NT-proBNP values at 72 hours were independent predictors of mortality in patients with sepsis.NT-proBNP is an independent predictor of mortality in patients with sepsis and its combination with APACHE-II and SAPS-II improves the predictive values of the scoring systems.

Diagnostic Value of High-Sensitivity Troponin T for Subclinical Left Ventricular Systolic Dysfunction in Patients with Sepsis

Background

Left ventricular systolic dysfunction (LVSD) is common in sepsis. Speckle-tracking echocardiography (STE) is a useful emerging tool for evaluating the intrinsic left ventricular systolic function. High-sensitivity cardiac troponin T (hs-cTnT) is the most sensitive biomarker of myocardial injury. However, there are limited data regarding the association between hs-cTnT level and left ventricular systolic dysfunction based on STE in septic patients. We performed this prospective study to evaluate the diagnostic value of hs-cTnT level for subclinical left ventricular systolic dysfunction measured by STE in septic patients according to the sepsis-3 definition.

Methods

Patients with sepsis based on sepsis-3 definition admitted to the intensive care unit were prospectively performed STE and hs-cTnT level within 24 hours after the onset of sepsis. Baseline clinical and echocardiographic variables were collected. Left ventricular systolic dysfunction was defined as a global longitudinal strain of ≥−15%.

Results

During a 19-month period, 116 patients were enrolled in the study. The elevated hs-cTnT level was seen in 86.2% of septic patients, and 43.1% of patients had LVSD on STE. The median hs-cTnT level and the proportion of elevated hs-cTnT level (>14 ng/L) were significantly higher in patients with LVSD than in patients without LVSD. The area under the ROC curves of hs-cTnT to detect LVSD was 0.73 (P < 0.001). In the multivariate analysis, hs-cTnT (HR, 1.002; 95% CI, 1.000 to 1.004; P = 0.025) and septic shock (HR, 7.6; 95% CI, 2.25 to 25.76; P = 0.001) were independent predictors of LVSD.

Conclusion

Our study indicated that the serum hs-cTnT level might be a useful biomarker for detecting LVSD in septic patients.

Is Sepsis a Cardiac Nemesis? Exploring New Vistas

How to cite this article: Kapoor A. Is Sepsis a Cardiac Nemesis? Exploring New Vistas. Indian J Crit Care Med 2020;24(2):83-84.

Elevated Plasma Histone H4 Levels Are an Important Risk Factor in the Development of Septic Cardiomyopathy

Background:

Myocardial impairment is a major complication and an important prognostic predictor of sepsis. Therefore, early and accurate diagnosis as well as timely management of septic cardiomyopathy is critical to achieve favorable outcomes.

Aims:

To investigate the risk factors of septic cardiomyopathy.

Study Design:

Cross-sectional study.

Methods:

This study performed between May 2016 and June 2018 recruited 93 septic patients from the intensive care unit. All patients received standardized treatments. Septic patients were divided into two groups: non cardiomyopathy (n=45) and septic cardiomyopathy group (n=48). Blood samples were collected and transthoracic echocardiography was performed within 24 hours of intensive care unit admission. Septic patients with one ultrasound abnormality but no history of heart disease were diagnosed as having septic cardiomyopathy. Plasma histones, cardiac troponin I, and N-terminal pro-brain natriuretic peptide were measured using ELISA. Sequential Organ Failure Assessment scores, vasopressor use, and the outcomes of intensive care unit stay were analyzed. Spearman rank analysis was used to determine the correlation between plasma histone H4 and other parameters. Binary logistic regression and receiver operating characteristic curve analysis were used to determine the risk factors for septic cardiomyopathy.

Results:

Compared with the non-cardiomyopathy group, the septic cardiomyopathy group had significantly higher plasma H4 and cardiac troponin I levels, a higher Sequential Organ Failure Assessment score, more frequent vasopressor use, and a higher mortality rate (p<0.05). Plasma histone H4 levels positively correlated with cardiac troponin I (r=0.577, p<0.001), N-terminal pro-brain natriuretic peptide (r=0.349, p=0.001), and Sequential Organ Failure Assessment scores (r=0.469, p<0.001). Binary logistic regression and receiver operating characteristic curve analyses revealed that elevated plasma histone H4 levels and vasopressor use were important risk factors for septic cardiomyopathy (p<0.05).

Conclusion:

Elevated plasma histone H4 levels could be used to predict septic cardiomyopathy in patients with sepsis.

The prognostic value of left ventricular systolic function and cardiac biomarkers in pediatric severe sepsis

Echocardiography and cardiac biomarkers, such as cardiac troponin I (cTnI) and N-terminal pro-B-type natriuretic peptide (NT-pro BNP) are useful tools to evaluate cardiac dysfunction. Left ventricular systolic dysfunction (LVSD) is common in pediatric severe sepsis. The aim of this study is to evaluate the prognostic value of LVSD, cTnI, and NT-pro BNP for pediatric severe sepsis.A prospective, single center, observational study was conducted. Severe sepsis children were enrolled in the study from December 2015 to December 2016 in pediatric intensive care unit of Shanghai Children's Medical Center. Recorded general information, transthoracic echocardiography were performed at day 1, 2, 3, 7, and 10, using Simpson to measure left ventricular end-diastolic dimension and left ventricular end-systolic dimension, obtained echocardiography parameters: left ventricular ejection fraction (LVEF), left ventricular fractional shortening, left ventricular end-diastolic volume, left ventricular end- systolic volume, stroke volume, cardiac output. At the same time collecting the blood sample to measure cTnI, NT-pro BNP. The definition of LVSD was LVEF <50%. According to the prognosis of 28 days, children with severe sepsis were divided into survived group and nonsurvived group.Total of 50 pediatric patients who were diagnosed with severe sepsis (including septic shock) were enrolled, the incidence of LVSD was 52%. The 28-day mortality rate of severe sepsis was 34%. Multivariate logistic regression analyses for predictors of death in pediatric severe sepsis revealed that the 28-day mortality of severe sepsis was associated with mechanical ventilation (MV) within the first 6 hours of admission (odds ratio [OR], 0.01; 95% confidence interval [CI], 0.00-0.07) and total MV time (OR, 0.81; 95% CI, 0.68-0.97). The receiver operating characteristic curves LVEF (area under curve = 0.526), cTnI (area under curve = 0.480), and NT-pro BNP (area under curve = 0.624) were used to predict the 28-day mortality in pediatric severe sepsis. Follow-up echocardiography parameters for survived group and nonsurvived group showed no significant changes in LVEF, LVFS, stroke volume index, cardiac index (CI), left ventricular end-diastolic volume index and left ventricular end-systolic volume index at day 1, 2, 3, 7, and 10, except for CI at day 1 and 2. Kaplan-Meier plot of 28-day mortality and LVSD in pediatric severe sepsis showed there were no statistical differences (χ = 0.042, P = .837).LVSD occurs frequently in pediatric with severe sepsis. The 28-day mortality rate of severe sepsis was also high. In this study, none of LVSD, cTnI, and NT-proBNP was associated with the prognosis of pediatric severe sepsis.

Septic Shock and Troponin I: Are They in a Relationship?

How to cite this article: Gupta S, Tomar DS. Septic Shock and Troponin I: Are They in a Relationship? Indian J Crit Care Med 2019;23(7):294.

Troponin I at admission in the intensive care unit predicts the need of dialysis in septic patients

Background

In a previous study we showed that troponin I (TnI) > 0.42 ng/mL predicted the need of dialysis in a group of 29 septic patients admitted to the intensive care unit (ICU). We aimed to confirm such finding in a larger independent sample.

Methods

All septic patients admitted to an ICU from March 2016 to February 2017 were included if age between 18 and 90 years, onset of sepsis < 24 h, normal left ventricular ejection fraction, and no previous coronary or kidney diseases. TnI was measured on day 1. Patients were followed by 30 days or until death.

Results

A total of 120 patients were included (51% male, 74 ± 13 years old). At ICU admission, 70 patients had TnI > 0.42 ng/mL. These patients had serum creatinine slightly higher (1.66 ± 0.34 vs. 1.32 ± 0.39 mg/dL; P <  0.0001) than those with lower TnI and similar urine output (1490 ± 682 vs. 1406 ± 631 mL; P = 0.44). At the end of the follow-up period, 70.0% of the patients with lower TnI were alive in comparison with 38.6% of those with higher TnI (p = 0.0014). After 30 days, 69.3 and 2.9% of the patients with lower and higher TnI levels remained free of dialysis, respectively (p <  0.0001). In a Cox regression model, after adjustment for gender, age, Charlson comorbidity index, serum creatinine, potassium, pH, brain natriuretic peptide and urine output, TnI > 0.42 ng/mL persisted as a strong predictor of dialysis need (hazard ratio 3.48 [95%CI 1.69–7.18]).

Conclusions

TnI levels at ICU admission are a strong independent predictor of dialysis need in sepsis.

Mortality in sepsis: Comparison of outcomes between patients with demand ischemia, acute myocardial infarction, and neither demand ischemia nor acute myocardial infarction

INTRODUCTION

Elevation in cardiac troponins is common with sepsis despite unclear impact.

HYPOTHESIS

We investigated whether demand ischemia(DI) resulted in variable outcomes compared to acute myocardial infarction(AMI) and those with neither DI nor AMI in sepsis.

METHODS

We analyzed data from the 2011-2014 National Inpatient Sample among patients admitted for sepsis. We compared outcomes among patients with DI i) versus AMI and ii) versus neither DI nor AMI, respectively using propensity matching. Primary study end-point was in-hospital mortality.

RESULTS

We studied 666,154 patients, with mean age 63.7 years and 50.8% female participants. Overall, 94.7% of the included patients had neither DI nor AMI, 4.4% had AMI and 0.83% had DI. Between 2011 and 2014, we observed an increasing trend for DI but decreasing trend for AMI in sepsis. Patients with DI experienced higher rates of atrial and ventricular arrhythmias, had longer length of stay and higher cost of stay compared to patients with neither demand ischemia nor AMI. Despite higher hospital mortality at baseline with DI, post-propensity matching revealed no difference in hospital mortality between patients with DI and those with neither (26.9% vs. 27.0%, adjusted odds ratio 0.99, 95% confidence intervals 0.92-1.07;p=0.87). Patients with DI experienced lower hospital mortality compared to those with AMI pre (28.5% vs. 48.3%;p<0.001) and post-propensity matching (41.1% vs. 29.1%, aOR 0.58, 95% CI 0.54-0.63;p<0.001).

CONCLUSION

Among patients with sepsis, those with DI had similar adjusted in-hospital mortality compared to those with neither DI nor AMI. Patients with AMI had the highest in-hospital mortality among all groups.

Cardiovascular Parameters Associated With Troponin I as Indicators for 14-Day Mortality in Patients With Septic Shock

BACKGROUND

Troponin I is better than other troponin isoforms for monitoring cardiocyte damage, and correlates with sepsis-related mortality. However, hemodynamic factors possibly interact with cardiac function to affect mortality in sepsis. Thus, this study used parameters from pulse-induced contour cardiac output (PiCCO) to investigate the possibility.

METHODS

Patients with troponin I tests and sequential organ failure assessment score ≥2 were selected and divided into survivors and nonsurvivors groups and blood troponin I levels between them were compared. Additionally, 65 patients with septic shock and PiCCO records were selected and divided into high cardiac function index (CFI) and low CFI groups and their cardiac function associated with troponin I levels was checked. Furthermore, the patients were classified into 4 subgroups based on CFI and another hemodynamical parameter of PiCCO for identifying if any interaction between CFI and the parameter existed.

RESULTS

High blood troponin I levels correlated with high mortality, and with low cardiac function (CFI < 4.5) alone or with low CFI combined with high stroke volume variation (SVV), but did not correlate with global end-diastolic index (GEDI), or systemic vascular resistance index. However, only the subgroup with low CFI and high SVV (CFI < 4.5 and SVV > 10) increased mortality.

CONCLUSIONS

Our data give an insight into interactions between cardiac and hemodynamic factors to cause cardiocyte damage and suggest that multiple factors (i.e., low CFI and high SVV) should be considered together to evaluate cardiocyte damage and mortality in sepsis.

Impact of Type 2 Myocardial Infarction (MI) on Hospital-Level MI Outcomes: Implications for Quality and Public Reporting

BACKGROUND

The International Classification of Diseases (ICD) coding system does not recognize type 2 myocardial infarction (MI) as a separate entity; therefore, patients with type 2 MI continue to be categorized under the general umbrella of non-ST-segment-elevation myocardial infarction (NSTEMI). We aim to evaluate the impact of type 2 MI on hospital-level NSTEMI metrics and discuss the implications for quality and public reporting.

METHODS AND RESULTS

We conducted a single-center retrospective analysis of 1318 patients discharged with a diagnosis of NSTEMI between July 2013 and October 2014. The Third Universal Definition was used to define type 1 and type 2 MI. Weighted Kaplan-Meier curves were used to analyze risk of mortality and readmission. Overall, 1039 patients met NSTEMI criteria per the Third Universal Definition; of those, 264 (25.4%) had type 2 MI. Patients with type 2 MI were older, were more likely to have chronic kidney disease, and had lower peak troponin levels. Compared with type 1 MI patients, those with type 2 MI had higher inpatient mortality (17.4% versus 4.7%, P<0.0001) and were more likely to die from noncardiovascular causes (71.7% versus 25.0%, P<0.0001). Despite weighting for patient characteristics and discharge medications, patients with type 2 MI had higher mortality at both 30 days (risk ratio: 3.63; 95% confidence interval, 1.67-7.88) and 1 year (risk ratio: 1.98; 95% confidence interval, 1.44-2.73) after discharge. Type 2 MI was also associated with a lower 30-day cardiovascular-related readmission (risk ratio: 0.49; 95% confidence interval, 0.12-2.06).

CONCLUSIONS

NSTEMI metrics are significantly affected by type 2 MI patients. Type 2 MI patients have distinct etiologies, are managed differently, and have higher mortality compared with patients with type 1 MI. Moving forward, it may be appropriate to exclude type 2 MI data from NSTEMI quality metrics.

Cardiac Troponin Release is Associated with Biomarkers of Inflammation and Ventricular Dilatation During Critical Illness

Introduction:

Troponin release is common during critical illness. We hypothesized that there was an association between cardiac troponin T (cTnT) and biomarkers of systemic inflammation and ventricular dilatation.

Methods:

In an observational prospective cohort study, we enrolled consecutive adult patients admitted for noncardiac reasons to the intensive care unit (ICU) in two tertiary care centers. We measured cTnT, C-reactive protein (CRP), interleukin-6 (IL-6), procalcitonin (PCT), and N-terminal pro brain natriuretic peptide (NT-proBNP) daily in the first week, and on alternate days in the second week. Using a peak cTnT cutoff ≥15 ng/L and concomitant changes on electrocardiogram, patients were categorized as “definite myocardial infarction (MI),” “possible MI,” “cTnT rise only,” or “no cTnT rise.” Within each group, associations between CRP, IL-6, PCT, NT-proBNP, and cTnT were investigated using mixed effect models.

Results:

One hundred seventy-two patients were included in the analysis of whom 84% had a cTnT rise ≥15 ng/L. Twenty-one patients (12%) had a definite MI, 51 (30%) had a possible MI, and 73 (42%) had a cTnT rise only. At the time of peak cTnT, 71% of patients were septic and 67% were on vasopressors.

Multivariable analysis showed a significant association between cTnT and IL-6 in all patients with a cTnT rise independent of age, gender, renal function, and cardiovascular risk factors. In patients without a definite MI, cTnT levels were significantly associated with PCT and NT-proBNP values. In patients without elevated cTnT levels, there was no associated NT-proBNP rise.

Conclusions:

In ICU patients admitted for non-cardiac reasons, serial cTnT levels were independently associated with markers of systemic inflammation and NT-proBNP.

Cardiac Troponin Is a Predictor of Septic Shock Mortality in Cancer Patients in an Emergency Department: A Retrospective Cohort Study

Background

Septic shock may be associated with myocardial damage; however, the prognostic value of cardiac enzymes in cancer patients with septic shock is unknown. In this study, we evaluated the prognostic significance of cardiac enzymes in combination with established prognostic factors in predicting the 7-day mortality rate of patients with septic shock, and we constructed a new scoring system, Septic Oncologic Patients in Emergency Department (SOPED), which includes cardiac enzymes, to predict 7-day mortality rates.

Methods and Findings

We performed a retrospective cohort study of 375 adult cancer patients with septic shock who visited the emergency department of a comprehensive cancer center between 01/01/2004 and 12/31/2013. The 7-day and 28-day mortality rates were 19.7% and 37.6%, respectively. The creatine kinase myocardial band fraction and troponin-I were significantly higher in patients who died in ≤7 days and ≤28 days than in those who did not. In Cox regression models, troponin-I >0.05 ng/mL plus Predisposition, Infection, Response, and Organ Failure (PIRO2011) or Mortality in Emergency Department Sepsis (MEDS) score was a significant predictor of survival for ≤7 days. With our new SOPED scoring system, the receiver operating characteristic area under the curve was 0.836, higher than those for PIRO2011 and MEDS.

Conclusions

Troponin-I >0.05 ng/mL was an important predictor of short-term mortality (≤7 days). The SOPED scoring system, which incorporated troponin-I, was more prognostically accurate than were other scores for 7-day mortality. Large multicenter studies are needed to verify our results and prospectively validate the prognostic performance of the SOPED score.

The non-cardiac use and significance of cardiac troponins

Cardiac Troponins are blood markers of myocardial damage and are widely utilised across all acute medical departments. However, with a massive rise in requests for this test, the interpretation of raised serum levels in the absence of cardiac sounding clinical features can become a clinical conundrum. This is especially true if the numerous causes of positive test results are not fully appreciated. A thorough understanding of the strengths and weaknesses of this blood test in light of a patient population living longer, increasing in comorbidities and possible causes of false test results can provide invaluable support in establishing an accurate diagnosis and instigating effective management. This article will describe the history of cardiac markers along with a discussion of the various causes of elevated cardiac troponins outside acute coronary syndrome. It will elaborate on the applications and significance of this blood test and the potential uses of positive results with elevated serum Troponin levels.

The prognostic and risk-stratified value of heart-type fatty acid-binding protein in septic patients in the emergency department

PURPOSE

To evaluate the prognostic and risk-stratified ability of heart-type fatty acid-binding protein (H-FABP) in septic patients in the emergency department (ED).

MATERIALS AND METHODS

From August to November 2012, 295 consecutive septic patients were enrolled. Circulating H-FABP was measured. The predictive value of H-FABP for 28-day mortality, organ dysfunction on ED arrival, and requirement for mechanical ventilation or a vasopressor within 6 hours after ED arrival was assessed by the receiver operating characteristic curve and logistic regression and was compared with Acute Physiology and Chronic Health Evaluation (APACHE) II score, Mortality in Emergency Department Sepsis (MEDS) score, and Sequential Organ Failure Assessment score.

RESULTS

The 28-day mortality, APACHE II, MEDS, and Sequential Organ Failure Assessment scores were much higher in H-FABP-positive patients. The incidence of organ dysfunction at ED arrival and requirement for mechanical ventilation or a vasopressor within 6 hours after ED arrival was higher in H-FABP-positive patients. Heart-type fatty acid-binding protein was an independent predictor of 28-day mortality and organ dysfunction. The area under the receiver operating characteristic curve for H-FABP predicting 28-day mortality and organ dysfunction was 0.784 and 0.755, respectively. Combination of H-FABP and MEDS improved the performance of MEDS in predicting organ dysfunction, and the difference of AUC was statistically significant (P<.05). The combinations of H-FABP and MEDS or H-FABP and APACHE II also improved the prognostic value of MEDS and APACHE II, but the areas under the curve were not statistically different.

CONCLUSIONS

Heart-type fatty acid-binding protein was helpful for prognosis and risk stratification of septic patients in the ED.

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.

High-sensitivity cardiac troponin T is an independent predictor of inhospital mortality in emergency department patients with suspected infection: a prospective observational derivation study

INTRODUCION

To assess the prognostic and discriminative accuracy of high-sensitivity cardiac troponin T (hs-cTnT) for prediction of inhospital mortality in emergency department (ED) patients with suspected infection.

METHODS

Prospective observational derivation study in ED patients with suspected infection. Prognostic performance of hs-cTnT (divided in four quartiles because of non-linearity) for prediction of inhospital mortality was assessed using multivariable logistic regression, correcting for predisposition, infection, response and organ failure (PIRO) score as a measure of illness severity and quality of ED treatment as quantified by the number of 'Surviving Sepsis Campaign' goals achieved. Discriminative power of hs-cTnT was assessed by receiver operator characteristics with area under the curve (AUC) analysis.

RESULTS

Hs-cTnT (median (IQR) was 57 (25-90) ng/L (n=23) in non-survivors, significantly higher than the 15 (7-28) ng/L in survivors (n=269, p<0.001). Additionally, the lowest quartile of hs-cTnT was a perfect predictor of survival because zero death occurred. Therefore, the second quartile was used as a reference category in the multivariable logistic regression analysis showing that hs-cTnT was an independent predictor of inhospital mortality: Corrected ORs were 2.2 (95% CI 0.4 to 12.1) and 5.8 (1.2 to 27.3) for the 3rd and 4th quartile compared with the 2nd hs-cTnT quartile. The AUCs of hs-TnT was 0.81 (0.74 to 0.88), similar to the AUC of 0.78 (0.68 to 0.87) of the PIRO score (p>0.05). Overall negative predictive value of hs-cTnT was 99%.

CONCLUSIONS

In ED patients with suspected infection, the routinely used biomarker hs-cTnT is an independent predictor of inhospital mortality with excellent discriminative performance. Future studies should focus on the additional value of hs-cTnT to existing risk stratification tools.

Cardiac ischemia in patients with septic shock randomized to vasopressin or norepinephrine

Introduction

Cardiac troponins are sensitive and specific biomarkers of myocardial necrosis. We evaluated troponin, CK, and ECG abnormalities in patients with septic shock and compared the effect of vasopressin (VP) versus norepinephrine (NE) on troponin, CK, and ECGs.

Methods

This was a prospective substudy of a randomized trial. Adults with septic shock randomly received, blinded, a low-dose infusion of VP (0.01 to 0.03 U/min) or NE (5 to 15 μg/min) in addition to open-label vasopressors, titrated to maintain a mean blood pressure of 65 to 75 mm Hg. Troponin I/T, CK, and CK-MB were measured, and 12-lead ECGs were recorded before study drug, and 6 hours, 2 days, and 4 days after study-drug initiation. Two physician readers, blinded to patient data and drug, independently interpreted ECGs.

Results

We enrolled 121 patients (median age, 63.9 years (interquartile range (IQR), 51.1 to 75.3), mean APACHE II 28.6 (SD 7.7)): 65 in the VP group and 56 in the NE group. At the four time points, 26%, 36%, 32%, and 21% of patients had troponin elevations, respectively. Baseline characteristics and outcomes were similar between patients with positive versus negative troponin levels. Troponin and CK levels and rates of ischemic ECG changes were similar in the VP and the NE groups. In multivariable analysis, only APACHE II was associated with 28-day mortality (OR, 1.07; 95% CI, 1.01 to 1.14; P = 0.033).

Conclusions

Troponin elevation is common in adults with septic shock. We observed no significant differences in troponin, CK, and ECGs in patients treated with vasopressin and norepinephrine. Troponin elevation was not an independent predictor of mortality.

Trial registration

Controlled-trials.com ISRCTN94845869

Elevated cardiac troponins in setting of systemic inflammatory response syndrome, sepsis, and septic shock

Elevation of cardiac troponins and creatinine kinase is frequently observed in setting of systemic inflammatory response syndrome (SIRS), sepsis, or septic shock. Underlying pathophysiologic mechanism for such troponin leak, its clinical significance, and what different could be done in such settings remain elusive. In this paper we have briefly overviewed the proposed pathogenic mechanisms for SIRS, sepsis, or septic shock-related troponin elevation (SRTE) and have provided brief overview on its clinical significance. Upon review of the relevant literature we found that majority of patients with the SRTE with no prior history of coronary artery disease (CAD) upon testing are found not to have any CADs. We have also briefly discussed the possible pharmacologic agents and potential targets which are important from pathophysiologic and pharmacologic point of view that may alter the outcomes of SRTE-related myocardial depression in near future.

Elevated troponin I and its prognostic significance in acute liver failure

Introduction

Acute liver failure (ALF) is a life-threatening multisystem illness complicated by multiple organ failure (MOF) and haemodynamic disturbances. Morbidity and mortality remains high and various prognostic and scoring models are in use to predict outcome. A recent observation in a large cohort of ALF patients suggested a prognostic value of troponin I (cTnI) and its role as a marker of subclinical myocardial injury and outcome.

Methods

Data from consecutive ALF patients over a four-year period from January 2007 to March 2011 were included. The aim of this study was to correlate any relationship that may exist between cTnI, mortality, severity of illness and non-hepatic organ failure.

Results

A total of 218 subjects (age 36 (16 to 90) years, M:F 103:115) were studied, of which 136 had an elevated cTnI > 0.05 μg/L. Higher organ failure scores were found with positive cTnI: APACHE II (19.5 (3 to 51) vs 14 (2 to 51), P = 0.001), APACHE III (81 (15 to 148) vs 59 (8 to 172), P = < 0.001) SOFA (15 (4 to 20) vs 13 (2 to 21), P = 0.027) and SAPS (48 (12 to 96) vs 34 (12 to 97), P = 0.001). Patients with positive cTnI had higher serum creatinine (192 μmol/l (38 to 550) vs 117 μmol/l (46 to 929), P < 0.001), arterial lactate (0.25, P < 0.001) and a lower pH (-0.21, P = 0.002). Also a higher proportion required renal replacement therapy (78% vs 60%, P = 0.006). Patients with elevated cTnI more frequently required vasopressors-norepinephrine (73% vs 50%, P = 0.008). Elevated cTnI did not predict outcome as effectively as other models (AUROC 0.61 (95% CI 0.52 to 0.68)).

Conclusions

More than 60% of ALF patients in this study demonstrated elevated cTnI. Despite a close correlation with organ failure severity, cTnI was a poor independent predictor of outcome. cTnI may not represent true myocardial injury and may be better viewed as a marker of metabolic stress.

Decitabine induced transient cardiomyopathy: a case report

Case report:

A 75-yr-old gentleman, with a past medical history of diabetes mellitus and Acute Myeloid Leukemia presented to our emergency department with a chief complaint of exertional dyspnea and chest pain. A week prior to this visit, he had recieved a cycle of decitabine chemotherapy at 20 mg/metered square for ten days. This was his second cycle of decitabine. His out patient medications included megesterol, omeprazole, morphine sulfate and insulin glargine. The patient was admitted to the Coronary Care Unit for Acute Coronary Syndrome. His cardiac enzymes were elevated (peak troponin 30 ng/mL, CKMB 67.4 ng/mL). His 12 lead EKG revealed sinus tachycardia with a ventricular rate of 113, but without acute ST–T wave changes. The BNP was 259 pg/mL. A 2D echo revealed moderate diffuse hypokinesis with an EF of 35%. He subsequently underwent a left heart catheterization, which showed non-obstructive CAD. In our patient, the elevated troponins (peak troponin 30 ng/mL) and BNP were seen concomitant with the onset of cardiogenic shock. Two months ago, his 2 D echocardiogram revealed an ejection fraction of about 55%–65% with slightly increased left ventricular (LV) wall thickness.

Discussion:

The most common adverse effects of decitabine include cytopenia, nausea, pain and erythema/nodules at the injection site. To date, there has been only one reported case of a hypomethylating agent inducing acute myocarditis. We a present a case of reversible, non-ischemic cardiomyopathy secondary to decitabine chemotherapy, which resolved after the drug was discontinued.

Trials involving decitabine for the treatment of MDS reported no myocarditis. In our case, the diagnosis of transient cardiomyopathy was highly probable since the patient’s troponins and echocardiogram returned to baseline after discontinuation of treatment. Also, the patient never had any further chest pain at his 6 month follow up. In this case, we believe that the elevated Troponin I levels, along with a cardiac catheterization revealing patent coronary vessels, favor our hypothesis that our patient suffered from acute myocarditis as a result of direct toxicity from decitabine chemotherapy. We doubt that there was an underlying infectious etiology, since the patient had three negative blood cultures, two negative urine cultures and a negative viral serology. Our case demonstrates that chest pains in a patient treated with hypomethylating agents should be further explored in order to rule out acute myocarditis.

N-terminal prohormone of brain natriuretic peptide: a useful tool for the detection of acute pulmonary artery embolism in post-surgical patients

BACKGROUND

Acute pulmonary embolism (APE) is an important clinical problem in patients after major surgery and often remains a difficult diagnosis because of unspecific clinical symptoms. Therefore, we investigated the role of N-terminal prohormone of brain natriuretic peptide (NT-proBNP) for the detection of APE.

METHODS

In 44 patients with suspected APE referred to the intensive care unit after major surgery, serum NT-proBNP, troponin-I, and D-dimers were measured according to the standard hospital protocol. To definitively confirm or exclude APE, all patients underwent an angiographic CT scan of the thorax.

RESULTS

APE was confirmed in 28 and excluded in 16 patients by CT scan. NT-proBNP was significantly (P<0.01) higher in patients with APE [4425 (sd 8826; range 63-35 000) pg ml(-1)] compared with those without [283 (sd 327; range 13-1133) pg ml(-1)]. The sensitivity of the NT-proBNP screening was 93%, specificity 63%, positive predictive value 81%, and negative predictive value 83%. There were no significant (P = 0.96) differences in D-dimers between subjects with and without APE [confirmed APE: 511 (sd 207; range 83-750) μg litre(-1); excluded APE: 509 (sd 170; range 230-750) μg litre(-1)]. Troponin-I levels were not elevated in 32% of the patients with APE.

CONCLUSIONS

D-dimer levels are frequently elevated in post-surgical patients and not applicable for confirmation or exclusion of APE. In contrast, NT-proBNP appears to be a useful biomarker for APE diagnosis in the postoperative setting. In the case of NT-proBNP levels below the upper reference limit, haemodynamically relevant APE is unlikely. Troponin-I in contrast is not considered to be helpful.

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.

Cardiac troponin I does not independently predict mortality in critically ill patients with severe sepsis

OBJECTIVE

Patients with sepsis often have elevated cardiac troponin I even in the absence of coronary artery disease. The prognostic value of cardiac troponins in critically ill patients with sepsis remains debatable. Our objective was to evaluate the prognostic value of cardiac troponin I in critically ill patients with severe sepsis.

METHODS

In this retrospective study, we included patients with severe sepsis who had troponin assayed within 12 h of admission to intensive care over a 6 year period. Patients who had myocardial infarction at intensive care admission in the setting of sepsis were excluded. Included patients were classified into two groups based on their serum troponin I levels: low troponin group (troponin ≤ 0.1 µg/L) and elevated troponin group (troponin > 0.1 µg/L). The primary outcome of interest was hospital mortality. The secondary outcome measures included intensive care mortality, intensive care and hospital length of stay.

RESULTS

A total of 382 patients were admitted to intensive care with sepsis. Of these, 293 patients were included in analyses. There was a statistically significant difference in hospital (15% vs 36.1%; P < 0.01) and intensive care (11% vs 25%; P < 0.01) mortality, but not in intensive care and hospital duration of stay. Logistic regression analysis revealed temperature, simplified acute physiology score II and serum lactate to be independent predictors of hospital mortality. Cardiac troponin I was not an independent predictor of hospital mortality.

CONCLUSION

Critically ill patients with severe sepsis who had elevated troponin had increased hospital and intensive care mortality. However, cardiac troponin I did not independently predict hospital mortality.

The adenosine A₂A receptor - myocardial protectant and coronary target in endotoxemia

BACKGROUND

Cardiac injury and dysfunction are contributors to disease progression and mortality in sepsis. This study evaluated the cardiovascular role of intrinsic A₂A adenosine receptor (A₂AAR) activity during lipopolysaccharide (LPS)-induced inflammation.

METHODS

We assessed the impact of 24 h of LPS challenge (20 mg/kg, IP) on cardiac injury, coronary function and inflammatory mediator levels in Wild-Type (WT) mice and mice lacking functional A₂AARs (A₂AAR KO).

RESULTS

Cardiac injury was evident in LPS-treated WTs, with ~7-fold elevation in serum cardiac troponin I (cTnI), and significant ventricular and coronary dysfunction. Absence of A₂AARs increased LPS-provoked cTnI release at 24 h by 3-fold without additional demise of contraction function. Importantly, A₂AAR deletion per se emulated detrimental effects of LPS on coronary function, and LPS was without effect in coronary vessels lacking A₂AARs. Effects of A₂AAR KO were independent of major shifts in circulating C-reactive protein (CRP) and haptoglobin. Cytokine responses were largely insensitive to A₂AAR deletion; substantial LPS-induced elevations (up to 100-fold) in IFN-γ and IL-10 were unaltered in A₂AAR KO mice, as were levels of IL-4 and TNF-α. However, late elevations in IL-2 and IL-5 were differentially modulated by A₂AAR KO (IL-2 reduced, IL-5 increased). Data demonstrate that in the context of LPS-triggered cardiac and coronary injury, A₂AAR activity protects myocardial viability without modifying contractile dysfunction, and selectively modulates cytokine (IL-2, IL-5) release. A₂AARs also appear to be targeted by LPS in the coronary vasculature.

CONCLUSIONS

These experimental data suggest that preservation of A₂AAR functionality might provide therapeutic benefit in human sepsis.

Cardiorenal syndromes

Cardiorenal syndromes (CRS) have been subclassified as five defined entities which represent clinical circumstances in which both the heart and the kidney are involved in a bidirectional injury and dysfunction via a final common pathway of cell-to-cell death and accelerated apoptosis mediated by oxidative stress. Types 1 and 2 involve acute and chronic cardiovascular disease (CVD) scenarios leading to acute kidney injury or accelerated chronic kidney disease. Types 2 and 3 describe acute and chronic kidney disease leading primarily to heart failure, although it is possible that acute coronary syndromes, stroke, and arrhythmias could be CVD outcomes in these forms of CRS. Finally, CRS type 5 describes a simultaneous insult to both heart and kidneys, such as sepsis, where both organs are injured simultaneously. Both blood and urine biomarkers are reviewed in this paper and offer a considerable opportunity to enhance the understanding of the pathophysiology and known epidemiology of these recently defined syndromes.

Cardiorenal syndromes: pathophysiology to prevention

There is a strong association between both acute and chronic dysfunction of the heart and kidneys with respect to morbidity and mortality. The complex interrelationships of longitudinal changes in both organ systems have been difficult to describe and fully understand due to a lack of categorization of the common clinical scenarios where these phenomena are encountered. Thus, cardiorenal syndromes (CRSs) have been subdivided into five syndromes which represent clinical vignettes in which both the heart and the kidney are involved in bidirectional injury and dysfunction via a final common pathway of cell-to-cell death and accelerated apoptosis mediated by oxidative stress. Types 1 and 2 involve acute and chronic cardiovascular disease (CVD) scenarios leading to acute kidney injury (AKI) or accelerated chronic kidney disease (CKD). Types 3 and 4 describe AKI and CKD, respectively, leading primarily to heart failure, although it is possible that acute coronary syndromes, stroke, and arrhythmias could be CVD outcomes in these forms of CRS. Finally, CRSs type 5 describe a systemic insult to both heart and the kidneys, such as sepsis, where both organs are injured simultaneously in persons with previously normal heart and kidney function at baseline. Both blood and urine biomarkers, including the assessment of catalytic iron, a critical element to the generation of oxygen-free radicals and oxidative stress, are reviewed in this paper.

The clinical significance of cardiac troponins in medical practice

Troponins are regulatory proteins that form the cornerstone of muscle contraction. The amino acid sequences of cardiac troponins differentiate them from that of skeletal muscles, allowing for the development of monoclonal antibody-based assay of troponin I (TnI) and troponin T (TnT). Along with the patient history, physical examination and electrocardiography, the measurement of highly sensitive and specific cardiac troponin has supplanted the former gold standard biomarker (creatine kinase-MB) to detect myocardial damage and estimate the prognosis of patients with ischemic heart disease. The current guidelines for the diagnosis of non-ST segment elevation myocardial infarction are largely based on an elevated troponin level. The implementation of these new guidelines in clinical practice has led to a substantial increase in the frequency of myocardial infarction diagnosis. Automated assays using cardiac-specific monoclonal antibodies to cardiac TnI and TnT are commercially available. They play a major role in the evaluation of myocardial injury and prediction of cardiovascular outcome in cardiac and non-cardiac causes. In this review we discuss the clinical applications of cardiac troponins and the interpretation of elevated levels in the context of various clinical settings.

Elevation of cardiac troponin I during non-exertional heat-related illnesses in the context of a heatwave

INTRODUCTION

The prognostic value of cardiac troponin I (cTnI) in patients having a heat-related illness during a heat wave has been poorly documented.

METHODS

In a post hoc analysis, we evaluated 514 patients admitted to emergency departments during the August 2003 heat wave in Paris, having a core temperature >38.5 degrees C and who had analysis of cTnI levels. cTnI was considered as normal, moderately elevated (abnormality threshold to 1.5 ngxmL-1), or severely elevated (>1.5 ngxmL-1). Patients were classified according to our previously described risk score (high, intermediate, and low-risk of death).

RESULTS

Mean age was 84 +/- 12 years, mean body temperature 40.3 +/- 1.2 degrees C. cTnI was moderately elevated in 165 (32%) and severely elevated in 97 (19%) patients. One-year survival was significantly decreased in patients with moderate or severe increase in cTnI (24 and 46% vs 58%, all P < 0.05). Using logistic regression, four independent variables were associated with an elevated cTnI: previous coronary artery disease, Glasgow coma scale <12, serum creatinine >120 micromolxL-1, and heart rate >110 bpm. Using Cox regression, only severely elevated cTnI was an independent prognostic factor (hazard ratio 1.93, 95% confidence interval 1.35 to 2.77) when risk score was taken into account. One-year survival was decreased in patients with elevated cTnI only in high risk patients (17 vs 31%, P = 0.04).

CONCLUSIONS

cTnI is frequently elevated in patients with non-exertional heat-related illnesses during a heat wave and is an independent risk factor only in high risk patients where severe increase (>1.5 ngxmL-1) indicates severe myocardial damage.

Prognostic significance of cardiac troponin I levels in hospitalized patients presenting with supraventricular tachycardia

Although cardiac troponin I (cTnI) elevation in patients presenting to the hospital with supraventricular tachycardia (SVT) is well recognized, the prevalence, predictors, and prognostic significance of cTnI elevation associated with SVT presentation are not known. We screened records of all patients presenting to 2 hospitals over a 4-year period with the diagnosis of SVT confirmed by 12-lead electrocardiogram, and who had at least 1 measured cTnI level and at least 1 year of follow-up after discharge. The primary endpoint was the occurrence of 1 of the following outcomes: death, myocardial infarction, or cardiovascular rehospitalization. Seventy-eight patients met the study criteria (54% female; mean age, 62.2 +/- 15.8 yr), and 29 patients (37.2%) had an elevated cTnI level of > or =0.06 ng/mL (range, 0.06-7.78 ng/mL). Univariate predictors of elevated cTnI included left ventricular ejection fraction (LVEF) <50%, renal dysfunction, ST-segment depression or left bundle branch block on the electrocardiogram, and moderate or severe regurgitation of any cardiac valve. Predictors of elevated cTnI after multivariate analysis included peak heart rate during SVT (per 15 bpm) (odds ratio [OR], 1.58; 95% confidence interval [CI], 1.01-2.46; p = 0.04) and LVEF <50% (OR, 6.12; 95% CI, 1.40-26.7; p = 0.02). After multivariable adjustment, the presence of elevated cTnI with SVT was associated with increased risk of the primary endpoint of death, myocardial infarction, or cardiovascular rehospitalization (hazard ratio [HR], 3.67; 95% CI, 1.22-11.1; p = 0.02). Mild elevation of cTnI is common in patients presenting to the hospital with SVT, and is associated with increased risk of future cardiovascular events. Further study is needed to determine the mechanisms of SVT-related cTnI elevation and its association with elevated cardiovascular risk.

Increases of cardiac troponin in conditions other than acute coronary syndrome and heart failure

BACKGROUND

Although cardiac troponin (cTn) is a cornerstone marker in the assessment and management of patients with acute coronary syndrome (ACS) and heart failure (HF), cTn is not diagnostically specific for any single myocardial disease process. This narrative review discusses increases in cTn that result from acute and chronic diseases, iatrogenic causes, and myocardial injury other than ACS and HF.

CONTENT

Increased cTn concentrations have been reported in cardiac, vascular, and respiratory disease and in association with infectious processes. In cases involving acute aortic dissection, cerebrovascular accident, treatment in an intensive care unit, and upper gastrointestinal bleeding, increased cTn predicts a longer time to diagnosis and treatment, increased length of hospital stay, and increased mortality. cTn increases are diagnostically and prognostically useful in patients with cardiac inflammatory diseases and in patients with respiratory disease; in respiratory disease cTn can help identify patients who would benefit from aggressive management. In chronic renal failure patients the diagnostic sensitivity of cTn for ACS is decreased, but cTn is prognostic for the development of cardiovascular disease. cTn also provides useful information when increases are attributable to various iatrogenic causes and blunt chest trauma.

SUMMARY

Information on the diagnostic and prognostic uses of cTn in conditions other than ACS and heart failure is accumulating. Although increased cTn in settings other than ACS or heart failure is frequently considered a clinical confounder, the astute physician must be able to interpret cTn as a dynamic marker of myocardial damage, using clinical acumen to determine the source and significance of any reported cTn increase.

Myocardial cell injury is common in children with septic shock

OBJECTIVE

To determine the prevalence of myocardial cell injury in children with septic shock by estimating the levels of biochemical markers of myocardial injury, troponin I (TnI) and creatine kinase MB (CK-MB).

PATIENTS

Children aged 3 months to 16 years were admitted to paediatric intensive care unit (PICU) with septic shock. Children with sepsis without shock and children with hypovolaemic shock were enrolled as controls.

MEASUREMENTS AND MAIN RESULTS

Serum TnI and CK-MB levels were measured at admission and serially at 24 h, 48 h and 96 h in children with septic shock, while baseline measurement of the same markers was taken from the controls. In total, 88% (15/18) of children with septic shock had elevated TnI levels compared with 25% (5/20) with sepsis and 6.7% (1/15) with hypovolaemic shock (p < 0.001). Serial TnI levels at admission, 24 h, 48 h and 96 h were higher in the nonsurvivors. There was a positive correlation between the baseline TnI levels and the predicted mortality using the paediatric index of mortality (PIM2) scores at admission (r = 0.51, p = 0.03).

CONCLUSION

A majority of children with septic shock have evidence of myocardial cell injury. The estimation of serum TnI levels may help in better prognostication of children with septic shock.