Serum cardiac troponin T as a prognostic marker in early sepsis

Cardiac troponin as a prognosticator of mortality in patients with sepsis: A systematic review and meta-analysis

BACKGROUND

The impact of cardiac troponin on the short-term and long-term prognosis of patients with sepsis remains uncertain. Therefore, we conducted a meta-analysis to investigate the role of cardiac troponin as a potential indicator for sepsis mortality.

METHODS

We performed a comprehensive search for articles published before November 2022 using Google Scholar, PubMed, and Web of Science. Inclusion criteria for the studies were: (1) investigation of cardiac troponin, and (2) investigation of sepsis. Exclusion criteria included: (1) inability to obtain or calculate hazard ratio (HR) and 95% confidence interval (CI) for the relationship between cardiac troponin level and sepsis mortality, and (2) reviews, meta-analyses, and case reports. Analysis of HRs and 95% CIs for the association between cardiac troponin level and sepsis mortality was conducted using STATA 12.0 software.

RESULTS

Our study included 24 prospective studies (comprising 20,457 sepsis patients) and 4 retrospective studies (comprising 1416 sepsis patients). Meta-analysis demonstrated that elevated cardiac troponin levels were significantly associated with increased sepsis mortality using a random effects model (HR = 1.57, 95% CI 1.41-1.75). Moreover, elevated cardiac troponin levels were also significantly associated with increased hospital mortality of sepsis (HR = 1.35, 95% CI 1.19-1.53) and long-term mortality of sepsis (HR = 1.96, 95% CI 1.51-2.55) using the random effects model.

CONCLUSIONS

Overall, our finding revealed that elevated cardiac troponin for sepsis patients was a predictor of hospital and long-term mortality. Clinicians may treat septic patients with elevated cardiac troponin more cautious to avoid extra death. Moreover, large clinical studies are warranted to validate this association.

Interpretation of Cardiac and Non-Cardiac Causes of Elevated Troponin T Levels in Non-Acute Coronary Syndrome Patients in the Emergency Department

The definition of myocardial infarction was updated in 2000 to include an elevation of cardiac troponin T or I (cTnT or xTnI) alongside clinical evidence of myocardial infarction. The redefinition was jointly done by the American College of Cardiology Committee and the European Society of Cardiology. Since then, cardiac troponin T and I have assumed the position as the primary biochemical markers for diagnosing myocardial infarction. The high sensitivity of cardiac troponin for myocardial necrosis influenced the decision to include cardiac troponins (cTn) in the diagnostic pathway. An elevated cTn level indicates the presence of myocardial injury. However, it does not give the underlying reason for the damage. Apart from acute myocardial infarction (AMI), a range of potential diseases feature troponin release, including heart failure, acute pulmonary embolism, end-stage renal disease, and myocarditis. However, regardless of the mechanism that triggers the release from cardiac myocytes, elevated cTnI and cTnT typically implies a poor prognosis. This review attempts to explain both the cardiac and non-cardiac causes of increased cTnT in emergency department patients.

Is cardiac Troponin I Considered as A Predictor of In-hospital Mortality among COVID-19 Patients? A Retrospective Cohort Study

Objective:

To describe the levels of troponin I in COVID-19 patients and its role in the prediction of their in-hospital mortality as a cardiac biomarker.

Methods:

The current retrospective cohort study was performed on the clinical records of 649 COVID-19-related hospitalized cases with at leat one positive polymerase chain reaction (PCR) test in Tehran, Iran from February 2020 to early June 2020. The on admission troponin I level divided into two groups of ≤0.03ng/mL (normal) and >0.03ng/mL (abnormal). The adjusted COX-regression model was used to determine the relationship between the studied variables and patient’s in-hospital mortality.

Results:

In this study, the median age of subjects was 65 years (54.8% men) and 29.53% of them had abnormal troponin I levels. Besides, the in-hospital mortality rate among patients with abnormal troponin I levels was found to be 51.56%; whereas, patients with normal levels exhibited 18.82% mortality. Also, the multivariable analysis indicated that the risk of death among hospitalized COVID-19 patients displaying abnormal troponin I levels was 67% higher than those with normal troponin I levels (Hazard ratio=1.67, 95% confidence interval=1.08-2.56, p=0.019).

Conclusion:

It seems that troponin I is one of the important factors related to in-hospital mortality of COVID-19 patients. Next, due to the high prevalence of cardiac complications in these patients, it is highly suggested to monitor and control cardiac biomarkers along with other clinical factors upon the patient’s arrival at the hospital.

Frontal QRS-T angle as a predictive marker for myocardial damage in acute carbon monoxide poisoning

INTRODUCTION

The present study was undertaken to investigate the prognostic value of the frontal QRS-T angle associated with adverse cardiac outcomes in patients with carbon monoxide (CO) poisoning in early stages in the emergency department.

MATERIALS AND METHODS

The data of 212 patients with CO poisoning who were admitted to the ED between January 2010 and May 2020 were retrospectively analyzed. The frontal QRS-T angle was obtained from the automatic reports of the EKG device.

RESULTS

Compared to patients without myocardial damage, among patients with myocardial damage, statistically high creatinine, creatine kinase MB, cardiac troponin I, and frontal QRS-T angle values were found (p < 0.001 for all parameters), while the saturation of arterial blood pH and arterial oxygen values were found to be lower (p = 0.002 and p < 0.001, respectively). The frontal QRS-T angle values were correlated with creatine kinase, creatine kinase-MB, cardiac troponin I, and oxygen saturation (SpO₂) in arterial blood (r = 0. 232, p = 0.001; r = 0. 253, p = < 0.001; r = 0. 389, p = < 0.001; r = -0. 198, p = 0.004, respectively). The optimum cut-off value of the frontal QRS-T angle was found to be 44.5 (area under the curve: 0.901, 95% confidence interval: 0.814-0.988, sensitivity: 87%, specificity: 84%).

CONCLUSIONS

The frontal QRS-T angle, a simple and inexpensive parameter that can be easily obtained from 12-lead surface electrocardiography, can be used as an early indicator in the detection of myocardial damage in patients with CO poisoning.

High troponin levels in patients hospitalized for coronavirus disease 2019: a maker or a marker of prognosis?

AIMS

Controversial data have been published regarding the prognostic role of cardiac troponins in patients who need hospitalization because of coronavirus disease 2019 (COVID-19). The aim of the study was to assess the role of high-sensitivity troponin plasma levels and of respiratory function at admission on all-cause deaths in unselected patients hospitalized because of COVID-19.

METHODS

We pooled individual patient data from observational studies that assessed all-cause mortality of unselected patients hospitalized for COVID-19. The individual data of 722 patients were included. The ratio of partial pressure arterial oxygen to fraction of inspired oxygen (PaO2/FiO2) and high-sensitivity troponins was reported at admission in all patients. This meta-analysis was registered on PROSPERO (CRD42020213209).

RESULTS

After a median follow-up of 14 days, 180 deaths were observed. At multivariable regression analysis, age [hazard ratio (HR) 1.083, 95% confidence interval (CI) 1.061-1.105, P < 0.0001], male sex (HR 2.049, 95% CI 1.319-3.184, P = 0.0014), moderate-severe renal dysfunction (estimated glomerular filtration rate  < 30 mL/min/m2) (HR 2.108, 95% CI 1.237-3.594, P = 0.0061) and lower PaO2/FiO2 (HR 0.901, 95% CI 0.829-0.978, P = 0.0133) were the independent predictors of death. A linear increase in the HR was associated with decreasing values of PaO2/FiO2 below the normality threshold. On the contrary, the HR curve for troponin plasma levels was near-flat with large CI for values above the normality thresholds.

CONCLUSION

In unselected patients hospitalized for COVID-19, mortality is mainly driven by male gender, older age and respiratory failure. Elevated plasma levels of high-sensitivity troponins are not an independent predictor of worse survival when respiratory function is accounted for.

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.

Association of Cardiac Troponin T Concentration on Admission with Prognosis in Critically Ill Patients without Myocardial Infarction: A Cohort Study

Purpose

To investigate the association of cardiac Troponin T (cTnT) with prognosis in critically ill patients without myocardial infarction.

Methods

Adult patients admitted to the intensive care units (ICUs) of the Beth Israel Deaconess Medical Center between 2008 and 2019 who were free of myocardial infarction with a length of ICU stay ≥24 hours and available cTnT records within 24 hours before and after ICU admission were included. The association between cTnT on ICU admission and hospital mortality was evaluated by multivariable logistic regression analysis. The discrimination capacity of cTnT on ICU admission for predicting hospital mortality was examined by receiver operating characteristic (ROC) analysis.

Results

A total of 2960 patients were included. Elevated cTnT (>0.01 ng/mL) was observed in 2730 (92.23%) patients with a higher hospital mortality compared to normal cTnT (11.21% versus 7.39%, P=0.075). There was no statistically significant association between elevated cTnT on ICU admission and hospital mortality (adjusted odds ratio 1.50, 95% confidence interval (CI) 0.88–2.57). Poor discrimination capacity was found for cTnT on ICU admission to predict hospital mortality (area under the ROC curve 0.48, 95% CI 0.44–0.53).

Conclusion

cTnT on ICU admission has limited prognostic value in critically ill patients without myocardial infarction.

Presepsin for pre-operative prediction of major adverse cardiovascular events in coronary heart disease patients undergoing noncardiac surgery: Post hoc analysis of the Leukocytes and Cardiovascular Peri-operative Events-2 (LeukoCAPE-2) Study

BACKGROUND

Accurate pre-operative evaluation of cardiovascular risk is vital to identify patients at risk for major adverse cardiovascular and cerebrovascular events (MACCE) after noncardiac surgery. Elevated presepsin (sCD14-ST) is associated with peri-operative MACCE in coronary artery disease (CAD) patients after noncardiac surgery.

OBJECTIVES

Validating the prognostic utility of presepsin for MACCE after noncardiac surgery.

DESIGN

Prospective patient enrolment and blood sampling, followed by post hoc evaluation of pre-operative presepsin for prediction of MACCE.

SETTING

Single university centre.

PATIENTS

A total of 222 CAD patients undergoing elective, inpatient noncardiac surgery.

INTERVENTION

Pre-operative presepsin measurement.

MAIN OUTCOME MEASURES

MACCE (cardiovascular death, myocardial infarction, myocardial ischaemia and stroke) at 30 days postsurgery.

RESULTS

MACCE was diagnosed in 23 (10%) patients. MACCE patients presented with increased pre-operative presepsin (median [IQR]; 212 [163 to 358] vs. 156 [102 to 273] pgml, P = 0.023). Presepsin exceeding the previously derived threshold of 184 pg ml was associated with increased 30-day MACCE rate. After adjustment for confounders, presepsin more than 184 pg ml [OR = 2.8 (95% confidence interval 1.1 to 7.3), P = 0.03] remained an independent predictor of peri-operative MACCE. Predictive accuracy of presepsin was moderate [area under the curve (AUC) = 0.65 (0.54 to 0.75), P = 0.023]. While the basic risk model of revised cardiac risk index, high-sensitive cardiac troponin T and N-terminal fragment of pro-brain natriuretic peptide resulted in an AUC = 0.62 (0.48 to 0.75), P = 0.072, addition of presepsin to the model led to an AUC = 0.67 (0.56 to 0.78), P = 0.009 and (ΔAUC = 0.05, P = 0.438). Additive risk predictive value of presepsin was demonstrated by integrated discrimination improvement analysis (integrated discrimination improvement = 0.023, P = 0.022). Net reclassification improvement revealed that the additional strength of presepsin was attributed to the reclassification of no-MACCE patients into a lower risk group.

CONCLUSION

Increased pre-operative presepsin independently predicted 30-day MACCE in CAD patients undergoing major noncardiac surgery. Complementing cardiovascular risk prediction by inflammatory biomarkers, such as presepsin, offers potential to improve peri-operative care. However, as prediction accuracy of presepsin was only moderate, further validation studies are needed.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT03105427.

Cardiovascular and Renal Disease in Chronic Critical Illness

With advances in critical care, patients who would have succumbed in previous eras now survive through hospital discharge. Many survivors suffer from chronic organ dysfunction and induced frailty, representing an emerging chronic critical illness (CCI) phenotype. Persistent and worsening cardiovascular and renal disease are primary drivers of the CCI phenotype and have pathophysiologic synergy, potentiating one another and generating a downward spiral of worsening disease and clinical outcomes manifest as cardio-renal syndromes. In addition to pharmacologic therapies (e.g., diuretics, beta adrenergic receptor blockers, angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, and blood pressure control), special consideration should be given to behavioral modifications that avoid the pitfalls of polypharmacy and suboptimal renal and hepatic dosing, to which CCI patients may be particularly vulnerable. Smoking cessation, dietary modifications (e.g., early high-protein nutrition and late low-sodium diets), and increased physical activity are advised. Select patients benefit from cardiac re-synchronization therapy or renal replacement therapy. Coordinated, patient-centered care bundles may improve compliance with standards of care and patient outcomes. Given the complex, heterogeneous nature of cardiovascular and renal disease in CCI and the dismal long-term outcomes, further research is needed to clarify pathophysiologic mechanisms of cardio-renal syndromes in CCI and develop targeted therapies.

Usefulness of a Point-of-Care Analyzer to Measure Cardiac Troponin I and D-Dimer Concentrations in Critically Ill Horses With Gastrointestinal Diseases

Point-of-care (POC) systems for the joint measurement of Troponin and D-dimers have not been studied in horses. The aim of this study was to perform the validation of a POC system (AQT90 FLEX) for the measurement of cardiac troponin I (cTnI) and D-dimers in the serum of horses with gastrointestinal diseases. The main objective was to evaluate whether or not this system can distinguish healthy animals from diseased animals. A sample of 33 horses was included in the study: control group (n = 10) and horses with gastrointestinal disorders (n = 21), which were classified according to their outcome in survivors (subgroup A = 9) and nonsurvivors (subgroup B = 12). Considering the diagnosis of the process, ill horses were classified into three groups: inflammatory (I = 7), obstructive (O = 9), and strangulating diseases (S = 5). The clinical usefulness of AQT90 FLEX was validated by the study of linearity, coefficient of variation, and detection limits. Later, concentrations of D-dimers and cTnI were measured. A significant increase in both parameters was detected in ill animals (cTnI: control: 0.014 ± 0.01 μg/mL, survivors: 0.27 ± 0.37 μg/mL, nonsurvivors: 0.60 ± 1.21 μg/mL; D-dimers: control: 104.90 ± 30.82 ng/mL, survivors: 1,217.22 ± 1,213.28 ng/mL, nonsurvivors: 1,613.67 ± 1,426.75 ng/mL), although there were no statistically significant differences in concentrations according to diagnosis and outcome. In conclusion, AQT90 FLEX POC analyzer can be used in horses with gastrointestinal diseases to measure cTnI and D-dimer concentrations. It is a quick, practical, and minimally invasive tool that helps in determining the severity of illness.

Cardiac Involvement in Travelers with Enteric Fever

Data regarding cardiac involvement in enteric fever among travelers are scarce. In this retrospective study, 59 patients were hospitalized with enteric fever during 2004-2017 and 28 had cardiac workups. Among those, four had evidence of cardiac involvement, including clinical myocarditis, electrocardiogram changes, or troponin elevation. Cardiac involvement was higher among patients infected with Salmonella Typhi than with Salmonella Paratyphi A (P = 0.08), with a significant relative risk of 6 (95% CI: 1.15-31.22, P = 0.03). Time from symptoms onset to effective treatment was longer for patients with cardiac involvement (13 versus 7.15 days, P < 0.05). It seems that cardiac involvement in enteric fever is not uncommon in travelers. Such involvement seems to be more common in patients with delay of effective treatment to the second week of illness. Although fatal or complicated cases are rare in travelers, the cardiac complication may be an important contributor to morbidity and mortality in this group.

Myocardial Injury in Patients With Sepsis and Its Association With Long-Term Outcome

BACKGROUND

Sepsis is frequently complicated by the release of cardiac troponin, but the clinical significance of this myocardial injury remains unclear. We studied the associations between troponin release during sepsis and 1-year outcomes.

METHODS AND RESULTS

We enrolled consecutive patients with sepsis in 2 Dutch intensive care units between 2011 and 2013. Subjects with a clinically apparent cause of troponin release were excluded. High-sensitivity cardiac troponin I (hs-cTnI) concentration in plasma was measured daily during the first 4 intensive care unit days, and multivariable Cox regression analysis was used to model its association with 1-year mortality while adjusting for confounding. In addition, we studied cardiovascular morbidity occurring during the first year after hospital discharge. Among 1258 patients presenting with sepsis, 1124 (89%) were eligible for study inclusion. Hs-cTnI concentrations were elevated in 673 (60%) subjects on day 1, and 755 (67%) ever had elevated levels in the first 4 days. Cox regression analysis revealed that high hs-cTnI concentrations were associated with increased death rates during the first 14 days (adjusted hazard ratio, 1.72; 95% confidence interval, 1.14-2.59 and hazard ratio, 1.70; 95% confidence interval, 1.10-2.62 for hs-cTnI concentrations of 100-500 and >500 ng/L, respectively) but not thereafter. Furthermore, elevated hs-cTnI levels were associated with the development of cardiovascular disease among 200 hospital survivors who were analyzed for this end point (adjusted subdistribution hazard ratio, 1.25; 95% confidence interval, 1.04-1.50).

CONCLUSIONS

Myocardial injury occurs in the majority of patients with sepsis and is independently associated with early-but not late-mortality, as well as postdischarge cardiovascular morbidity.

Prognostic Value of High-sensitivity Troponin I in Patients with Septic Shock: A Prospective Observational Study

BACKGROUND

Myocardial dysfunction is one of the mechanisms involved in the pathophysiology of septic shock. The role of troponin as a surrogate of myocardial injury in septic shock is still debated. The aim of this study was to assess the prognostic value of high-sensitivity cardiac troponin I (hs-cTnI) assay in predicting 28-day mortality in patients with septic shock.

MATERIALS AND METHODS

Prospective study including 75 patients with septic shock admitted to a medico-surgical ICU from January to December 2017. Patients under the age of 18 years, known pregnancy and patients in post-cardiac arrest were excluded. Clinical and demographic data including age, gender, comorbidities, SAPS II and SOFA scores were collected. Hs-cTnI was measured soon after admission and 12, 24, 48 and 72 after. Receiver operating characteristic (ROC) analysis was performed to identify the most useful troponin I cut-off level for the prediction of 28-day mortality. A p <0.05 was considered significant.

RESULTS

Seventy-five (M/F = 53/22) patients with septic shock were included in the study. The median SOFA and SAPS II scores were 10 and 42, respectively. The median duration of mechanical ventilation was 8 days and the median length of ICU stay was 11 days. The 28-day mortality was 54.6%. We found a high prevalence (47%) of elevated hs-cTnI in patients with septic shock. Median hs-cTnI on admission in the whole group was 36 ng/L. The 28-day mortality was found to be related to age (p <0.001), SAPS II score (p = 0.001), mean arterial pressure (p = 0.038), lactate (p <0.001) and glomerular filtration rate (p <0.001).Hs-cTnI levels were significantly higher in non-survival group than survival one at all time points: H12 (p = 0.006), H24 (p = 0.003), H48 (p = 0.005) and H72 (p=0.001). In multivariate analysis, hs-cTnI at H72 was independently associated with 28-day mortality.

CONCLUSION

Hs-cTnI elevation at 72 hours was associated with 28-day mortality in septic shock patients.

HOW TO CITE THIS ARTICLE

Jendoubi A, Jerbi S, Maamar E, Abbess A, Samoud Z, Kanzari L, et al. Prognostic Value of High-Sensitivity Troponin I in Patients with Septic Shock: A Prospective Observational Study. Indian J Crit Care Med 2019;23(7):320-325.

Cardiovascular biomarkers in dogs with systemic inflammatory response syndrome

OBJECTIVE

To measure plasma N-terminal fragments of pro-B-type natriuretic peptides (NT-proBNP) and cardiac troponin T (cTnT) concentration in hospitalized dogs and relate these markers to underlying conditions and evaluate their potential as prognostic markers in dogs with systemic inflammatory response syndrome (SIRS).

DESIGN

Prospective, observational, clinical study.

SETTING

Emergency department of a university teaching hospital.

ANIMALS

Sixty-nine dogs with SIRS examined in the emergency department were prospectively studied. Patient age ranged from 5 months to 15 years, and weight ranged from 5.5 to 75 kg.

MEASUREMENTS AND MAIN RESULTS

Blood samples were obtained at presentation, during hospitalization until discharge or death, and at a "control" visit (T1m) at least 1 month after hospital discharge. NT-proBNP was assayed with a commercially available canine ELISA, while cTnT was measured with an automated immunoassay previously used in dogs. A correlation procedure, mixed procedure on a linear model, and a logistic procedure were performed. Forty-four patients survived, 19 of which had control visits. cTnT concentrations were significantly higher than T0 and T1m at T12, T24, and T72. In 28 dogs, cTnT was detected during hospitalization, but cTnT was not detected in any dog at the control visits. Higher concentrations of cTnT were negatively associated with survival, irrespective of disease category. NT-proBNP concentrations were significantly higher than T0, T6, T12, and T1m at T24, T72, and T120, but were not associated with survival.

CONCLUSIONS

NT-proBNP and cTnT increased significantly in dogs with SIRS, regardless of the underlying disease process. Nonsurvivors displayed significantly higher cTnT concentrations during hospitalization.

Prevalence and Outcome of Sepsis-induced Myocardial Dysfunction in Children with 'Sepsis' 'With' and 'Without Shock'-A Prospective Observational Study

OBJECTIVE

To estimate the prevalence and effects of sepsis-induced myocardial dysfunction (SIMD) in children with septic shock.

METHODOLOGY

Enrolled children with septic shock (n = 31) and sepsis (n = 30) underwent echocardiography and cardiac troponin-I (cTnI) estimation within first 3 h. SIMD was defined as presence of systolic/diastolic dysfunction by echocardiography.

RESULTS

The prevalence of SIMD was 71% in 'septic shock' and 23% in 'sepsis'. Diastolic dysfunction (45.2%) was more prevalent than systolic dysfunction (32.3%). Children with SIMD had higher requirement of inotropes [81 vs. 44%; adjusted odds ratio: 1.41 (1.04-1.92)] in first 48 h. cTnI had low sensitivity (62.5%) and specificity (55.1%) for detecting SIMD. On follow-up at 3 months, there was no residual dysfunction in the majority (71.3%).

CONCLUSION

SIMD, especially diastolic dysfunction, is common in septic shock and may increase inotrope requirement. It is reversible in majority. Sepsis patients may have asymptomatic underlying SIMD. cTnI does not correlate with the degree of SIMD.

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.

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.

Elevated modified shock index in early sepsis is associated with myocardial dysfunction and mortality

PURPOSE

The aim of this study was to explore the association of an elevated modified shock index (MSI) in sepsis and myocardial dysfunction.

METHODS

This single center exploratory retrospective cohort study was conducted at Mayo Clinic from 2011 to 2014. It includes adults admitted to the medical intensive care unit with severe sepsis or septic shock. The time MSI>1.3, area under the curve, in the first 6h was assessed using logistic regression for primary outcomes of myocardial dysfunction and depression and secondary outcomes including mortality and SOFA score.

RESULTS

Overall 578 individuals met inclusion criteria, 169 (29%) developed myocardial dysfunction and 23 (4%) myocardial depression. Adjusted for age, gender, Charlson score, and baseline APACHE 3 score, area MSI>1.3 was associated with increased odds of myocardial dysfunction (OR 1.10, 95% CI 1.00-1.21; p=0.058) and depression (OR 1.28, 95% CI 1.07-1.53; p=0.007). Associations were also seen with ICU mortality (OR 1.17, 95% CI 1.04-1.32; p=0.011), hospital mortality (OR 1.13, 95% CI 1.02-1.25; p=0.025) and SOFA score.

CONCLUSION

Elevated modified shock index during early sepsis is associated with the development of myocardial dysfunction and depression, SOFA score and mortality.

Biomarkers of Cardiac Injury: An Update

Conventional and promising new markers of myocardial injury have become an important diagnostic tool and their prognostic significance is also recognized. In addition, they help identify patients who will derive the most benefit from therapeutic interventions. The literature was searched from the websites of the National Library of Medicine (http://www.ncbi.nlm.nih.gov/) and PubMed Central, the U.S. National Library of Medicine’s digital archive of life sciences journal literature (http://www.pubmedcentral.nih.gov/). The data were accessed from books and journals that published relevant articles in this field. The diagnosis of acute myocardial infarction (AMI) has traditionally relied on the combination of chest pain, ECG features, and elevation in serum markers. However, chest symptoms are frequently atypical or absent and ECG changes may be nonspecific or absent. Hence, the diagnosis of acute coronary syndromes has become increasingly dependent on serum markers of cardiac injury. Among them, creatine kinase (CK) is an effective and widely used test, with the recent CKMB assay offering greater specificity and sensitivity. Cardiac troponins facilitate early and rapid diagnosis, enable effective risk stratification in patients with AMI (with or without traditional criteria for MI), and identify those who will benefit from aggressive medical or surgical intervention. Recent data suggest the potential of myoglobin and CKMB isoforms as sensitive markers in the early hours after symptom onset. Cardiac-specific troponins help in rapid diagnosis, prognostication, and treatment of AMI. Troponins also facilitate early detection of recent infarction owing to their prolonged diagnostic window and also aid in the detection of “microinfarction.” CKMB is used to detect reinfarction or infarct extension, if levels rise again after declining. Finally, novel biochemical markers are receiving attention in ongoing trials. They may prove to be more effective in diagnosis and prognosis than their existing counterparts.

Use of Admission Troponin in Critically Ill Medical Patients

Serum troponin I (TnI) is a sensitive marker of cardiac injury. A relation between elevated TnI and mortality has been suggested. In this retrospective chart review of 221 patients admitted to the medical intensive care unit (MICU) during a 6-month period, the authors studied the use of admission TnI levels in predicting mortality in MICU-admitted patients. Data retrieved included demographics, admission diagnosis, troponin, electrocardiogram, Acute Physiology and Chronic Health Evaluation (APACHE) II score, echocardiogram, requirements for mechanical ventilation and vasopressor support, development of multiorgan failure, mortality, and discharge disposition. There were 132 patients for whom TnI level was sent within 24 hours of admission; these patients comprised the study group. The median age was 70 years; 59% were female. The mean APACHE II score was 22. Troponin I was positive in 31% of patients (median level, 0.4 Ug/L; range 0-358 Ug/L). The hospital mortality was 39%. Positive TnI showed a weak association with intensive care unit (ICU) mortality ( P= .049) but not with overall mortality. There was no significant correlation between admission TnI concentration and APACHE II score ( P= .33), administration of vasopressor medications ( P= .115), or development of multiorgan failure ( P= .64). The authors concluded that there is no benefit in obtaining a routine admission troponin level in MICU patients when an acute coronary event is not suspected.

Levosimendan Versus Dobutamine in Myocardial Injury Patients with Septic Shock: A Randomized Controlled Trial

BACKGROUND We aimed to investigate the effect of levosimendan on biomarkers of myocardial injury and systemic hemodynamics in patients with septic shock. MATERIAL AND METHODS After achieving normovolemia and a mean arterial pressure of at least 65 mmHg, 38 septic shock patients with low cardiac output (left ventricular ejective fraction), LEVF £45%) were randomly divided into two groups: levosimendan dobutamine. Patients in the levosimendan and dobutamine groups were maintained with intravenous infusion of levosimendan (0.2 μg/kg/minute) and dobutamine (5 μg/kg/minute) for 24 hours respectively. During treatment we monitored hemodynamics and LVEF, and measured levels of heart-type fatty acid binding protein (HFABP), troponin I (TNI), and brain natriuretic peptide(BNP). In addition, the length of mechanical ventilation, intensive care unit (ICU) stay, hospital stay, and 28-day mortality were compared between the two groups. RESULTS The levosimendan group and the dobutamine group were well matched with respect to age (years, 55.4 ± 1 7.5 versus 50.2 ± 13.6) and gender (males, 68.4% versus 57.9%). Levosimendan-treated patients had higher stroke volume index (SVI), cardiac index (CI), LVEF, and left ventricular stroke work index (LVSWI), and lower extravascular lung water index (EVLWI) compared to dobutamine-treated patients (p<0.05). HFABP, TNI, and BNP in the levosimendan group were less than in the dobutamine group (p<0.05). There was no difference in the mechanical ventilation time, length of stay in ICU and hospital, and 28-day mortality between the two groups. CONCLUSIONS Compared with dobutamine, levosimendan reduces biomarkers of myocardial injury and improves systemic hemodynamics in patients with septic shock. However, it does not reduce the days on mechanical ventilation, length of stay in ICU and hospital, or 28-day mortality.

Elevation of NT-proBNP and cardiac troponins in sepsis-related deaths: a forensic perspective

In the present study, the levels of NT-proBNP, troponin T, and troponin I were measured in postmortem serum from femoral blood in a series of sepsis-related fatalities that had undergone forensic autopsies. We aimed to assess whether a possible increase in the concentrations of these biomarkers was correlated to macroscopic or microscopic observations that suggest myocardial damage or cardiac dysfunction. Two study groups were retrospectively formed, a sepsis-related fatalities group and a control group. Both groups consisted of 16 forensic autopsy cases. Unenhanced computed tomography scan, autopsy, histological, toxicological, microbiological, and biochemical analyses were performed for all cases in both groups. Levels of procalcitonin, C-reactive protein, NT-proBNP, troponin T, and troponin I were systematically measured in postmortem serum from femoral blood. The preliminary results suggest that the postmortem serum troponin I, troponin T, and NT-proBNP levels are increased in sepsis-related deaths in the absence of any relevant coronary artery disease, myocardial ischemia, or signs of heart failure. These findings corroborate clinical data from previous studies pertaining to the usefulness of troponins and natriuretic peptides as indicators of toxic and inflammatory damage to the heart in cases of severe sepsis and septic shock without concomitant underlying coronary syndromes.

Catecholamines for inflammatory shock: a Jekyll-and-Hyde conundrum

Catecholamines are endogenous neurosignalling mediators and hormones. They are integral in maintaining homeostasis by promptly responding to any stressor. Their synthetic equivalents are the current mainstay of treatment in shock states to counteract myocardial depression and/or vasoplegia. These phenomena are related in large part to decreased adrenoreceptor sensitivity and altered adrenergic signalling, with resultant vascular and cardiomyocyte hyporeactivity. Catecholamines are predominantly used in supraphysiological doses to overcome these pathological consequences. However, these adrenergic agents cause direct organ damage and have multiple 'off-target' biological effects on immune, metabolic and coagulation pathways, most of which are not monitored or recognised at the bedside. Such detrimental consequences may contribute negatively to patient outcomes. This review explores the schizophrenic 'Jekyll-and-Hyde' characteristics of catecholamines in critical illness, as they are both necessary for survival yet detrimental in excess. This article covers catecholamine physiology, the pleiotropic effects of catecholamines on various body systems and pathways, and potential alternatives for haemodynamic support and adrenergic modulation in the critically ill.

Microcirculatory dysfunction and tissue oxygenation in critical illness

Severe sepsis is defined by organ failure, often of the kidneys, heart, and brain. It has been proposed that inadequate delivery of oxygen, or insufficient extraction of oxygen in tissue, may explain organ failure. Despite adequate maintenance of systemic oxygen delivery in septic patients, their morbidity and mortality remain high.

The assumption that tissue oxygenation can be preserved by maintaining its blood supply follows from physiological models that only apply to tissue with uniformly perfused capillaries. In sepsis, the microcirculation is profoundly disturbed, and the blood supply of individual organs may therefore no longer reflect their access to oxygen.

We review how capillary flow patterns affect oxygen extraction efficacy in tissue, and how the regulation of tissue blood flow must be adjusted to meet the metabolic needs of the tissue as capillary flows become disturbed as observed in critical illness. Using the brain, heart, and kidney as examples, we discuss whether disturbed capillary flow patterns might explain the apparent mismatch between organ blood flow and organ function in sepsis. Finally, we discuss diagnostic means of detecting capillary flow disturbance in animal models and in critically ill patients, and address therapeutic strategies that might improve tissue oxygenation by modifying capillary flow patterns.

Levosimendan reduces mortality in patients with severe sepsis and septic shock: A meta-analysis of randomized trials

PURPOSE

There is controversy about the use of inotropes in the treatment of severe sepsis and septic shock. The objective of this study was to evaluate if levosimendan, as compared with standard inotropic therapy (eg, dobutamine), reduces mortality in septic patients.

MATERIALS AND METHODS

BioMedCentral, PubMed, EMBASE, and the Cochrane Central Register were searched for pertinent studies, up to 1st May 2015. Randomized trials on the use of levosimendan in patients with severe sepsis and septic shock were included if reporting mortality data. The primary outcome was mortality, whereas secondary outcomes were blood lactate, cardiac index, total fluid infused, norepinephrine dosage, and mean arterial pressure.

RESULTS

Seven studies for a total of 246 patients were included in the analysis. Levosimendan was associated with significantly reduced mortality compared with standard inotropic therapy (59/125 [47%] in the levosimendan group and 74/121 [61%] in the control group; risk difference = -0.14, risk ratio = 0.79 [0.63-0.98], P for effect = .03, I(2) = 0%, numbers needed to treat = 7). Blood lactate was significantly reduced in the levosimendan group, whereas cardiac index and total fluid infused were significantly higher in the levosimendan group. No difference in mean arterial pressure and norepinephrine usage was noted.

CONCLUSIONS

In patients with severe sepsis and septic shock, levosimendan is associated with a significant reduction in mortality compared with standard inotropic therapy. A large ongoing multicenter randomized trial will have to confirm these findings.

Raised cardiac troponin in intensive care patients with sepsis, in the absence of angiographically documented coronary artery disease: A systematic review

Elevated cardiac troponin in the critically ill has been associated with increased hospital mortality. However, in critically ill patients with sepsis the results are heterogeneous and less easy to interpret. The objectives of this systematic review were to describe the pathophysiology, clinical relevance and prognostic significance of raised troponin in intensive care patients with sepsis. Articles were identified through a detailed MEDLINE search and additional references were retrieved from the selected studies. A growing body of clinical evidence suggests that although troponins are sensitive biomarkers with prognostic value, they are not independent predictors of mortality. However, vigilance for objective evidence of coronary artery disease is required and patients with atherosclerotic risk factors and elevated troponins may benefit from cardiac imaging. In patients with low pre-test probability for coronary artery disease and elevated troponins, therapy should target management of sepsis and optimisation of myocardial oxygen demand/supply balance.

The prognostic significance of troponin elevation in patients with sepsis: a meta-analysis

OBJECTIVE

To confirm the association between troponin elevation in patients with sepsis and mortality.

BACKGROUND

Cardiac troponins are sensitive and specific biomarkers of myocardial injury; however their prognostic significance in patients with sepsis is still debated.

METHODS

PubMed and Ovid MEDLINE were searched for original articles using MeSH terms 'Troponin' and 'Sepsis.' Studies reporting on mortality in patients with sepsis, severe sepsis or septic shock who had troponin measured were eligible for inclusion. Meta-analysis was conducted with Review Manager.

RESULTS

Seventeen studies, with total sample size of 1857 patients were included. Elevated troponin was found to be significantly associated with mortality (Risk ratio: 1.91; 95% CI: 1.65-2.22; p < 0.05).

CONCLUSIONS

Troponin elevation in patients with sepsis confers poorer prognosis and is a predictor of mortality. Further studies are needed to see if more aggressive treatment of this subset of patients, or utilizing new therapeutic approaches will improve mortality.

Prevalence and outcome of diastolic dysfunction in children with fluid refractory septic shock--a prospective observational study

OBJECTIVES

Our primary objective was to determine the prevalence and outcome of diastolic dysfunction in children with fluid refractory septic shock. The secondary objective was to determine possible early predictors of diastolic dysfunction.

DESIGN

Prospective observational study.

SETTING

PICU of a tertiary care teaching hospital.

PATIENTS

Consecutive children 17 years old or younger with fluid refractory septic shock and not on mechanical ventilation admitted to our ICU from June 2011 to August 2012 were included. Survivors were followed up till 1 year of discharge (July 2013).

INTERVENTIONS

Children were subjected to 2D echocardiography and qualitative cardiac troponin-T test within the first 6 hours of admission.

MEASUREMENTS AND MAIN RESULTS

A total of 56 children were included. Median age was 7 years (interquartile range, 1.5, 14) and majority (52%) were males. Most common underlying diagnoses were meningitis and pneumonia. The prevalence of diastolic dysfunction was 41.1% (95% CI, 27.8-54.4), and mortality rate was 43% in those with diastolic dysfunction. At 1-year follow-up, residual dysfunction was present in only one of 11 of the survivors (11%). On univariable analysis of possible early predictors of diastolic dysfunction, we observed that these children tended to have higher mean central venous pressure (13 vs 6; p < 0.0001) and greater positivity for cardiac troponin-T (70% vs 36%; p = 0.01) compared with others. Although factors such as duration of illness and diastolic blood pressure were also lower in children with diastolic dysfunction compared with others, the difference was not statistically significant. On multivariable analysis, only the variable central venous pressure remained significant (adjusted odds ratio, 1.6; 95% CI, 1.12-2.14; p = 0.008).

CONCLUSIONS

Diastolic dysfunction is common in children with fluid refractory septic shock, and immediate outcomes may be poorer in such patients. Increased central venous pressure after initial fluid resuscitation may be an early indicator of diastolic dysfunction and warrant urgent bedside echocardiography to guide further management.

Early identification and management of patients with severe sepsis and septic shock in the emergency department

Severe sepsis and septic shock have great relevance to Emergency Medicine physicians because of their high prevalence, morbidity, and mortality. Treatment is time-sensitive, depends on early identification risk stratification, and has the potential to significantly improve patient outcomes. In this article, we review the pathophysiology of, and evidence basis for, the emergency department management of severe sepsis and septic shock.

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.

A prospective study of the impact of serial troponin measurements on the diagnosis of myocardial infarction and hospital and six-month mortality in patients admitted to ICU with non-cardiac diagnoses

INTRODUCTION

Troponin T (cTnT) elevation is common in patients in the Intensive Care Unit (ICU) and associated with morbidity and mortality. Our aim was to determine the epidemiology of raised cTnT levels and contemporaneous electrocardiogram (ECG) changes suggesting myocardial infarction (MI) in ICU patients admitted for non-cardiac reasons.

METHODS

cTnT and ECGs were recorded daily during week 1 and on alternate days during week 2 until discharge from ICU or death. ECGs were interpreted independently for the presence of ischaemic changes. Patients were classified into four groups: (i) definite MI (cTnT ≥15 ng/L and contemporaneous changes of MI on ECG), (ii) possible MI (cTnT ≥15 ng/L and contemporaneous ischaemic changes on ECG), (iii) troponin rise alone (cTnT ≥15 ng/L), or (iv) normal. Medical notes were screened independently by two ICU clinicians for evidence that the clinical teams had considered a cardiac event.

RESULTS

Data from 144 patients were analysed (42% female; mean age 61.9 (SD 16.9)). A total of 121 patients (84%) had at least one cTnT level ≥15 ng/L. A total of 20 patients (14%) had a definite MI, 27% had a possible MI, 43% had a cTNT rise without contemporaneous ECG changes, and 16% had no cTNT rise. ICU, hospital and 180-day mortality was significantly higher in patients with a definite or possible MI.

CONCLUSIONS

The majority of critically ill patients (84%) had a cTnT rise and 41% met criteria for a possible or definite MI of whom only 20% were recognised clinically. Mortality up to 180 days was higher in patients with a cTnT rise.

Myocardial injury in critically ill children: a case control study

Objectives. The aim of this study was to investigate the occurrence of myocardial injury in critically ill children through assessment of cardiac troponin T levels and whether levels are associated with disease severity and myocardial dysfunction measured by echocardiography. Methods. Over a 6-month period, this case control study included 50 patients admitted to Pediatric Intensive Care Unit of Zagazig University Children's Hospital. Twenty-five healthy children were included as a control group. Demographic and clinical data including the pediatric index of mortality II score were recorded. Echocardiographic examination was done and level of cardiac troponin T was measured using Elecsys Troponin T STAT Immunoassay. Results. Cardiac troponin T levels were significantly higher in critically ill in comparison to healthy children (median 22 (18–28) pg/mL versus 10 (10-10) pg/mL, P < 0.05). Cardiac troponin T levels correlated positively with duration of ventilation as well as with disease severity and correlated negatively with left ventricular fractional shortening. Moreover, cardiac troponin T levels were significantly higher in nonsurvivors when compared to survivors (median 34.5 (27.5–41.5) pg/mL versus 20 (18–24) pg/mL, P < 0.05). Conclusion. In critically ill children, cardiac troponin T levels were elevated and were associated with duration of ventilation and disease severity.

Blood cardiac troponin in toxic myocardial injury: archetype of a translational safety biomarker

A translational safety biomarker for toxic myocardial injury is needed in drug discovery and development. This need reflects the increasing recognition of occurrence of cardiotoxicities, prior lack of preclinical blood biomarkers for toxic cardiac injury, introduction of troponin as a biomarker, and regulatory and industry drivers. Cardiac troponin is considered the gold-standard biomarker in humans for cardiac injury due to ischemic injury and drug toxicity. It has been demonstrated to correlate highly with histopathological extent of injury, degree of impairment of cardiac function, and prognosis. Numerous studies have now clearly demonstrated that both cardiac troponin T and cardiac troponin I are sensitive and specific biomarkers of cardiac injury in laboratory animals. Their use is highly recommended for incorporation into preclinical drug-safety studies, especially whenever there is any history of cardiac effect in prior studies with a compound of the same or similar chemical or pharmacological class. The main caveats with respect to cross-species use of specific cardiac troponin assays are the need for species-specific validation, definition of cut-offs based on relevant assessments of imprecision and reference ranges or concurrent controls, and knowledge of the species-dependent kinetics of release into, and clearance from, the blood. Future development of high-sensitivity assays should determine whether minimal increases below a threshold concentration of troponin might reflect reversible myocardial effects.

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

Prognostic value of troponins in sepsis: a meta-analysis

RATIONALE

The role of biomarkers such as troponin in risk stratification of sepsis is still debated. The aim of this meta-analysis is to assess the relation between troponin elevation in sepsis and mortality.

METHODS

All observational studies from Embase, Medline and those manually searched up to September 2010 were included. Studies identified were those which reported on patients with a diagnosis of sepsis and if a 2 × 2 table could be constructed based on troponins and death. We pooled the relative risk (RR) and odds-ratio (OR) using the inverse variance method in studies that conducted univariate and multivariable (adjusted) analysis.

MAIN RESULTS

Thirteen studies encompassing 1,227 patients were included. The prevalence of elevated troponin was 61 % ([95 %] CI 58-64 %). Elevated troponin was significantly associated with all-cause mortality (RR 1.91; CI 1.63-2.24), with homogeneity across studies. In adjusted analysis (four studies comprising 791 patients) according to prognostic scores, elevated troponin was associated with an increased risk of death (OR 1.92; CI 1.35-2.74). The area under the ROC curve was 0.68 (CI 0.63-0.71). Pooled sensitivity and specificity were 77 % (CI 61-88) and 47 % (CI 30-64) with heterogeneity across studies. It corresponded to positive and negative likelihood ratios of 1.50 (95 % CI: 1.20-1.90) and 0.49 (CI 0.38-0.64), respectively.

CONCLUSIONS

Elevated troponin identifies a subset of patients with sepsis at higher risk of death. Further studies are needed to define the precise role of troponins and their optimal cut-offs.

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.

The evolving concepts of haemodynamic support: from pulmonary artery catheter to echocardiography and theragnostics

Echocardiography is a non-invasive tool, aimed towards the anatomical and functional characterization of the heart. In Intensive Care it is considered nowadays as a necessary tool for patient evaluation. However, the information obtained using echocardiography is not the same as provided by other means, namely the invasive ones. In recent years there has been a significant evolution in the general concepts of haemodynamic support for the critically ill patient. In this new environment, echocardiography has gained particular relevance. In this text the new positioning of echocardiography in the light of the new concepts for hemodynamic support is described, as well as, the need for a specific formative program directed towards Intensive Care physicians. A new generation of biomarkers can also add relevant information and start a new era in haemodynamic support. They may help to further characterize the disease process, identifying patients at risk, as well as, characterize specific organ failure as well as monitoring therapy.

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.

Association of genome-wide variation with highly sensitive cardiac troponin-T levels in European Americans and Blacks: a meta-analysis from atherosclerosis risk in communities and cardiovascular health studies

BACKGROUND

High levels of cardiac troponin T, measured by a highly sensitive assay (hs-cTnT), are strongly associated with incident coronary heart disease and heart failure. To date, no large-scale genome-wide association study of hs-cTnT has been reported. We sought to identify novel genetic variants that are associated with hs-cTnT levels.

METHODS AND RESULTS

We performed a genome-wide association in 9491 European Americans and 2053 blacks free of coronary heart disease and heart failure from 2 prospective cohorts: the Atherosclerosis Risk in Communities Study and the Cardiovascular Health Study. Genome-wide association studies were conducted in each study and race stratum. Fixed-effect meta-analyses combined the results of linear regression from 2 cohorts within each race stratum and then across race strata to produce overall estimates and probability values. The meta-analysis identified a significant association at chromosome 8q13 (rs10091374; P=9.06×10(-9)) near the nuclear receptor coactivator 2 (NCOA2) gene. Overexpression of NCOA2 can be detected in myoblasts. An additional analysis using logistic regression and the clinically motivated 99th percentile cut point detected a significant association at 1q32 (rs12564445; P=4.73×10(-8)) in the gene TNNT2, which encodes the cardiac troponin T protein itself. The hs-cTnT-associated single-nucleotide polymorphisms were not associated with coronary heart disease in a large case-control study, but rs12564445 was significantly associated with incident heart failure in Atherosclerosis Risk in Communities Study European Americans (hazard ratio=1.16; P=0.004).

CONCLUSIONS

We identified 2 loci, near NCOA2 and in the TNNT2 gene, at which variation was significantly associated with hs-cTnT levels. Further use of the new assay should enable replication of these results.

MicroRNAs as biomarkers for myocardial infarction

MicroRNAs (miRs) are short non-coding RNA molecules involved in post-transcriptional gene regulation by binding to the 3' untranslated region of a messenger RNA (mRNA), thereby inhibiting the translation or inducing mRNA destabilization. MiRs are generally considered to act as intracellular mediators essential for normal cardiac function, and their deregulated expression profiles have been associated with cardiovascular diseases. Recent studies have revealed the existence of freely circulating miRs in human peripheral blood, which are present in a stable nature. This has raised the possibility that miRs may be released in the circulation and can serve as novel diagnostic markers for acute or chronic human disorders, including myocardial infarction (MI). This review summarizes the recent findings of miRs that fulfill the criteria of candidate biomarkers for MI.