Improved detection of cardiac contusion with cardiac troponin I

Clinical relevance and advances in detection of translational biomarker cardiac troponin

Cardiovascular diseases (CVD) are a range of diseases, pointing the functional hindrances in the heart and blood vessels of the human system that contributes to 48.6 % of the world's adult death rate. The diagnosis of CVD relies upon the Electro Cardio Gram (ECG) and detection of muscle markers such as troponins. Among the cardiac trio, Cardiac Troponin I (cTnI) weighing 23 KiloDalton (kDa) is a sorted biomarker for CVD. cTnI remains high in the blood after 1-2 weeks of myocardial damage. Testing of cTnI in CVD patients aids in diagnosis and risk stratification of the disease. Different determination systems including optical, electrochemical, and acoustic have been put forward for monitoring the cTnI which are Point of Care (POC) that promotes simple and sensitive detection of cTnI. The modern era has paved way to high-sensitivity Troponin I (hscTnI) devices that can detect up to 0.01 ng/ml in human blood/plasma/serum. Yet, the practice of hscTnI is impracticable due to cost inefficiency. Development of new hscTnI devices with minimal investment and maximal detection range will meet the global requirement. This review gives an over view on different detection systems of cardiac troponin I which stands as a translational detection molecule for CVDs.

Accuracy of diagnostic tests in cardiac injury after blunt chest trauma: a systematic review and meta-analysis

INTRODUCTION

The diagnosis of cardiac contusion, caused by blunt chest trauma, remains a challenge due to the non-specific symptoms it causes and the lack of ideal tests to diagnose myocardial damage. A cardiac contusion can be life-threatening if not diagnosed and treated promptly. Several diagnostic tests have been used to evaluate the risk of cardiac complications, but the challenge of identifying patients with contusions nevertheless remains.

AIM OF THE STUDY

To evaluate the accuracy of diagnostic tests for detecting blunt cardiac injury (BCI) and its complications, in patients with severe chest injuries, who are assessed in an emergency department or by any front-line emergency physician.

METHODS

A targeted search strategy was performed using Ovid MEDLINE and Embase databases from 1993 up to October 2022. Data on at least one of the following diagnostic tests: electrocardiogram (ECG), serum creatinine phosphokinase-MB level (CPK-MB), echocardiography (Echo), Cardiac troponin I (cTnI) or Cardiac troponin T (cTnT). Diagnostic tests for cardiac contusion were evaluated for their accuracy in meta-analysis. Heterogeneity was assessed using the I² and the QUADAS-2 tool was used to assess bias of the studies.

RESULTS

This systematic review yielded 51 studies (n = 5,359). The weighted mean incidence of myocardial injuries after sustaining a blunt force trauma stood at 18.3% of cases. Overall weighted mean mortality among patients with blunt cardiac injury was 7.6% (1.4-36.4%). Initial ECG, cTnI, cTnT and transthoracic echocardiography TTE all showed high specificity (> 80%), but lower sensitivity (< 70%). TEE had a specificity of 72.1% (range 35.8-98.2%) and sensitivity of 86.7% (range 40-99.2%) in diagnosing cardiac contusion. CK-MB had the lowest diagnostic odds ratio of 3.598 (95% CI: 1.832-7.068). Normal ECG accompanied by normal cTnI showed a high sensitivity of 85% in ruling out cardiac injuries.

CONCLUSION

Emergency physicians face great challenges in diagnosing cardiac injuries in patients following blunt trauma. In the majority of cases, joint use of ECG and cTnI was a pragmatic and cost-effective approach to rule out cardiac injuries. In addition, TEE may be highly accurate in identifying cardiac injuries in suspected cases.

Evaluating the Utility of High Sensitivity Troponin in Blunt Cardiac Injury

INTRODUCTION

Screening for blunt cardiac injury (BCI) includes obtaining a serum troponin level and an electrocardiogram for patients diagnosed with a sternal fracture. Our institution has transitioned to the use of a high sensitivity troponin I (hsTnI). The aim of this study was to determine whether hsTnI is comparable to troponin I (TnI) in identifying clinically significant BCI.

MATERIALS AND METHODS

Trauma patients presenting to a level I trauma center over a 24-mo period with the diagnosis of sternal fracture were screened for BCI. Any initial TnI more than 0.04 ng/mL or hsTnI more than 18 ng/L was considered positive for potential BCI. Clinically significant BCI was defined as a new-bundle branch block, ST wave change, echocardiogram change, or need for cardiac catheterization.

RESULTS

Two hundred sixty five patients with a sternal fracture were identified, 161 underwent screening with TnI and 104 with hsTnI. For TnI, the sensitivity and specificity for detection of clinically significant BCI was 0.80 and 0.79, respectively. For hsTnI, the sensitivity and specificity for detection of clinically significant BCI was 0.71 and 0.69, respectively. A multivariate analysis demonstrated the odds ratio for significant BCI with a positive TnI was 14.4 (95% confidence interval, 3.9-55.8, P < 0.0001) versus an odds ratio of 5.48 (95% confidence interval 1.9-15.7, P = 0.002) in the hsTnI group.

CONCLUSIONS

The sensitivity of hsTnI is comparable to TnI for detection of significant BCI. Additional investigation is needed to determine the necessity and interval for repeat testing and the need for additional diagnostic testing.

High-Sensitivity Troponin T Testing for Pediatric Patients in the Emergency Department

Debate exists on the usefulness of high-sensitivity cardiac troponin (hs-cTn) testing in pediatric patients due to the perceived low incidence of myocardial injury and lack of data concerning its efficacy. We evaluated the contribution of an increased hs-cTnT above the 99th percentile upper-reference limit (URL) to clinical diagnoses made in pediatric patients presenting to the emergency department (ED). Retrospective cohort study including patients aged 0-18 years presenting to the ED from 2018 to 2020 where hs-cTnT was measured. Sex-specific 99th percentile URLs of 15 and 10 ng/L for males and females, respectively, were used, with concentrations above these thresholds considered indicative of myocardial injury. Overall, 356 patients were identified in whom hs-cTnT concentrations were measured during ED clinical evaluation. Hs-cTnT was increased above the 99th percentile on presentation in 36 patients (10.1%). Twelve patients (3.4%) had a clinical cardiac diagnosis made. Hs-cTnT was increased in 6 of these (50.0%). Serial hs-cTnT from 106 patients with an initial hs-cTnT < 99th percentile was subsequently elevated in 5 (4.6%); none of whom had a final clinical cardiac diagnosis. Hs-cTnT has high specificity, but low sensitivity when used as a screening tool for myocardial injury when the gold standard is mostly clinical assessment. In present practice, however, they do not appear to track well with clinical diagnoses. Further studies are needed to more clearly define the role of hs-cTnT in this patient population.

Antibody coated conductive polymer for the electrochemical immunosensing of Human Cardiac Troponin I in blood plasma

Cardiac troponin I (cTnI) is a sensitive biomarker for cardiovascular disease (CVD). Rapid determination of cTnI concentration in blood can greatly reduce the potential of significant heart damage and heart failure. Herein, we demonstrate a new electrochemical immunosensor for selective affinity binding and rapid detection of cTnI in blood plasma by an electrochemical method. A conductive film of "poly 2,5-bis(2-thienyl)3,4-diamine-terthiophene (PDATT)" was deposited onto an Indium Tin Oxide (ITO) electrode using chronoamperometry. Anti-cardiac troponin I antibody was then attached to the two amine (NH₂) groups substituted on the central thiophene of terthiophene repeating unit of the polymer chain via amide bond formation. The gaps on the surface of the antibody coated immunosensor were backfilled with bovine serum albumin (BSA) to prevent nonspecific binding of interfering molecules. Differential pulse voltammetry (DPV) was used to determine cTnI upon the formation of cTnI immunocomplex on the sensing surface, appearing a peak at 0.27 V. The response range was 0.01-100 ng mL^-1 with limit of quantification down to 0.01 ng mL^-1. The developed immunosensor was used to determine cTnI in spiked blood plasma without interference from cardiac troponin T (cTnT). Therefore, this new sensor can be utilised for the detection of cTnI biomarker in pathological laboratories and points of care in less than 15 min.

Blunt Trauma to the Heart: A Review of Pathophysiology and Current Management

Blunt cardiac injury (BCI), defined as an injury to the heart from blunt force trauma, ranges from minor to life-threatening. The majority of BCIs are due to motor vehicle accidents; however, injuries caused by falls, blasts, and sports-related injuries also can be sources of BCI. A significant proportion of patients with BCI do not survive long enough to receive medical care, succumbing to their injuries at the scene of the accident. Additionally, patients with blunt trauma often have coexisting injuries (brain, spine, orthopedic) that can obscure the clinical picture; therefore, a high degree of suspicion often is required to diagnose BCI. Traditionally, hemodynamically stable injuries suspicious for BCI have been evaluated with electrocardiograms and chest radiographs, whereas hemodynamically unstable BCIs have received operative intervention. More recently, computed tomography and echocardiography increasingly have been utilized to identify injuries more rapidly in hemodynamically unstable patients. Transesophageal echocardiography can play an important role in the diagnosis and management of several BCIs that require operative repair. Close communication with the surgical team and access to blood products for potentially massive transfusion also play key roles in maintaining hemodynamic stability. With proper surgical and anesthetic care, survival in cases involving urgent cardiac repair can reach 66%-to-75%. This narrative review focuses on the types of cardiac injuries that are caused by blunt chest trauma, the modalities and techniques currently used to diagnose BCI, and the perioperative management of injuries that require surgical correction.

Big Tests in Little People

Can laboratory tests that are routinely used in adult patients also be used in pediatric patients? Does the current literature support the routine use of troponin, brain natriuretic peptide, D-dimer, and lactate in children? Adult problems such as acute coronary syndrome and pulmonary embolism are rare in pediatrics, and there is a paucity of literature on how blood tests commonly used to help diagnose these conditions in adults play a role in the diagnosis and management of children. This article presents the literature about 4 common blood tests and examines the clinical applications of each.

MR-guided pulsed focused ultrasound improves mesenchymal stromal cell homing to the myocardium

Image-guided pulsed focused ultrasound (pFUS) is a non-invasive technique that can increase tropism of intravenously (IV)-infused mesenchymal stromal cells (MSC) to sonicated tissues. MSC have shown promise for cardiac regenerative medicine strategies but can be hampered by inefficient homing to the myocardium. This study sonicated the left ventricles (LV) in rats with magnetic resonance imaging (MRI)-guided pFUS and examined both proteomic responses and subsequent MSC tropism to treated myocardium. T2-weighted MRI was used for pFUS targeting of the entire LV. pFUS increased numerous pro- and anti-inflammatory cytokines, chemokines, and trophic factors and cell adhesion molecules in the myocardial microenvironment for up to 48 hours post-sonication. Cardiac troponin I and N-terminal pro-B-type natriuretic peptide were elevated in the serum and myocardium. Immunohistochemistry revealed transient hypoxia and immune cell infiltration in pFUS-targeted regions. Myocardial tropism of IV-infused human MSC following pFUS increased twofold-threefold compared with controls. Proteomic and histological changes in myocardium following pFUS suggested a reversible inflammatory and hypoxic response leading to increased tropism of MSC. MR-guided pFUS could represent a non-invasive modality to improve MSC therapies for cardiac regenerative medicine approaches.

Diagnostic approach for myocardial contusion: a retrospective evaluation of patient data and review of the literature

Purpose

Myocardial contusion can be a life-threatening condition in patients who sustained blunt thoracic trauma. The diagnostic approach remains a subject of debate. The aim of this study was to determine the sensitivity and specificity of echocardiography, electrocardiography, troponins T and I (TnT and TnI), and creatine kinase muscle/brain (CK-MB) for identifying patients with a myocardial contusion following blunt thoracic trauma.

Methods

Sensitivity and specificity were first determined in a 10-year retrospective cohort study and second by a systematic literature review with meta-analysis.

Results

Of the 117 patients in the retrospective study, 44 (38%) were considered positive for myocardial contusion. Chest X-ray, chest CT scan, electrocardiograph, and echocardiography had poor sensitivity (< 15%) but good specificity (≥ 90%). Sensitivity to cardiac biomarkers measured at presentation ranged from 59% for TnT to 77% for hs-TnT, specificity ranged from 63% for CK-MB to 100% for TnT. The systematic literature review yielded 28 studies, with 14.5% out of 7242 patients reported as positive for myocardial contusion. The pooled sensitivity of electrocardiography, troponin I, and CK-MB was between 62 and 71%, versus only 45% for echocardiography and 38% for troponin T. The pooled specificity ranged from 63% for CK-MB to 85% for troponin T and 88% for echocardiography.

Conclusion

The best diagnostic approach for myocardial contusion is a combination of electrocardiography and measurement of cardiac biomarkers. If abnormalities are found, telemonitoring is necessary for the early detection of life-threatening arrhythmias. Chest X-ray and CT scan may show other thoracic injuries but provide no information on myocardial contusion.

Electronic supplementary material

The online version of this article (10.1007/s00068-020-01305-4) contains supplementary material, which is available to authorized users.

Interventricular Septal Pseudoaneurysm After Blunt Chest Trauma in a 6 Year Old: An Illustrative Case and Review

Motor vehicle accident is the most common cause of blunt cardiac injury (BCI) in children (85.3%) due to the height of the child in relation to proper restraints and the compliant pediatric rib cage (J Trauma. 1996;40:200-202). Trauma to the chest wall may lead to injury of the myocardium, resulting in myocardial contusion, ventricular septal defect (VSD), ventricular free wall rupture, or valve compromise (J Trauma. 1996;40; 200-202; Heart Lung. 2012;41:200-202; J Inj Violence Res. 2012;4:98-100). There are several proposed mechanisms for the formation of VSD after blunt chest trauma including rupture of ischemic myocardium related to the initial trauma and reopening of a spontaneously closed congenital VSD. Also, chest trauma during isovolumetric contraction of the ventricles may generate enough intraventricular force to cause myocardial rupture (J Trauma. 1996;40:200-202; J Inj Violence Res. 2012;4:98-100; Korean J Pediatr. 2011;54:86-89; Ann Thorac Surg. 2012;94:1714-1716; J Emerg Trauma Shock. 2012;5:184-187). Previous case reports highlight the formation of a true VSD after BCI and the requirement of emergent repair (J Emerg Trauma Shock. 2012;5:184-187; Am Heart J. 1996;131:1039-1041; Korean Circ J. 2011;41:625-628; Ann Thorac Surg 2013;96:297-298; Kardiol Pol. 2013;71:992; Chin Med J. 2013;126:1592-1593). Reported is a case of a 6-year-old girl who developed an interventricular septal pseudoaneurysm after a motor vehicle accident of pedestrian versus car. On the day of presentation, she developed bradycardia after emergent surgical repair for abdominal trauma that required cardiopulmonary resuscitation including 5 minutes of chest compressions. At the time of resuscitation, an emergent transthoracic echocardiogram noted an interventricular pseudoaneurysm. She has been followed with serial transthoracic echocardiograms and has not required surgical intervention. We discuss the risk factors, prevalence, and diagnostic studies and recommended treatment options for structural heart disease after BCI.

Molecular and histological effects of MR-guided pulsed focused ultrasound to the rat heart

BACKGROUND

Image-guided high intensity focused ultrasound has been used as an extracorporeal cardiac pacing tool and to enhance homing of stem cells to targeted tissues. However, molecular changes in the myocardium after sonication have not been widely investigated. Magnetic-resonance (MR)-guided pulsed focused ultrasound (pFUS) was targeted to the rat myocardium over a range of pressures and the microenvironmental and histological effects were evaluated over time.

METHODS

Eight-to-ten-week-old Sprague-Dawley rats received T2-weighted MR images to target pFUS to the left ventricular and septum without cardiac or respiratory gating. Rats were sonicated through the thoracic wall at peak negative pressures (PNP) from 1 to 8 MPa at a center frequency of 1 MHz, 10 ms pulse duration and 1 Hz pulse repetition frequency for 100 pulses per focal target. Following pFUS, myocardium was harvested over 24 h and subjected to imaging, proteomic, and histological measurements.

RESULTS

pFUS to the myocardium increased expression of cytokines, chemokines, and trophic factors characterized by an initial increase in tumor necrosis factor (TNF)-α followed by increases in pro- and anti-inflammatory factors that returned to baseline by 24 h. Immediately after pFUS, there was a transient (< 1 h) increase in N-terminal pro b-type natriuretic peptide (NT-proBNP) without elevation of other cardiac injury markers. A relationship between PNP and expression of TNF-α and NT-proBNP was observed with significant changes (p < 0.05 ANOVA) ≥ 4 MPa compared to untreated controls. Contrast-enhanced ex vivo T1-weighted MRI revealed vascular leakage in sonicated myocardium that was accompanied by the presence of albumin upon immunohistochemistry. Histology revealed infiltration of neutrophils and macrophages without morphological myofibril changes in sonicated tissue accompanied by pulmonary hemorrhage at PNP > 4 MPa.

CONCLUSIONS

MR-guided pFUS to myocardium induced transient proteomic and histological changes. The temporal proteomic changes in the myocardium indicate a short-lived sterile inflammatory response consistent with ischemia or contusion. Further study of myocardial function and strain is needed to determine if pFUS could be developed as an experimental model of cardiac injury and chest trauma.

Myocardial contusion

Myocardial contusion can be a difficult diagnosis to make. There is currently no gold standard of investigation that allows its accurate diagnosis in the clinical setting. Trauma surgeons need to have a high degree of clinical suspicion when dealing with patients who have received blunt thoracic injuries in order that the diagnosis of myocardial contusion may be made. In this article we discuss the diagnosis, potential complications and investigation of patients with suspected myocardial contusion and also present a fl ow diagram for the possible management of patients with trauma who may have suspected myocardial contusion.

ST Segment Elevation with Normal Coronaries

Noncardiac causes should be kept in the differential while evaluating ST elevation on EKG. Rarely abdominal pathologies like acute pancreatitis can present with ST elevation in the inferior leads. Once acute coronary syndrome is ruled out by emergent cardiac catheterization alternative diagnosis should be sorted. Abdominal pathologies, like acute pancreatitis and acute cholecystitis, can present with ST elevation in the inferior leads. Treating the underlying condition would result in resolution of these EKG changes.

Cardiac Troponins in Dogs and Cats

Cardiac troponins are sensitive and specific markers of myocardial injury. The troponin concentration can be thought of as a quantitative measure of the degree of injury sustained by the heart, however, it provides no information on the cause of injury or the mechanism of troponin release. Conventionally, the cardiac troponins have been used for diagnosis of acute myocardial infarction in humans and have become the gold standard biomarkers for this indication. They have become increasingly recognized as an objective measure of cardiomyocyte status in both cardiac and noncardiac disease, supplying additional information to that provided by echocardiography and ECG. Injury to cardiomyocytes can occur through a variety of mechanisms with subsequent release of troponins. Independent of the underlying disease or the mechanism of troponin release, the presence of myocardial injury is associated with an increased risk of death. As increasingly sensitive assays are introduced, the frequent occurrence of myocardial injury is becoming apparent, and our understanding of its causes and importance is constantly evolving. Presently troponins are valuable for detecting a subgroup of patients with higher risk of death. Future research is needed to clarify whether troponins can serve as monitoring tools guiding treatment, whether administering more aggressive treatment to patients with evidence of myocardial injury is beneficial, and whether normalizing of troponin concentrations in patients presenting with evidence of myocardial injury is associated with reduced risk of death.

Blunt Cardiac Injury in the Severely Injured - A Retrospective Multicentre Study

Background

Blunt cardiac injury is a rare trauma entity. Here, we sought to evaluate the relevance and prognostic significance of blunt cardiac injury in severely injured patients.

Methods

In a retrospective multicentre study, using data collected from 47,580 patients enrolled to TraumaRegister DGU (1993-2009), characteristics of trauma, prehospital / hospital trauma management, and outcome analysis were correlated to the severity of blunt cardiac injury. The severity of cardiac injury was assessed according to the abbreviated injury score (AIS score 1-6), the revised injury severity score (RISC) allowed comparison of expected outcome with injury severity-dependent outcome. N = 1.090 had blunt cardiac trauma (AIS 1-6) (2.3% of patients).

Results

Predictors of blunt cardiac injury could be identified. Sternal fractures indicate a high risk of the presence of blunt cardiac injury (AIS 0 [control]: 3.0%; AIS 1: 19.3%; AIS 2-6: 19.1%). The overall mortality rate was 13.9%, minor cardiac injury (AIS 1) and severe cardiac injury (AIS 2-6) are associated with higher rates. Severe blunt cardiac injury (AIS 4 and AIS 5-6) is associated with a higher mortality (OR 2.79 and 4.89, respectively) as compared to the predicted average mortality (OR 2.49) of the study collective.

Conclusion

Multiple injured patients with blunt cardiac trauma are at high risk to be underestimated. Careful evaluation of trauma patients is able to predict the presence of blunt cardiac injury. The severity of blunt cardiac injury needs to be stratified according to the AIS score, as the patients’ outcome is dependent on the severity of cardiac injury.

Cardiac trauma during teenage years

The spectrum of blunt cardiac trauma ranges from asymptomatic myocardial contusion to fatal cardiac arrhythmias and/or cardiac rupture. Although cardiac rupture is common in fatal traffic accidents, these patients rarely reach hospital care. Insignificant blunt cardiac injury during sports may cause fatal arrhythmia in teens. Penetrating cardiac trauma is fairly common in the United States, encountered frequently in major urban centers. Most cases are dead at the scene and never reach hospital. The incidence of cardiac sequelae in survivors is high, and these patients should be evaluated with early and late echocardiography to detect anatomic or functional cardiac involvement.

Combining aspirin with cholecalciferol (vitamin D3)--a potential new tool for controlling possum populations

The introduced Australian brushtail possum is a major vertebrate pest in New Zealand, with impacts on conservation and agriculture being managed largely through poisoning operations. Cholecalciferol (vitamin D3) is registered for use in controlling possums and despite its many advantages it is expensive and relatively inhumane. Combination of a high proportion of aspirin with a low proportion of cholecalciferol was effective in killing high proportions of groups of acclimatised, caged possums: this is attributed to both an unexpectedly high toxicity of the type of cholecalciferol used, and a proposed synergistic mechanism between the two compounds. Death was caused by localised damage to heart ventricles by aspirin, and inhibition of tissue repair by both aspirin and cholecalciferol. The observed toxicosis had lower impact on the welfare of possums than either compound administered alone, particularly aspirin alone. Residue analyses of bait remains in the GI tract suggested a low risk of secondary poisoning by either compound. The combination of cholecalciferol and aspirin has the potential to meet key requirements of cost-effectiveness and humaneness in controlling possum populations, but the effect of the combination in non-target species has yet to be tested.

Serum troponin-I as an indicator of clinically significant myocardial injury in paediatric trauma patients

Myocardial injury is a cause of mortality in paediatric trauma, but it is often difficult to diagnose. The objectives of this pilot study were to (1) determine the prevalence of elevated cardiac troponin I (TnI) in paediatric trauma patients and (2) to determine whether elevated TnI correlates with clinically significant myocardial injury, defined as abnormalities on echocardiogram (ECHO) and/or electrocardiograms (ECG). To this end, we investigated a convenient sample size of 59 paediatric trauma patients with an Injury Severity Score (ISS)>12. TnI and creatine kinase-MB (CK-MB) were measured on admission, at then at regular intervals until TnI had normalized. Patients with elevated TnI levels had an ECHO performed within 24h of admission and underwent daily ECGs until TnI normalized. Elevated serum TnI was found in n=16/59 (27%; 95% CI: 18-40%) patients and was associated with elevated CK-MB in all cases. Abnormal ECHOs were seen in 4/16 patients with elevated TnI, but peak TnI values did not correlate with abnormalities on ECHO (p=0.23). Only 1 patient had a clinically significant, albeit mild, decrease in cardiac function. All ECGs were normal. Patients with elevated TnI were more likely to be intubated (p=0.04), to have higher Injury Severity Scores (p=0.02), required more resuscitation fluid (p=0.001), and to have thoracic injuries (p<0.001). Our data indicates that the prevalence of elevated TnI in paediatric trauma patients is 27%; and whilst elevated TnI reflects overall trauma severity, it is frequently elevated without a clinically significance myocardial injury. Hence, large scale studies are required to determine if an elevated threshold TnI value can be identified to accurately diagnose severe myocardial injury in paediatric trauma.

Use and misuse of serum troponin assays in pediatric practice

Cardiac troponin (cTn) is instrumental in screening and diagnosing myocardial ischemia in adults. However, the role of cTn screening in the pediatric population is less clear. The purpose of this study was to evaluate the current clinical practice, diagnostic and prognostic value, and resource utilization associated with cTn assays in the pediatric population. A multicenter, retrospective review of all cTn assays performed on patients aged ≤18 years from January 2003 to December 2010 in the Intermountain Healthcare system was conducted. Data collected included patient demographics, location, presenting symptoms, provisional and discharge diagnoses, additional tests, clinical outcomes (hospitalization days, ventilation, and death), and patient charges. During the study period, cTn assays were performed on 3,497 pediatric patients. The most common presenting diagnoses were chest pain (40%), trauma (11%), and poisoning or drug overdose (9%). Irrespective of diagnosis, elevated cTn was associated with an increased rate of hospitalization, ventilation, and death. Overall, 12% of patients had elevated cTn. Of the patients with chest pain, 4% had elevated cTn, 53% of whom were diagnosed with myopericarditis. In the myopericarditis group, 66% presented with fever, and 98% had abnormal electrocardiographic findings. For patients presenting with chest pain, approximately $162,000 was spent per positive result. In conclusion, cTn screening has strong prognostic value in pediatric patients, even in noncardiac diagnoses such as trauma or drug overdose. However, cTn screening in pediatric patients with chest pain provides minimal benefits and is associated with increased resource utilization, unless patients have constitutional symptoms, such as fever and/or electrocardiographic abnormalities.

Elevated cardiac troponin I level in cases of thoracic nonaccidental trauma

BACKGROUND

Injury patterns in nonaccidental trauma (NAT) often include injury to the chest. However, signs and symptoms of cardiac insult are often nonspecific and may be missed. Evaluation with serum cardiac troponin I (CTnI), a specific indicator of myocardial injury, could improve the comprehensive evaluation of patients with suspected NAT.

OBJECTIVE

The objective of this study was to describe the patient characteristics and results of CTnI testing in children with thoracic NAT.

METHODS

Children presenting to the emergency department were included if CTnI was obtained and they had at least one of the following: history of blunt trauma to the chest, bruising or abrasions to the chest, or fractures of the ribs, sternum, or clavicles. A serum CTnI level above 0.04 ng/mL was considered elevated.

RESULTS

Ten patients (6 males) with an age range from 2 months to 4 years (mean [SD], 20 [20] months) were identified during the 17-month study period. All patients were evaluated with NAT. Cardiac troponin I level was elevated in 7 (70%) of 10 patients with levels between 2 and 50 times the upper limit of normal.

CONCLUSIONS

This report is the first to document elevation of CTnI levels in cases of thoracic NAT. The elevation of the level of this specific biomarker may be indicative of sufficient chest trauma to result in the heart being injured, independent of the presence of cardiac decompensation or shock from other causes. Prospective evaluation of the forensic and clinical use of CTnI in this population is warranted.

Blunt cardiac injury in trauma patients with thoracic aortic injury

Trauma patients with thoracic aortic injury (TAI) suffer blunt cardiac injury (BCI) at variable frequencies. This investigation aimed to determine the frequency of BCI in trauma patients with TAI and compare with those without TAI. All trauma patients with TAI who had admission electrocardiography (ECG) and serum creatine kinase-MB (CK-MB) from January 1999 to May 2009 were included as a study group at a level I trauma center. BCI was diagnosed if there was a positive ECG with either an elevated CK-MB or abnormal echocardiography. There were 26 patients (19 men, mean age 45.1 years, mean ISS 34.4) in the study group; 20 had evidence of BCI. Of 52 patients in the control group (38 men, mean age 46.9 years, mean ISS 38.7), eighteen had evidence of BCI. There was a significantly higher rate of BCI in trauma patients with TAI versus those without TAI (77% versus 35%, P < 0.001).

The utility of troponin measurement to detect myocardial infarction: review of the current findings

Myocardial infarction (MI) is defined by the presence of myocardial necrosis in combination with clinical evidence of myocardial ischemia. Cardiac troponins are regulatory proteins within the myocardium that are released into the circulation when damage to the myocyte has occurred. Therefore, serum troponin is an exquisitely sensitive marker of myocardial injury and is necessary for establishing the diagnosis of MI. High-sensitivity troponin assays are improving the diagnostic accuracy and rapid detection of myocardial infarction. The early identification of MI is vital for the institution of anti-thrombotic therapy to limit myocardial damage and preserve cardiac function. Troponin has both diagnostic and prognostic significance in the setting of acute coronary syndrome (ACS). Increased troponin levels in the absence of ACS should prompt an evaluation for an alternative, non-thrombotic mechanism of troponin elevation and direct management at the underlying cause. This review describes the role of troponin in the evaluation of patients with suspected myocardial infarction.

Dissection of the left main coronary artery after blunt thoracic trauma: Case report and literature review

Blunt chest trauma is commonly encountered by surgeons and is rarely associated with cardiac injuries. The incidence of cardiac injury is rare but can be rapidly fatal, requiring prompt recognition and treatment. We review the case of a 37 year-old male who was involved in a head-on motor vehicle collision at highway speed and was found to have an isolated left main coronary artery dissection. We then review the supporting literature for evaluation of blunt cardiac injuries and the treatment options for traumatic coronary dissection.

Clinical applications of highly sensitive troponin assays

Cardiac troponin is the biomarker of choice for the diagnosis of acute myocardial infarction. Recent consensus recommendations have adopted a concentration of troponin above the 99th percentile of a healthy population to diagnose myocardial infarction. Until recently, there was no assay capable of achieving recommended precision; however, with the development of "highly sensitive" troponin assays, it is now possible to accurately measure troponin concentrations at and below the current 99th percentile of a healthy population. These assays have enormous potential in not only identifying more patients with acute myocardial infarction, and providing superior risk prediction in those so afflicted, in addition highly sensitive troponins assays may be useful for long-term risk assessment of the patient with coronary disease. In this article, we will review the clinical applications, novel concepts, challenges, and limitations of using highly sensitive troponins assays.

Trauma Associated with Cardiac Conduction Abnormalities: Population-Based Perspective, Mechanism and Review of Literature

OBJECTIVES

Various cardiac conduction abnormalities have been described as being a result of trauma in many case reports. The aim of this research was to look at the association between trauma (thoracic and cardiac) and conduction abnormalities in a large hospitalized population.

METHODS

Cases diagnosed with trauma and various cardiac conduction disorders were identified based on ICD-9-CM discharge diagnoses from 986 acute general hospitals across 33 states in 2001.

RESULTS

Independent of potential confounding factors, discharge for blunt cardiac injury (BCI) was associated with a threefold increased risk for cardiac conduction abnormalities (95% confidence interval 2.45-4.51) during hospitalization in 2001. Both BCI and thoracic trauma had a significant association with right bundle branch block (RBBB) in this study (OR 6.04; 95% confidence interval (CI) 3.77-9.67 and OR 1.75; 95% CI 1.38-2.23 respectively).

CONCLUSIONS

The results of this study demonstrate the impact of trauma on cardiac conduction abnormalities. This study represents an attempt to consider a mechanism of a complex traumatic cardiac event from a population-based perspective, and may improve the prognosis for patients diagnosed with cardiac or thoracic injuries.

Challenges in the diagnosis of blunt cardiac injuries

INTRODUCTION

Blunt thoracic injuries (BTIs) are directly responsible for 20-25% of all deaths, worldwide. Involvement of heart in BTIs is largely underestimated and ignored, but reasonable estimate would be around 15%. This study was planned to emphasize on clinical-presentation and diagnosis of blunt cardiac injuries (BCIs).

RESULTS

Clinical presentation of BCIs, varied from mild chest discomfort to haemodynamic shock secondary to rapid exsanguinations. Non-specific presentation with associated injuries diverts physician's attention and delayed appearance of clinical features makes diagnosis further difficult. Cardiac markers and ECG are not specific, but high sensitivity of 100% could be reached using combination of elevated cardiactroponin levels and alterations in ECG. Transoesophageal or transthoracic echocardiography, angiography, intravascular ultrasound and nuclear scan have proven to detect cardiac injuries in BTIs, but lack specificity.

CONCLUSION

Patients with suspicious-ECG finding need cardiac-monitoring for at least 24 hours. Haemodynamically stable young (<55 years) subjects, without underlying cardiac diseases and with normal-ECG and cardiac marker, could be discharged safely.

[Cardiac biomarkers for diagnosis of myocardial infarction]

Diagnosis of postoperative myocardial infarction is often difficult, based on tools with a low sensitivity (clinical symptoms, EKG), or with a low specifity (old biomarkers, echocardiographic abnormalities) or inadequate for clinical practice (scintigraphy). Since 1995, clinicians may use more cardiospecific markers (troponin) allowing to modify strategy for postoperative myocardial infarction diagnosis. The aim of this review is to resume such an attitude.

Effects of an aqueous extract of Croton bonplandianum Baill in rats

We have investigated the cytotoxic and biochemical effects of injecting aqueous phytoextract of Croton bonplandianum (Baill) leaves in male rats. Subchronic dosages of 3.25, 4.65 and 6.97mgphytoextractg(-1)b.wt.week(-1) were administered to rats. To test ameliorative effects, rats were injected with phytoextract mixed with 0.2mgg(-1)b.wt. of cyclophosphamide. Positive controls received only cyclophosphamide, while negative control groups were kept on normal diet and water. Our results demonstrate that phytoextract did not induce micronuclei formation in rats and shows insignificant amelioration (P<0.05). However, differences in serum LDH isoenzymes, ALP, SGOT, SGPT activities and bilirubin were remarkable and displayed dose as well as duration dependent variations. The most outstanding observation of this study was the release of cardiac TnI in sera of rats injected with 6.97mgg(-1)b.wt. of phytoextract for 21 days. Our findings suggest that at the highest concentrations used here phytoextract of C. bonplandianum is not clastogenic; instead it is cardio- and hepatotoxic.

Troponin ratio and risk stratification in subjects with acute coronary syndrome undergoing percutaneous coronary intervention

BACKGROUND

Cardiac enzyme release after percutaneous coronary intervention (PCI) seems to play a role in risk stratification. After PCI, CK-MB plasmatic concentrations three times above the upper level of normal (ULN) are currently the most used risk stratification parameters. We sought to assess whether peak cardiac troponin I (cTn-I) concentration/base concentration ratio (PBTR) may act as a predictor of major adverse cardiac events (MACEs) after PCI, regardless of cTn-I ULN.

METHODS

We evaluated 326 consecutive patients with acute coronary syndrome (ACS) who underwent PCI. Baseline and post-PCI cTn-I values were evaluated over serial blood samples every 6h for at least 72h. Patients were further divided into four groups according to their PBTR values (<1, 1-4, 4-10, >10). MACEs were recorded over a 6-month follow-up period. Patients with primary PCI or unsuccessful PCI were excluded from the study.

RESULTS

Higher values of PBTR significantly correlated with a worse prognosis at 6 months (<1, 16.30% of MACEs; 1-4, 19.42%; 4-10, 24.39%; >10, 35.63%; p<0.05), both in Q-wave myocardial infarction (MI) and unstable angina (UA) subgroups. The correlation remained statistically significant, even considering subjects with peak cTn-I less than three times the ULN (p < 0.05) and after correction for age, gender, risk factors, diagnosis (MI versus UA), and peak cTn-I levels in a multiple Cox' regression analysis (HR 1.62, p<0.05).

CONCLUSIONS

PBTR is an independent predictor of MACEs after PCI in a 6-month follow-up period. This risk stratification tool may be useful to predict adverse events in PCI patients, even in the case of apparently non-elevated peak cTn-I concentrations.

Transient trifascicular block complicating myocardial contusion after blunt chest trauma: a case report

Cardiac contusion may be frequently found in patients with blunt chest trauma, and it presents clinically as a spectrum of injuries of varying severity, including transient disorders of impulse formation and propagation. A rare observation of transient trifascicular block in a previously fit 32-year-old man involved in a car accident is reported. The importance of ECG monitoring and biochemical assessment of markers to unmask myocardial contusion is discussed.

Troponin I in the intensive care unit setting: from the heart to the heart

When measured in the plasma, cardiac troponins T (cTnT) and I (cTnI) are considered to be highly specific markers of myocardial cell damage; however, research has demonstrated that troponin elevation may associated with causes other than coronary artery disease. In the intensive care unit (ICU) setting, increased cTnI levels are quite common findings and when documented, even on admission, intensivists should bear in mind that this laboratory finding holds a prognostic role independent of the reason for ICU admission. The mechanism(s) (such as demand ischemia, myocardial strain, etc.) and not simply the cause (i.e., renal failure) of the increment in serum cTnI should be investigated to better tailor the therapeutical regimen in the single patient. In this review, we therefore consider the nonthrombotic causes of troponin elevation in the critical setting.

Postmortem cardiac troponin-I levels predict intramyocardial damage at autopsy

Serum cardiac troponin levels are now widely used in the diagnosis of myocardial infarct (MI) and injury in living patients, but their utility in postmortem diagnosis has not been established. We evaluated postmortem cardiac troponin-I (cTnI) levels in serum from 53 hospital patients undergoing autopsy and correlated the levels with anatomic findings at postmortem examination. Among patients with nonischemic cardiac disease, those with intramyocardial disease (e.g., cardiac transplant rejection, intramyocardial tumor) had significantly higher cTnI levels than those with disease confined to the pericardium (e.g., epicardial tumor implants, pericarditis) (p = 0.004). No correlation was found between recent MI and cTnI level. There was also no correlation between cTnI level and the presence of chronic ischemic features, a history of cardiopulmonary resuscitation, or postmortem interval. We conclude that cTnI is detectable in postmortem serum samples and, although its levels did not correlate specifically with ischemia or infarction in our series, its levels appear to correlate significantly with intramyocardial injury. Use of cardiac troponin in the postmortem diagnosis of cardiac disease may be warranted.

[A case of chest trauma-induced acute myocardial infarction]

The occurrence of an acute myocardial infarction (MI) after chest trauma is a rare complication. We report a case of a 58-year-old man presenting with an acute anterolateral MI secondary to blunt chest trauma. Coronary angiography revealed a non significant lesion of a first diagonal branch without any atherosclerosis lesion on coronary artery. He was conservatively managed and resulted in a good prognosis. Based on this case, we discuss the path physiologic mechanism of MI following chest trauma.

Use and Misuse of Cardiac Troponins in Clinical Practice

Cardiac troponins are very sensitive and specific markers of myocardial injury. Elevated troponin levels in the setting of acute coronary syndrome are diagnostic of acute myocardial infarction and provide guidance to clinicians with regard to appropriate use of intensive medical and revascularization therapies. However, elevated troponin levels are commonly seen in several noncoronary ischemia presentations and create considerable confusion among clinicians in these settings. In this review article, we discuss the utility of troponins in various clinical settings and present a "common sense" approach to interpreting troponin elevation outside the setting of acute coronary syndrome.

[Delayed tamponade and traumatic myocardial contusion: evaluate the risk after blunt chest trauma]

Cardiac contusion is frequently found in patients with blunt chest trauma. It is important to note that even if there is a low incidence of pericardial effusion, iterative echocardiography should be used to provide essential information for the diagnosis of cardiac tamponade which can be life-threatening during hospitalisation. The case has been reported of a 17-year-old patient with blunt thoracic trauma in whom the introduction of anticoagulant treatment induced a delayed cardiac tamponade with myocardiac failure 3 weeks after a cardiac contusion. Thoracic computed tomography confirmed the diagnosis and moreover, revealed a pleural effusion with pulmonary embolism. The drainage of the pericardial effusion (700 ml) rapidly restored haemodynamic stability and as such has been proved to be life-saving.