Clinical and biomarker profile of trauma-induced secondary cardiac injury

Is it time to reframe resuscitation in trauma?

Trauma remains a significant cause of mortality and morbidity. Non-compressible torso haemorrhage is one of the key drives of these mortality data. Our contemporary management has focused on damage control resuscitation, with a focus on haemorrhage control, haemostatic resuscitation and permissive hypotension. The evidence for permissive hypotension lacks the robustness as other treatments, such as tranexamic acid. Despite this clinicians still target arbitrary systolic blood pressure cutoffs as both goals and ceilings of therapy. In this paper, we suggest that perhaps more consideration should be given to the diastolic blood pressure in bleeding trauma patients. The diastolic blood pressure is critical for coronary perfusion, and in turn the cardiac output responsible for cerebral blood flow. We suggest that a move to reframing resuscitation in terms of physiology may change the way that we resuscitate these patients and allow for more nuanced treatment strategies.

Risk factors and outcomes associated with systolic dysfunction following traumatic brain injury

Systolic dysfunction has been observed following isolated moderate-severe traumatic brain injury (Ims-TBI). However, early risk factors for the development of systolic dysfunction after Ims-TBI and their impact on the prognosis of patients with Ims-TBI have not been thoroughly investigated. A prospective observational study among patients aged 16 to 65 years without cardiac comorbidities who sustained Ims-TBI (Glasgow Coma Scale [GCS] score ≤12) was conducted. Systolic dysfunction was defined as left ventricular ejection fraction <50% or apparent regional wall motion abnormality assessed by transthoracic echocardiography within 24 hours after admission. The primary endpoint was the incidence of systolic dysfunction after Ims-TBI. The secondary endpoint was survival on discharge. Clinical data and outcomes were assessed within 24 hours after admission or during hospitalization. About 23 of 123 patients (18.7%) developed systolic dysfunction after Ims-TBI. Higher admission heart rate (odds ratios [ORs]: 1.05, 95% confidence interval [CI]: 1.02-1.08; P = .002), lower admission GCS score (OR: 0.77, 95% CI: 0.61-0.96; P = .022), and higher admission serum high-sensitivity cardiac troponin T (Hs-cTnT) (OR: 1.14, 95% CI: 1.06-1.22; P < .001) were independently associated with systolic dysfunction among patients with Ims-TBI. A combination of heart rate, GCS score, and serum Hs-cTnT level on admission improved the predictive performance for systolic dysfunction (area under curve = 0.85). Duration of mechanical ventilation, intensive care unit length of stay, and in-hospital mortality of patients with systolic dysfunction was higher than that of patients with normal systolic function (P < .05). Lower GCS (OR: 0.66, 95% CI: 0.45-0.82; P = .001), lower admission oxygen saturation (OR: 0.82, 95% CI: 0.69-0.98; P = .025), and the development of systolic dysfunction (OR: 4.85, 95% CI: 1.36-17.22; P = .015) were independent risk factors for in-hospital mortality in patients with Ims-TBI. Heart rate, GCS, and serum Hs-cTnT level on admission were independent early risk factors for systolic dysfunction in patients with Ims-TBI. The combination of these 3 parameters can better predict the occurrence of systolic dysfunction.

Contemporary management of major haemorrhage in critical care

Haemorrhagic shock is frequent in critical care settings and responsible for a high mortality rate due to multiple organ dysfunction and coagulopathy. The management of critically ill patients with bleeding and shock is complex, and treatment of these patients must be rapid and definitive. The administration of large volumes of blood components leads to major physiological alterations which must be mitigated during and after bleeding. Early recognition of bleeding and coagulopathy, understanding the underlying pathophysiology related to specific disease states, and the development of individualised management protocols are important for optimal outcomes. This review describes the contemporary understanding of the pathophysiology of various types of coagulopathic bleeding; the diagnosis and management of critically ill bleeding patients, including major haemorrhage protocols and post-transfusion management; and finally highlights recent areas of opportunity to better understand optimal management strategies for managing bleeding in the intensive care unit (ICU).

Evaluation of New Cardiac Damage Biomarkers in Polytrauma: GDF-15, HFABP and uPAR for Predicting Patient Outcomes

Background: Polytrauma is one of the leading mortality factors in younger patients, and in particular, the presence of cardiac damage correlates with a poor prognosis. Currently, troponin T is the gold standard, although troponin is limited as a biomarker. Therefore, there is a need for new biomarkers of cardiac damage early after trauma. Methods: Polytraumatized patients (ISS ≥ 16) were divided into two groups: those with cardiac damage (troponin T > 50 pg/mL, n = 37) and those without cardiac damage (troponin T < 12 pg/mL, n = 32) on admission to the hospital. Patients' plasma was collected in the emergency room 24 h after trauma, and plasma from healthy volunteers (n = 10) was sampled. The plasma was analyzed for the expression of HFABP, GDF-15 and uPAR proteins, as well as miR-21, miR-29, miR-34, miR-122, miR-125b, miR-133, miR-194, miR-204, and miR-155. Results were correlated with patients' outcomes. Results: HFABP, uPAR, and GDF-15 were increased in polytraumatized patients with cardiac damage (p < 0.001) with a need for catecholamines. HFABP was increased in non-survivors. Analysis of systemic miRNA concentrations showed a significant increase in miR-133 (p < 0.01) and miR-21 (p < 0.05) in patients with cardiac damage. Conclusion: All tested plasma proteins, miR-133, and miR-21 were found to reflect the cardiac damage in polytrauma patients. GDF-15 and HFABP were shown to strongly correlate with patients' outcomes.

Endoplasmic reticulum stress caused by traumatic injury promotes cardiomyocyte apoptosis through acetylation modification of GRP78

Cardiomyocyte apoptosis is an important cause of trauma-induced secondary cardiac injury (TISCI), in which the endoplasmic reticulum stress (ERS)-mediated apoptosis signaling pathway is known to be first activated, but the mechanism remains unclear. In this study, rat models of traumatic injury are established by using the Noble-Collip trauma device. The expression of glucose-regulating protein 78 (GRP78, a molecular chaperone of the cardiomyocyte ER), acetylation modification of GRP78 and apoptosis of cardiomyocytes are determined. The results show that ERS-induced GRP78 elevation does not induce cardiomyocyte apoptosis in the early stage of trauma. However, with prolonged ERS, the GRP78 acetylation level is elevated, and the apoptosis of cardiomyocytes also increases significantly. In addition, in the early stage of trauma, the expression of histone acetyl-transferase (HAT) P300 is increased and that of histone deacetylase 6 (HDAC6) is decreased in cardiomyocytes. Inhibition of HDAC function could induce the apoptosis of traumatic cardiomyocytes by increasing the acetylation level of GRP78. Our present study demonstrates for the first time that post-traumatic protracted ERS can promote cardiomyocyte apoptosis by increasing the acetylation level of GRP78, which may provide an experimental basis for seeking early molecular events of TISCI.

Early Fibrinogen Replacement to Treat the Endotheliopathy of Trauma: Novel Resuscitation Strategies in Severe Trauma

The authors provide a comprehensive review of the endothelial glycocalyx, the components that may be targeted to improve clinical outcomes, and the next steps for evaluation in human subjects.

High-dimensional proteomics identifies organ injury patterns associated with outcomes in human trauma

INTRODUCTION

Severe traumatic injury with shock can lead to direct and indirect organ injury; however, tissue-specific biomarkers are limited in clinical panels. We used proteomic and metabolomic databases to identify organ injury patterns after severe injury in humans.

METHODS

Plasma samples (times 0, 24, and 72 hours after arrival to trauma center) from injured patients enrolled in two randomized prehospital trials were subjected to multiplexed proteomics (SomaLogic Inc., Boulder, CO). Patients were categorized by outcome: nonresolvers (died >72 hours or required ≥7 days of critical care), resolvers (survived to 30 days and required <7 days of critical care), and low Injury Severity Score (ISS) controls. Established tissue-specific biomarkers were identified through a literature review and cross-referenced with tissue specificity from the Human Protein Atlas. Untargeted plasma metabolomics (Metabolon Inc., Durham, NC), inflammatory mediators, and endothelial damage markers were correlated with injury biomarkers. Kruskal-Wallis/Mann-Whitney U tests with false discovery rate correction assessed differences in biomarker expression across outcome groups (significance; p < 0.1).

RESULTS

Of 142 patients, 78 were nonresolvers (median ISS, 30), 34 were resolvers (median ISS, 22), and 30 were low ISS controls (median ISS, 1). A broad release of tissue-specific damage markers was observed at admission; this was greater in nonresolvers. By 72 hours, nine cardiac, three liver, eight neurologic, and three pulmonary proteins remained significantly elevated in nonresolvers compared with resolvers. Cardiac damage biomarkers showed the greatest elevations at 72 hours in nonresolvers and had significant positive correlations with proinflammatory mediators and endothelial damage markers. Nonresolvers had lower concentrations of fatty acid metabolites compared with resolvers, particularly acyl carnitines and cholines.

CONCLUSION

We identified an immediate release of tissue-specific biomarkers with sustained elevation in the liver, pulmonary, neurologic, and especially cardiac injury biomarkers in patients with complex clinical courses after severe injury. The persistent myocardial injury in nonresolvers may be due to a combination of factors including metabolic stress, inflammation, and endotheliopathy.

Myocardial Injury Is Associated with the Incidence of Major Adverse Cardiac Events in Patients with Severe Trauma

BACKGROUND

Severe trauma potentially results in end-organ damage such as myocardial injury. Data suggest that myocardial injury is associated with increased mortality in this cohort, but the association with the incidence of in-hospital major adverse cardiac events (MACE) remains undetermined.

METHODS

Retrospective cohort study including adult patients with severe trauma treated at the University Hospital Duesseldorf between January 2016 and December 2019. The main exposure was myocardial injury at presentation. Endpoints were in-hospital incidence of MACE and incidence of acute kidney injury (AKI) within 72 h. Discrimination of hsTnT for MACE and AKI was examined by the receiver operating characteristic curve (ROC) and the area under the curve (AUC). We conducted multivariate logistic regression analysis.

RESULTS

We included 353 patients in our final analysis (72.5% male (256/353), age: 55 ± 21 years). The AUC for hsTnT and MACE was 0.68 [95% confidence interval (CI): 0.59-0.78]. The AUC for hsTnT and AKI was 0.64 [95% (CI): 0.55-0.72]. The adjusted odds ratio (OR) for myocardial injury and MACE was 2.97 [95% (CI): 1.31-6.72], and it was 2.14 [95% (CI): 1.03-4.46] for myocardial injury and AKI.

CONCLUSION

Myocardial injury at presentation in patients with severe trauma is independently associated with the incidence of in-hospital MACE and AKI.

Assessment of left ventricle myocardial deformation in a hemorrhagic shock swine model by two-dimensional speckle tracking echocardiography

BACKGROUND

Trauma-induced secondary cardiac injury has been associated with significant adverse cardiovascular events. Speckle tracking echocardiography is a novel technology that allows an accurate and reproducible cardiac structure and function assessment. We evaluated the left ventricle (LV) myocardial deformation by speckle tracking echocardiography in a hemorrhagic shock (HS) swine model.

METHODS

Seven healthy male Landrace pigs were included in this study. Severe HS was reached through three sequentially blood withdraws of 20% of estimated blood volume, and it was maintained for 60 minutes. Volume resuscitation was performed using all precollected blood volume. A 1.8- to 4.2-MHz phased-array transducer was used to acquire the two-dimensional echocardiography images. Strain measurements were obtained semiautomatically by wall motion tracking software. Results are presented as medians and interquartile ranges and compared using Wilcoxon rank-sum test. A p value of <0.05 was considered statistically significant.

RESULTS

The median weight was 32 (26.1-33) kg, and the median total blood volume withdrawn was 1,100 (1,080-1,190) mL. During the severe HS period, the median arterial systemic pressure was 39 (36-46) mm Hg, and the cardiac index was 1.7 (1.6-2.0) L/min/m 2 . There was statistically significant absolute decrease in the global longitudinal strain 2 hours postresuscitation comparing with the basal measurements (-9.6% [-10.7 to -8.0%] vs. -7.9% [-8.1 to -7.4%], p = 0.03). There were no statistically significant differences between the basal and 2 hours postresuscitation assessments in the invasive/noninvasive hemodynamic, other two-dimensional echocardiogram (LV ejection fraction, 49.2% [44-54.3%] vs. 53.2% [51.5-55%]; p = 0.09), and circumferential strain (-10.6% [-14.4 to -9.0%] vs. -8.5% [-8.6 to -5.2%], p = 0.06) parameters.

CONCLUSION

In this experimental swine model of controlled HS, LV global longitudinal strain analysis accurately characterizes the timing and magnitude of subclinical cardiac dysfunction associated with trauma-induced secondary cardiac injury.

Irisin Preserves Cardiac Performance and Insulin Sensitivity in Response to Hemorrhage

Irisin, a cleaved product of the fibronectin type III domain containing protein-5, is produced in the muscle tissue, which plays an important role in modulating insulin resistance. However, it remains unknown if irisin provides a protective effect against the detrimental outcomes of hemorrhage. Hemorrhages were simulated in male CD-1 mice to achieve a mean arterial blood pressure of 35–45 mmHg, followed by resuscitation. Irisin (50 ng/kg) and the vehicle (saline) were administrated at the start of resuscitation. Cardiac function was assessed by echocardiography, and hemodynamics were measured through femoral artery catheterization. A glucose tolerance test was used to evaluate insulin sensitivity. An enzyme-linked immunosorbent assay was performed to detect inflammatory factors in the muscles and blood serum. Western blot was carried out to assess the irisin production in skeletal muscles. Histological analyses were used to determine tissue damage and active-caspase 3 apoptotic signals. The hemorrhage suppressed cardiac performance, as indicated by a reduced ejection fraction and fractional shortening, which was accompanied by enhanced insulin resistance and hyperinsulinemia. Furthermore, the hemorrhage resulted in a marked decrease in irisin and an increase in the production of tumor necrosis factor-α (TNF-α) and interleukin-1 (IL-1). Additionally, the hemorrhage caused marked edema, inflammatory cell infiltration and active-caspase 3 positive signals in skeletal muscles and cardiac muscles. Irisin treatment led to a significant improvement in the cardiac function of animals exposed to a hemorrhage. In addition, irisin treatment improved insulin sensitivity, which is consistent with the suppressed inflammatory cytokine secretion elicited by hemorrhages. Furthermore, hemorrhage-induced tissue edema, inflammatory cell infiltration, and active-caspase 3 positive signaling were attenuated by irisin treatment. The results suggest that irisin protects against damage from a hemorrhage through the modulation of insulin sensitivity.

Cardiac alterations following experimental hip fracture - inflammaging as independent risk factor

Background

Cardiac injuries following trauma are associated with a worse clinical outcome. So-called trauma-induced secondary cardiac injuries have been recently described after experimental long bone fracture even in absence of direct heart damage. With the progressive aging of our society, the number of elderly trauma victims rises and therefore the incidence of hip fractures increases. Hip fractures were previously shown to be associated with adverse cardiac events in elderly individuals, which have mainly been attributed to pre-conditioned cardiac diseases. The aim of the present study was to investigate the effect of hip fractures on the heart in healthy young and middle-aged mice.

Materials and Methods

Young (12-week-old) and middle-aged (52-week-old) female C57BL/6 mice either received an intramedullary stabilized proximal femur fracture or sham treatment. The observation time points included 6 and 24 h. Systemic levels of pro-inflammatory mediators as well as local inflammation and alterations in myocardial structure, metabolism and calcium homeostasis in left ventricular tissue was analyzed following hip fracture by multiplex analysis, RT-qPCR and immunohistochemistry.

Results

After hip fracture young and middle-aged mice showed increased systemic IL-6 and KC levels, which were significantly elevated in the middle-aged animals. Furthermore, the middle-aged mice showed enhanced myocardial expression of HMGB1, TLR2/4, TNF, IL1β and NLRP3 as well as considerable alterations in the myocardial expression of glucose- and fatty acid transporters (HFABP, GLUT4), calcium homeostasis proteins (SERCA) and cardiac structure proteins (desmin, troponin I) compared to the young animals following hip fracture.

Conclusion

Young and middle-aged mice showed local myocardial alterations, which might predispose for the development of secondary cardiac injury following hip fracture. Age and the age-associated phenomenon of ‘inflammaging’ seemed to be an independent risk factor aggravating and accelerating cardiac alterations following hip fracture.

Characteristics and Risk Factors of Myocardial Injury after Traumatic Hemorrhagic Shock

Myocardial injury increases major adverse cardiovascular events and mortality in patients with traumatic hemorrhagic shock, but its prevalence and risk factors remain unclear. This study aimed to assess the prevalence and risk factors of myocardial injury after traumatic hemorrhagic shock. This was an observational, retrospective cohort study of patients with traumatic hemorrhagic shock at a tertiary university hospital from November 2012 to July 2021. Patient characteristics and clinical variables were recorded in 314 patients. The outcome was the occurrence of myocardial injury after traumatic hemorrhagic shock. Risk factors for myocardial injury were identified using logistic regression. The incidence of myocardial injury after the traumatic hemorrhagic shock was 42.4%, and 95.5% of myocardial injuries occurred within the first three days after trauma. In the multivariate analysis, the independent risk factors for myocardial injury after traumatic hemorrhagic shock included heart rate of >100 beats/min (OR [odds ratio], 3.33; 95% confidence interval [CI], 1.56−7.09; p = 0.002), hemoglobin level of <70 g/L (OR, 3.50; 95% CI, 1.15−10.60; p = 0.027), prothrombin time of >15 s (OR, 2.39; 95% CI, 1.12−5.10; p = 0.024), acute kidney injury (OR, 2.75; 95% CI, 1.27−5.93; p = 0.01), and a higher APACHE II score (OR, 1.08; 95% CI, 1.01−1.15; p = 0.018). The area under the receiver operating characteristic curve for the prediction of myocardial injury after a traumatic hemorrhagic shock was 0.67 (95% CI, 0.68−0.79) for a heart rate of >100 beats/min, 0.67 (95% CI, 0.61−0.73) for hemoglobin level of <70 g/L, 0.66 (95% CI, 0.60−0.73) for prothrombin time of >15 s, 0.70 (95% CI, 0.64−0.76) for acute kidney injury, and 0.78 (95% CI, 0.73−0.83) for APACHE II scores. The incidence rate of myocardial injury in traumatic hemorrhagic shock is high, and heart rates of >100 beats/min, hemoglobin levels of <70 g/L, prothrombin times of >15 s, AKI and higher APACHE II scores are independent risk factors for myocardial injury after traumatic hemorrhagic shock. These findings may help clinicians to identify myocardial injury after traumatic hemorrhagic shock early and initiate appropriate treatment.

Exploratory Investigation of the Plasma Proteome Associated with the Endotheliopathy of Trauma

BACKGROUND

The endotheliopathy of trauma (EoT) is associated with increased mortality following injury. Herein, we describe the plasma proteome related to EoT in order to provide insight into the role of the endothelium within the systemic response to trauma.

METHODS

99 subjects requiring the highest level of trauma activation were included in the study. Enzyme-linked immunosorbent assays of endothelial and catecholamine biomarkers were performed on admission plasma samples, as well as untargeted proteome quantification utilizing high-performance liquid chromatography and tandem mass spectrometry.

RESULTS

Plasma endothelial and catecholamine biomarker abundance was elevated in EoT. Patients with EoT (n = 62) had an increased incidence of death within 24 h at 21% compared to 3% for non-EoT (n = 37). Proteomic analysis revealed that 52 out of 290 proteins were differentially expressed between the EoT and non-EoT groups. These proteins are involved in endothelial activation, coagulation, inflammation, and oxidative stress, and include known damage-associated molecular patterns (DAMPs) and intracellular proteins specific to several organs.

CONCLUSIONS

We report a proteomic profile of EoT suggestive of a surge of DAMPs and inflammation driving nonspecific activation of the endothelial, coagulation, and complement systems with subsequent end-organ damage and poor clinical outcome. These findings support the utility of EoT as an index of cellular injury and delineate protein candidates for therapeutic intervention.

Incidence and prognosis of myocardial injury in patients with severe trauma

Purpose

Severe trauma can lead to end organ damages of varying severity, including myocardial injury. In the non-cardiac surgery setting, there is extensive evidence that perioperative myocardial injury is associated with increased morbidity and mortality. The impact of myocardial injury on outcome after severe trauma has not been investigated adequately yet. We hypothesized that myocardial injury is associated with increased in-hospital mortality in patients with severe trauma.

Materials/methods

This retrospective cohort study included patients ≥ 18 years with severe trauma [defined as injury severity score (ISS) ≥ 16] that were admitted to the resuscitation room of the Emergency Department of the University Hospital Duesseldorf, Germany, between 2016 and 2019. The main endpoint was in-hospital mortality. Main exposure was myocardial injury at arrival [defined as high-sensitive troponin T (hsTnT) > 14 ng/l]. For statistical analysis, receiver operating characteristic curve (ROC) and multivariate binary logistic regression were performed.

Results

Out of 368 patients, 353 were included into statistical analysis (72.5% male, age: 55 ± 21, ISS: 28 ± 12). Overall in-hospital mortality was 26.1%. Myocardial injury at presentation was detected in 149 (42.2%) patients. In-hospital mortality of patients with and without myocardial injury at presentation was 45% versus 12.3%, respectively. The area under the curve (AUC) for hsTnT and mortality was 0.76 [95% confidence interval (CI) 0.71–0.82]. The adjusted odds ratio of myocardial injury for in-hospital mortality was 2.27 ([95%CI 1.16–4.45]; p = 0.017).

Conclusion

Myocardial injury after severe trauma is common and independently associated with in-hospital mortality. Thus, hsTnT might serve as a new prognostic marker in this cohort.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00068-021-01846-2.

Systemic and local cardiac inflammation after experimental long bone fracture, traumatic brain injury and combined trauma in mice

Background

Trauma is the leading cause of death and disability worldwide, especially in the young population. Cardiac injuries are an independent predictor for a poor overall outcome after trauma. The aim of the present study was to analyze systemic inflammation as well as local cardiac inflammation after experimental limb-, neuro- and combined trauma in mice.

Methods

Male C57BL/6 mice received either a closed tibia fracture (Fx), isolated traumatic brain injury (TBI) or a combination of both (Fx ​+ ​TBI). Control animals underwent sham procedure. After 6 and 24 ​h, systemic levels of inflammatory mediators were analyzed, respectively. Locally, cardiac inflammation and cardiac structural alterations were investigated in left ventricular tissue of mice 6 and 24 ​h after trauma.

Results

Mice showed enhanced systemic inflammation after combined trauma, which was manifested by increased levels of KC, MCP-1 and G-CSF. Locally, mice exhibited increased expression of inflammatory cytokines (IL-1β, TNF) in heart tissue, which was probably mediated via toll-like receptor (TLR) signaling. Furthermore, mice demonstrated a redistribution of connexin 43 in cardiac tissue, which appeared predominantly after combined trauma. Besides inflammation and structural cardiac alterations, expression of glucose transporter 4 (GLUT4) mRNA was increased in the heart early after TBI and after combination of TBI and limb fracture, indicating a modification of energy metabolism. Early after combination of TBI and tibia fracture, nitrosative stress was increased, manifested by elevation of nitrotyrosine in cardiac tissue. Finally, mice showed a trend of increased systemic levels of cardiac troponin I and heart-fatty acid binding protein (HFABP) after combined trauma, which was associated with a significant decrease of troponin I and HFABP mRNA expression in cardiac tissue after TBI and combination of TBI and limb fracture.

Conclusion

Mice exhibited early cardiac alterations as well as alterations in cardiac glucose transporter expression, indicating a modification of energy metabolism, which might be linked to increased systemic- and local cardiac inflammation after limb-, neuro- and combined trauma. These cardiac alterations might predispose individuals for secondary cardiac damage after trauma that might compromise cardiac function after TBI and long bone fracture.

Translational potential statement

Injuries to the head and extremities frequently occur after severe trauma. In our study, we analyzed the effects of closed tibia fracture, isolated TBI, and the combination of both injuries with regard to the development of post-traumatic secondary cardiac injuries.

Modeling Cardiac Dysfunction Following Traumatic Hemorrhage Injury: Impact on Myocardial Integrity

Cardiac dysfunction (CD) importantly contributes to mortality in trauma patients, who survive their initial injuries following successful hemostatic resuscitation. This poor outcome has been correlated with elevated biomarkers of myocardial injury, but the pathophysiology triggering this CD remains unknown. We investigated the pathophysiology of acute CD after trauma using a mouse model of trauma hemorrhage shock (THS)-induced CD with echocardiographic guidance of fluid resuscitation, to assess the THS impact on myocardial integrity and function. Mice were subjected to trauma (soft tissue and bone fracture) and different degrees of hemorrhage severity (pressure controlled ~MABP < 35 mmHg or <65 mmHg) for 1 h, to characterize the acute impact on cardiac function. In a second study, mice were subjected to trauma and hemorrhage (MABP < 35 mmHg) for 1 h, then underwent two echocardiographic-guided resuscitations to baseline stroke volume at 60 and 120 min, and were monitored up to 180 min to study the longer impact of THS following resuscitation. Naïve and sham animals were used as controls. At 60 min post-THS injury, animals showed a lower cardiac output (CO) and stroke volume (SV) and an early rise of heart fatty acid-binding protein (H-FABP = 167 ± 38 ng/ml; 90% increase from shams, 3.54 ± 3.06 ng/ml), when subjected to severe hemorrhage and injury. Despite resuscitation, these animals maintained lower CO (6 ml/min vs. 23 ml/min), lower SV (10 μl vs. 46 μl; both ~75% decreased), and higher H-FABP (levels (340 ± 115 ng/ml vs. 10.3 ± 0.2 ng/ml; all THS vs. shams, P < 0.001) at 180 min post-THS injury. Histopathological and flow-cytometry analysis of the heart confirmed an influx of circulatory leukocytes, compared to non-injured hearts. Myocardial injury was supported by an increase of troponin I and h-FABP and the widespread ultrastructural disorganization of the morphology of sarcomeres and mitochondria. DNA fragmentation and chromatin condensation driven by leakage of apoptosis-inducing factor (AIF) may suggest a mitochondria-driven progressive cell death. THS modeling in the mouse results in cardiomyocyte damage and reduced myocardial function, which mimics the cardiac dysfunction seen in trauma patients. This CD model may, therefore, provide further understanding to the mechanisms underlying CD and act as a tool for developing cardioprotective therapeutics to improve survival after injury.

Significance of Cardiac Troponin I Elevation in Traumatic Brain Injury Patients

Background

Myocardial dysfunction is frequently described as an underlying cause of mortality in traumatic brain injury (TBI) known as brain-cardiac link. However the impact on prognosis of a disease remains uncertain.

Objectives

The current study aimed at investigating the correlation between TBI and cardiac troponin I (cTnI) rise and in-hospital mortality rate among patients with TBI.

Methods

In the current prospective study TBI patients with abbreviated injury scale score (AIS) > 3 and Glasgow coma scale (GCS) score ≤ 8 with cTnI measurement within the first 24 hours of admission were evaluated. Chi-square, Kruskal-Wallis, Mann-Whitney U and Logistic Regression tests were used for data analysis.

Results

A total of 166 eligible patients were studied .The mean age of the cases was 37.64 ± 17.21 years, largely under 65 (93.4%) and male (86.7%).The most common injuries were cerebral contusion (35.1%), while motor vehicle crash (MVC) was the most common cause of injuries (83.73%); 59 % of the patients showed detectable cTnI concentrations within 24 hours of admission; 65.7% of the patients expired; they showed higher levels of cTnI compared to survivors that showed lower levels, 0.148 ± 0.074 vs 0.057 ± 0.055, respectively (P < 0.001). Moreover, a significant association was observed between mortality rate and lower admission GCS 3.49 ± 1.08 vs 6.79 ± 1.66, respectively (P < 0.001).

Conclusions

Increased cTnI levels could be a predictor of mortality among patients with TBI. Its measurement and investigation for therapeutic strategies could lead to better management of these cases.

Cardiac troponin T is associated with mortality in patients admitted to critical care in a UK major trauma centre: a retrospective database analysis

Background

Elevated levels of cardiac troponin T are associated with poor outcome in critically ill patients and have been proposed as a prognostic marker in major trauma. This study investigated the relationship between cardiac troponin T levels on admission to intensive care unit (ICU) and all-cause mortality in major trauma patients.

Methods

A retrospective database analysis of cardiac troponin T levels on admission to the ICU in major trauma patients between 1 August 2015 and 31 December 2016 at a UK Major Trauma Centre was performed.

Results

Of the 243 patients, 69 (28.4%) died. Cardiac troponin T levels were significantly higher in patients who died compared to survivors: 42 vs. 13 ng/L, respectively (p < 0.0001); the odds of all-cause mortality increased significantly as troponin increased, independent of age or Acute Physiology and Chronic Health Evaluation score.

Discussion

This confirms cardiac troponin T at ICU admission as a marker of mortality in major trauma. Elevated cardiac troponin T may be seen in patients without evidence of direct cardiac trauma.

The role of cardiac troponin I in prognostication of patients with isolated severe traumatic brain injury

BACKGROUND

Cardiac dysfunction is frequently observed after severe traumatic brain injury (sTBI); however, its significance is poorly understood. Our study sought to elucidate the association of cardiac troponin I (cTnI) elevation with all-cause in-hospital mortality following isolated sTBI (brain Abbreviated Injury Scale score ≥3 and admission Glasgow Coma Scale score ≤8, no Abbreviated Injury Scale score ≥3 to any other bodily regions).

METHODS

We retrospectively reviewed all adult patients (aged ≥18 years) with isolated sTBI admitted to a Level I trauma center between June 2007 and January 2014. Patients must have cTnI values within 24 hours of admission. Mortality risks were examined by Cox proportional hazard model.

RESULTS

Of 580 patients identified, 30.9% had detectable cTnI in 24 hours of admission. The median survival time was 4.19 days (interquartile range, 1.27-11.69). When adjusted for potential confounders, patients in the highest cTnI category (≥0.21 ng/mL) had a significantly higher risk of in-hospital mortality (hazard ratio, 1.39; 95% confidence interval, 1.04-1.88) compared with patients with undetectable cTnI. Mortality risk increased with higher troponin levels (p < 0.0001). This association was more pronounced in patients aged 65 years or younger (hazard ratio, 2.28; 95% confidence interval, 1.53-3.40; p < 0.0001) while, interestingly, insignificant in those older than 65 years (p = 0.0826).

CONCLUSION

Among patients with sTBI, cTnI elevation is associated with all-cause in-hospital mortality via a nonlinear positive trend. Age modified the effect of cTnI on mortality.

LEVEL OF EVIDENCE

Prognostic and epidemiologic study, level III.

Diabetic patients have increased perioperative cardiac risk in heart-type fatty acid-binding protein-based assessment

OBJECTIVE

To test the potential role of heart-type fatty acid-binding protein (H-FABP) in detecting increased perioperative cardiac risk in comparison with cardiac troponin I (cTnI) in the early postoperative period.

SUBJECTS AND METHODS

Sixty-seven patients who had clinical risk factors and underwent elective intermediate - or high-risk noncardiac surgery were included in this study. Serum specimens were analyzed for H-FABP and cTnI levels before and at 8 h after surgery. None of the patients had chest pain; 27 had a history of ischemic heart disease, 3 of heart failure, 5 of cerebrovascular diseases, 40 of diabetes and 46 of hypertension.

RESULTS

The mean duration of the operations was 2.33 ± 1.27 h (range 1-6). In the postoperative period, 27 (40.3%) patients had increased H-FABP levels (≥7.5 ng/ml); the median preoperative serum H-FABP level was 0.13 ng/ml (<0.1-5.9) and the median postoperative H-FABP level was 6.86 ng/ml (<0.1-13.7). Only 1 (1.5%) patient had cTnI >0.1 µg/l during the postoperative period. Correlation analysis revealed that the presence of diabetes was associated with an increased H-FABP level (r = 0.30, p = 0.01). Of the 27 patients with H-FABP ≥7.5 ng/ml, 21 (87%) had diabetes. There was no significant correlation with other clinical risk factors, type or duration of surgery.

CONCLUSION

The H-FABP levels significantly increased in the postoperative period. Most patients with increased postoperative H-FABP levels were diabetic. High H-FABP levels could alert clinicians to increased perioperative cardiovascular risk and could prevent underdiagnosis, especially in diabetic patients.

Dynamic detection of N-terminal pro-B-type natriuretic peptide helps to predict the outcome of patients with major trauma

INTRODUCTION

NT-proBNP and BNP have been demonstrated to be prognostic markers in cardiac disease and sepsis. However, the prognostic value and the dynamic changes of BNP or NT-proBNP in trauma patients remain unclear. The present study was conducted to investigate the dynamic changes of NT-proBNP in patients with major trauma (injury severity score ≥16), determine whether NT-proBNP could be used as a simple index to predict mortality in major trauma patients.

METHODS

This prospective observational study included 60 patients with major trauma. Serum NT-proBNP levels were measured on the 1st, 3rd and 7th day after injury The NT-proBNP levels in survivors were compared with those in non-survivors. The efficacy of NT-proBNP to predict survival was analyzed using receiver operating characteristic curves. An analysis of correlations between NT-proBNP and various factors, including injury severity score, Glasgow coma score, acute physiology and chronic health evaluation II, central venous pressure, creatine kinase-MB, cardiac troponin I and procalcitonin (PCT) was performed. NT-proBNP levels in patients with traumatic brain injury were compared with those in patients without traumatic brain injury. A comparison of NT-proBNP levels between patients with and without sepsis was also performed at each time point.

RESULTS

NT-proBNP levels in non-survivors were significantly higher than those in survivors at all the indicated time points. In the group of non-survivors, NT-proBNP levels on the 7th day were markedly higher than those on the 1st day. In contrast, NT-proBNP levels in survivors showed a reduction over time. The efficacy of NT-proBNP to predict survival was analyzed using ROC curves, and there was no difference in the area under the ROC between NT-proBNP and APACHE II/ISS at the three time points. A significant correlation was found between NT-proBNP and ISS on the 1st day, NT-proBNP and CK-MB, Tn-I and APACHE II on the 3rd day, NT-proBNP and PCT on the 7th day. There were no significant differences in NT-proBNP levels between patients with or without brain trauma at all the indicated time points. NT-proBNP levels in patients with sepsis were significantly higher than those in patients without sepsis at all the indicated time points.

CONCLUSION

These findings suggest that dynamic detection of serum NT-proBNP might help to predict death in patients with major trauma. A high level of NT-proBNP at admission or maintained for several days after trauma indicates poor survival.

Pelvic trauma: What are the predictors of mortality and cardiac, venous thrombo-embolic and infectious complications following injury?

INTRODUCTION

This study sought to determine risk factors that influence mortality, cardiac events, venous thrombo-embolic disease (VTED), and infection following fractures of the pelvis and/or acetabulum.

METHODS

The 2008 National Sample Program (NSP) of the National Trauma Databank was queried to identify all patients who sustained pelvic and acetabular fractures. Demographic data, injury-specific and surgical characteristics, and medical co-morbidities were abstracted. The occurrence of in-hospital mortality, cardiac events, VTED and infections were documented. Univariate testing, weighted logistic regression, and sensitivity analyses were performed to identify significant independent predictors of mortality and the complications under study.

RESULTS

The NSP contained 41,297 cases of pelvic trauma. In-hospital mortality was documented in 3055 (7%) and one or more complications occurred in 6932 (17%). Cardiac events transpired in 2% of patients, VTED in 4% and infections in 3%. Increasing age, shock, time to procedure, ISS, and GCS were predictive of mortality. Cardiac events were found to be influenced by obesity, diabetes, ISS, GCS, age, and trauma mechanism. VTED was impacted by obesity, history of respiratory disease, male sex, ISS, GCS, medical co-morbidities, and time to procedure. Injuries caused by mechanisms other than blunt trauma, shock, age, ISS, GCS, medical co-morbidities, and time to procedure were associated with infection.

CONCLUSIONS

Several important predictors were identified for specific complications and mortality following pelvic trauma. The design of this study may render it more generalisable to American patients with pelvic injuries.

LEVEL OF EVIDENCE

II - Prognostic retrospective study of a prospective dataset.

Trauma-induced secondary cardiac injury is associated with hyperacute elevations in inflammatory cytokines

INTRODUCTION

Clinical evidence supports the existence of a trauma-induced secondary cardiac injury. Experimental research suggests inflammation as a possible mechanism. The study aimed to determine if there was an early association between inflammation and secondary cardiac injury in trauma patients.

METHODS

A cohort study of critically injured patients between January 2008 and January 2010 was undertaken. Levels of the cardiac biomarkers troponin I and heart-specific fatty acid-binding protein and the cytokines tumor necrosis factor α (TNF-α), interleukin (IL)-6, IL-1β, and IL-8 were measured on admission to hospital, and again at 24 and 72 h. Participants were reviewed for adverse cardiac events (ACEs) and in-hospital mortality.

RESULTS

Of 135 patients recruited, 18 (13%) had an ACE. Patients with ACEs had higher admission plasma levels of TNF-α (5.4 vs. 3.8 pg/mL; P = 0.03), IL-6 (140 vs. 58.9 pg/mL, P = 0.009), and IL-8 (19.3 vs. 9.1 pg/mL, P = 0.03) compared with those without events. Hour 24 cytokines were not associated with events, but IL-8 (14.5 vs. 5.8 pg/mL; P = 0.01) and IL-1β (0.55 vs. 0.19 pg/mL; P = 0.04) were higher in patients with ACEs at 72 hours. Admission IL-6 was independently associated with heart-specific fatty acid-binding protein increase (P < 0.05). Patients who presented with an elevated troponin I combined with either an elevated TNF-α (relative risk [RR], 11.0; 95% confidence interval [CI], 1.8-66.9; P = 0.015), elevated IL-6 (RR, 17.3; 95% CI, 2.9-101.4; P = 0.001), or elevated IL-8 (RR, 15.0; 95% CI, 3.1-72.9; P = 0.008) were at the highest risk of in-hospital death when compared with individuals with normal biomarker and cytokine values.

CONCLUSIONS

There is an association between hyperacute elevations in inflammatory cytokines with cardiac injury and ACEs in critically injured patients. Biomarker evidence of cardiac injury and inflammation on admission is associated with a higher risk of in-hospital death.