Myocardial function at the early phase of traumatic brain injury: a prospective controlled study

Carbon monoxide-releasing molecule-3 ameliorates traumatic brain injury-induced cardiac dysfunctions via inhibition of pyroptosis and apoptosis

Traumatic brain injury (TBI) frequently results in cardiac dysfunction and impacts the quality of survivors' life. It has been reported that carbon monoxide-releasing molecule-3 (CORM-3) administration immediately after hemorrhagic shock and resuscitation (HSR) ameliorated the HSR‑induced cardiac dysfunctions. The purpose of this study was to determine whether the application of CORM-3 on TBI exerted therapeutic effects against TBI-induced cardiac dysfunctions. Rats were randomly divided into four groups (n = 12) including Sham, TBI, TBI/CORM-3 and TBI/inactive CORM-3 (iCORM-3) groups. TBI was established by a weight-drop model. The rats in the TBI/CORM-3 group and TBI/iCORM-3 group were intravenously injected with CORM-3 and iCORM-3 (4 mg/kg) following TBI, respectively. The time of death in the rats that did not survive within 24 h was recorded. 24 h post-trauma, the cardiac function, pathological change, serum troponin T and creatine kinase-MB (CK-MB) levels, pyroptosis, apoptosis and expressions of TUNEL staining, Gasdermin D (GSDMD), IL-1β, IL-18, ratio Bax/Bcl-2 were assessed by echocardiography, hematoxylin-eosin staining, chemiluminescence, immunofluorescence, and western blot assays, respectively. TBI-treated rats exhibited dramatically decreased ejection fraction and aggravated myocardial injury, increased mortality rate, elevated levels of serum troponin T and CK-MB, promoted cardiac pyroptosis and apoptosis, and upregulated expressions of cleaved caspase-3, GSDMD N-terminal fragments, IL-1β, IL-18, and ratio of Bax/Bcl-2, whereas CORM-3 partially reversed these changes. CORM-3 ameliorated TBI-induced cardiac injury and dysfunction. This mechanism may be responsible for the inhibition of pyroptosis and apoptosis in cardiomyocyte.

Traumatic brain injury: Symptoms to systems in the 21st century

Severe traumatic brain injury (TBI) is a devastating injury with a mortality of ∼ 25-30 %. Despite decades of high-quality research, no drug therapy has reduced mortality. Why is this so? We argue two contributing factors for the lack of effective drug therapies include the use of specific-pathogen free (SPF) animals for translational research and the flawed practice of single-nodal targeting for drug design. A revolution is required to better understand how the whole body responds to TBI, identify new markers of its progression, and discover new system-acting drugs to treat it. In this review, we present a brief history of TBI, discuss its system's pathophysiology and propose a new research strategy for the 21st century. TBI progression develops from injury signals radiating from the primary impact, which can cause local ischemia, hemorrhage, excitotoxicity, cellular depolarization, immune dysfunction, sympathetic hyperactivity, blood-brain barrier breach, coagulopathy and whole-body dysfunction. Metabolic reprograming of immune cells drives neuroinflammation and secondary injury processes. We propose if sympathetic hyperactivity and immune cell activation can be corrected early, cardiovascular function and endothelial-glycocalyx-mitochondrial coupling can be restored, and secondary injury minimized with improved patient outcomes. The therapeutic goal is to switch the injury phenotype to a healing phenotype by restoring homeostasis and maintaining sufficient tissue O2 delivery. We have been developing a small-volume fluid therapy comprising adenosine, lidocaine and magnesium (ALM) to treat TBI and have shown that it blunts the CNS-stress response, supports cardiovascular function and reduces secondary injury. Future research will investigate its suitability for human translation.

A prospective observational study of electrocardiographic and echocardiographic changes in traumatic brain injury - effect of surgical decompression

BACKGROUND

Traumatic brain injury (TBI) causes significant changes in myocardial function, which is represented by ECG and echocardiographic changes. We intended to study the effect of surgical decompression on these changes.

MATERIALS AND METHODS

We recruited adult TBI patients undergoing surgery within 48 h of injury. Preoperatively, the patient's demographic and clinical details were recorded. ECG and TTE were performed before surgery and 24 h later (first postoperative day [POD1]). ECG was analyzed for heart rate, PR, QRS, and QTc intervals, morphologic end-repolarization abnormalities (MERA), and ST-segment and T wave changes. TTE data included left ventricular ejection fraction (LVEF) and regional wall motion abnormalities (RWMA). Glasgow coma scale (GCS) at discharge was recorded. ECG and TTE changes before and after surgery were compared, and its association with discharge GCS was analyzed. Preoperative predictors of LV dysfunction were analyzed.

RESULTS

Of the 110 patients recruited, common ECG changes were prolonged QTc interval (42%) and MERA (47%). TTE showed poor LVEF (<50%) in 10% and RWMA in 10.8% of patients. Following surgery, both ECG and TTE changes improved. Preoperative LVEF <50% and/or RWMA were associated with a lower GCS score at discharge. Preoperative poor GCS motor score and prolonged QTc interval were independent predictors of LV dysfunction.

CONCLUSIONS

Poor LV function was associated with poor admission GCS and prolonged QTc interval. Patients with reduced LV function had lower GCS at discharge.

Cardiac Injury After Traumatic Brain Injury: Clinical Consequences and Management

Traumatic brain injury (TBI) is a significant public health issue because of its increasing incidence and the substantial short-term and long-term burden it imposes. This burden includes high mortality rates, morbidity, and a significant impact on productivity and quality of life for survivors. During the management of TBI, extracranial complications commonly arise during the patient's stay in the intensive care unit. These complications can have an impact on both mortality and the neurological outcome of patients with TBI. Among these extracranial complications, cardiac injury is a relatively frequent occurrence, affecting approximately 25-35% of patients with TBI. The pathophysiology underlying cardiac injury in TBI involves the intricate interplay between the brain and the heart. Acute brain injury triggers a systemic inflammatory response and a surge of catecholamines, leading to the release of neurotransmitters and cytokines. These substances have detrimental effects on the brain and peripheral organs, creating a vicious cycle that exacerbates brain damage and cellular dysfunction. The most common manifestation of cardiac injury in TBI is corrected QT (QTc) prolongation and supraventricular arrhythmias, with a prevalence up to 5 to 10 times higher than in the general adult population. Other forms of cardiac injury, such as regional wall motion alteration, troponin elevation, myocardial stunning, or Takotsubo cardiomyopathy, have also been described. In this context, the use of β-blockers has shown potential benefits by intervening in this maladaptive process. β-blockers can limit the pathological effects on cardiac rhythm, blood circulation, and cerebral metabolism. They may also mitigate metabolic acidosis and potentially contribute to improved cerebral perfusion. However, further clinical studies are needed to elucidate the role of new therapeutic strategies in limiting cardiac dysfunction in patients with severe TBI.

Cardiac cycle timing and contractility following acute sport-related concussion

Cardiac sequelae following sport-related concussion are not well understood. This study describes changes in the cardiac cycle timing intervals and contractility parameters during the acute phase of concussion. Twelve athletes (21 ± 2 years, height = 182 ± 9 cm, mass = 86 ± 15 kg, BMI = 26 ± 3 kg/m2) were assessed within 5 days of sustaining a diagnosed concussion against their own pre-season baseline. A non-invasive cardiac sensor (LLA RecordisTM) was used to record the cardiac cycle parameters of the heart for 1 minute during supine rest. Cardiac cycle timing intervals (Isovolumic relaxation and contraction time, Mitral valve open to E wave, Rapid ejection period, Atrial systole to mitral valve closure, Systole, and Diastole) and contractile forces (Twist force and Atrial systole: AS) were compared. Systolic time significantly decreased during acute concussion (p = 0.034). Magnitude of AS significantly increased during acute concussion (p = 0.013). These results imply that concussion can result in altered systolic function.

Incidence of Myocardial Injury and Cardiac Dysfunction After Adult Traumatic Brain Injury: A Systematic Review and Meta-analysis

Myocardial injury and cardiac dysfunction after traumatic brain injury (TBI) have been reported in observational studies, but there is no robust estimate of their incidences. We conducted a systematic review and meta-analysis to estimate the pooled incidence of myocardial injury and cardiac dysfunction among adult patients with TBI. A literature search was conducted using MEDLINE and EMBASE databases from inception to November 2022. Observational studies were included if they reported at least one abnormal electrocardiographic finding, elevated cardiac troponin level, or echocardiographic evaluation of systolic function or left ventricular wall motion in adult patients with TBI. Myocardial injury was defined as elevated cardiac troponin level according to the original studies and cardiac dysfunction was defined as the presence of left ventricular ejection fraction <50% or regional wall motion abnormalities assessed by echocardiography. The meta-analysis of the pooled incidence of myocardial injury and cardiac dysfunction was performed using random-effect models. The pooled estimated incidence of myocardial injury after TBI (17 studies, 3,773 participants) was 33% (95% CI: 27%-39%, I2:s 93%), and the pooled estimated incidence of cardiac dysfunction after TBI (9 studies, 557 participants) was 16.% (95% CI: 9%-25.%, I2: 84%). Although there was significant heterogeneity between studies and potential overestimation of the incidence of myocardial injury and cardiac dysfunction, our findings suggest that myocardial injury occurs in approximately one-third of adults after TBI, and cardiac dysfunction occurs in approximately one-sixth of patients with TBI.

Neural-Cardiac Inflammasome Axis after Traumatic Brain Injury

Traumatic brain injury (TBI) affects not only the brain but also peripheral organs like the heart and the lungs, which influences long-term outcomes. A heightened systemic inflammatory response is often induced after TBI, but the underlying pathomechanisms that contribute to co-morbidities remain poorly understood. Here, we investigated whether extracellular vehicles (EVs) containing inflammasome proteins are released after severe controlled cortical impact (CCI) in C57BL/6 mice and cause activation of inflammasomes in the heart that result in tissue damage. The atrium of injured mice at 3 days after TBI showed a significant increase in the levels of the inflammasome proteins AIM2, ASC, caspases-1, -8 and -11, whereas IL-1β was increased in the ventricles. Additionally, the injured cortex showed a significant increase in IL-1β, ASC, caspases-1, -8 and -11 and pyrin at 3 days after injury when compared to the sham. Serum-derived extracellular vesicles (EVs) from injured patients were characterized with nanoparticle tracking analysis and Ella Simple Plex and showed elevated levels of the inflammasome proteins caspase-1, ASC and IL-18. Mass spectrometry of serum-derived EVs from mice after TBI revealed a variety of complement- and cardiovascular-related signaling proteins. Moreover, adoptive transfer of serum-derived EVs from TBI patients resulted in inflammasome activation in cardiac cells in culture. Thus, TBI elicits inflammasome activation, primarily in the atrium, that is mediated, in part, by EVs that contain inflammasome- and complement-related signaling proteins that are released into serum and contribute to peripheral organ systemic inflammation, which increases inflammasome activation in the heart.

A prospective exploratory study to assess echocardiographic changes in patients with supratentorial tumors - Effect of craniotomy and tumor decompression

Background

Functional changes in the myocardium secondary to increased intracranial pressure (ICP) are studied sparingly. Direct echocardiographic changes in patients with supratentorial tumors have not been documented. The primary aim was to assess and compare the transthoracic echocardiography changes in patients with supratentorial tumors presenting with and without raised intracranial pressure for neurosurgery.

Methods

Patients were divided into two groups based on preoperative radiological and clinical evidence of midline shift of <6 mm without features of raised ICP (Group 1) or greater than 6mm with features of raised ICP (Group 2). Hemodynamic, echocardiographic, and optic nerve sheath diameter (ONSD) parameters were obtained during the preoperative period and 48 h after the surgery.

Results

Ninety patients were assessed, 88 were included for analysis. Two were excluded based on a poor echocardiographic window (1) and change in the operative plan (1). Demographic variables were comparable. About 27% of the patients in Group 2 had ejection fraction <55% and 21.2% had diastolic dysfunction in Group 2 in the preoperative period. There was a decrease in the number of patients with a left ventricular (LV) function <55% from 27% before surgery to 19% in the postoperative period in group 2. About 5.8% patients with moderate LV dysfunction in the preoperative period had normal LV function postoperatively. We found a positive correlation between ONSD parameters and radiological findings of raised intracranial pressure.

Conclusion

The study demonstrated that in patients with supratentorial tumors with ICP, cardiac dysfunction might be present in the preoperative period.

Impact of Left Ventricular Systolic Function After Moderate-to-Severe Isolated Traumatic Brain Injury: A Systematic Review and Meta-Analysis

Traumatic brain injury (TBI) can result in left ventricular dysfunction, which can lead to hypotension and secondary brain injuries. However, the association between left ventricular systolic dysfunction (LVSD) and in-hospital mortality in patients with moderate-to-severe isolated TBI is controversial. Therefore, we conducted a systematic review and meta-analysis to identify the prevalence of LVSD and evaluate whether LVSD following moderate-to-severe isolated TBI increases the in-hospital mortality. We searched PubMed, EMBASE, and the Cochrane Library database from January 1, 2010, through June 30, 2020. Meta-analysis was performed to determine the incidence of LVSD and related mortality in patients with moderate-to-severe isolated TBI. A systematic review identified 5 articles appropriate for meta-analysis. The total number of patients pooled was 256. LVSD was reported in 4 studies, of which the estimated incidence of patients with LVSD was 18.7% (95% confidence interval, 11.9-26.6). Five studies reported on in-hospital mortality, and the estimated in-hospital mortality was 14.1% (95% confidence interval, 5.3-25.6). Finally, 3 studies were eligible for analyzing the association of LVSD and in-hospital mortality. On meta-analysis, in-hospital mortality was significantly higher in patients with LVSD (risk ratio, 6.57; 95% confidence interval, 3.71-11.65; P < 0.001). In conclusion, LVSD after moderate-to-severe TBI is common and may be associated with worse in-hospital outcomes.

Changes in Subendocardial Viability Ratio in Traumatic Brain Injury Patients

Background: Traumatic brain injury (TBI) is often associated with cardiac dysfunction, which is a consequence of the brain-heart cross talk. The subendocardial viability ratio (SEVR) is an estimate of myocardial perfusion. The aim of this study was to analyze changes in the SEVR in patients with severe TBI without previous cardiac diseases. Methods: Adult patients treated for severe TBI with a Glasgow coma score <8 were studied. Pressure waveforms were obtained by a high-fidelity tonometer in the radial artery for SEVR calculation at five time points: immediately after admission to the intensive care unit and 24, 48, 72, and 96 h after admission. SEVRs and other clinically important parameters were analyzed in patients who survived and did not survive after 28 days of treatment, as well as in patients who underwent decompressive craniectomy (DC). Results: A total of 64 patients (16 females and 48 males) aged 18-64 years were included. Fifty patients survived and 14 died. DC was performed in 23 patients. SEVRs decreased 24 h after admission in nonsurvivors (p < 0.05) and after 48 h in survivors (p < 0.01) and its values were significantly lower in nonsurvivors than in survivors at 24, 72, and 96 h from admission (p < 0.05). The SEVR increased following DC (p < 0.05). Conclusions: A decreased SEVR is observed in TBI patients. Surgical decompression increases the SEVR, indicating improvement in coronary microvascular perfusion. The results of our study seem to confirm that brain injury affects myocardium function.

Multipotential and systemic effects of traumatic brain injury

Traumatic brain injury (TBI) is one of the leading causes of disability and mortality of people at all ages. Biochemical, cellular and physiological events that occur during primary injury lead to a delayed and long-term secondary damage that can last from hours to years. Secondary brain injury causes tissue damage in the central nervous system and a subsequent strong and rapid inflammatory response that may lead to persistent inflammation. However, this inflammatory response is not limited to the brain. Inflammatory mediators are transferred from damaged brain tissue to the bloodstream and produce a systemic inflammatory response in peripheral organs, including the cardiovascular, pulmonary, gastrointestinal, renal and endocrine systems. Complications of TBI are associated with its multiple and systemic effects that should be considered in the treatment of TBI patients. Therefore, in this review, an attempt was made to examine the systemic effects of TBI in detail. It is hoped that this review will identify the mechanisms of injury and complications of TBI, and open a window for promising treatment in TBI complications.

Bidirectional Brain-Systemic Interactions and Outcomes After TBI

Traumatic brain injury (TBI) is a debilitating disorder associated with chronic progressive neurodegeneration and long-term neurological decline. Importantly, there is now substantial and increasing evidence that TBI can negatively impact systemic organs, including the pulmonary, gastrointestinal (GI), cardiovascular, renal, and immune system. Less well appreciated, until recently, is that such functional changes can affect both the response to subsequent insults or diseases, as well as contribute to chronic neurodegenerative processes and long-term neurological outcomes. In this review, we summarize evidence showing bidirectional interactions between the brain and systemic organs following TBI and critically assess potential underlying mechanisms.

The Association of Early Electrocardiographic Abnormalities With Brain Injury Severity and Outcome in Severe Traumatic Brain Injury

The aim of this study was to evaluate the frequency of electrocardiographic (ECG) abnormalities in the acute phase of severe traumatic brain injury (TBI) and the association with brain injury severity and outcome. In contrast to neurovascular diseases, sparse information is available on this issue. Data of adult patients with severe TBI admitted to the Intensive Care Unit (ICU) for intracranial pressure monitoring of a level-1 trauma center from 2002 till 2018 were analyzed. Patients with a cardiac history were excluded. An ECG recording was obtained within 24 h after ICU admission. Admission brain computerized tomography (CT)-scans were categorized by Marshall-criteria (diffuse vs. mass lesions) and for location of traumatic lesions. CT-characteristics and maximum Therapy Intensity Level (TILmax) were used as indicators for brain injury severity. We analyzed data of 198 patients, mean (SD) age of 40 ± 19 years, median GCS score 3 [interquartile range (IQR) 3–6], and 105 patients (53%) had thoracic injury. In-hospital mortality was 30%, with sudden death by cardiac arrest in four patients. The incidence of ECG abnormalities was 88% comprising ventricular repolarization disorders (57%) mostly with ST-segment abnormalities, conduction disorders (45%) mostly with QTc-prolongation, and arrhythmias (38%) mostly of supraventricular origin. More cardiac arrhythmias were observed with increased grading of diffuse brain injury (p = 0.042) or in patients treated with hyperosmolar therapy (TILmax) (65%, p = 0.022). No association was found between ECG abnormalities and location of brain lesions nor with thoracic injury. Multivariate analysis with baseline outcome predictors showed that cardiac arrhythmias were not independently associated with in-hospital mortality (p = 0.097). Only hypotension (p = 0.029) and diffuse brain injury (p = 0.017) were associated with in-hospital mortality. In conclusion, a high incidence of ECG abnormalities was observed in patients with severe TBI in the acute phase after injury. No association between ECG abnormalities and location of brain lesions or presence of thoracic injury was present. Cardiac arrhythmias were indicative for brain injury severity but not independently associated with in-hospital mortality. Therefore, our findings likely suggest that ECG abnormalities should be considered as cardiac mimicry representing the secondary effect of traumatic brain injury allowing for a more rationale use of neuroprotective measures.

Crosstalk between brain, lung and heart in critical care

Extracerebral complications, especially pulmonary and cardiovascular, are frequent in brain-injured patients and are major outcome determinants. Two major pathways have been described: brain-lung and brain-heart interactions. Lung injuries after acute brain damages include ventilator-associated pneumonia (VAP), acute respiratory distress syndrome (ARDS) and neurogenic pulmonary œdema (NPE), whereas heart injuries can range from cardiac enzymes release, ECG abnormalities to left ventricle dysfunction or cardiogenic shock. The pathophysiologies of these brain-lung and brain-heart crosstalk are complex and sometimes interconnected. This review aims to describe the epidemiology and pathophysiology of lung and heart injuries in brain-injured patients with the different pathways implicated and the clinical implications for critical care physicians.

Speckle Tracking Analysis of Left Ventricular Systolic Function Following Traumatic Brain Injury: A Pilot Prospective Observational Cohort Study

BACKGROUND

Systolic dysfunction and reduction in left ventricular ejection fraction (LVEF) has been documented after traumatic brain injury (TBI). Speckle tracking is an emerging technology for myocardial strain assessment which has been utilized to identify subclinical myocardial dysfunction, and is most commonly reported as global longitudinal strain (GLS). We examined myocardial strain and regional strain patterns following moderate-severe TBI.

MATERIALS AND METHODS

We conducted a prospective cohort study of moderate-severe TBI patients (Glasgow Coma Scale≤12) and age/sex-matched controls. Transthoracic echocardiography was performed within the first day and 1 week following TBI. Myocardial function was assessed using both GLS and LVEF, and impaired systolic function was defined as GLS >-16% or LVEF ≤50%. Regional strain patterns and individual strain trajectories were examined.

RESULTS

Thirty subjects were included, 15 patients with TBI and 15 age/sex-matched controls. Among patients with adequate echocardiographic windows, systolic dysfunction was observed in 2 (17%) patients using LVEF and 5 (38%) patients using GLS within the first day after TBI. Mean GLS was impaired in patients with TBI compared with controls (-16.4±3.8% vs. -20.7±1.8%, P=0.001). Regional myocardial examination revealed impaired strain primarily in the basal and mid-ventricular segments. There was no improvement in GLS from day 1 to day 7 (P=0.81).

CONCLUSIONS

Myocardial strain abnormalities are common and persist for at least 1 week following moderate-severe TBI. Speckle tracking may be useful for the early diagnosis and monitoring of systolic dysfunction following TBI.

The Short-Term Effects of Isolated Traumatic Brain Injury on the Heart in Experimental Healthy Rats

BACKGROUND

To date, cardiac dysfunction after traumatic brain injury (TBI) has not been consistent. In this study, we hypothesized that TBI may play a role in the development of new-onset cardiac dysfunction in healthy experimental rats.

MATERIALS AND METHODS

Anesthetized healthy male Sprague-Dawley rats were divided into two groups: a sham-operated control group and a TBI group. The brain was injured with 2.4 atm percussion via a fluid percussion injury model. During the 120 min after TBI, we continuously measured brain parameters, including intracranial pressure (ICP) and cerebral perfusion pressure (CPP), and cardiac parameters, such as heart rate (HR), inter-ventricular septum dimension (IVSD), left ventricular internal dimension diastole (LVIDd), end-diastolic volume (EDV), ejection fraction (EF), fractional shortening (FS), and LV mass diastole (LVd mass) by cardiac echo. On days 1, 3, 7, and 14 after TBI, the brain damage volume was evaluated with triphenyltetrazolium chloride; the physiological parameters of the heart, including HR, IVSd, LVIDd, EDV, EF, FS, and LVd mass, were evaluated with cardiac echo; the morphology of cardiomyocytes was examined by hematoxylin and eosin (HE) and Masson trichrome staining; and the biomarkers of cardiac injury troponin I and B-type natriuretic peptide (BNP) were also examined.

RESULTS

Compared to sham-operated controls, the TBI groups had higher ICP, lower CPP, and higher brain neuronal apoptosis and infarction contusion volume. The impact of TBI on heart function showed hyperdynamic response trends in IVSd, LVIDd, EDV, EF, FS, and LVd mass within 30 min after TBI; however, EF and FS exhibited eventual decreasing trends. Simultaneously, the values of the biomarkers troponin I and BNP were within normal limits, and HE and Mass trichrome staining revealed no significant differences between the sham-operated control group and the TBI group.

CONCLUSIONS

Our results suggest that TBI due to 2.4 atm fluid percussion injury in healthy experimental rats may cause significant damage to the brain and affect the heart function as investigated by cardiac echo but not as investigated by HE and Masson trichrome stainings or troponin I and BNP evaluation.

Early cardiovascular function and associated hemodynamics in adults with isolated moderate-severe traumatic brain injury: A pilot study

BACKGROUND

While cardiac dysfunction has been described following traumatic brain injury (TBI), its association with systemic and cerebral hemodynamics is not known. We examined the contemporaneous relationship between early cardiac function with systemic and cerebral hemodynamic parameters after moderate-severe TBI.

METHODS

Bedside transthoracic echocardiography (TTE) and transcranial Doppler (TCD) ultrasonography were performed within 24 h in patients > 18 years with isolated moderate-severe TBI. Systemic hemodynamic parameters were quantified using routine monitoring [heart rate and mean arterial pressures (MAP)] and calculation from echocardiographic data [stroke volume index (SVI), cardiac index (CI), and systemic vascular resistance index (SVRI)]. Systolic dysfunction was defined using TTE as global longitudinal strain (GLS) > -16%. Mean middle cerebral artery velocity (FVm) was the measure of cerebral hemodynamics and quantified using TCD.

RESULTS

Among 15 patients [mean age 43 ± 13 years, GCS 5 ± 3, 73% male], 15 TTE and 15 TCD exams were performed simultaneously. Five (33%) patients had systolic dysfunction, with significantly worse GLS (median [IQR] -12.1% [-14.1, -12] vs. -19.1% [-19.9, -17.7], p = 0.004). Median (IQR) MAP was 97 (89, 107) mmHg, SVI (29.0 [20.5, 31.0] mL m^-2), and CI (2.83 [2.05, 3.10] L/min m^-2) were low to normal, while SVRI (2704 dyne sec/cm⁵ m^-2 [2210, 4084]) was normal to high. None of the patients had abnormal TCDs. Higher GLS (reduced systolic function) was associated with lower SVI (r² = 0.274, p = 0.03) but not other parameters.

CONCLUSION

Systemic hemodynamic parameters were consistent with an early catecholamine-excess state. While reduced systolic function was associated with lower SVI, there was no relationship with reduced cerebral perfusion, possibly due to normal MAP.

Making sense of gut feelings in the traumatic brain injury pathogenesis

Traumatic brain injury (TBI) is a devastating condition which often initiates a sequel of neurological disorders that can last throughout lifespan. From metabolic perspective, TBI also compromises systemic physiology including the function of body organs with subsequent malfunctions in metabolism. The emerging panorama is that the effects of TBI on the periphery strike back on the brain and exacerbate the overall TBI pathogenesis. An increasing number of clinical reports are alarming to show that metabolic dysfunction is associated with incidence of long-term neurological and psychiatric disorders. The autonomic nervous system, associated hypothalamic-pituitary axis, and the immune system are at the center of the interface between brain and body and are central to the regulation of overall homeostasis and disease. We review the strong association between mechanisms that regulate cell metabolism and inflammation which has important clinical implications for the communication between body and brain. We also discuss the integrative actions of lifestyle interventions such as diet and exercise on promoting brain and body health and cognition after TBI.

Cardiac Dysfunction in Adult Patients with Traumatic Brain Injury: A Prospective Cohort Study

BACKGROUND

There are limited data regarding the development of myocardial dysfunction after a traumatic brain injury (TBI). We investigated incidence, risk factors, and prognostic importance of cardiac dysfunction in adult patients admitted to the intensive care unit (ICU) after a moderate to severe TBI.

METHODS

Prospective observational study of consecutive patients admitted to neuro-trauma ICU with moderate to severe TBI from August 2014 to June 2015.

RESULTS

A total of 46 patients were included. Patients' mean (±SD) age was 44.7 (±20.7) years and mean Glasgow Coma Scale value was 5.6 (±3). Motor vehicle accident was the most common mechanism of TBI, with subdural and subarachnoid hemorrhages as the most common pathologies. Cardiac dysfunction developed in 6 of 46 (13%) patients. Patients with cardiac dysfunction had higher prevalence of diabetes mellitus (50% vs. 10%, P = 0.03) and higher proportion of electrocardiogram abnormalities (83% vs. 27%, P = 0.02) compared to the patients without cardiac dysfunction. Mean Glasgow Coma Scale scores were not significantly different between patients who developed cardiac dysfunction from those who did not (5.5 vs. 5.6, P = 0.95). Requirement for vasopressor support (33.3% vs. 40%, P = 1.0) and median ventilator days (5.2 vs. 4.7, P = 0.9) were similar between patients with and without cardiac dysfunction. There were no significant differences in hospital lengths of stay (12.3 vs. 13.8 days, P = 0.34) and hospital mortality (33% vs. 17.5%, P = 0.58) between the two groups.

CONCLUSIONS

Cardiac dysfunction occurs in patients after moderate to severe TBI, with mild to moderate reduction in left ventricular ejection fraction. Patients who developed cardiac dysfunction after TBI had a higher prevalence of diabetes mellitus and higher proportion of abnormalities in electrocardiograms. Development of cardiac dysfunction was not associated with adverse clinical outcomes.

Immune Response Mediates Cardiac Dysfunction after Traumatic Brain Injury

Cardiovascular complications are common after traumatic brain injury (TBI) and are associated with increased morbidity and mortality. In this study, we investigated the possible role of the immune system in mediating cardiac dysfunction post-TBI in mice. Adult male C57BL/6J mice were subjected to a TBI model of controlled cortical impact (CCI) with or without splenectomy (n = 20/group). Splenectomy was performed immediately prior to induction of TBI. Cardiac function was measured using echocardiography prior to and after TBI. Neurological and cognitive functional tests and flow cytometry and immunostaining were performed. TBI mice exhibited significant cardiac dysfunction identified by decreased left ventricular ejection fraction and fractional shortening at 3 and 30 days post-TBI. In addition, these mice exhibited significantly increased cardiomyocyte apoptosis, inflammation, and oxidative stress at 3 and 30 days post-TBI, as well as cardiac hypertrophy and fibrosis and ventricular dilatation at 30 days after TBI. TBI mice subjected to splenectomy showed significantly improved cardiac function, and decreased cardiac fibrosis, oxidative stress, cardiomyocyte apoptosis, and infiltration of immune cells and inflammatory factor expression in the heart compared with TBI control mice. TBI mice exhibited severe neurological and cognitive function deficits. However, splenectomy did not improve neurological and cognitive functional outcome after TBI compared with the TBI control group. TBI induces immune cell infiltration and inflammatory factor expression in the heart as well as cardiac dysfunction. Splenectomy decreases heart inflammation and improves cardiac function after TBI. Immune response may contribute to TBI-induced cardiac dysfunction.

Brain-Heart Interactions in Traumatic Brain Injury

The cardiovascular manifestations associated with nontraumatic head disorders are commonly known. Similar manifestations have been reported in patients with traumatic brain injury (TBI); however, the underlying mechanisms and impact on the patient's clinical outcomes are not well explored. The neurocardiac axis theory and neurogenic stunned myocardium phenomenon could partly explain the brain-heart link and interactions and can thus pave the way to a better understanding and management of TBI. Several observational retrospective studies have shown a promising role for beta-adrenergic blockers in patients with TBI in reducing the overall TBI-related mortality. However, several questions remain to be answered in clinical randomized-controlled trials, including population selection, beta blocker type, dosage, timing, and duration of therapy, while maintaining the optimal mean arterial pressure and cerebral perfusion pressure in patients with TBI.

Risk factors for myocardial dysfunction after traumatic brain injury: A one-year follow-up study

INTRODUCTION

Traumatic brain injury has been associated with an increased risk of myocardial dysfunction. Common abnormalities accompanying this pathology include electrocardiographic abnormalities, elevated creatine kinase levels, arrhythmias, and pathologic changes of the myocardium. The aim of this study was to determine if TBI patients have a higher risk of myocardial dysfunction than the general population and to identify the risk factors of myocardial dysfunction in TBI patients.

PATIENTS AND METHODS

The study sample was drawn from Taiwan's National Health Insurance Research Database of reimbursement claims, and comprised 26,860 patients who visited ambulatory care centers or were hospitalized with a diagnosis of TBI. The comparison group consisted of 134,300 randomly selected individuals. The stratified Fine and Gray regression was performed to evaluate independent risk factors for myocardial dysfunction in all patients and to identify risk factors in TBI patients.

RESULTS

During a 1-year follow-up period, 664 patients with TBI and 1494 controls developed myocardial dysfunction. TBI was independently associated with increased risk of myocardial dysfunction. Diabetes, hypertension, peptic ulcer disease, chronic liver disease and chronic renal disease were risk factors of myocardial dysfunction in TBI patients.

CONCLUSIONS

Individuals with TBI are at greater risk of developing myocardial dysfunction after adjustments for possible confounding factors. Early monitor should be initiated to decrease disability and dependence in patients with TBI.