Elevated serum cardiac troponin I in rhabdomyolysis

Ribonuclease inhibitor 1 emerges as a potential biomarker and modulates inflammation and iron homeostasis in sepsis

Sepsis, marked by organ dysfunction, necessitates reliable biomarkers. Ribonuclease inhibitor 1 (RNH1), a ribonuclease (RNase) inhibitor, emerged as a potential biomarker for acute kidney injury and mortality in thoracoabdominal aortic aneurysm patients. Our study investigates RNH1 dynamics in sepsis, its links to mortality and organ dysfunction, and the interplay with RNase 1 and RNase 5. Furthermore, we explore RNH1 as a therapeutic target in sepsis-related processes like inflammation, non-canonical inflammasome activation, and iron homeostasis. We showed that RNH1 levels are significantly higher in deceased patients compared to sepsis survivors and correlate with creatine kinase, aspartate and alanine transaminase, bilirubin, serum creatinine and RNase 5, but not RNase 1. RNH1 mitigated LPS-induced TNFα and RNase 5 secretion, and relative mRNA expression of ferroptosis-associated genes HMOX1, FTH1 and HAMP in PBMCs. Monocytes were identified as the predominant type of LPS-positive PBMCs. Exogenous RNH1 attenuated LPS-induced CASP5 expression, while increasing IL-1β secretion in PBMCs and THP-1 macrophages. As RNH1 has contradictory effects on inflammation and non-canonical inflammasome activation, its use as a therapeutic agent is limited. However, RNH1 levels may play a central role in iron homeostasis during sepsis, supporting our clinical observations. Hence, RNH1 shows promise as biomarkers for renal and hepatic dysfunction and hepatocyte injury, and may be useful in predicting the outcome of septic patients.

Clinical Interpretation of Serum Troponin in the Era of High-Sensitivity Testing

Cardiac troponin (Tn) plays a central role in the evaluation of patients with angina presenting with acute coronary syndrome. The advent of high-sensitivity assays has improved the analytic sensitivity and precision of serum Tn measurement, but this advancement has come at the cost of poorer specificity. The role of clinical judgment is of heightened importance because, more so than ever, the interpretation of serum Tn elevation hinges on the careful integration of findings from electrocardiographic, echocardiographic, physical exam, interview, and other imaging and laboratory data to formulate a weighted differential diagnosis. A thorough understanding of the epidemiology, mechanisms, and prognostic implications of Tn elevations in each cardiac and non-cardiac etiology allows the clinician to better distinguish between presentations of myocardial ischemia and myocardial injury-an important discernment to make, as the treatment of acute coronary syndrome is vastly different from the workup and management of myocardial injury and should be directed at the underlying cause.

Mortality Cases of Mushroom Poisoning with Russula subnigricans

Mushroom poisoning is increasing worldwide, as well as the incidence of fatal mushroom poisoning. Several new syndromes associated with mushroom poisoning have been described in the literature. Notably, 1 of the newly identified mushroom poisonings is Russula subnigricans poisoning. R subnigricans can be classified as causing a delayed-onset rhabdomyolytic syndrome as patients with this severe poisoning present with severe rhabdomyolysis, acute kidney injury, and cardiomyopathy. However, there are only a few reports on the toxicity of R subnigricans. We recently treated 6 patients with R subnigricans mushroom poisoning, of whom 2 died. The 2 patients showed severe rhabdomyolysis, metabolic acidosis, acute renal failure, electrolyte imbalance, and irreversible shock, which caused their deaths. Mushroom poisoning should be considered in the evaluation of rhabdomyolysis of unknown origin. In addition, in cases of mushroom poisoning with severe rhabdomyolysis, R subnigricans poisoning should be promptly identified.

A prospective study on myocardial injury after BNT162b2 mRNA COVID-19 fourth dose vaccination in healthy persons

AIMS

To prospectively evaluate the incidence of myocardial injury after the administration of the fourth dose BNT162b2 mRNA vaccine (Pfizer-BioNTech) against COVID-19.

METHODS AND RESULTS

Health care workers who received the BNT162b2 vaccine during the fourth dose campaign had blood samples collected for high-sensitivity cardiac troponin (hs-cTn) during vaccine administration and 2-4 days afterward. Vaccine-related myocardial injury was defined as hs-cTn elevation above the 99th percentile upper reference limit and >50% increase from baseline measurement. Participants with evidence of myocardial injury underwent assessment for possible myocarditis. Of 324 participants, 192 (59.2%) were female and the mean age was 51.8 ± 15.0 years. Twenty-one (6.5%) participants had prior COVID-19 infection, the mean number of prior vaccine doses was 2.9 ± 0.4, and the median time from the last dose was 147 (142-157) days. Reported vaccine-related adverse reactions included local pain at injection site in 57 (17.59%), fatigue in 39 (12.04%), myalgia in 32 (9.88%), sore throat in 21 (6.48%), headache in 18 (5.5%), fever ≥38°C in 16 (4.94%), chest pain in 12 (3.7%), palpitations in 7 (2.16%), and shortness of breath in one (0.3%) participant. Vaccine-related myocardial injury was demonstrated in two (0.62%) participants, one had mild symptoms and one was asymptomatic; both had a normal electrocardiogram and echocardiography.

CONCLUSION

In a prospective investigation, an increase in serum troponin levels was documented among 0.62% of healthy health care workers receiving the fourth dose BNT162b2 vaccine. The two cases had mild or no symptoms and no clinical sequela.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT05308680.

Modern View on the Role of Sex-Specific Levels of High-Sensitive Cardiospecific Troponins T and I in the Diagnosis of Myocardial Infarction

It is well known that the molecules of cardiospecific troponins T and I are localized in the troponin-tropomyosin complex of the cytoplasm of cardiac myocytes and, due to the specific localization, these cardiospecific troponins are widely used as diagnostic biomarkers of myocardial infarction. Cardiospecific troponins are released from the cytoplasm of cardiac myocytes as a result of irreversible cell damage (for example, ischemic necrosis of cardiomyocytes in myocardial infarction or apoptosis of cardiac myocytes in cardiomyopathies and heart failure) or reversible damage (for example, intense physical exertion, hypertension, the influence of stress factors, etc.). Current immunochemical methods for determining cardiospecific troponins T and I have extremely high sensitivity to subclinical (minor) damage to myocardial cells and, thanks to modern high-sensitive methods, it is possible to detect damage to cardiac myocytes in the early (subclinical) stages of a number of cardiovascular pathologies, including myocardial infarction. So, recently, leading cardiological communities (the European Society of Cardiology, the American Heart Association, the American College of Cardiology, etc.) have approved algorithms for early diagnosis of myocardial infarction based on the assessment of serum levels of cardiospecific troponins in the first 1 - 3 h after the onset of pain syndrome. An important factor that may affect early diagnostic algorithms of myocardial infarction are sex-specific features of serum levels of cardiospecific troponins T and I. This manuscript presents a modern view on the role of sex-specific serum levels of cardiospecific troponins T and I in the diagnosis of myocardial infarction and the mechanisms of formation of sex-specific serum levels of troponins.

Gender Specificities of Cardiac Troponin Serum Levels: From Formation Mechanisms to the Diagnostic Role in Case of Acute Coronary Syndrome

Cardiac troponins T and I are the main (most sensitive and specific) laboratory indicators of myocardial cell damage. A combination of laboratory signs of myocardial cell damage (elevated levels of cardiac troponins T and I) with clinical (severe chest pain spreading to the left side of the human body) and functional (rise or depression of the ST segment, negative T wave or emergence of the Q wave according to electrocardiography and/or decrease in the contractility of myocardial areas exposed to ischemia according to echocardiography) signs of myocardial ischemia is indicative of the ischemic damage to cardiomyocytes, which is characteristic of the development of acute coronary syndrome (ACS). Today, with early diagnostic algorithms for ACS, doctors rely on the threshold levels of cardiac troponins (99th percentile) and on the dynamic changes in the serum levels over several hours (one, two, or three) from the moment of admission to the emergency department. That said, some recently approved highly sensitive methods for determining troponins T and I show variations in 99th percentile reference levels, depending on gender. To date, there are conflicting data on the role of gender specificities in the serum levels of cardiac troponins T and I in the diagnostics of ACS, and the specific mechanisms for the formation of gender differences in the serum levels of cardiac troponins T and I are unknown. The purpose of this article is to analyze the role of gender specificities in cardiac troponins T and I in the diagnostics of ACS, and to suggest the most likely mechanisms for the formation of differences in the serum levels of cardiac troponins in men and women.

Earlier continuous renal replacement therapy is associated with reduced mortality in rhabdomyolysis patients

Background

Continuous renal replacement therapy (CRRT) is commonly employed for rhabdomyolysis (RM) patients. However, the optimal initiation timing of CRRT and prognostic factors were not well evaluated for patients with RM. We aimed to investigate the efficacy of CRRT timing on mortality and the risk factors for death in RM patients who received CRRT.

Methods

RM patients who received CRRT between 1 May 2010 and 31 May 2021 in our center were retrospectively included. Univariate and multivariate logistic analyses were performed to identify the risk factors for primary outcome (90-day mortality).

Results

A total of 134 patients were included in our study. The 90-day mortality rate was 38.06%. The median time from CRRT initiation to peak CK occurrence was 4.8 h (IQR −16, 14), 67 patients received CRRT before 4.8 h after peak CK occurrence (early CRRT), and 67 patients received CRRT beyond 4.8 h after peak CK occurrence (late CRRT). Multivariate logistic regression analysis showed that the time from CRRT initiation to the peak CK (per 1 h, OR 1.026, 95% CI 1.004–1.049, p = 0.023), late CRRT (OR 3.082, 95% CI 1.072–8.859, p = 0.037), elevated serum cardiac troponin I (cTnI) (per 1 ng/mL, OR 1.218, 95% CI 1.011–1.468, p = 0.038), older age (per 1 year, OR 1.042, 95% CI 1.003–1.081, p = 0.032), and need of mechanical ventilation support (OR 4.632, 95% CI 1.292–16.61, p = 0.019) were independent risk factors for 90-day mortality.

Conclusions

Earlier CRRT initiation before 4.8 h after peak CK occurrence was associated with lower 90-day patient mortality.

A review of cardiac troponin I detection by surface enhanced Raman spectroscopy: Under the spotlight of point-of-care testing

Cardiac troponin I (cTnI) is a biomarker widely related to acute myocardial infarction (AMI), one of the leading causes of death around the world. Point-of-care testing (POCT) of cTnI not only demands a short turnaround time for its detection but the highest accuracy levels to set expeditious and adequate clinical decisions. The analytical technique Surface-enhanced Raman spectroscopy (SERS) possesses several properties that tailor to the POCT format, such as its flexibility to couple with rapid assay platforms like microfluidics and paper-based immunoassays. Here, we analyze the strategies used for the detection of cTnI by SERS considering POCT requirements. From the detection ranges reported in the reviewed literature, we suggest the diseases other than AMI that could be diagnosed with this technique. For this, a section with information about cardiac and non-cardiac diseases with cTnI release, including their release kinetics or cut-off values are presented. Likewise, POCT features, the use of SERS as a POCT technique, and the biochemistry of cTnI are discussed. The information provided in this review allowed the identification of strengths and lacks of the available SERS-based point-of-care tests for cTnI and the disclosing of requirements for future assays design.

Russula subnigricans Poisoning Causes Severe Rhabdomyolysis That Could be Misdiagnosed as Non-ST Segment Elevation Myocardial Infarction

Mushroom poisoning and subsequently the number of patients visiting emergency rooms are increasing, as well as the proportion of fatal mushroom poisonings. Myocytic mushroom poisoning is one of the new clinical classifications. This report documents the course of a family with Russula subnigricans poisoning complicated by severe rhabdomyolysis, including a case that was misdiagnosed as myocardial infarction. A 64-y-old man visited our hospital with symptoms including substernal chest discomfort, nausea, vomiting, and myalgia, lasting for 12 h. His laboratory tests showed elevated serum high-sensitive troponin I. He was diagnosed with non-ST segment elevation myocardial infarction. After that, 2 family members who ate mushrooms together were transferred from a local emergency room with the diagnosis of rhabdomyolysis. Consequently, rhabdomyolysis due to mushroom poisoning was diagnosed. They were hospitalized in the intensive care unit. After admission, conservative management, including primary fluid resuscitation, was performed, and the patients were discharged without complications. R subnigricans poisoning was revealed after investigation and should be considered in mushroom poisoning with rhabdomyolysis. Early recognition and intensive supportive care are important for mushroom poisoning patients.

[Hypoxic and hypoglycemic brain damage as a result of an adrenal cortex crisis-An important differential diagnosis in cases of unspecific symptoms]

Acute adrenal cortex insufficiency is a rare disease, which is hard to diagnose because of its diffuse symptoms. Symptoms, such as general weakness, nausea or vomiting, fatigue, hyponatremia, hyperkalemia, hypoglycemia and pronounced hypotension up to shock can be crucial in the diagnosis of an adrenal cortex crisis. The underlying disease of adrenal cortex insufficiency is also characterized by not always obvious symptoms, which are differently expressed depending on whether it is the primary or secondary type.After the diagnosis is made it is important to educate the patients, determine the optimal dosage of the substitution and ensure the compliance of the patients to optimize the further process and avoid an adrenal crisis. An adrenal crisis is one of the reasons for a higher mortality of these patients, which is well-described in the current literature. Descriptions of fatal courses and their reasons are rare; however, knowledge of the disease and the importance of rapid intervention is very important, especially for physicians who work in the emergency room or intensive care unit (ICU).This article reports about a female patient with a known secondary adrenal cortex insufficiency who developed the complete picture of an adrenal crisis. Despite rapid diagnosis and initiation of treatment massive brain damage could not be averted due to hypoxia and hypoglycemia. This case report demonstrates the potential symptoms, in particular a massive hypoglycemia and an initial shock refractory to catecholamine. It also shows the severity of that disease and the importance of rapid treatment even though it is difficult to make the diagnosis.

Some Common Causes of False Positive Increases in Serum Levels of Cardiac Troponins

Cardiac troponin molecules (cTnI and cTnT) are the most valuable and in-demand biomarkers for detecting various types of myocardial damage (reversible and irreversible, ischemic, inflammatory, toxic, etc.) in current clinical practice. These biomarkers are widely used for early diagnosis of acute myocardial infarction (AMI) and risk stratification of patients suffering from a number of cardiac (such as myocarditis, heart failure, cardiomyopathy, etc.) and extra-cardiac diseases (such as sepsis, renal failure, pulmonary embolism, neurological pathologies, etc.) that negatively affect the cells of cardiac muscle tissue. However, in daily routine clinical activities, internists and cardiologists often encounter cases of false increases in the concentrations of cardiospecific troponins. A false increase in the concentration of troponins contributes to an incorrect diagnosis and incorrect therapy, which can harm the patient. A false increase in the concentration of troponins contributes to an incorrect diagnosis and incorrect therapy, which can harm the patient, therefore, internists and cardiologists should be well aware of the main reasons and mechanisms for false-positive results cTnI and cTnT. This review article mainly focuses on the causes of falsepositive increases in serum levels of cTnI and cTnT, which provide helpful clues for the accurate diagnosis of AMI and evidence for the differential diagnosis.

[Mechanisms of increase and diagnostic role of highly sensitive troponins in arterial hypertension]

Improvement in immunochemical methods for the determination of key biomarkers of acute myocardial infarction has led not only to an improvement in the early diagnosis of acute myocardial infarction, but also to a change in many of our ideas about the biology and diagnostic role of cardiac troponins. Modern (highly and ultrasensitive) laboratory methods for the determination of cardiac troponin molecules in human biological fluids are highly sensitive, which makes it possible to detect even the smallest damage to cardiomyocytes that occur at the early stages of many pathologies of cardiac (coronary heart disease, arterial hypertension, etc.) and extracardiac etiology (renal failure, sepsis, chronic obstructive pulmonary disease and others), as well as under the influence of a number of physiological conditions, including the influence of physical exercises, psychoemotional stress, gender characteristics (higher levels of cardiac troponins in men, compared with women), age characteristics (an increase in the concentration of cardiac troponins with age) and circadian characterisics (prevalence of morning values of cardiac troponins concentration over evening ones). In this regard, the diagnostic capabilities of the use of highly sensitive cardiac troponins have been significantly expanded. One of the promising areas for the use of highly sensitive cardiac troponins includes the assessment of the risk of adverse cardiovascular events both in healthy patients and in patients with various risk factors for their development, one of which can be considered arterial hypertension. This article systematizes the results of clinical studies evaluating the diagnostic role of highly sensitive cardiac troponins in biological fluids (blood serum and urine) in hypertension and discusses in detail the mechanisms of increasing the levels of highly sensitive troponins in this pathological condition.

Found Down Extremity Compartment Syndrome Secondary to Substance Use: An Observational Multicenter Study

With the worsening opioid epidemic in America, more patients are developing found down extremity compartment syndrome (FDECS). The purpose of this study was to describe this patient population, including their presenting symptoms, laboratory test results, and clinical outcomes.

Methods

We performed a 2-center retrospective review of adult patients who developed FDECS secondary to substance use from January 2006 to December 2019. Patients were managed operatively or nonoperatively at the surgeon's discretion. Data on patient demographic characteristics, laboratory values, hospital course, and clinical outcomes were collected from electronic medical records.

Results

In this study, 91 patients were included: 85 patients were managed operatively, and 6 patients were managed nonoperatively. Most patients were male, and the mean patient age (and standard deviation) was 37 ± 11 years. Opioids were the most common substance used. Patients managed operatively underwent a mean of 4 ± 3 surgical procedures, 44% received a skin graft, 25% developed a wound infection, and 11% underwent limb amputation. Patients managed nonoperatively did not undergo a subsequent fasciotomy or amputation. At a mean follow-up of 2.3 years, persistent weakness (66%), pain (78%), persistent sensory deficits (53%), and contractures (18%) were common.

Conclusions

Patients who develop FDECS secondary to substance use have high surgical complication rates and poor clinical outcomes. We found high rates of wound infection, revision surgical procedures, and amputation, often leaving young adults with lifelong disability.

Level of Evidence

Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Diagnosis, Investigation and Management of Patients with Acute and Chronic Myocardial Injury

The application of high-sensitivity cardiac troponins in clinical practice has led to an increase in the recognition of elevated concentrations in patients without myocardial ischaemia. The Fourth Universal Definition of Myocardial Infarction encourages clinicians to classify such patients as having an acute or chronic myocardial injury based on the presence or absence of a rise or a fall in cardiac troponin concentrations. Both conditions may be caused by a variety of cardiac and non-cardiac conditions, and evidence suggests that clinical outcomes are worse than patients with myocardial infarction due to atherosclerotic plaque rupture, with as few as one-third of patients alive at 5 years. Major adverse cardiovascular events are comparable between populations, and up to three-fold higher than healthy individuals. Despite this, no evidence-based strategies exist to guide clinicians in the investigation of non-ischaemic myocardial injury. This review explores the aetiology of myocardial injury and proposes a simple framework to guide clinicians in early assessment to identify those who may benefit from further investigation and treatment for those with cardiovascular disease.

Myocardial Injury in the Era of High-Sensitivity Cardiac Troponin Assays: A Practical Approach for Clinicians

Importance

Traditionally, elevated troponin concentrations were synonymous with myocardial infarction. But with improvements in troponin assays, elevated concentrations without overt myocardial ischemia are now more common; this is referred to as myocardial injury. Physicians may be falsely reassured by the absence of myocardial ischemia; however, recent evidence suggests that myocardial injury is associated with even more detrimental outcomes. Accordingly, this article reviews the definition, epidemiology, differential diagnosis, diagnostic evaluation, and management of myocardial injury.

Observations

Current epidemiological evidence suggests that myocardial injury without overt ischemia represents about 60% of cases of abnormal troponin concentrations when obtained for clinical indications, and 1 in 8 patients presenting to the hospital will have evidence of myocardial injury. Myocardial injury is a concerning prognosis; the 5-year mortality rate is approximately 70%, with a major adverse cardiovascular event rate of 30% in the same period. The differential diagnosis is broad and can be divided into acute and chronic precipitants. The initial workup involves an assessment for myocardial ischemia. If infarction is ruled out, further evaluation includes a detailed history, physical examination, laboratory testing, a 12-lead electrocardiogram, and (if there is no known history of structural or valvular heart disease) an echocardiogram. Unfortunately, no consensus exists on routine management of patients with myocardial injury. Identifying and treating the underlying precipitant is the most practical approach.

Conclusion and Relevance

Myocardial injury is the most common cause of abnormal troponin results, and its incidence will likely increase with an aging population, increasing prevalence of cardiovascular comorbidities, and greater sensitivity of troponin assays. Myocardial injury represents a challenge to clinicians; however, given its serious prognosis, it warrants a thorough evaluation of its underlying precipitant. Future strategies to prevent and/or manage myocardial injury are needed.

Troponin elevation in the setting of exercise-induced rhabdomyolysis in an athletic teenager

Troponin levels are often obtained when chest pain is evaluated in the paediatric emergency department. Elevations in troponin levels can be due to different causes, and it is important to fully understand all of these possible causes to help streamline further evaluation and therapy. We present the case of a teenager who had two episodes of troponin elevation in the setting of rhabdomyolysis.

Is rhabdomyolysis an anaesthetic complication in patients undergoing robot-assisted radical prostatectomy?

BACKGROUND:

In patients undergoing robot-assisted radical prostatectomy (RARP), pneumoperitoneum, intraoperative fluid restriction and prolonged Trendelenburg position may cause rhabdomyolysis (RM) due to hypoperfusion in gluteal muscles and lower extremities. In this study, it was aimed to assess effects of body mass index (BMI), comorbidities, intra-operative positioning, fluid restriction and length of surgery on the development of RM in RARP patients during the perioperative period.

SUBJECTS AND METHODS:

The study included 52 American Society of Anesthesiologists I–II patients aged 50–80 years with BMI >25 kg/m², who underwent RARP. Fluid therapy with normal saline (1 ml/kg/h) and 6% hydroxyethyl starch 200/05 (1 ml/kg/h) was given during the surgery. Charlson comorbidity index (CCI), operation time (OT) and Trendelenburg time (TT) were recorded. Blood samples for creatine phosphokinase (CPK), blood urea nitrogen, creatinine (Cr), aspartate aminotransferase (AST), alanine transferase (ALT), lactate dehydrogenase (LDH), creatinine kinase-MB, cardiac troponin I and arterial blood gases were drawn at baseline and on 6, 12, 24 and 48 h. RM was defined by serum CPK level exceeding 5000 IU/L.

RESULTS:

Seven patients met predefined criteria for RM. There were positive correlations among serum CPK and Cr, AST, ALT and LDH levels. However, there was no significant difference in BMI, OT and TT between patients with or without RM (P > 0.05). CCI scores were higher in patients with RM than those without (3.00 ± 0.58 vs. 2.07 ± 0.62; P < 0.01). No renal impairment was detected among patients with RM at the post-operative period.

CONCLUSIONS:

It was found that comorbid conditions are more important in the development of RM during RARP rather than BMI, OT or TT. Patients with higher comorbidity are at risk for RM development and that this should be kept in mind at follow-up and when informing patients.

A series of cases of rhabdomyolysis after ingestion of Tricholoma equestre

Tricholoma equestre (hereinafter – T. equestre) is a common edible fungus that is considered to be toxic under certain conditions. Here, we report four cases of acute poisoning caused by T. equestre, including one lethal outcome in Lithuania between 2004 and 2013. In the severe case, fatigue, nausea without vomiting and muscle pain, profuse sweating without fever, and respiratory insufficiency occurred. Laboratory tests showed an elevation of creatine kinase (CK), aspartate aminotransferase (AST), and alanine aminotransferase (ALT). Although clinical findings and laboratory tests support evidence of rhabdomyolysis, no renal insufficiency was observed. Significance of T. equestre in cardiac changes is feasible but remains unclear.

Compartment syndrome of the deltoid: a case report of a common presentation in a rare location

Compartment syndrome presents with a slow onset of pain. Anything that causes an increased intra-compartmental pressure can lead to surgical emergency. A 45-year-old male presents to the emergency department with prolonged syncope. The patient is unable to recall the previous night except for using oxycodone. Patient medical history is significant for ischemic cardiomyopathy and myocardial infarction. Physical exam showed left arm pain and swelling, decreased sensation to light touch, and decreased range of motion. The left forearm was cool to touch with decreased pulses. Blood urea nitrogen/creatinine ratio was 47/4.0, white blood cell was 15.1, troponin was 34.2, and creatine kinase was immeasurable. Electrocardiogram showed non-specific T-wave abnormalities. Computed tomography showed left hemithoracic musculature enlargement. The patient's symptoms continued to worsen. The patient underwent emergency fasciotomy to relieve intra-compartmental pressure. Compartment syndrome of the deltoid is rare and yielded less than ten cases in our literature review. Although compartment syndrome usually affects the forearm, one must consider its possibility in any anatomical location.

Prognostic Impact of Myocardial Injury Related to Various Cardiac and Noncardiac Conditions

BACKGROUND

Elevated cardiac troponins in clinical conditions other than myocardial infarction are well known. For such occurrences, the term "myocardial injury" has been proposed. The long-term outcome in patients with myocardial injury related to various cardiac and noncardiac clinical disorders is unknown.

METHODS

During January 2010 to January 2011, we prospectively studied hospitalized patients who had cardiac troponin I measured on clinical indication. Patients with cardiac troponin I values >30 ng/L and no evidence of myocardial ischemia were diagnosed as having myocardial injury. Patients were classified into 5 categories of plausible related conditions: cardiac ischemic, cardiac nonischemic, noncardiac, multifactorial, or indeterminate. Follow-up was a minimum of 3 years, with all-cause mortality as the single end-point.

RESULTS

A total of 3762 patients were considered, of whom 1089 (29%) had myocardial injury. The most common associated conditions were noncardiac (n = 346) or multifactorial (n = 359). Cardiac ischemic (n = 183) and cardiac nonischemic (n = 134) conditions occurred less frequently. After a median of 3.2 years, 645 patients (59%) had died. A multivariate Cox regression analysis showed no difference in mortality between patients with cardiac ischemic and cardiac nonischemic conditions (hazard ratio [HR] 0.75; 95% confidence interval [CI], 0.50-1.13; P = .2). Patients with noncardiac or multifactorial disorders, however, had significantly higher mortality than those with associated cardiac ischemic conditions (HR 1.39; 95% CI, 1.06-1.80; P = .02, and HR 1.94; 95% CI, 1.50-2.51; P <.001), respectively.

CONCLUSIONS

In patients with myocardial injury, the most common associated conditions were noncardiac or multifactorial. Of notice, these patients had significantly higher long-term mortality when compared with those with associated cardiac conditions.

Drug-Induced Rhabdomyolysis with Elevated Cardiac Troponin T

The essential role of cardiac troponin in the diagnosis of acute myocardial infarction has led to the development of high-sensitivity assays, which are able to detect very small amounts of myocardial necrosis. The high-sensitivity cardiac troponin T assay, however, is not entirely specific for myocardial injury. This case report describes a 48-year-old woman, who, two years after cardiac transplantation, presented with rhabdomyolysis. During the course of the disease, her troponin T level was elevated on repeated occasions, but other definitive evidence of myocardial injury was not found. Asymptomatic cardiac troponin T elevations during rhabdomyolysis may be due to either cardiac involvement or false positive results stemming from skeletal muscle injury.

Troponin elevation after black widow spider envenomation

Black widow spider envenomation generally results in self-limiting pain that can be treated in the emergency department (ED) with analgesics and benzodiazepines, usually with no further intervention. Occasionally, a patient has to be admitted or treated with antivenom for refractory pain or a venom-induced complication. We present the case of an 84-year-old man who presented to our ED with chest pain and dyspnea after being bitten on the foot by a western black widow spider (Lactrodectus hesperus). His initial cardiac troponin I (cTnI) was elevated at 0.07 ng/ml and continued to rise to a peak of 0.17 ng/ml. He also had rhabdomyolysis, another uncommon complication of black widow envenomation. An elevated cTnI generally signifies myocardial injury and is rarely seen after black widow envenomation. We discuss the possible etiologies for an elevated cardiac biomarker, in this context, and review potentially serious complications of widow spider envenomation presenting with chest symptoms and an elevated cardiac biomarker.

Severe human poisoning with a flufenoxuron-containing insecticide: Report of a case with transient myocardial dysfunction and review of the literature

CONTEXT

Flufenoxuron (Cascade™) is a new benzoylurea insecticide. We describe a case of human poisoning with previously unreported cardiac complications and review other case reports in the literature.

CASE DETAILS

A 54-year-old stuporous man who had ingested a flufenoxuron-containing insecticide presented to the emergency department with severely unstable vital signs and lactic acidosis which continued to worsen over time. He was treated with gastric lavage and infusion of sodium bicarbonate, crystalloid, and dopamine. The patient was initially unresponsive, but recovered from shock after norepinephrine treatment. While electrocardiography showed no abnormal findings, cardiac enzymes remained elevated for several days. Initial echocardiography showed global left ventricular hypokinesia and a left ventricular ejection fraction of 40%, but echocardiography after 45 h showed normal results. On the sixth day, he was discharged after rejecting medical advice for further evaluation.

DISCUSSION

Severe lactic acidosis, shock, elevation of cardiac enzymes, and global left ventricular hypokinesia can occur in human poisoning with flufenoxuron-containing insecticide, and norepinephrine is preferable for the management of shock.

Potassium toxicity at low serum potassium levels with refeeding syndrome

Refeeding syndrome is a life-threatening condition occurring in severely malnourished patients after initiating feeding. Severe hypophosphatemia with reduced adenosine triphosphate production has been implicated, but little data are available regarding electrolyte abnormalities. In this case, we report electrocardiographic changes consistent with hyperkalemia during potassium replacement after a serum level increase from 1.9 to 2.9 mEq/L. This was reversed by lowering serum potassium back to 2.0 mEq/L. In conclusion, the patient with prolonged malnutrition became adapted to low potassium levels and developed potassium toxicity with replacement.

Peripheral blood miRNAs as a biomarker for chronic cardiovascular diseases

Vascular diseases are the most prevalent diseases worldwide. This study intended to analyze peripheral blood miRNA levels and their correlation with NT-pro-BNP and cTN-I in patients with atherosclerosis or pre-atherosclerotic conditions to build a dynamic correlation between vascular diseases and their biomarkers. Serum NT-pro-BNP and cTN-I levels were measured by their respective ELISA kits. The miRNA levels were assayed by quantitative PCR. Unique miRNA signatures were identified for both atherosclerosis and pre-atherosclerosis. The levels of miR-92a, 126, 130a, 222, and 370 levels were decreased in the peripheral blood of pre-atherosclerotic subjects. In atherosclerosis, miR-21, 122, 130a, and 211 were significantly increased whereas miR-92a, 126, and 222 were markedly decreased. Serum levels of NT-pro-BNP and cTN-I correlated with each other and increased with the progression of atherosclerosis. Moreover, the levels of cTN-I and NT-pro-BNP were positively correlated with miR-21 and negatively correlated with miR-126. Integrating specific pattern of miRNA levels with NT-pro-BNP and/or cardiac troponin may improve the diagnosis of cardiovascular diseases.

Myopericarditis and exertional rhabdomyolysis following an influenza A (H3N2) infection

BACKGROUND

Acute myopericarditis and exertional rhabdomyolysis, two uncommon but well-described diseases with potentially life-threatening effects, are generally considered as independent clinical entities. However, they may in fact be pathophysiologically related under certain circumstances. This is the first ever report of influenza myopericarditis provoked by exertional rhabdomyolysis to the best of our knowledge.

CASE PRESENTATION

A 25-year-old immunocompetent Chinese man presented with bilateral leg pain, dizziness, and shortness of breath on admission soon after completing vigorous training comprising running drills. Exertional rhabdomyolysis was diagnosed with 44 fold high serum creatine phosphokinase. Then he developed chest pain, pericardial effusion, changes of electrocardiography and positive troponin I suggestive of myopericarditis. Influenza A (H3N2) virus infection was confirmed by polymerase chain reaction analysis of nasopharyngeal wash samples. Other possible infective and autoimmune causes were excluded. Patient recovered completely with anti-inflammatory therapy and the supportive care.

CONCLUSION

This case suggests that clinicians who treat patients with exertional rhabdomyolysis should be aware of the potential vulnerability to acute myopericarditis, especially in the presence of recent influenza A infection.

Elevated cardiac troponin T contributes to prediction of worse in-hospital outcomes after endovascular therapy for acute limb ischemia

INTRODUCTION

The present study evaluated whether elevated cardiac troponin T (cTnT) was predictive of an increased risk for death or amputation in patients with acute lower limb ischemia (ALI). ALI is one of the most frequent causes of amputation, with mortality rates for ALI ranging from 15% to 20%.

METHODS

This study included 254 consecutive ALI patients (155 men, 99 women; mean age, 71.6 ± 13.2 years) presenting with Rutherford categories I, IIA, or IIB according to the classification for ALI.

RESULTS

ALI was caused by thromboembolism (29.5%), local arterial thrombosis (53.1%), or bypass graft occlusion (16.9%). Restoration of arterial blood flow was obtained by an endovascular approach, with a primary success rate of 98.4%. Rates were low for in-hospital mortality (3.9%) and amputation (5.1%). Patients who died or required amputation more frequently presented with elevated cTnT ≥0.01 ng/mL (52.2% vs 25.5%, P = .01) and impaired renal function (chronic kidney disease stage 3-5; 60.9% vs 38.1%; P = .04). After controlling for age, sex, C-reactive protein, renal function, presence or absence of coronary artery disease, and traditional vascular risk factors, as well as the interval between symptom onset and revascularization, the relationship between cTnT and a worse in-hospital outcome remained significant (hazard ratio, 3.4; 95% confidence interval, 1.3-8.5; P = .010).

CONCLUSIONS

ALI patients frequently have elevated cTnT, which is associated with increased in-hospital mortality and amputation. Even small cTnT elevations predict a markedly increased risk of worse in-hospital outcome; however, the overall mortality and amputation rate in our study was low.

Prognostic significance of troponin T elevation in patients without chest pain

Increased cardiac troponin with chest pain is important for the diagnosis, triage, and treatment of patients in the emergency department. However, the use of troponin for the diagnosis and triage of patients without chest pain is poorly established. The aim of this study was to determine 30-day and 1-year mortality and morbidity of troponin T increases in patients without chest pain. This retrospective study compared 92 hospitalized patients without (study group) and 91 patients with chest pain (control group), followed up for 1 year. Study group patients had troponin T >0.04 microg/L, normal creatine kinase or creatine kinase-MB fraction <5%, and no electrocardiographic ischemia. Excluded were high-risk patients with end-stage kidney disease, those with left ventricular ejection fraction <40%, and the critically ill. Outcome variables included 30-day and 1-year death, myocardial infarction, unstable angina, and coronary revascularization rates. Thirty-day (13.0% vs 4.4%; p = 0.032) and 1-year (33% vs 4.6%; p <0.001) mortality rates were significantly higher in the study group, whereas myocardial infarction, unstable angina, and revascularization were infrequent. In conclusion, patients with increased troponin T and no chest pain had a high mortality rate and required careful follow-up.

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.

Valeurs de la troponine I au cours des rhabdomyolyses chez les personnes âgées admises aux urgences

OBJECTIVE

The objective of this study was to assess the utility of determining serum cardiac troponin I (TcI) levels in the elderly.

METHODS

During the nine-month study period, all patients older than 70 years admitted to the emergency department presenting rhabdomyolysis (defined by creatine kinase>500 IU/L) were included in this prospective descriptive study, except for those with acute coronary syndrome or pulmonary embolism. Patients were classified into two groups according to their serum TcI level:>0.15 or<or=0. 15 ng/mL. The groups were compared for clinical, laboratory and treatment variables at inclusion and for mortality at six months.

RESULTS

The study included 67 patients: 30 in the group with TcI>0.15 ng/mL group and 37 in the other group. Clinical and laboratory indicators were similar in the two groups. In contrast, significantly more patients in the TcI>0.15 ng/mL group had been treated with a curative dose of heparin (14 versus 2, p=0.01). This difference between the two groups was noted in both the emergency department and other hospital units. Serum TcI levels were not correlated with creatine kinase levels. Concordance between emergency department diagnosis and discharge diagnosis was 95%. No patient was discharged with a diagnosis of acute coronary syndrome; one patient, with a serum TcI level<or=0.15 ng/mL, was diagnosed with a pulmonary embolism. Fewer than half the patients underwent cardiac ultrasonography. Segmental hypokinesia was observed in only a few cases (6% in the TcI>0. 15 ng/mL group versus 8% in the other group). Mortality at six months was higher among patients with an elevated serum TcI level, but the difference was not significant (23% versus 8%, p=0.07).

CONCLUSION

This study indicated a trend toward higher mortality among patients with elevated serum TcI levels, although the factors underlying these increased concentrations remain unclear.

Rhabdomyolysis in an obese patient after total knee arthroplasty

We report the case of a morbidly obese patient who developed rhabdomyolysis with acute renal failure, hepatic dysfunction, and an increase of cardiac troponin-1 after total knee arthroplasty. Postoperative rhabdomyolysis has a wide range of triggers and differential diagnoses that should be considered by the anaesthesiologist and surgeons. We would like to emphasize that morbidly obese patients have an increased risk of developing postoperative rhabdomyolysis potentially leading to life-threatening disease. Intensified postoperative observation seem justified in these patients.

Role of biochemical markers in diagnosis of myocardial infarction

An ideal cardiac biochemical marker should have not only high sensitivity but also high specificity to myocardial infarction. The creatine kinase-MB, a relatively specific cardiac marker, could be elevated in situations other than acute myocardial infarction, such as renal failure, muscular injury, and myopathy. Although these are more specific than creatine kinase-MB, cardiac troponins have also been reported to be elevated in conditions other than acute myocardial infarction, such as chronic renal failure, acute myocarditis, cardiomyopathy, congestive heart failure, pulmonary embolism, rhabdomyolysis, sepsis, and left ventricular hypertrophy. With the ongoing research in this field, future holds hopes of finding an ideally specific marker of myocardial infarction, but until then biochemical markers should be used in conjunction with clinical assessment and electrocardiography in making the diagnosis of myocardial infarction, and the patients should not be treated merely on the basis of elevated serum levels of cardiac biochemical markers.

The prevalence of false-positive cardiac troponin I in ED patients with rhabdomyolysis

OBJECTIVE

Cardiac troponin I (cTnI) is considered the most specific marker of cardiac muscle injury. We encountered several patients with rhabdomyolysis and elevated cTnI, although they did not otherwise have evidence of cardiac injury. We determined the prevalence of false-positive cTnI in emergency department (ED) patients with rhabdomyolysis.

METHODS

We conducted a retrospective cohort study of ED patients admitted with a diagnosis of rhabdomyolysis. Patients were included in the study if they had a serum creatine kinase (CK) of 1000 U/L or greater and at least one serum cTnI determination. Patients with positive cTnI were considered true positives if they had either electrocardiography (EKG) or echocardiography abnormalities; false positives if both the EKG and the echocardiography were considered normal; or indeterminate if they did not have both an EKG and an echocardiogram. The primary outcome of the study was the prevalence of false-positive cTnI. Secondary outcomes included risk stratification by cocaine use, myoglobinuria, and renal failure and correlation of peak CK and troponin levels.

RESULTS

One hundred nine patients were included in the final analysis; 55 (50%) patients had a positive cTnI. Of the 55 patients with positive cTnI, 32 (58%) were true positives, 18 (33%) were false positives, and 5 (9%) were indeterminate. The prevalence of false-positive cTnI was 17% (18/109, 95% confidence interval 0.10-0.25). There was no association between false-positive cTnI and cocaine use, renal failure, or myoglobinuria. There was poor correlation between peak CK and peak cTnI levels (r = -.08, 95% confidence interval -0.34 to 0.19).

CONCLUSION

The prevalence of false-positive cTnI in ED patients with rhabdomyolysis is 17%.

Coup de chaleur d'exercice avec hépatite fulminante : intérêt du système MARS® ?

Exertional heat stroke (EHS) is a life-threatening condition caused by an extreme elevation in core body temperature. Acute liver failure has been reported during EHS justifying liver transplantation in some cases. The Molecular Adsorbent Recirculating System (MARS) could be indicated in such situations. We report a case of a 58-year old patient who suffered acute liver failure occurring after EHS. The patient was referred for liver transplantation and benefited of MARS therapy. After three sessions of MARS, liver function improved progressively and the transplantation was not necessary. The patient completely recovered.