Biochemical Markers Of Myocardial Injury Research Articles

Significance of biochemical markers of myocardial injury in patients with acute myocardial infarction and COVID-19

Significance of biochemical markers of myocardial injury in patients with acute myocardial infarction and COVID-19

Study of Postmortem Pericardial Fluid Concentrations of Troponin T (cTnT) in Sudden Natural Death

Background: Cardiovascular diseases are the most common cause of sudden natural deaths. Cardiac troponin T is a specific biochemical marker of myocardial injury. It may help in diagnosis of early myocardial ischemia when macroscopic or microscopic evidence of necrosis is not available after autopsy. Aim of this study was to assess the effectiveness of pericardial fluid troponin T in predicting the cause of death in sudden natural death and in estimating the post mortem interval. Materials and methods: It was a pilot study. Sudden natural deaths brought to Forensic Medicine department of GMCH Nagpur for autopsy were included in this observational cross sectional study. Deaths were grouped into cardiac and non cardiac deaths. Pericardial fluid samples were collected by opening pericardial sac with sterile syringe and processed on Roche Cobas e411 autoanalyzer for estimation of levels of Troponin T. Results: There was a statistically significant difference seen for the values between the groups (p<0.05) for Trop-T (ng/ml) with higher values in Cardiac cause. There was a statistically non significant correlation between postmortem interval vs Trop T (p>0.05). Conclusion: Estimation of pericardial fluid Troponin-T may be used to predict the cause of death in sudden natural death.

Combining anatomical and biochemical markers in the detection and risk stratification of coronary artery disease.

We aimed to test the hypothesis if combining coronary artery calcium score (Ca-score) as a quantitative anatomical marker of coronary atherosclerosis with high-sensitivity cardiac troponin as a quantitative biochemical marker of myocardial injury provided incremental value in the detection of functionally relevant coronary artery disease (fCAD) and risk stratification. Consecutive patients undergoing myocardial perfusion single-photon emission computed tomography (MPS) without prior CAD were enrolled. The diagnosis of fCAD was based on the presence of ischaemia on MPS and coronary angiography; fCAD was centrally adjudicated in the diagnostic and prognostic domain. Diagnostic accuracy was evaluated using the area under the receiver-operating characteristic curve (AUC). The composite of cardiovascular death and non-fatal acute myocardial infarction (AMI) within 730 days was the primary prognostic endpoint. Among 1715 patients eligible for the diagnostic analysis, 399 patients had fCAD. The combination of Ca-score and high-sensitivity cardiac troponin T (hs-cTnT) had good diagnostic accuracy for the diagnosis of fCAD (AUC 0.79, 95% confidence interval (CI) 0.77-0.81), but no incremental value compared with the Ca-score alone (AUC 0.79, 95% CI 0.77-0.81, P = 0.965). Similar results were observed using high-sensitivity cardiac troponin I (AUC 0.80, 95% CI 0.77-0.82) instead of hs-cTnT. Among 1709 patients (99.7%) with available follow-up, 59 patients (3.5%) suffered the composite primary prognostic endpoint (non-fatal AMI, n = 34; CV death, n = 28). Both Ca-score and hs-cTnT had independent prognostic value. Increased risk was restricted to patients with elevation in both markers. The combination of the Ca-score with hs-cTnT increases the prognostic accuracy for future events but does not provide incremental value vs. the Ca-score alone for the diagnosis of fCAD. Clinical trial registration: NCT00470587.

Assessing Myocardial Involvement in Systemic Lupus Erythematosus Patients without Cardiovascular Symptoms by Technetium-99m-sestamibi Myocardial Perfusion Imaging: A Correlation Study on NT-proBNP.

In patients with systemic lupus erythematosus (SLE), myocardial involvement is the third leading course of death after lupus nephropathy (LN) and infections. Previous autopsy studies have demonstrated a high incidence of cardiovascular abnormalities in the myocardium. However, the patients with typical symptoms are far much fewer than expected from post-mortem examinations. The current study aimed to evaluate the technetium-99m-sestamibi (99mTc-MIBI) gated myocardial perfusion imaging (GMPI) characteristics of lupus patients without cardiovascular symptoms, and the relationships between GMPI characteristics and biochemical markers of myocardial injury, and to explore the role of GMPI in assessing myocardial involvement. Thirty patients were studied with rest myocardial perfusion imaging, and summed rest score (SRS), summed motion score (SMS), and summed thickening score (STS) were calculated automatically. Biomarkers, including N-terminal prohormone of brain natriuretic peptide (NT-proBNP) and creatine-kinase-MB (CK-MB), were detected simultaneously. GMPI parameters, LV functions and biomarkers were compared between two NT-proBNP groups. The relationships between these parameters were studied by correlation analysis. SMS, STS, and glomerular filtration rate (eGFR) were the main influencing factors of NTproBNP level (p = 0.001, <0.001, 0.042, respectively). Thirteen patients with an evaluated concentration of NT-proBNP had the lower left ventricular ejection fraction (LVEF), peak filling rate (PFR), eGFR and higher levels of CK-MB (in all comparisons, p < 0.05), and SRS was the only influencing factor of NT-proBNP (p = 0.007). Within thirteen patients with SRS≥2, there was a significant correlation between SRS and NT-proBNP (p < 0.001). 99mTc-MIBI GMPI could evaluate the left ventricular function and prompt the cardiomyocyte function at the cellular level. SMS and STS were the main influencers for plasma NT-proBNP, and SRS was the independent factor for elevated NT-proBNP. This radionuclide imaging method could provide additional diagnostic information on myocardial involvement in patients with SLE.

THE IMPORTANCE OF MYOSIN AND ACTIN CALCIUM-DEPENDENT REGULATORY COMPLEX MARKERS IN THE CLINICAL AND DIAGNOSTIC MANAGEMENT OF ACUTE MYOCARDIAL INFARCTION

Currently cardiovascular diseases are one of the main causes of mortality worldwide, one of the most important is the Acute Myocardial Infarction (AMI), its early diagnosis for patient survival is extremely necessary. Biochemical markers of myocardial injury have the function of facilitating the diagnosis of these cardiac events. The present study aimed to evaluate the accuracy, as well as the limitations of the cardiac biomarkers of troponins and myoglobin as an aid in acute myocardial infarction. It was possible to observe that recently, troponins have received increasing attention as extremely specific markers of cellular injury, these form a complex that regulates the calcium-dependent interaction of myosin with actin, being constituted of three different proteins (troponin I, C and T ) existing in both skeletal and cardiac muscle and encoded by different genes. Acute circulatory failure causes cellular changes that can vary from small losses of some membrane properties to cell death. With this it is possible to conclude that in some intracellular substances gain the interstitial space and blood circulation, resulting in a transient increase in circulating levels, aspartate aminotransferase, myoglobin, creatine kinase, lactic dehydrogenase, troponins, among others, being identified as cardiac injury markers represent great tools that help in the diagnosis of acute myocardial infarction

BRD4 Inhibition Protects Against Myocardial Ischemia/Reperfusion Injury by Suppressing Inflammation and Oxidative Stress Through the PI3K/AKT Signaling Pathway.

:This study aims to investigate the effect and the related mechanisms of bromodomain-containing protein 4 (BRD4) inhibition on myocardial ischemia/reperfusion (I/R) injury. In vivo and in vitro myocardial I/R models were constructed. Expression of BRD4 was examined by RT-qPCR and Western blot. I/R injury was evaluated by analyzing cardiac function and the activity of biochemical markers of myocardial injury. Inflammation and oxidative stress were determined by measuring the levels of myeloperoxidase, TNF-α, IL-6, malondialdehyde, and superoxide dismutase. The activation of the PI3K/AKT signaling pathway was tested by the phosphorylation of p85 and AKT. We found BRD4 was significantly increased in the myocardial tissues after myocardial I/R injury. BRD4 inhibition suppressed the indices of cardiac function and the biochemical markers of myocardial injury. I/R-induced inflammation and oxidative stress were suppressed by shBRD4 in vivo and in vitro. In addition, BRD4 inhibition significantly increased the relative protein expression levels of p-p85, p-AKT T308, and p-AKT S473. In conclusion, this study for the first time demonstrated the protective effect of BRD4 inhibition on myocardial I/R injury in vivo and in vitro, and this effect was related to the suppression of inflammation and oxidative stress through the activation of the PI3K/AKT signaling pathway.

Carbon Monoxide Releasing Molecule A1 Reduces Myocardial Damage After Acute Myocardial Infarction in a Porcine Model.

Infarct size is a major determinant of outcomes after acute myocardial infarction (AMI). Carbon monoxide-releasing molecules (CORMs), which deliver nanomolar concentrations of carbon monoxide to tissues, have been shown to reduce infarct size in rodents. We evaluated efficacy and safety of CORM-A1 to reduce infarct size in a clinically relevant porcine model of AMI. We induced AMI in Yorkshire White pigs by inflating a coronary angioplasty balloon to completely occlude the left anterior descending artery for 60 minutes, followed by deflation of the balloon to mimic reperfusion. Fifteen minutes after balloon occlusion, animals were given an infusion of 4.27 mM CORM-A1 (n = 7) or sodium borate control (n = 6) over 60 minutes. Infarct size, cardiac biomarkers, ejection fraction, and hepatic and renal function were compared amongst the groups. Immunohistochemical analyses were performed to compare inflammation, cell proliferation, and apoptosis between the groups. CORM-A1-treated animals had significant reduction in absolute infarct area (158 ± 16 vs. 510 ± 91 mm2, P < 0.001) and infarct area corrected for area at risk (24.8% ± 2.6% vs. 45.2% ± 4.0%, P < 0.0001). Biochemical markers of myocardial injury also tended to be lower and left ventricular function tended to recover better in the CORM-A1 treated group. There was no evidence of hepatic or renal toxicity with the doses used. The cardioprotective effects of CORM-A1 were associated with a significant reduction in cell proliferation and inflammation. CORM-A1 reduces infarct size and improves left ventricular remodeling and function in a porcine model of reperfused MI by a reduction in inflammation. These potential cardioprotective effects of CORMs warrant further translational investigations.

Interventions related to cardiovascular complications in people hospitalized by covid-19: a scoping review.

To describe the scientific evidence of complications and the need for cardiovascular interventions in people hospitalized by Covid-19. a scoping review carried out according to The Joanna Briggs Institute recommendations, in the MEDLINE, CINAHL, SCOPUS and Web of Science databases. A total of 11 published studies from December of 2019 to April of 2020, presenting low levels of evidence were selected. The evidence described the myocardial injury as the most common cardiac complication reported in Covid-19, reported in approximately 8% to 12% of all severe individuals, with indications for oxygen therapy interventions, thrombotic disorders prevention and treatment, hemodynamic monitoring and assessment tests of cardiac function's performance, along with biochemical markers of myocardial injury, yet not addressing nursing interventions. Cardiovascular complications and interventions have not shown consensus on the found evidence, requiring causal analysis by explanatory studies that support multi-professional clinical protocols in health.

Risk stratification vs routine intensive care stay in non ST segment elevation myocardial infarction (NSTEMI)

Non-ST-segment-elevation acute coronary syndromes (NSTE ACS) encompass a wide spectrum of clinical conditions characterised by acute ischemic symptoms, electrocardiographic signs of myocardial ischemia (which may or may not be evident), and elevation of the biochemical markers of myocardial injury: when troponin values are within normal range, the case will be defined as unstable angina, if this clinical entity has not been declared deceased after the introduction of high-sensitivity troponin measurements [1].

The remodelling index risk stratifies patients with hypertensive left ventricular hypertrophy.

Aims Hypertensive left ventricular hypertrophy (LVH) is associated with increased cardiovascular events. We previously developed the remodelling index (RI) that incorporated left ventricular (LV) volume and wall-thickness in a single measure of advanced hypertrophy in hypertensive patients. This study examined the prognostic potential of the RI in reference to contemporary LVH classifications.Methods and results Cardiovascular magnetic resonance was performed in 400 asymptomatic hypertensive patients. The newly derived RI (, where EDV is LV end-diastolic volume and t is the maximal wall thickness across 16 myocardial segments) stratified hypertensive patients: no LVH, LVH with normal RI (LVHNormal-RI), and LVH with low RI (LVHLow-RI). The primary outcome was a composite of all-cause mortality, acute coronary syndromes, strokes, and decompensated heart failure. LVHLow-RI was associated with increased LV mass index, fibrosis burden, impaired myocardial function and elevated biochemical markers of myocardial injury (high-sensitive cardiac troponin I), and wall stress. Over 18.3 ± 7.0 months (601.3 patient-years), 14 adverse events occurred (2.2 events/100 patient-years). Patients with LVHLow-RI had more than a five-fold increase in adverse events compared to those with LVHNormal-RI (11.6 events/100 patient-years vs. 2.0 events/100 patient-years, respectively; log-rank P < 0.001). The RI provided incremental prognostic value over and above a model consisting of clinical variables, LVH and concentricity; and predicted adverse events independent of clinical variables, LVH, and other prognostic markers. Concentric and eccentric LVH were associated with adverse prognosis (log-rank P = 0.62) that was similar to the natural history of hypertensive LVH (5.1 events/100 patient-years).Conclusion The RI provides prognostic value that improves risk stratification of hypertensive LVH.

P962 The Remodeling Index risk stratifies patients with hypertensive left ventricular hypertrophy

Abstract Funding Acknowledgements National Medical Research Council BACKGROUND Hypertensive left ventricular hypertrophy (LVH) is associated with increased cardiovascular events. The authors previously developed the Remodeling Index (RI) that incorporated LV volume and wall-thickness in a single measure of advanced hypertrophy in hypertensive patients. PURPOSE This study examined the mechanisms and prognostic potential of the RI in reference with current LVH classifications. METHODS Cardiovascular magnetic resonance (CMR) was performed in 400 asymptomatic hypertensive patients. The newly derived RI ([(EDV)^1/3]/t; where EDV is LV end-diastolic volume and t is the maximal wall thickness across 16 myocardial segments) stratified hypertensive patients into 3 groups: without LVH, LVH with normal RI (LVH_Normal-RI) and LVH with low RI (LVH_Low-RI). The primary outcome was a composite of all-cause mortality, acute coronary syndromes, strokes and decompensated heart failure. RESULTS LVH_Low-RI was associated with increased LV mass index, fibrosis burden, impaired myocardial function and elevated biochemical markers of myocardial injury and wall stress. Over 18.3 ± 7.0 months (601.3 patient-years), patients with LVH_Low-RI had more than a 5-fold increase in adverse events compared to those with LVH_Normal-RI (11.6 events/100patient-years versus 2.0 events/100 patient-years, respectively; log-rank P &amp;lt; 0.001; Figure A). The RI provided incremental prognostic value over and above a model consisting of clinical variables and LVH (P = 0.02). Conversely concentric and eccentric LVH were associated with adverse prognosis (4.5 events/100patient-years versus 6.0 events/100patient-years, respectively; log-rank P = 0.62) that was similar as the natural history of hypertensive LVH (5.1 events/100patient-years). CONCLUSIONS The RI provides mechanistic insights and prognostic value that improves risk-stratification of hypertensive LVH. Abstract P962 Figure.

Effects of Acute Resistance Training on Biochemical Markers of Myocardial Injury (cTnT, cTnI, CK-MB) in Non-Athlete Women

Background: The purpose of this study was to evaluate the effects of acute resistance training on changes in biochemical markers of myocardial injury (cTnT, cTnI, CK-MB) in non-athlete women. Methods: In this study, 18 healthy young women with a mean age (23.41 years) and body fat percent (21.62) participated voluntarily. Untrained women performed 7 resistance exercises at 70% 1RM in 3 sets and 10 repetitions. Rest interval between sets was 2 minutes. Blood samples were obtained before, immediately, 1, 24, and 48 hours after exercise. Statistical analyses were conducted using ANOVA with repeated measure (P ≤ 0.05). Results: The results revealed a significant difference in troponin I in pre-test immediately and 1 hour after exercise, but 24 hours and 48 hours after, it returned to baseline. There was also a significant difference in troponin T and CK-MB in pre-test immediately and 1 hour and 24 hours after exercise, but they returned to baseline after 48 hours. Conclusions: It can be concluded that resistance exercise may lead to an increase in cardiac troponin and CK iso-enzyme. However, it seems to be a temporary increment and do not cause cardiac damage.

The Effect of High-Dose Vitamin C on Biochemical Markers of Myocardial Injury in Coronary Artery Bypass Surgery.

ObjectiveTo evaluate the effect of high-dose vitamin C on cardiac reperfusion injury and plasma levels of creatine kinase-muscle/brain (CK-MB), troponin I, and lactate dehydrogenase (LDH) in patients undergoing coronary artery bypass grafting (CABG).MethodsThis is a double-blind randomized clinical trial study. Fifty patients (50-80 years old) who had CABG surgery were selected. The intervention group received 5 g of intravenous vitamin C before anesthesia induction and 5 g of vitamin C in cardioplegic solution. The control group received the same amount of placebo (normal saline). Arterial blood samples were taken to determine the serum levels of CK-MB, troponin I, and LDH enzymes. Left ventricular ejection fraction was measured and hemodynamic parameters were recorded at intervals.ResultsHigh doses of vitamin C in the treatment group led to improvement of ventricular function (ejection fraction [EF]) and low Intensive Care Unit (ICU) stay. The cardiac enzymes level in the vitamin C group was lower than in the control group. These changes were not significant between the groups in different time intervals (anesthesia induction, end of bypass, 6 h after surgery, and 24 h after surgery) for CK-MB, LDH, and troponin I. Hemodynamic parameters, hematocrit, potassium, urinary output, blood transfusion, arrhythmia, and inotropic support showed no significant difference between the groups.ConclusionVitamin C has significantly improved the patients’ ventricular function (EF) 72 h after surgery and reduced the length of ICU stay. No significant changes in cardiac biomarkers, including CK-MB, troponin I, and LDH, were seen over time in each group.IRCT codeIRCT2016053019470N33

Several clinical hotspots in the diagnosis and treatment of myocardial injury and myocarditis in children

Myocardial injury and myocarditis are the two diagnostic words frequently used by pediatricians, myocardial enzymes and cardiac troponin are also frequently detected in laboratory tests.But up to now, some pediatricians still lack a comprehensive understanding of the clinical significance of cardiac enzymes and their isoenzymes.There are still some misunderstandings about how to interpret the test results correctly.Currently, it is not uncommon for myocardial injury and myocarditis to be over-diagnosed and over-treated.In addition, new biochemical markers of myocardial injury (cardiac troponin and highly sensitive troponin) are not well understood.This paper discussed the above clinical hot issues and introduced the related progress.It is expected that correct cognition can guide the diagnosis and treatment of myocardial injury and myocarditis in children in the future. Key words: Myocardial injury; Myocarditis; Myocardial enzymes; Cardiac troponin; Biochemical marker; Children

Association between serum concentration of parathyroid hormone and left ventricle ejection fraction, and markers of heart failure and inflammation in ST elevation myocardial infarction patients treated with primary percutaneous coronary intervention

Background/Aim. Previous studies have shown increased serum concentration of parathyroid hormone (PTH) in acute myocardial infarction and heart failure. In this study we examined the relation-ships between parathyroid hormone status and biochemical markers of myocardial injury and heart failure, as well as electrocardio-graphic (ECG) and echocardiographic indicators of infarction size and heart failure. Methods. In 390 consecutive patients with ST segment elevation myocardial infarction (STEMI), average age 62 ? 12 years, laboratory analysis of serum concentrations of creatine kinase MB isoenzyme (CK-MB), C-reactive protein (CRP) and in-tact PTH and plasma concentration of brain natriuretic peptide (BNP) were done during the first three days after admission. All patients were treated with primary percutaneous coronary intervention (PCI). Exclusion criterion was severe renal insufficiency (glomerular filtration rate ? 30 mL/min). Serum concentration of PTH was measured on the 1st, 2nd and, in some cases, on the 3rd morning after admission and maximum level of PTH was taken for analysis. Patient cohort was divided into four groups according to quartiles of PTH maximum serum concentration (I ? 4.4 pmol/L; II &gt; 4.4 pmol/L and &lt; 6.3 pmol/L; III ? 6.3 pmol/L and &lt; 9.2 pmol/L; IV ? 9.2 pmol/L). Selvester?s ECG score, left ventricle ejection fraction and wall motion index (WMSI) were determined at discharge between 5?14 days after admission. Results. We found that LVEF at discharge significantly decreased (p &lt; 0.001) and WMSI at discharge and ECG Selvester?s score significantly increased across the quartiles of PTH max. level (p &lt; 0.001 for both parameters). BNP, CRP and CK-MB isoenzyme level significantly increased across the quartiles of PTH max. level (p &lt; 0.001; p &lt; 0.001 and p = 0.004, retrospectively). Conclusion. The patients in the 4th quartile of PTH had significantly lower LVEF and higher WMSI and Selvester?s ECG score at discharge. This group of patients also had higher levels of BNP, CRP and CK-MB in blood in the early course of STEMI.

Tolerance of isolated rabbit hearts to short ischemic periods is affected by increased LV mass fraction.

Hypertrophied hearts are known for increased risk of arrhythmias and are linked with reduced ischemic tolerance. However, still little is known about state characterized only by increased left ventricle (LV) mass fraction. Seventeen isolated rabbit hearts with various LV mass were divided into two groups according to LV weight/heart weight ratio (LVW/HW ratio), namely group H and L (with higher and lower LVW/HW ratio, respectively) and underwent three short cycles of global ischemia and reperfusion. The differences in electrogram (heart rate, QRS(max), mean number, onset and dominant form of ventricular premature beats) and in biochemical markers of myocardial injury (creatine kinase, lactate dehydrogenase - LDH) and lipid peroxidation (4-hydroxy-2-nonenal - 4-HNE) were studied. As compared to group L, hearts in group H exhibited lower tolerance to ischemia expressed as higher incidence and severity of arrhythmias in the first ischemic period as well as increase of LDH and 4-HNE after the first reperfusion. In the third cycle of ischemia-reperfusion, the preconditioning effect was observed in both electrophysiological parameters and LDH release in group H. Our results showed consistent trends when comparing changes in electrograms and biochemical markers. Moreover, 4-HNE seems to be good potential parameter of moderate membrane alteration following ischemia-reperfusion injury.

The Effectiveness of Preoperative Trimetazidine on Myocardial Preservation in Coronary Artery Bypass Graft Patients: A Systematic Review and Meta-Analysis

Background: Coronary artery bypass grafting (CABG) is a key and effective surgical treatment modality for coronary artery disease. Unfortunately, ischemia-reperfusion injury during and after CABG can lead to reversible and irreversible myocardial damage. Trimetazidine [1-(2,3,4-trimethoxybenzyl)piperazine dihydrochloride] is a metabolic anti-ischemic agent with demonstrated cardioprotective effects; however, its effects with respect to myocardial preservation in CABG patients remain unclear. Methods: We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) to investigate the effectiveness of myocardial preservation of preoperative trimetazidine therapy in CABG patients by assessing the postoperative levels of several blood-based biochemical markers of myocardial injury, including creatine kinase (CK), creatine kinase-muscle and brain (CK-MB), creatine phosphokinase (CPK), troponin T (TnT) and troponin I (TnI). The RCTs were classified into two subgroup analyses by the timing of sample collection (either ≤12 or >12 h after CABG). Results: Six RCTs were finally included in the meta-analysis. The pooled effect sizes showed significantly lower postoperative levels of CK, CK-MB, TnT and TnI in the trimetazidine-treated CABG patients relative to control CABG patients. However, there were no significant differences in the postoperative CPK levels between trimetazidine-treated CABG patients relative to control CABG patients. In both the ≤12 and >12 h post-CABG subgroup analyses, significant differences in CK, CK-MB, TnT and TnI were detected between the trimetazidine-treated CABG patients relative to control CABG patients. Conclusions: Preoperative trimetazidine therapy appears to have a positive effect on myocardial preservation in CABG patients.

AVALIAÇÃO DOS MARCADORES DE LESÃO MIOCÁRDICA SOLICITADOS EM HOSPITAL PAULISTA

A mensuração dos marcadores bioquímicos de necrose miocárdica é essencial para diagnosticar precocemente o Infarto Agudo do Miocárdio e garantir um melhor prognóstico ao paciente. No entanto, cada marcador possui um perfil, que deve se adequar às características do quadro clínico que está sendo avaliado. Sendo assim, o objetivo do presente trabalho foi verificar o perfil de solicitações de marcadores cardíacos séricos junto ao laboratório clínico do Hospital Heliópolis, e discutir as implicações de tais escolhas. Por meio da verificação dos mapas de resultados do laboratório, foi feito um levantamento dos marcadores bioquímicos de lesão miocárdica solicitados, em um período de três meses, de pacientes admitidos no pronto socorro com sintomas sugestivos de um evento cardíaco isquêmico. Do total de 2242 exames provenientes de 1084 pacientes, 47% eram para CK total, 43% para CK-MB e 10% para troponinas, não havendo solicitações de dosagem de mioglobina durante o período estudado. Do total de exames solicitados e alterados, a maioria referiu-se a pacientes do gênero masculino. O presente artigo sugere que no momento da admissão do paciente no serviço de emergência, haja a solicitação combinada da mioglobina e um marcador mais específico de necrose miocárdica (CK-MB) para a exclusão precoce de um infarto do miocárdio. Isto seria, além de eficaz para o diagnóstico, uma maneira mais viável financeiramente. Neste contexto, uma atenção especial deveria ser dada às mulheres atendidas com sintomas isquêmicos, tendo em vista a alta taxa de mortalidade a elas associada.

Obstructive sleep apnea: no independent association to troponins

Cardiac troponins (cTn) are to date the most sensitive and specific biochemical markers of myocardial injury. Abnormal breathing patterns in patients with obstructive sleep apnea (OSA) may cause myocardial cell stress detectable by novel cTn assays. The objectives of this study were to investigate whether a new single-molecule cTnI (S-cTnI) assay and a commercially available high-sensitivity cTnT (hs-cTnT) assay would detect myocyte injury in individuals evaluated for possible OSA, and to explore their relation to variables of disordered breathing during sleep. Consecutive individuals referred to Lovisenberg Diakonale Hospital's sleep laboratory between 1 October 2009 and 1 March 2010 were included. We measured cTn in specimens collected the morning after sleep and studied these in relation to variables recorded during polygraphy or polysomnography. All 222 (100 %) individuals had measurable cTn levels using either assay. Stratified into categories according to the apnea-hypopnea index (AHI), patients with OSA (AHI ≥5) had a different distribution of S-cTnI (P = 0.036) and hs-cTnT (P = 0.002) compared to those without (AHI <5). The median (quartiles 1-3) were 3.0 (1.9-6.0) versus 2.3 (1.6-3.8) ng/l for S-cTnI, and 7.0 (5.5-8.7) versus 6.2 (4.9-7.2) ng/l for hs-cTnT. However, in multiple median regression analyses adjusted for conventional predictors, neither S-cTnI (P = 0.57) nor hs-cTnT (P = 0.80) were significantly associated with AHI. This study reveals no association independent of conventional predictors between OSA and myocardial cell injury measured by S-cTnI and hs-cTnT assays. Our findings support a search for novel biomarkers for prognostication of OSA.

Speckle tracking derived strain in infants with severe perinatal asphyxia: a comparative case control study

BackgroundSpeckle tracking echocardiography is increasingly being used to assess cardiac function in neonates. The objective was to compare speckle tracking strain indices between asphyxiated infants and healthy controls and to ascertain correlations between strain and 2D Doppler derived indices and cardiac troponin (biochemical marker of myocardial injury).MethodsClinical and echocardiographic data from severely asphyxiated infants undergoing therapeutic hypothermia was evaluated retrospectively. This was compared with prospective data from healthy infants. Correlations between variables were assessed using Pearson’s coefficient of correlation.ResultsTwenty four infants with severe perinatal asphyxia were admitted during the study period of which 3 were not cooled and were excluded. The gestational age and birth weights of cases and controls were comparable. The mean left ventricular global longitudinal strain (GLS) from apical 4 chamber view was noted to be significantly impaired in the asphyxiated infants (– 11.01% ± 2.48 vs – 21.45% ± 2.74, p <0.001). Cardiac output was significantly lower in the asphyxiated infants (97 ± 26 vs 230 ± 60 ml/kg/min). In asphyxiated infants, GLS correlated positively with cardiac output (r2 = 0.86, p< 0.001) and negatively with serum troponin levels (r2 = 0.64, p< 0.001). GLS was less impaired in infants on inotropes compared to those not on inotropic support, -12.55% (1.9) vs -10.2% (1.3), p= 0.018. Infants who died had a lower global strain value compared to survivors, – 9.7% (1.6) vs – 12.8% (2.6), p = 0.02.Conclusions2D Speckle derived strain was impaired in asphyxiated infants. Significant correlations between GLS and cardiac output and troponin were noted.