Role of NT-proBNP and Troponin I in Assessing the Severity of Pulmonary Embolism

Introduction: Pulmonary embolism is a diagnostic and therapeutic emergency that can be life-threatening. Its mortality is largely attributable to severe forms classically defined by clinical and morphological criteria. The aim of this study is to establish the role of two cardiac biomarkers (NT-proBNP and troponin) in assessing the severity of pulmonary embolism. Patients and Methods: We conducted a descriptive and analytical cross-sectional study. Data collection was retrospective over the period from January 1, 2011 to December 31, 2021. All patients hospitalized for pulmonary embolism in two cardiology referral clinics in Cotonou (Atinkanmey Polyclinic and CICA Clinic) were included. Results: The hospital prevalence of pulmonary embolism was 9.08%. The mean age was 52.6 years, with extremes of 18 and 92 years. The sex ratio was 0.73. Pulmonary embolism was severe according to hemodynamic, morphological and sPESI criteria in 12%, 24% and 39% of cases respectively, and mortality was 61.53%. Mean NT-ProBNP and troponin I levels were significantly higher in patients with severe criteria than in those without. NT-proBNP and troponin had good specificity for predicting cardiovascular arrest (99% and 90%), shock (100% and 98%), and hypotension (99% and 96%). NT-proBNP has the best positive predictive values in relation to the occurrence of shock (100%) and right ventricular dilatation (93%). The best correlation coefficient was obtained between right ventricular dilatation and NT-proBNP (0.78). Conclusion: NT-proBNP and troponin I are good biomarkers for predicting the severity of pulmonary embolism and allowing therapeutic adaptation when they are elevated.

Association between preoperative high sensitive troponin I levels and cardiovascular events after hip fracture surgery in the elderly

Objective Cardiovascular complications contribute to postoperative morbidity and mortality in elderly hip fracture patients. Limited data are available regarding which preoperative risk factors predict cardiovascular course following hip fracture surgery （HFS）. We used high sensitive troponin I （hs-TnI） assays and clinical parameters to identify preoperative risk factors associated with major adverse cardiac events （MACE） in elderly hip frac^u＇e patients. Method From August 2014 to November 2016, 575 patients with hip fracture were enrolled in a retrospective, single-center registry. A total of 262 of these patients underwent HFS and hs-TnI assays. MACE was defined as postoperative all-cause deaths, heart failure （HF）, new-onset atrial fibrillation （AF）, myocardial infarction （MI） and cardiovascular re-hospitalization that occurred within 90 days postoperative. Results Of 262 HFS patients, MACE developed following HFS in 65 （24.8%）. Patients with MACE were older and had higher rates of renal insufficiency, coronary artery disease, prior HF, low left ventricular ejection fraction and use of beta blockers; higher levels of hs-Tnl and N-terminal pro-brain natriuretic peptide （NT-proBNP） and higher revised cardiac risk index. A preoperative hs-TnI≥ 6.5 ng/L was associated with high risk of postoperative HF, new-onset AF and MACE. In multivariable analysis, pre-operative independent predictors for MACE were age 〉 80 years [adjusted hazard ratio （HR）： 1.79, 95% confident interval （CI）： 1.03-3.13, P = 0.04], left ventricular ejection fraction （LVEF） 〈 50% （adjusted HR： 3.17, 95% CI： 1.47-5.82, P 〈 0.01） and hs-TnI 〉 6.5 ng/L （adjusted HR： 3.75, 95% CI： 2.09~5.17, P 〈 0.01）. Conclusion In elderly patients with hip fracture who undergo HFS, a preoperative assessment of hs-TnI may help the risk refinement of cardiovascular complications.

Preparation of Anti-cardiac Troponin I Monoclonal Antibodies and Their Characterization with Surface Plasmon Resonance Biosensor

Cardiac troponin I(cTnI) was separated and purified from human left ventricular tissue by affinity chromatographic method and used to immunize Balb/c mice by intraperitoneal injection and four hybridoma cell lines, which secreted monoclonal antibody(mAb) against human cTnI, were obtained by cell fusion, identification and cloning twice. Three mAbs(9F5, 2F11, 8C12) were produced from the ascites of Balb/c mice injected intraperitoneally the hybridoma cells and characterized by means of a surface plasmon resonance(SPR) biosensor. An optimal and specific sensing membrane for troponin I was prepared with staphylococcal protein A(SPA) as the intermediate layer and mAb against human cTnI as the capture antibody. On the basis of the sensing membrane, two modes of operation of the SPR biosensor were developed, i.e ., a direct detection of antigen antibody affinity and a sandwich assay. In the sandwich assay detection mode, the mAbs competition was measured by monitoring whether the secondary antibody had been attached to the cTnI already captured by the first antibody on the sensor surface. The SPR biosensor was shown to be able to directly detect the antigen antibody affinity and the order of the affinity was found to be 9F5>2F11>8C12. In the sandwich detection mode, it was found that the different epitopes on the cTnI molecules were recognized by the three mAbs respectively, but the asymmetrical competition was shown between 2F11 and 8C12 and no competition was found between 9F5 and 2F11 or 8c12. Based on these results, a double monoclonal sandwich immunoassay for cTnI was developed by using the optimal antibody pair of 9F5 and 2F11 and the SPR biosensor with SPA substrate membrane, which showed an excellent sensitivity of 0.8 μg/L for both the buffer and the serum samples compared with the direct detection of cTnI for the buffer with the lowest detection limit of 4 μg/L and conventional ELISA with the sensitivity of 1.9 μg/L.

Characteristics of elevated cardiac troponin I in patients with acute ischemic stroke

Objective To study prognostic characteristics of cardiac troponin I （cTnI） elevation in acute ischemic stroke. Methods We retrospectively studied patients （n = 248） with acute ischemic stroke, acute ST-segment elevation myocardial infarction, and acute non-ST-elevation myocardial infarction who were treated between January 2013 and October 2015. Baseline demographic data and changes in cTnI levels among these three groups were compared. Patients with acute ischemic stroke were assigned to either the cTnI elevation group （cTnI 〉 0.034 ng/mL） or the no cTnI elevation group （cTnI ≤ 0.034 ng/mL）. Logistic regression analysis was used to identify risk factors associated with elevated serum cTnI in patients with acute ischemic stroke. Moreover, the duration of hospital stay and incidence of major cardiovascular outcomes were compared in patients with acute ischemic stroke, with or without elevated cTnI. Results In this study population of patients with acute ischemic stroke （n = 178）, acute ST-segment elevation myocardial infarction （n = 35）, and acute non-ST-elevation myocardial infarction （n = 35）, patients with acute ischemic stroke with elevated cTnI comprised 18.54% of subjects. Patients with elevated cTnI were older and more likely to have a history of hypertension. In addition, these patients had higher levels of inflammatory markers, reduced renal functions, increased D-dimer levels, higher NIH stroke scores, and lower left ventricular ejection fractions. Logistic regression analysis showed that both percentage of neutrophil and NIH stroke scores were elevated; estimated glomerular filtration rate and left ventricular ejection fraction were decreased in patients with acute ischemic stroke who had elevated cTnI, and they had more frequent major cardiovascular events during hospital stay. Conclusion Elevated cTnI detected in patients with acute ischemic stroke, indicated a greater likelihood of poor short-term prognosis during hospital stay.

A MXene-functionalized paper-based electrochemical immunosensor for label-free detection of cardiac troponin I

Convenient,rapid,and accurate detection of cardiac troponin I(cTnI)is crucial in early diagnosis of acute myocardial infarction(AMI).A paper-based electrochemical immunosensor is a promising choice in this field,because of the flexibility,porosity,and cost-efficacy of the paper.However,paper is poor in electronic conductivity and surface functionality.Herein,we report a paper-based electrochemical immunosensor for the label-free detection of cTnI with the working electrode modified by MXene(Ti_(3)C_(2))nanosheets.In order to immobilize the bio-receptor(anti-cTnI)on the MXene-modified working electrode,the MXene nanosheets were functionalized by aminosilane,and the functionalized MXene was immobilized onto the surface of the working electrode through Nafion.The large surface area of the MXene nanosheets facilitates the immobilization of antibodies,and the excellent conductivity facilitates the electron transfer between the electrochemical species and the underlying electrode surface.As a result,the paper-based immunosensor could detect cTnI within a wide range of 5-100 ng/mL with a detection limit of 0.58 ng/mL.The immunosensor also shows outstanding selectivity and good repeatability.Our MXene-modified paper-based electrochemical immunosensor enables fast and sensitive detection of cTnI,which may be used in real-time and cost-efficient monitoring of AMI diseases in clinics.

Construction of a Muscle cDNA Library of Chinese Shrimp Fenneropenaeus chinensis and Sequence Analysis of the Troponin I Gene

A muscle cDNA library of Chinese shrimp (Fenneropenaeus chinensis) was constructed with the SMARTTM cDNA Library Construction Kit.The titer of optimal primary library was 7.7×105 pfu mL-1 and that of the amplified library was 3.0×109 pfu mL-1.The percentages of the recombinant clones of primary and amplified libraries were over 98%.The insert sizes were longer than 400 bp with an average of 1000 bp.A positive clone containing a 794 bp insert was sequenced and identified encoding fast skeletal troponin I gene.This library provided a useful resource for the functional genomic research of F.chinensis.

Highly sensitive troponin I assay in the diagnosis of coronary artery disease in patients with suspected stable angina

BACKGROUND Evaluation of suspected stable angina patients with probable coronary artery disease(CAD)in the community is challenging.In the United Kingdom,patients with suspected stable angina are referred by community physicians to be assessed by specialists within the hospital system in rapid access chest pain clinics(RACPC).The role of a highly sensitive troponin I(uscTnI)assay in the diagnosis of suspected CAD in a RACPC in a“real-life”setting in a non-academic hospital has not been explored.AIM To examine the diagnostic value of uscTnI(detection limit 0.12 ng/L,upper reference range 8.15 ng/L,and detected uscTnI in 96.8%of the reference population),in the evaluation of stable CAD in a non-selected patient group,with several co-morbidities,who presented to the RACPC.METHODS One hundred and seventy two RACPC patients were assigned to either functional or anatomical testing according to the hospital protocol.RESULTS The investigations offered to patients were exercise tolerance test 7.6%,24 h ECG 1.2%,Echocardiogram 14.5%,stress echocardiogram 8.1%,coronary computed tomography angiography(CCTA)12.8%,coronary angiogram 13.4%,17.4%were diagnosed with non-cardiac chest pain,3.5%treated as stable angina,8.2%reviewed by cardiologists,electronic medical records were not available in 10.4%.Receiver operating characteristic curves for CAD used uscTnI values measured in patients who underwent functional testing,angiogram or CCTA.Values>0.52 ng/L showed 100%sensitivity and at>11.6 ng/L showed 100%specificity.In the range>0.52-11.6 ng/L,uscTnI may not have the same diagnostic potential.In patients assigned to coronary angiogram higher concentrations of uscTnI was associated with severe CAD.Low levels of uscTnI and low pre-test probability of CAD(QRISK3)may decrease patient numbers assigned to CCTA.CONCLUSION The uscTnI diagnostic cut-off values in a RACPC will depend on patient population and their presenting co-morbidity.In the presence of clinical comorbidities and previous CAD the uscTnI needs to be used in conjunction with clinical assessment.

Changes and significance of serum troponin in trauma patients: A retrospective study in a level I trauma center

BACKGROUND: Elevated troponin I(TnI) is common among trauma patients. TnI is an indicator of myocardial injury, but clinical diagnosis of blunt cardiac injury cannot be based solely on an increase in TnI. Therefore, this study aims to explore the changes and clinical significance of serum TnI in trauma patients. METHODS: The clinical data of consecutive trauma patients admitted to our trauma center between July 1, 2017 and July 31, 2020 were retrospectively analyzed. According to TnI levels within 24 hours of admission, patients were divided into the elevated and normal TnI groups. According to the TnI levels after 7 days of admission, a graph depicting a change in trend was drawn and then analyzed whether TnI was related to in-hospital mortality. RESULTS: A total of 166 patients(69 and 97 cases with elevated and normal TnI, respectively) were included in this study. The average hospital stay, intensive care time, mechanical ventilation time, and in-hospital mortality were higher in the elevated TnI group than in the normal TnI group(P<0.05). The TnI level of trauma patients gradually increased after admission and peaked at 48 hours(7.804±1.537 ng/mL). Subsequently, it decreased, and then recovered to normal within 7 days. However, 13 patients did not recover. Logistic regression analysis revealed that abnormal TnI at 7 days was independently related to in-hospital mortality. CONCLUSIONS: Trauma patients with elevated TnI levels may have a worse prognosis. Monitoring the changes in serum TnI is important, which can reflect the prognosis better than the TnI measured immediately after admission.

人Troponin I的表达载体构建诱导表达和纯化及活性测定

以人肝脏cDNA文库为模板,通过PCR方法扩增出Tropon in基因,将其克隆到pCR-TOPO质粒中,构建表达质粒pET-22 b(+)-TnI,转化大肠杆菌BL 21(DE 3)-RPX并进行诱导表达,表达的目的蛋白占菌体总蛋白的20%以上并主要以可溶形式存在。建立了Tropon in I的非亲和色谱纯化工艺,纯化后蛋白产量约为20 mg/L,纯度在90%以上。体外活性实验表明重组蛋白具有良好的抗血管生成。

Risk Stratification with Serum Cardiac Troponin I in Acute Myocardial Infarction on Admission

Objective To assess the prognostic significance of serum cardiac troponin I (cTnI) concentration in patients with acute myocardial infarction on admission. Methods Serum samples of 108 patients with established AMI were collected on admission for measuring cTnI and were grouped according to the intervals between the onset of chest pain and admission. Results In each of these groups, the serum cTnI concentrations in patients died after admission were significantly higher than those who survived (all P<0.05). Conclusions A higher serum cTnI concentration on admission in patients with AMI was associated with an increased risk of subsequent cardiac death during hospitalization.

RELEASE OF SERUM TROPONIN I AND ITS RELATIONSHIP TO MULTIFACTORS FOLLOWING OPEN HEART SURGERY IN CHILDREN

Objective To be released specifically after myocardial damage. The goal of this study was to measure serum cardiac troponin I levels after open heart surgery in children, and to evaluate relevance between TnTi and perioperative multi-factors. Methods Fifty-seven consecutive pediatric patients undergoing elective correction of congenital heart diseases were divided into group A （ TOF, n =31 ） and group B （ VSD, n =26）. Blood sampies were drawn preoperatively, 5min（ T0 ） , 6h（ T6 ） , 12h（ T12 ） , 24h（ T24 ） , 48h（ T48 ） , 72h（ T72 ） after removal of aortic cross clamping. Myocardial protection consisted of moderate systemic hypothermia （ 30℃- 32℃ ）, cold crystalloid cardioplegia and topical cooling. Demographic information, cardiac defect, repair procedure, duration of bypass （ CPBT） , cross-clamping time （ CCT） , clinical score for cardiac function, electrocardiographic changes and outcomes were recorded. Results Compared with the baseline value, serum concentration of troponin I peaked at T0 （ P 〈 0. 01 ）, and fell to normal level at T72 （ P 〉 0. 05 ）. Peak CTnI was 118 and 55 times higher than the baseline value, respectively in group A and group B. There was a positive correlation between peak CTnI and CPBT, CCT （ r = 0. 51 ; P 〈 0. 01 ）, myocardial operative injury after ventriculotomy and muscle resection （ r = 0. 35, P 〈0. 01 ）. Also the peak CTnl value was correlated to the clinical score for cardiac function （r = -0. 52; P 〈0. 01）. 2.3μg/L was a cutoff value which was highly predictive for postoperative recovery and inotropic support. Conclusion Postoperative serum troponin I is a highly specific and sensitive marker for myocardial ischemia and injury; therefore, its measurement may contribute to the assessment of recovery and outcome after open heart surgery.

Typical rise and fall of troponin in(peri-procedural) myocardial infarction:A systematic review

AIM: To identify the typical shape of the rise and fall curve of troponin(Tn) following the different types of myocardial infarction(MI). METHODS: We conducted a systematic search in PubM ed and Embase including all studies which focused on the kinetics of Tn in MI type 1, type 4 and type 5. Tn levels were standardized using the 99 th percentile, a pooled mean with 95%CI was calculated from the weighted means for each time point until 72 h. RESULTS: A total of 34 of the 2528 studies identified in the systematic search were included. The maximum peak level of the Tn was seen after 6 h after successful reperfusion of an acute MI, after 12 h for type 1 MI and after 72 h for type 5 MI. In type 1 MI there were additional smaller peaks at 1 h and at 24 h. After successful reperfusion of an acute MI there was a second peak at 24 h. There was not enough data available to analyze the Tn release after MI associated with percutaneous coronary intervention(type 4).CONCLUSION: The typical rise and fall of Tn is different for type 1 MI, successful reperfusion of an acute MI and type 5 MI, with different timing of the peak levels and different slopes of the fall phase.

Molecular Cloning and Tissue Distribution of Troponin I from the Japanese Pearl Oyster, <i>Pinctada fucata</i>

Troponin is a complex of three proteins (troponin I, troponin C, and troponin T) that binds Ca2+ and is a thin filament-associated regulator of vertebrate striated muscle contraction. The function of troponin I (TnI) in vertebrates has been extensively characterized, but its role in molluscan muscles has not yet been elucidated. Our previous work suggested that the troponin C subunit has a role in adductor phasic muscle but not in catch muscle. Here, we investigated the molecular characteristics of TnI from the bivalve Japanese pearl oyster, Pinctada fucata to aid the elucidation of the function of molluscan muscle troponin. We determined the primary structure of the full-length TnI protein from the P. fucata adductor muscle (Pifuc-TnI) and found that it is composed of 286 amino acid residues with a predicted molecular weight of 33,737. Motif structure predictions and multiple sequence alignments revealed that Pifuc-TnI has a 138 residue extension at its N-terminus compared with rabbit TnI. This is analogous to characterized TnIs from other mollusks. However, unlike scallop TnI, Pifuc-TnI is predicted to contain two cAMP-dependent protein kinase phosphorylation sites, at residues 39 - 45 (RRGTEDD) and 145 - 151 (KKKSKRK). Phylogenetic analysis indicated that Pifuc-TnI and molluscan TnIs were grouped into the same clade. Pifuc-TnI gene structure predictions using Splign alignment of our obtained cDNA and genome sequences indicated that Pifuc-TnI consists of fifteen exons, with the start and stop codons located in exon 2 and exon 11, respectively. Using quantitative real-time PCR, we determined that the Pifuc-TnI gene is predominantly expressed in adductor phasic muscle, weakly in adductor catch muscle, and is not expressed in the gill, mantle or foot. These findings suggest that TnI, as a component of the troponin complex, plays a regulatory role in adductor phasic muscle contraction, but not in catch contraction.

The Differences of Cord Blood Troponin I (TnI) Level between Normal and Asphyxiated Infants and Its Correlation with APGAR Score

Asphyxia could increase infant morbidity and mortality. Ante- and intrapartum cardiotocography (CTG) examination could lead to a false positive diagnosis of asphyxia (fetal distress). Troponin I (TnI) is an important factor to the pathogenesis of asphyxia. Cord blood TnI level is increased in infants with fetal cardiac dysfunction, causing pathological CTG and low APGAR score (<7). In the future, TnI is expected to reduce false positive diagnosis of asphyxia caused by CTG. This research was conducted to examine and analyze the differences of cord blood TnI level between normal and asphyxiated infants and to determine the correlation between TnI level and APGAR score. An observational analytical cross sectional study was conducted to a total of 36 patients with asphyxiated infants (18 patients) and normal infants (18 patients). Subjects were selected according to the inclusion and exclusion criteria. Cardiotocography, TnI level, and APGAR score were examined. Umbilical cord blood samples were taken from each subject for the measurement of TnIlevel using a highly sensitive indirect sandwich Enzyme Linked Immunosorbent Assay (ELISA). Statistical analysis was performed by Mann-Whitney and Rank Spearman correlation coefficient test. Cord blood TnI level of asphyxia andnormal groups were 1615.77 ± 1199.98 pg/mL and 819.88 ± 145.82 pg/mLrespectively (p ≤ 0.05). Rank Spearman correlation coefficient between cord blood TnI level and 1’ and 5’ APGAR score was -0.523 (p = 0.026;p ≤ 0.05)and -0.502 respectively (p = 0.034;p ≤ 0.05). There was a statistically significant difference between cord blood TnI level of asphyxia and normal groups;cord blood TnI level of asphyxia group was higher than normal group. Furthermore, negative correlation was observed between cord blood TnI level and APGAR score.

Marked elevation of troponin I without wall motion abnormality in a patient with myocarditis: Cardiac enzymes may not predict the outcome in myocarditis

A seventeen-year-old male presented with severe substernal chest pain after an episode of upper respiratory tract infection. On clinical grounds, a diagnosis of myocarditis was established. He had a peak troponin I level as high as 40.4 ng/dl but interestingly with no abnormal wall motion and normal ejection fraction in echocardiography. Coronary artery disease was excluded with normal coronary angiography. Diagnosis of myocarditis was confirmed with cardiac MRI. After one month, patient had no complaint and ejection fraction were still normal. Our case emphasizes that the troponin levels predict neither the early nor the late outcome of the left ventricular functions in myocarditis, therefore serum troponin I may not be helpful in determining the prognosis of patients with myocarditis.

Differential IFN-Gamma (IFN-γ), Interleukin 10 (IL-10) and Cardiac Troponin I (cTnI) Responses in Natural Bovine Trypanosomosis in Nigeria

Trypanosomosis is major drawback to profitable livestock production in sub-Sahara African, including Nigeria. Knowledge of the cytokines production in the phase of natural infection may help to better diagnose, treat and prevent bovine trypanosomosis. The purpose of the this study was to determine the levels of interferon-gamma (IFN-γ), interleukin-10 (IL-10) and cardiac troponin–I (cTnI) in the sera of cattle naturally infected with T. brucei, T. congolense and T. vivax and correlate these levels with parasitaemia and PCV of the infected animals. Five milliliter of blood samples were collected via the jugular vein from 411 randomly selected cattle into EDTA and non-citrated bottle. PCV was determined manually using HCT. Trypansomes were detected and characterized by microscopy and PCR, respectively. Serum levels of IFN-γ, IL-10 and cTnI were determined using commercial ELISA kit. Data were summarized using descriptive statistic and significance of differences determined by ANOVA. Of the 62 samples positive for trypanosomes by microscopy, 50 samples were confirmed to species level by PCR. The sera levels of IFN-γ, IL-10 and cTnI of infected cattle were higher than non-infected cattle. The differences were not significant (p γ, IL-10 and cTnI in cattle with natural trypanosomosis. Further investigation is required to understand the specific effect of trypanosomes on myocardiac integrity and interaction between the two cytokines in natural trypanosomosis in cattle.

Penetrating Atherosclerotic Ulcer with Elevated Troponin in A Patient with Old Myocardial Infarction: A Case Report

Penetrating atherosclerotic ulcer(PAU),an uncommon etiology of acute aortic syndrome(AAS),is a potential cause of chest pain seen in emergency departments.As PAU may lead to electrocardiogram(ECG)changes or rarely,elevated troponin levels,it is most likely misdiagnosed as acute coronary syndrome(ACS).Hence,individuals with PAU may be offered potentially life-threatening treatment.This paper reports a case of a 81-year-old male who presented with intermittent chest pain with a history of old inferior myocardial infarction and stent placement in the left circumflex coronary artery(LCX)three years ago.Initially,he was diagnosed with non-ST-elevation myocardial infarction(NSTEMI)based on abnormal ECG changes and raised troponin I.However,emergency coronary angiography(CAG)showed no restenosis in the left circumflex coronary artery(LCX)but with mild stenosis in the left anterior descending artery(LAD)and right coronary artery(RCA).Computed tomographic angiography(CIA)of the whole aorta showed multiple atherosclerotic plaques with penetrating atherosclerotic ulcer in the aortic arch and descending aorta.Endovascular aortic repair with Ankura II covered stent was performed.This case study reminds us that it is clinically difficult to distinguish PAU from ACS.Upon excluding ACS from the diagnosis,we should take into consideration of PAU,especially in elderly patients with positive cTnI.

Good Outcome after More Than a Million Troponin in Serum

A troponin in serum of more than one Million in vivo is rare insult. We report a case of 85-year-old woman who was transferred to our institution because of acute ST elevated myocardial infarction and the troponin level reached a peak of 1,032,904.2 pg/ml. She was discharged with highly reduced left ventricular function, however in the three months follow up after a coronary bypass operation she completely was free from heart failure symptoms and echocardiography showed a totally normal function of both ventricles. This case study highlights that the initial serum troponin in acute settings can mislead the long-term prognosis and gives prominence to the expeditious myocardial revascularization.