Troponin I as a Predictor of Transcranial Doppler Sonography Defined Vasospasm in Intensive Care Unit Patients After Spontaneous Subarachnoid Hemorrhage.

OBJECTIVE: Elevation of Troponin I (TnI) in spontaneous subarachnoid hemorrhage (SAH) patients is a well-known phenomenon and associated with cardiopulmonary complications and poor outcome. The present study was conducted to investigate the association of the TnI value on admission, and the occurrence of cerebral vasospam in SAH patients. PATIENTS AND METHODS: A total of 142 patients with SAH, who were admitted to the neurosurgical intensive care unit (ICU) between December 2014 and January 2021 were evaluated. Blood samples were drawn on admission to determine TnI value. Each patient's demographic, radiological and medical data on admission, the modified Ranking Scale score at discharge as well as continuous measurements of transcranial Doppler sonography were analyzed. A maximum mean flow velocity (MMFV) > 120 cm/sec was defined as any vasospasm. These were stratified into severe vasospasms, which were defined as at least two measurements of MMFVs > 200 cm/sec or an increase of MMFV > 50 cm/sec/24 h over two consecutive days or a new neurological deterioration and mild vasospasm defined as MMFVs > 120 cm/sec in absence of severe vasospasm criteria. The total study population was dichotomized into patients with an initially elevated TnI (>0.05 µg/L) and without elevated TnI (≤0.05 µg/L). RESULTS: A total of 52 patients (36.6%) had an elevated TnI level upon admission, which was significantly associated with lower GCS score (p < 0.001), higher WFNS score (p < 0.001) and higher Fisher grade (p = 0.01) on admission. In this context a higher rate of ischemic brain lesions (p = 0.02), a higher modified Rankin Scale score (p > 0.001) and increased mortality (p = 0.02) at discharge were observed in this group. In addition, TnI was identified as an independent predictor for the occurrence of any vasospasm and severe vasospasm. CONCLUSION: An initially elevated TnI level is an independent predictor for the occurrence of any and severe vasospasm in patients with SAH.

A novel integrated lateral flow immunoassay platform for the detection of cardiac troponin I using hierarchical dendritic copper-nickel nanostructures.

Cardiac troponin I (cTnI) is a critical biomarker for the diagnosis of acute myocardial infarction (AMI). Herein, we report a novel integrated lateral flow immunoassay (LFIA) platform for highly sensitive point-of-care testing (POCT) of cTnI using hierarchical dendritic copper-nickel (HD-nanoCu-Ni) nanostructures. The electrodeposited HD-nanoCu-Ni film (∼22 µm thick) on an ITO-coated glass substrate exhibits superior capillary action and structural integrity. These properties enable efficient sample transport and antibody immobilization, making it a compelling alternative to conventional multi-component paper-based LFIA test strips, which are often plagued by structural fragility and susceptibility to moisture damage. The biofunctionalized HD-nanoCu-Ni substrates were laser-etched with lateral flow channels, including a sample loading/conjugate release zone, a test zone, and a control zone. Numerical simulations were used to further optimize the design of these channels to achieve optimal fluid flow and target capture. The HD-nanoCu-Ni LFIA device utilizes a fluorescence quenching based sandwich immunoassay format using antibody-labeled gold nanoparticles (AuNPs) as quenchers. Two different fluorescent materials, fluorescein isothiocyanate (FITC) and CdSe@ZnS quantum dots (QDs), were used as background fluorophores in the device. Upon the formation of a sandwich immunocomplex with cTnI on the HD-nanoCu-Ni device, introduced AuNPs led to the fluorescence quenching of the background fluorophores. The total assay time was approximately 15 min, demonstrating the rapid and efficient nature of the HD-nanoCu-Ni LFIA platform. For FITC, both inner filter effect (IFE) and fluorescence resonance energy transfer (FRET) contributed to the AuNP-mediated quenching. In the case of CdSe@ZnS QDs, IFE dominated the AuNP-induced quenching. Calibration curves were established based on the relationship between the fluorescence quenching intensity and cTnI concentration in human serum samples, ranging from 0.5 to 128 ng/mL. The limits of detection (LODs) were determined to be 0.27 ng/mL and 0.40 ng/mL for FITC and CdSe@ZnS QDs, respectively. A method comparison study using Passing-Bablok regression analysis on varying cTnI concentrations in human serum samples confirmed the equivalence of the HD-nanoCu-Ni LFIA platform to a commercial fluorescence cTnI LFIA assay kit, with no significant systematic or proportional bias observed.

Kiwi-Inspired Rational Nanoarchitecture with Intensified and Discrete Magneto-Fluorescent Functionalities for Ultrasensitive Point-of-Care Immunoassay.

Fluorescent lateral flow immunoassays (FLFIA) is a well-established rapid detection technique for quantitative analysis. However, achieving accurate analysis of biomarkers at the pg mL-1 level using FLFIA still poses challenges. Herein, an ultrasensitive FLFIA platform is reported utilizing a kiwi-type magneto-fluorescent silica nanohybrid (designated as MFS) that serves as both a target-enrichment substrate and an optical signal enhancement label. The spatially-layered architecture comprises a Fe3O4 core, an endocarp-fibers like dendritic mesoporous silica, seed-like quantum dots, and a kiwi-flesh like silica matrix. The MFS demonstrates heightened fluorescence brightness, swift magnetic response, excellent size uniformity, and dispersibility in water. Through liquid-phase capturing and fluorescence-enhanced signal amplification, as well as magnetic-enrichment sample amplification and magnetic-separation noise reduction, the MFS-based FLFIA is successfully applied to the detection of cardiac troponin I that achieved a limit of detection at 8.4 pg mL-1, tens of times lower than those of previously published fluorescent and colorimetric lateral flow immunoassays. This work offers insights into the strategic design of magneto-fluorescent synergetic signal amplification on LFIA platform and underscores their prospects in high-sensitive rapid and on-site diagnosis of biomarkers.

Photoelectrochemical immunoassay of cardiac troponin I based on ZnTCPP/CdIn2S4 type-II heterojunction and co-catalyzed precipitation biolabeling.

CdIn2S4 and zinc tetrakis(4-carboxyphenyl)porphyrin (ZnTCPP) were synthesized by hydrothermal method, and an organic dye-sensitized inorganic semiconductor ZnTCPP/CdIn2S4 type II heterojunction was constructed on a fluorine-doped tin oxide (FTO) substrate electrode. A sandwich immunostructure for signal-attenuation photoelectrochemical (PEC) detection of cardiac troponin I (cTnI) was constructed using the ZnTCPP/CdIn2S4/FTO photoanode and a horseradish peroxidase (HRP)-ZnFe2O4-Ab2-bovine serum albumin (BSA) immunolabeling complex. The bioenzyme HRP and the HRP-like nanozyme ZnFe2O4 can co-catalyze the oxidation of 4-chloro-1-naphthol (4-CN) by H2O2 to produce an insoluble precipitate on the photoanode, thus notably reducing the anodic photocurrent for quantitative determination of cTnI. Under the optimal conditions, the photocurrent at 0 V vs. SCE in 0.1 M phosphate buffer solution (pH 7.40) containing 0.1 M ascorbic acid was linear with the logarithm of cTnI concentration from 500 fg mL-1 to 50.0 ng mL-1, and the limit of detection (LOD, S/N = 3) is 0.15 pg mL-1. Spiked recoveries were 95.1% ~ 104% for assay of cTnI in human serum samples.

[Cardiac biomarkers prior to noncardiac surgery]. / Kardiale Biomarker vor nicht-kardiochirurgischen Eingriffen.

BACKGROUND: Cardiac biomarkers, such as high-sensitivity cardiac troponin (hs-cTn) and brain natriuretic peptide (BNP) or N­terminal prohormone of brain natriuretic peptide (NT-proBNP) are measured perioperatively to improve the prognosis and risk prediction. The European Society of Cardiology (ESC), European Society of Anesthesiology and Intensive Care (ESAIC) and the German Society of Anesthesiology and Intensive Care Medicine (DGAI) have recently published guidelines on the use of cardiac biomarkers prior to surgery. OBJECTIVE/RESEARCH QUESTION: This article provides an overview of the available evidence on perioperative troponin and BNP/NT-proBNP measurements. Current guideline recommendations are presented and discussed. MATERIAL AND METHODS: MEDLINE, Cochrane and google.scholar were searched for relevant keywords. Titles and abstracts of identified papers were checked for relevance and published results were summarized. Guideline recommendations from the ESC, ESAIC and DGAI are presented, compared and evaluated based on the available literature. In addition, the significance of new perioperative cardiac biomarkers is discussed based on the existing evidence. RESULTS: The definitions, diagnosis and management of cardiovascular events in the perioperative context differ from those in the nonsurgical setting. The evidence for the measurement of hs-cTn and BNP/NT-proBNP is evaluated differently in the guidelines and the resulting recommendations are partly contradictory. In particular, recommendations for changes in perioperative management based on biomarker measurements diverge. The ESC guidelines propose an algorithm that uses preoperative biomarkers as the basis for additional cardiac investigations. In particular, invasive coronary angiography is recommended for patients with stable chronic coronary syndrome who have no preoperative cardiac symptoms but elevated biomarkers. In contrast, the ESAIC guidelines emphasize that the available evidence is not sufficient to use perioperative biomarker measurements as a basis for a change in perioperative management. DISCUSSION: Treating physicians should coordinate interdisciplinary (surgery, anesthesiology, cardiology) recommendations for clinical practice based on the aforementioned guidelines. If cardiac biomarkers are routinely determined in high-risk patients, this should be done in accordance with the ESC algorithm.

Elevated Troponins and Diagnosis of Non-ST-Elevation Myocardial Infarction in the Emergency Department.

Background In the emergency department (ED), the diagnosis of non-ST-elevation myocardial infarction (NSTEMI) is primarily based on the presence or absence of elevated cardiac troponin levels, ECG changes, and clinical presentation. However, limited data exist regarding the incidence, clinical characteristics, and predictive value of different cardiac diagnostic tests and outcomes in patients with non-acute coronary syndrome (ACS)-related troponin elevation. Our study aimed to determine the percentage of patients with elevated troponin levels who had true ACS and identify various risk factors associated with true ACS in these patients. Methodology This was a single-center retrospective study. We performed a chart review of patients who presented to the ED from January 1, 2016, to December 31, 2017, and were admitted to the hospital with an elevated cardiac troponin I level in the first 12 hours after ED presentation with a diagnosis of NSTEMI. True ACS was defined as (a) patients with typical symptoms of ischemia and ECG ischemic changes and (b) patients with atypical symptoms of myocardial ischemia or without symptoms of ischemia and new segmental wall motion abnormalities on echocardiogram or evidence of culprit lesion on angiography. A logistic regression model was used to determine the association between risk factors and true ACS. Results A total of 204 patients were included in this study. The mean age of the study group was 67.4 ± 14.5 years; 53.4% (n = 109) were male, and 57.4% (n = 117) were Caucasian. In our study, 51% of patients were found to have true ACS, and the remaining 49% had a non-ACS-related elevation in troponins. Most patients without ACS had alternate explanations for elevated troponin levels. The presence of chest pain (odds ratio (OR) = 3.7, 95% confidence interval (CI) = 1.8-7.7, p = 0.001), tobacco smoking (OR = 4, 95% CI = 1.06-3.8, p = 0.032), and wall motion abnormalities on echocardiogram (OR = 3.8, 95% CI = 1.8-6.5, p = 001) were associated with increased risk of true ACS in patients with elevated troponins. Conclusions Cardiac troponin levels can be elevated in hospitalized patients with various medical conditions, in the absence of ACS. The diagnosis of ACS should not be solely based on elevated troponin levels, as it can lead to expensive workup and utilization of hospital resources.

Point-of-care high-sensitivity cardiac troponin in suspected acute myocardial infarction assessed at baseline and 2†h.

BACKGROUND AND AIMS: Strategies to assess patients with suspected acute myocardial infarction (AMI) using a point-of-care (POC) high-sensitivity cardiac troponin I (hs-cTnI) assay may expedite emergency care. A 2-h POC hs-cTnI strategy for emergency patients with suspected AMI was derived and validated. METHODS: In two international, multi-centre, prospective, observational studies of adult emergency patients (1486 derivation cohort and 1796 validation cohort) with suspected AMI, hs-cTnI (Siemens Atellica® VTLi) was measured at admission and 2 h later. Adjudicated final diagnoses utilized the hs-cTn assay in clinical use. A risk stratification algorithm was derived and validated. The primary diagnostic outcome was index AMI (Types 1 and 2). The primary safety outcome was 30-day major adverse cardiac events incorporating AMI and cardiac death. RESULTS: Overall, 81 (5.5%) and 88 (4.9%) patients in the derivation and validation cohorts, respectively, had AMI. The 2-h algorithm defined 66.1% as low risk with a sensitivity of 98.8% [95% confidence interval (CI) 89.3%-99.9%] and a negative predictive value of 99.9 (95% CI 99.2%-100%) for index AMI in the derivation cohort. In the validation cohort, 53.3% were low risk with a sensitivity of 98.9% (95% CI 92.4%-99.8%) and a negative predictive value of 99.9% (95% CI 99.3%-100%) for index AMI. The high-risk metrics identified 5.4% of patients with a specificity of 98.5% (95% CI 96.6%-99.4%) and a positive predictive value of 74.5% (95% CI 62.7%-83.6%) for index AMI. CONCLUSIONS: A 2-h algorithm using a POC hs-cTnI concentration enables safe and efficient risk assessment of patients with suspected AMI. The short turnaround time of POC testing may support significant efficiencies in the management of the large proportion of emergency patients with suspected AMI.

Cardiovascular medications, high-sensitivity cardiac troponin T concentrations, and long-term outcome in non-ST segment elevation acute coronary syndrome.

AIMS: Cardiac troponin plays an essential role in the management of non-ST segment elevation acute coronary syndrome (NSTE-ACS). However, it is not clear whether troponin concentrations provide guidance regarding the initiation of prognostically beneficial cardiovascular medications [i.e. betablockers, renin-angiotensin-aldosterone system (RAAS) inhibitors, and statins] in NSTE-ACS. METHODS AND RESULTS: Registry-based study investigating three NSTE-ACS cohorts (n = 43 075, 40 162, and 46 698) with elevated high-sensitivity cardiac troponin concentrations >14 ng/L. Cox proportional regression models with the addition of interaction terms were used to analyse the interrelations of high-sensitivity cardiac troponin T (hs-cTnT) concentrations, new initiated medications with the respective three drug classes, and long-term risk of all-cause mortality and major adverse events (MAE). Betablockers were associated with risk reductions of 8 and 5% regarding all-cause mortality and MAE, respectively. There was no evidence of an interaction with hs-cTnT concentrations. RAAS inhibitors were associated with 13 and 8% risk reductions, respectively, with a weak interaction between hs-cTnT and MAE (Pinteraction = 0.016). However, no increasing prognostic benefit was noted at hs-cTnT concentrations >100 ng/L. Statins were associated with 38 and 32% risk reductions, respectively, with prognostic benefit across the entire range of hs-cTnT concentrations, and with a weak interaction regarding MAE (Pinteraction = 0.011). CONCLUSION: Cardiovascular medications provide different prognostic benefit in patients with NSTE-ACS with elevated hs-cTnT, and there was some evidence of greater treatment effects regarding MAE along with higher hs-cTnT concentrations. However, hs-cTnT appears only to have limited value overall for customizing such treatments.

V-A ECMO for neonatal coxsackievirus B fulminant myocarditis: a case report and literature review.

Background: Neonatal (enteroviral) myocarditis (NM/NEM) is rare but unpredictable and devastating, with high mortality and morbidity. We report a case of neonatal coxsackievirus B (CVB) fulminant myocarditis successfully treated with veno-arterial extracorporeal membrane oxygenation (V-A ECMO). Case presentation: A previously healthy 7-day-old boy presented with fever for 4 days. Progressive cardiac dysfunction (weak heart sounds, hepatomegaly, pulmonary edema, ascites, and oliguria), decreased left ventricular ejection fraction (LVEF) and fractional shortening (FS), transient ventricular fibrillation, dramatically elevated creatine kinase-MB (405.8 U/L), cardiac troponin I (25.85 ng/ml), and N-terminal pro-brain natriuretic peptide (NT-proBNP > 35,000 ng/L), and positive blood CVB ribonucleic acid indicated neonatal CVB fulminating myocarditis. It was refractory to mechanical ventilation, fluid resuscitation, inotropes, corticosteroids, intravenous immunoglobulin, and diuretics during the first 4 days of hospitalization (DOH 1-4). The deterioration was suppressed by V-A ECMO in the next 5 days (DOH 5-9), despite the occurrence of bilateral grade III intraventricular hemorrhage on DOH 7. Within the first 4 days after ECMO decannulation (DOH 10-13), he continued to improve with withdrawal of mechanical ventilation, LVEF > 60%, and FS > 30%. In the subsequent 4 days (DOH 14-17), his LVEF and FS decreased to 52% and 25%, and further dropped to 37%-38% and 17% over the next 2 days (DOH 18-19), respectively. There was no other deterioration except for cardiomegaly and paroxysmal tachypnea. Through strengthening fluid restriction and diuresis, and improving cardiopulmonary function, he restabilized. Finally, notwithstanding NT-proBNP elevation (>35,000 ng/L), cardiomegaly, and low LVEF (40%-44%) and FS (18%-21%) levels, he was discharged on DOH 26 with oral medications discontinued within 3 weeks postdischarge. In nearly three years of follow-up, he was uneventful, with interventricular septum hyperechogenic foci and mild mitral/tricuspid regurgitation. Conclusions: Dynamic cardiac function monitoring via real-time echocardiography is useful for the diagnosis and treatment of NM/NEM. As a lifesaving therapy, ECMO may improve the survival rate of patients with NM/NEM. However, the "honeymoon period" after ECMO may cause the illusion of recovery. Regardless of whether the survivors of NM/NEM have undergone ECMO, close long-term follow-up is paramount to the prompt identification and intervention of abnormalities.

Changes in the investigation and management of suspected myocardial infarction and injury during COVID-19: a multi-centre study using routinely collected healthcare data.

Objective: The COVID-19 pandemic was associated with a reduction in the incidence of myocardial infarction (MI) diagnosis, in part because patients were less likely to present to hospital. Whether changes in clinical decision making with respect to the investigation and management of patients with suspected MI also contributed to this phenomenon is unknown. Methods: Multicentre retrospective cohort study in three UK centres contributing data to the National Institute for Health Research Health Informatics Collaborative. Patients presenting to the Emergency Department (ED) of these centres between 1st January 2020 and 1st September 2020 were included. Three time epochs within this period were defined based on the course of the first wave of the COVID-19 pandemic: pre-pandemic (epoch 1), lockdown (epoch 2), post-lockdown (epoch 3). Results: During the study period, 10,670 unique patients attended the ED with chest pain or dyspnoea, of whom 6,928 were admitted. Despite fewer total ED attendances in epoch 2, patient presentations with dyspnoea were increased (p < 0.001), with greater likelihood of troponin testing in both chest pain (p = 0.001) and dyspnoea (p < 0.001). There was a dramatic reduction in elective and emergency cardiac procedures (both p < 0.001), and greater overall mortality of patients (p < 0.001), compared to the pre-pandemic period. Positive COVID-19 and/or troponin test results were associated with increased mortality (p < 0.001), though the temporal risk profile differed. Conclusions: The first wave of the COVID-19 pandemic was associated with significant changes not just in presentation, but also the investigation, management, and outcomes of patients presenting with suspected myocardial injury or MI.

Urine high-sensitive troponin I in children cannot offer an applicable alternative to serum.

Introduction: In children, congenital heart defects represent the primary cause of increased serum troponin I. The elimination process of cardiac troponin I from the bloodstream and the factors influencing this process remain unknown. The objective of this study was to explore the role of troponin I as an indicator of cardiac damage in children both in serum and urine, a concept previously investigated in adults. Methods: Our prospective study involved 70 children under 24 months of age. The first group underwent ventricular septal defect repair, while the second group involved children who had undergone partial cavopulmonary anastomosis. For these groups, urine and serum troponin I were assessed on four occasions. The third group, consisting of healthy children, underwent a single measurement of urine troponin I. Results: Serum troponin I values exhibited an expected elevation in the early postoperative period, followed by a return to lower levels. Significantly higher concentrations of serum troponin I were observed in the first group of children (p < 0.05). A positive correlation was found between troponin I in the first three measurements and cardiopulmonary bypass and aortic cross-clamping time. There was no discernible increase in urine troponin I directly related to myocardial damage; troponin I couldn't be detected in most urine samples. Discussion: The inability to detect troponin I in urine remains unexplained. Potential explanatory factors may include the isoelectric point of troponin I, elevated urinary concentrations of salts and urea, variations in urine acidity (different pH levels), and a relatively low protein concentration in urine.

A rapid and ultrasensitive cardiac troponin I aptasensor based on an ion-sensitive field-effect transistor with extended gate.

Acute myocardial infarction (AMI) is a life-threatening disease with a short course and a high mortality rate. However, it is still a great challenge to achieve the on-site diagnosis of this disease within minutes, meaning there is an urgent need to develop an efficient technology for realizing the rapid diagnosis and early warning of AMI in clinical emergencies. In this study, an ultrasensitive electrochemical aptasensor based on an extended-gate ion-sensitive field-effect transistor (EGISFET) was designed to achieve the quantitative assay of cardiac troponin I (cTnI), which is a highly sensitive and specific biomarker of AMI, within only 5 min. The EGISFET exhibits extremely high detection sensitivity due to its separated structure with a large sensing area and the surface-modified Prussian blue-gold nanoparticles (PB-AuNPs) composite, which serves as a signal magnifier and DNA loading platform for good electrocatalytic ability with a large specific area. Additionally, a target-induced strand-release strategy is proposed to shorten the recognition time of cTnI using a particular DNA strand. Under optimal conditions, the as-prepared aptasensor exhibits a wide linear range of 1-1000 pg/mL, an ultralow detection limit of 0.3 pg/mL, and reliable detection results in real serum samples. It is highly anticipated that this EGISFET-based aptasensor will have broad applications in the early warning and rapid diagnosis of AMI and other acute diseases in emergency treatment.

Markedly elevated high-sensitivity troponin and in-hospital mortality after cardiac surgery.

BACKGROUND: High-sensitivity troponin (hsTnI) is correlated with cardiac mortality; however, studies on the relationship of markedly elevated hsTnI with in-hospital mortality after cardiac surgery are sparse. Therefore, we aimed to define this relationship in order to help guide in-hospital, acute management of post-surgical patients. METHODS: We retrospectively analyzed all cardiac surgeries completed at our institution between January 2020 and June 2022 in which a peak hsTnI was noted to be >35× upper limit of normal (ULN = 34 ng/L). The primary outcome was in-hospital death. Subgroup analysis was performed to assess differences between coronary artery bypass grafting (CABG) and other cardiac surgeries. RESULTS: A total of 1382 cases met inclusion criteria. The patients' mean age was 64.8 years and 68.2 % were male. Median peak hsTnI after surgery was 4202 ng/L (interquartile ratio: 2427-7654). Univariate analysis of troponin level with mortality found that for every 1000 ng/L increase in hsTnI, odds of in-hospital death increased by 3.8 % (odds ratio [OR]: 1.038; 95 % confidence interval [CI] 1.027-1.050; p < 0.0001). In a multivariate model, troponin (OR 1.02; 95 % CI 1.01-1.04; p = 0.004) maintained a significant association with in-hospital death. CABG was associated with a lower risk of in-hospital death for any given hsTnI level up to 60,000 ng/L compared to other cardiac surgeries. CONCLUSION: Increasing hsTnI level is associated with increasing probability of in-hospital mortality and, therefore, serves as an additional, objective measure of risk to help guide in-hospital clinical management.

Detectable troponin below the 99th percentile predicts survival in patients undergoing coronary angiography.

Background: Cardiac troponin I (cTnI) above the 99th percentile is associated with an increased risk of major adverse events. Patients with detectable cTnI below the 99th percentile are a heterogeneous group with a less well-defined risk profile. The purpose of this study is to investigate the prognostic relevance of detectable cTnI below the 99th percentile in patients undergoing coronary angiography. Methods: The study included 14,776 consecutive patients (mean age of 65.4 ± 12.7 years, 71.3 % male) from the Essen Coronary Artery Disease (ECAD) registry. Patients with cTnI levels above the 99th percentile and patients with ST-segment elevation acute myocardial infarction were excluded. All-cause mortality was defined as the primary endpoint. Results: Detectable cTnI below the 99th percentile was present in 2811 (19.0 %) patients, while 11,965 (81.0 %) patients were below detection limit of the employed assay. The mean follow-up was 4.25 ± 3.76 years. All-cause mortality was 20.8 % for patients with detectable cTnI below the 99th percentile and 15.0 % for those without detectable cTnI. In a multivariable Cox regression analysis, detectable cTnI was independently associated with all-cause mortality with a hazard ratio of 1.60 (95 % CI 1.45-1.76; p < 0.001). There was a stepwise relationship with increasing all-cause mortality and tertiles of detectable cTnI levels with hazard ratios of 1.63 (95 % CI 1.39-1.90) for the first tertile to 2.02 (95 % CI 1.74-2.35) for the third tertile. Conclusions: Detectable cTnI below the 99th percentile is an independent predictor of mortality in patients undergoing coronary angiography with the risk of death growing progressively with increasing troponin levels.

Noninvasive cardiac-specific biomarkers for the diagnosis and prevention of vascular stenosis in cardiovascular disorder.

Background: The most frequent lesion in the blood vessels feeding the myocardium is vascular stenosis, a condition that develops slowly but can prove to be deadly in a long run. Non-invasive biomarkers could play a significant role in timely diagnosis, detection and management for vascular stenosis events associated with cardiovascular disorders. Aims: The study aimed to investigate high sensitivity troponin I (hs-TnI), cardiac troponin I (c-TnI) and high sensitivity C-reactive protein (hs-CRP) that may be used solely or in combination in detecting the extent of vascular stenosis in CVD patients. Methodology: 274 patients with dyspnea/orthopnea complaints visiting the cardiologists were enrolled in this study. Angiographic study was conducted on the enrolled patients to examine the extent of stenosis in the five prominent vessels (LDA, LCX, PDA/PLV, RCA, and OM) connected to the myocardium. Samples from all the cases suspected to be having coronary artery stenosis were collected, and subjected to biochemical evaluation of certain cardiac inflammatory biomarkers (c-TnI, hsTn-I and hs-CRP) to check their sensitivity with the level of vascular stenosis. The extent of mild and culprit stenosis was detected during angiographic examination and the same was reported in the form significant (≥50% stenosis in the vessels) and non-significant (<50% stenosis in the vessels) Carotid Stenosis. Ethical Clearance for the study was provided by Dr. Ram Manohar Lohia Institute of Medical Sciences Institutional Ethical Committee. Informed consent was obtained from all the participants enrolled in the study. Results: We observed that 85% of the total population enrolled in this study was suffering from hypertension followed by 62.40% detected with sporadic episodes of chest pain. Most of the subjects (42% of the total population) had stenosis in their LAD followed by 38% who had stenosis in their RCA. Almost 23% patients were reported to have stenosis in their LCX followed by OM (18% patients), PDA/PLV (13%) and only 10% patients had blockage problem in their diagonal. 24% of the subjects were found to have stenosis in a single vessel and hence were categorized in the Single Vessel Disease (SVD) group while 76% were having stenosis in two or more than two arteries (Multiple Vessel Disease). hs-TnI level was found to be correlated with the levels of stenosis and was higher in the MVD group as compared to the SVD group. Conclusion: hs-TnI could be used as a novel marker as it shows prominence in detecting the level of stenosis quite earlier as compared to c-TnI which gets detected only after a long duration in the CVD patients admitted for angiography. hs- CRP gets readily detected as inflammation marker in these patients and hence could be used in combination with hs-TnI to detect the risk of developing coronary artery disease.

Cardiac Biomarker Change at 1 Year After Tafamidis Treatment and Clinical Outcomes in Patients With Transthyretin Amyloid Cardiomyopathy.

BACKGROUND: Although tafamidis treatment improves prognosis in patients with wild-type transthyretin amyloid cardiomyopathy, an optimal surrogate marker monitoring its therapeutic effect remains unclear. This study investigated the association between changes in cardiac biomarkers, high-sensitivity cardiac troponin T (hs-cTnT) and B-type natriuretic peptide (BNP) during the first year after tafamidis treatment and clinical outcomes. METHODS AND RESULTS: In 101 patients with wild-type transthyretin amyloid cardiomyopathy receiving tafamidis at our institution, change in cardiac biomarkers from baseline to 1 year after tafamidis administration and its association with composite outcomes (composite of all-cause death and hospitalization attributable to heart failure) was assessed. During the follow-up period (median, 17 months), 16 (16%) patients experienced composite outcomes. The hs-cTnT level significantly decreased at 1 year after tafamidis treatment, unlike the BNP level. The frequencies of increased hs-cTnT and BNP levels were significantly higher in those with composite outcomes than in those without (44% versus 15%; P=0.01). Kaplan-Meier survival analysis showed that patients in whom both hs-cTnT and BNP levels increased at 1 year after tafamidis had a higher probability of composite outcomes compared with those with decreased hs-cTnT and BNP levels (log-rank P<0.01). Cox regression analysis identified increased hs-cTnT and BNP levels at 1 year after tafamidis administration as an independent predictor of higher cumulative risk of composite outcomes. CONCLUSIONS: Deterioration in cardiac biomarkers during the first year after tafamidis treatment predicted a worse prognosis, suggesting the utility of serial assessment of cardiac biomarkers for monitoring the therapeutic response to tafamidis in patients with wild-type transthyretin amyloid cardiomyopathy.

Early myocardial injury in children on doxorubicin for cancer chemotherapy: a cross-sectional study in a tertiary referral centre in Kenya.

INTRODUCTION: Use of doxorubicin, an anthracycline chemotherapeutic agent has been associated with late-occurring cardiac toxicities. Detection of early-occurring cardiac effects of cancer chemotherapy is essential to prevent occurrence of adverse events including toxicity, myocardial dysfunction, and death. OBJECTIVE: To investigate the prevalence of elevated cardiac troponin T (cTnT) and associated factors of myocardial injury in children on doxorubicin cancer chemotherapy. METHODS: Design: A cross-sectional study. SETTING AND SUBJECTS: A hospital-based study conducted on children aged 1-month to 12.4-years who had a diagnosis of cancer and were admitted at Kenyatta National Hospital (KNH). INTERVENTIONS AND OUTCOMES: The patients underwent Echocardiography (ECHO) before their scheduled chemotherapy infusion. Twenty-four (24) hours after the chemotherapy infusion the patients had an evaluation of the serum cardiac troponin T (cTnT) and a repeat ECHO. Myocardial injury was defined as cTnT level > 0.014 ng/ml or a Fractional Shortening (FS) of < 29% on ECHO. RESULTS: One hundred (100) children were included in the final analysis. Thirty-two percent (32%) of the study population had an elevated cTnT. A cumulative doxorubicin dose of > 175 mg/m2 was significantly associated with and elevated cTnT (OR, 10.76; 95% CI, 1.18-97.92; p = 0.035). Diagnosis of nephroblastoma was also associated with an elevated cTnT (OR, 3.0; 95% CI, 1.23-7.26) but not statistically significant (p = 0.105). Nine percent (9%) of the participants had echocardiographic evidence of myocardial injury. CONCLUSION: When compared to echocardiography, elevated levels of cTnT showed a higher association with early-occurring chemotherapy-induced myocardial injury among children on cancer treatment at a tertiary teaching and referral hospital in Kenya.

Exercise-induced cardiac troponin elevations and cardiac ventricular dysfunction assessed by tissue Doppler echocardiography and speckle tracking among non-elite runners in Beijing marathon.

OBJECTIVES: We aimed to identify the major determinants of cardiac troponin changes response to exercise among non-elite runners participating in the Beijing 2022 marathon, with a particular focus on the associations with the cardiac function assessed by tissue Doppler echocardiography and speckle tracking. DESIGN: A prospective study. METHODS: A total of 33 non-elite participants in the 2022 Beijing Marathon were included in the study. Echocardiographic assessment and blood sample collection were conducted before, immediately after, and two weeks after the marathon. Blood samples were analyzed using the same Abbot high-sensitivity cTnI STAT assay. Echocardiography included tissue Doppler and speckle tracking echocardiography. RESULTS: Following the marathon, significant increases were observed in cardiac biomarkers, with hs-cTnI elevating from 3.1 [2.3-6.7] to 49.6 [32.5-76.9] ng/L (P < 0.0001). Over 72 % of participants had post-race hs-TnI levels surpassing the 99th percentile upper reference limit. There was a notable correlation between pre-marathon hs-cTnI levels (ß coefficient, 0.56 [0.05, 1.07]; P = 0.042), weekly average training (ß coefficient, -1.15 [-1.95, -0.35]; P = 0.009), and hs-cTnI rise post-marathon. Echocardiography revealed significant post-race cardiac function changes, including decreased E/A ratio (P < 0.0001), GWI (P < 0.0001), and GCW (P < 0.0001), with LVEF (ß coefficients, 0.112 [0.01, 0.21]; P = 0.042) and RV GLS (ß coefficients, 0.124 [0.01, 0.23]; P = 0.035) changes significantly associated with hs-TnI alterations. All echocardiographic and laboratory indicators reverted to baseline levels within two weeks. CONCLUSIONS: Baseline hs-cTnI levels and weekly average training influence exercise-induced hs-cTnI elevation in non-elite runners. Echocardiography revealed post-race changes in cardiac function, with LVEF and RV GLS significantly associated with hs-TnI alterations. These findings contribute to understanding the cardiac response to exercise and could guide training and recovery strategies.

Macrotroponin in the COVID-19 Era: An Under-Recognised Cause of Persistent Troponin Elevation.

Troponin is an important diagnostic tool, however, as the assay sensitivity and frequency of testing has increased in the COVID-19 era, a new cohort of patients with persistently elevated troponin has emerged. Interfering antibodies should be considered in patients with persistent and stable troponin elevation, where there is no ongoing cause.