Human heart-type cytoplasmic fatty acid-binding protein (H-FABP) for the diagnosis of acute myocardial infarction. Clinical evaluation of H-FABP in comparison with myoglobin and creatine kinase isoenzyme MB

Differential gene expression patterns in ST-elevation Myocardial Infarction and Non-ST-elevation Myocardial Infarction

The ST-elevation Myocardial Infarction (STEMI) and Non-ST-elevation Myocardial Infarction (NSTEMI) might occur because of coronary artery stenosis. The gene biomarkers apply to the clinical diagnosis and therapeutic decisions in Myocardial Infarction. The aim of this study was to introduce, enrich and estimate timely the blood gene profiles based on the high-throughput data for the molecular distinction of STEMI and NSTEMI. The text mining data (50 genes) annotated with DisGeNET data (144 genes) were merged with the GEO gene expression data (5 datasets) using R software. Then, the STEMI and NSTEMI networks were primarily created using the STRING server, and improved using the Cytoscape software. The high-score genes were enriched using the KEGG signaling pathways and Gene Ontology (GO). Furthermore, the genes were categorized to determine the NSTEMI and STEMI gene profiles. The time cut-off points were identified statistically by monitoring the gene profiles up to 30 days after Myocardial Infarction (MI). The gene heatmaps were clearly created for the STEMI (high-fold genes 69, low-fold genes 45) and NSTEMI (high-fold genes 68, low-fold genes 36). The STEMI and NSTEMI networks suggested the high-score gene profiles. Furthermore, the gene enrichment suggested the different biological conditions for STEMI and NSTEMI. The time cut-off points for the NSTEMI (4 genes) and STEMI (13 genes) gene profiles were established up to three days after Myocardial Infarction. The study showed the different pathophysiologic conditions for STEMI and NSTEMI. Furthermore, the high-score gene profiles are suggested to measure up to 3 days after MI to distinguish the STEMI and NSTEMI.

Advances in congestive heart failure biomarkers

Congestive heart failure (CHF) is the leading cause of morbidity and mortality in the elderly worldwide. Although many biomarkers associated with in heart failure, these are generally prognostic and identify patients with moderate and severe disease. Unfortunately, the role of biomarkers in decision making for early and advanced heart failure remains largely unexplored. Previous studies suggest the natriuretic peptides have the potential to improve the diagnosis of heart failure, but they still have significant limitations related to cut-off values. Although some promising cardiac biomarkers have emerged, comprehensive data from large cohort studies is lacking. The utility of multiple biomarkers that reflect various pathophysiologic pathways are increasingly being explored in heart failure risk stratification and to diagnose disease conditions promptly and accurately. MicroRNAs serve as mediators and/or regulators of renin-angiotensin-induced cardiac remodeling by directly targeting enzymes, receptors and signaling molecules. The role of miRNA in HF diagnosis is a promising area of research and further exploration may offer both diagnostic and prognostic applications and phenotype-specific targets. In this review, we provide insight into the classification of different biochemical and molecular markers associated with CHF, examine clinical usefulness in CHF and highlight the most clinically relevant.

N, Adigal S, Lukose J, Kartha VB, Chidangil S. Cardiovascular biomarkers in body fluids: progress and prospects in optical sensors

Cardiovascular diseases (CVD) are the major causative factors for high mortality and morbidity in developing and developed nations. The biomarker detection plays a crucial role in the early diagnosis of several non-infectious and life-threatening diseases like CVD and many cancers, which in turn will help in more successful therapy, reducing the mortality rate. Biomarkers have diagnostic, prognostic and therapeutic significances. The search for novel biomarkers using proteomics, bio-sensing, micro-fluidics, and spectroscopic techniques with good sensitivity and specificity for CVD is progressing rapidly at present, in addition to the use of gold standard biomarkers like troponin. This review is dealing with the current progress and prospects in biomarker research for the diagnosis of cardiovascular diseases.

Expert opinion.

Fast diagnosis of cardiovascular diseases (CVDs) can help to provide rapid medical intervention, which can affect the patient’s short and long-term health. Identification and detection of proper biomarkers for early diagnosis are crucial for successful therapy and prognosis of CVDs. The present review discusses the analysis of clinical samples such as whole blood, blood serum, and other body fluids using techniques like high-performance liquid chromatography-LASER/LED-induced fluorescence, Raman spectroscopy, mainly, optical methods, combined with nanotechnology and micro-fluidic technologies, to probe patterns of multiple markers (marker signatures) as compared to conventional techniques.

Cardiovascular Biomarkers: Lessons of the Past and Prospects for the Future

Cardiovascular diseases (CVDs) are a major healthcare burden on the population worldwide. Early detection of this disease is important in prevention and treatment to minimise morbidity and mortality. Biomarkers are a critical tool to either diagnose, screen, or provide prognostic information for pathological conditions. This review discusses the historical cardiac biomarkers used to detect these conditions, discussing their application and their limitations. Identification of new biomarkers have since replaced these and are now in use in routine clinical practice, but still do not detect all disease. Future cardiac biomarkers are showing promise in early studies, but further studies are required to show their value in improving detection of CVD above the current biomarkers. Additionally, the analytical platforms that would allow them to be adopted in healthcare are yet to be established. There is also the need to identify whether these biomarkers can be used for diagnostic, prognostic, or screening purposes, which will impact their implementation in routine clinical practice.

Evaluation of Heart-type Fatty Acid-binding Protein in Early Diagnosis of Acute Myocardial Infarction

BACKGROUND

Although electrocardiography and cardiac troponin play important roles in the diagnosis of acute coronary syndrome (ACS), there remain unmet clinical needs. Heart-type fatty acid-binding protein (H-FABP) has been identified as an early diagnostic marker of acute myocardial infarction (AMI). In this study, we examined the diagnostic and prognostic value of H-FABP in patients suspected with ACS.

METHODS

We conducted an observational single-center cohort study, including 89 adults aged 30 years or older, who presented to the emergency room (ER) within 24 hours after the onset of chest pain and/or dyspnea. We performed laboratory analysis and point-of-care testing (POCT) for cardiac markers, including H-FABP, troponin I, and creatine kinase-myocardial band. We also evaluated the correlation between cardiac markers and left ventricular (LV) dysfunction and extent of coronary artery disease (CAD).

RESULTS

In patients presented to ER within 4 hours after symptom onset (n = 49), the diagnostic accuracy of H-FABP for AMI, as quantified by the area under the receiver operating characteristic curve, was higher (0.738; 95% confidence interval [CI], 0.591-0.885) than other cardiac markers. In POCT, the diagnostic accuracy of H-FABP (56%; 95% CI, 45-67) was significantly higher than other cardiac markers. H-FABP was correlated with not extent of CAD but post-AMI LV dysfunction.

CONCLUSION

H-FABP is a useful cardiac marker for the early diagnosis of AMI and prediction of myocardia injury. Difference in the circulatory release timeline of cardiac markers could explain its utility in early-stage of myocardial injury.

[Assessment of the Dynamics of Oxidative Stress Indicators and Early Markers of Myocardial Damage and Dysfunction in Patients with Aggressive Lymphoproliferative Diseases During of Anticancer Therapy]

Aim      To evaluate the dynamics of indexes of oxidative stress and markers of myocardial injury and dysfunction in patients with aggressive type lymphomas during the antitumor therapy.Material and methods  This study included 75 patients with lymphoproliferative diseases of aggressive type. The main group consisted of 53 patients who received one course of antitumor therapy during the study. The comparison group consisted of 22 patients who have not received any specific treatment so far. Troponin I (TnI), high-sensitivity troponin (hsTnI), heart-type fatty acid binding protein (Н-FAВР), N-terminal pro-brain natriuretic peptide (NT-prоBNP), superoxide dismutase (SOD), and myeloperoxidase (MPO) were measured in patients of both groups at baseline, and in the main group, they were measured at 4 hours after administration of antitumor agents and on completion of the course. Functional status of the cardiovascular system was evaluated by electrocardiography in all patients at baseline and after the course of antitumor treatment and by echocardiography.Results The chemotherapy was associated with increased levels of NT-prоBNP, SOD, and MPO (30.670±15.367 vs. 52.309±25.718 pmo l/l; 1.61±0.135 vs. 1.74±0.193 U/ml; and 507.54±91.51 vs. 742.3±49.01 ng/ml, respectively). The study results indicated activation of oxidative stress on the background of the administered antitumor therapy, progressive myocardial dysfunction, and increased frequency of arrhythmic episodes.Conclusion      The study results allowed identifying NT-prоBNP, MPO, and SOD as important indexes for determining a patient group at high risk of cardiotoxicity during the antitumor treatment.

Assessing the Performance of a Novel Point-of-Care Qualitative Assay for Early Diagnosis of Acute Coronary Syndrome

BACKGROUND

Early and accurate diagnosis of acute coronary syndrome (ACS) is essential for initiating lifesaving interventions. In this article, the diagnostic performance of a novel point-of-care rapid assay (SensAheart©) is analyzed. This assay qualitatively determines the presence of 2 cardiac biomarkers troponin I and heart-type fatty acid-binding protein that are present soon after onset of myocardial injury.

METHODS

We conducted a prospective observational study of consecutive patients who presented to the emergency department with typical chest pain. Simultaneous high-sensitive cardiac troponin T (hs-cTnT) and SensAheart testing was performed upon hospital admission. Diagnostic accuracy was computed using SensAheart or hs-cTnT levels versus the final diagnosis defined as positive/negative.

RESULTS

Of 225 patients analyzed, a final diagnosis of ACS was established in 138 patients, 87 individuals diagnosed with nonischemic chest pain. In the overall population, as compared to hs-cTnT, the sensitivity of the initial SensAheart assay was significantly higher (80.4 vs. 63.8%, p = 0.002) whereas specificity was lower (78.6 vs. 95.4%, p = 0.036). The overall diagnostic accuracy of SensAheart assay was similar to the hs-cTnT (82.7% compared to 76.0%, p = 0.08).

CONCLUSIONS

Upon first medical contact, the novel point-of-care rapid SensAheart assay shows a diagnostic performance similar to hs-cTnT. The combination of 2 cardiac biomarkers in the same kit allows for very early detection of myocardial damage. The SensAheart assay is a reliable and practical tool for ruling-in the diagnosis of ACS.

Biomarkers for Heart Failure Prognosis: Proteins, Genetic Scores and Non-coding RNAs

Heart failure (HF) is a complex disease in which cardiomyocyte injury leads to a cascade of inflammatory and fibrosis pathway activation, thereby causing decrease in cardiac function. As a result, several biomolecules are released which can be identified easily in circulating body fluids. The complex biological processes involved in the development and worsening of HF require an early treatment strategy to stop deterioration of cardiac function. Circulating biomarkers provide not only an ideal platform to detect subclinical changes, their clinical application also offers the opportunity to monitor disease treatment. Many of these biomarkers can be quantified with high sensitivity; allowing their clinical application to be evaluated beyond diagnostic purposes as potential tools for HF prognosis. Though the field of biomarkers is dominated by protein molecules, non-coding RNAs (microRNAs, long non-coding RNAs, and circular RNAs) are novel and promising biomarker candidates that encompass several ideal characteristics required in the biomarker field. The application of genetic biomarkers as genetic risk scores in disease prognosis, albeit in its infancy, holds promise to improve disease risk estimation. Despite the multitude of biomarkers that have been available and identified, the majority of novel biomarker candidates are not cardiac-specific, and instead may simply be a readout of systemic inflammation or other pathological processes. Thus, the true value of novel biomarker candidates in HF prognostication remains unclear. In this article, we discuss the current state of application of protein, genetic as well as non-coding RNA biomarkers in HF risk prognosis.

H-FABP: A beacon of hope for prediabetic heart disease

Background:

Prediabetes is increasingly being studied in the context of its association with cardiovascular disease (CVD). Besides raised HbA1c and sugar levels, the major underlying defect seems to be insulin resistance (IR). Subclinical atherosclerosis, measured by high sensitivity C reactive protein (hsCRP) and carotid artery intima media thickness (CIMT) underlies the pathogenesis of CVD in prediabetes. Heart-type fatty acid binding protein (H-FABP), a novel cardiac biomarker also might have a role in predictin prediabetic heart disease.

Aims:

The aim of the study is to compare serum levels of H-FABP in prediabetics and controls and correlate them with the atherosclerotic markers, hsCRP and CIMT.

Setting and Design:

50 prediabetic patients and 50 age, sex and BMI matched controls were employed in the case control study. Serum F & PPBS, (HbA1c), fasting insulin levels were measured in cases and controls. Serum H-FABP was measured in both cases and controls. All cases and controls were subjected to bilateral CIMT measurements and Serum hsCRP levels. The values were compared between both the groups and subjected to appropriate statistical analysis.

Statistical Analysis Used:

Categorical variables were presented in number and percentage (%) and continuous variables were presented as mean ± SD and median. Normality of data was tested by Kolmogorov-Smirnov test. If the normality was rejected then non parametric test was used. Quantitative variables were compared using Independent t test/Mann-Whitney Test (when the data sets were not normally distributed) between the two groups. Qualitative variables were correlated using Chi-Square test/Fisher's Exact test. Spearman rank correlation coefficient was used to find out the correlation of various parameters with each other. Univariate linear regression was used to find out the cause and effect relationship between various parameters. A p <0.05 was considered statistically significant. The data analysis was done using Statistical Package for Social Sciences (SPSS) version 21.0.

Results:

The mean serum levels of H-FABP among cases and controls were 6.38± 2.76ng/ml and 3.24 ± 2.47 ng/ml respectively (p <0.0001). Mean CIMT was found to be higher in prediabetics (0.59 ± 0.11 mm ) compared to controls (0.45 ± 0.07mm) (p<0.0001). Serum hsCRP levels were also statistically higher in prediabetics (5.75± 4.16 mg/l) then that of controls (1.86± 1.67 mg/l) (p <0.0001). The correlations of the two variables, hsCRP and CIMT with H-FABP were both strongly positive (r = 0.687) & (r = 0.779) respectively [both cases (p < 0.0001)].

Conclusion:

The novel cardiac biomarker H-FAPB might be a good predictor of cardiovascular risks in prediabetics.

Cardiac biomarkers of heart failure in chronic kidney disease

Heart failure remains a continuing threat to patients with chronic kidney disease (CKD). Although various heart failure biomarkers have been applied for early detection, diagnosis and prognosis in CKD, these are easily affected by renal insufficiency thus limiting use in these patients. In this review, the major four groups of heart failure biomarkers are explored. These include those associated with: myocardial stretch, ie, brain natriuretic peptide (BNP), N-terminal pro-BNP (NT-proBNP) and mid-regional proatrial natriuretic peptide (MR-proANP); myocyte injury, ie, high-sensitivity troponin T (hsTnT), heart-type fatty acid-binding protein (H-FABP); fibrosis, matrix remodelling and inflammation, ie, soluble growth stimulating gene 2 (sST2), galectin-3 (Gal-3), growth differentiation factor-15 (GDF-15); and renal function, ie, neutrophil gelatinase-associated lipocalin (NGAL) kidney injury molecule-1 (KIM-1), cystatin C (CysC), urinary sodium and urinary albumin. This review highlights classic heart failure biomarkers with critical values adjusted to glomerular filtration rate, summarizes research progress of new heart failure biomarkers and future research directions. Because diagnostic and prognostic usefulness of a single time point biomarker is limited, biomarkers should be combined and monitored at multiple times for optimal clinical impact.

Heart-Type Fatty Acid-Binding Protein (H-FABP) and its Role as a Biomarker in Heart Failure: What Do We Know So Far?

BACKGROUND

Heart failure (HF) remains one of the leading causes of death to date despite extensive research funding. Various studies are conducted every year in an attempt to improve diagnostic accuracy and therapy monitoring. The small cytoplasmic heart-type fatty acid-binding protein (H-FABP) has been studied in a variety of disease entities. Here, we provide a review of the available literature on H-FABP and its possible applications in HF. Methods: Literature research using PubMed Central was conducted. To select possible studies for inclusion, the authors screened all available studies by title and, if suitable, by abstract. Relevant manuscripts were read in full text.

RESULTS

In total, 23 studies regarding H-FABP in HF were included in this review.

CONCLUSION

While, algorithms already exist in the area of risk stratification for acute pulmonary embolism, there is still no consensus for the routine use of H-FABP in daily clinical practice in HF. At present, the strongest evidence exists for risk evaluation of adverse cardiac events. Other future applications of H-FABP may include early detection of ischemia, worsening of renal failure, and long-term treatment planning.

Complementary Diagnostic Value of Heart Type Fatty Acid-binding Protein in Early Detection of Acute Myocardial Infarction

BACKGROUND

Heart-type fatty acid-binding protein (H-FABP) is a novel biomarker for myocardial injury. We compared the use of H-FABP with serum levels of cardiac troponin-T (cTnT) and creatine kinase-MB (CK-MB) in the diagnosis of patients suspicious to acute myocardial infarction (AMI).

METHODS

From October 2013 to December 2014, 182 consecutive patients suspicious to acute coronary syndrome were enrolled in this study, who presented within the past 6 hours from the onset of symptoms. Venous blood samples were drawn at baseline to measure serum biochemistry, high-sensitive cardiac troponin T (hs-cTNT), creatine kinase-MB, and H-FABP, and the measurements were repeated after 8 hours. The patients were categorized into 3 groups based on the baseline and second measurements of cTnT and general characteristics, and changes of H-FABP levels were then compared between the groups. Sensitivity and specificity of H-FABP in predicting the presence of AMI was calculated.

RESULTS

A total of 91 patients had AMI. Changes of H-FABP through time were also significantly different between the AMI and non-AMI patients (P < 0.001). A cutoff point of 7.15 for H-FABP could predict AMI with a sensitivity of 51.5%, specificity of 96.3%, and diagnostic accuracy of 68.3%. The area under the receiver operating characteristic curve for H-FABP at 8 hours was 79.4% (95% confidence interval: 73.0-85.9; P < 0.001). Positive predictive value and negative predictive value for H-FABP were 85% and 60%, respectively.

CONCLUSIONS

H-FABP can be used as an additional cardiac biomarker in the diagnosis of AMI.

Acute Responses of Novel Cardiac Biomarkers to a 24-h Ultra-Marathon

The aim of the present study was to examine the acute effect of an ultra-endurance performance on N-terminal pro-brain natriuretic peptide (NT-proBNP), cardiac specific troponin T (cTnT), creatinine kinase-myocardial band (CK-MB), high sensitive C-reactive protein (hsCRP), ischemia modified albumin (IMA), heart-type fatty acid binding protein (H-FABP) and cardiovascular function. Cardiac biomarkers were evaluated in 14 male ultra-marathoners (age 40 ± 12 years) during a 24 h ultra-marathon at five points (i.e., Pre-race; Marathon, 12-h run, 24-h run, and 48-h post-race). All subjects underwent baseline echocardiography assessment at least 10 days prior to the ultra-marathon and 48 h post-race. The average distance covered during the race was 149.4 ± 33.0 km. Running the ultra-marathon led to a progressive increase in hsCRP and H-FABP concentrations (p < 0.001). CK-MB and cTnT levels were higher after a 24-h run compared to pre-race (p < 0.05). Diastolic function was altered post-race characterized by a reduction in peak early to late diastolic filling (p < 0.01). Running an ultra-marathon significantly stimulates specific cardiac biomarkers; however, the dynamic of secretion of biomarkers linked to myocardium ischemia were differentially regulated during the ultra-marathon race. It is suggested that both exercise duration and intensity play a crucial role in cardiovascular adaptive mechanisms and cause risk of cardiac stress in ultra-marathoners.

Administration of Fenofibrate Markedly Elevates Fabp3 in Rat Liver and Plasma and Confounds Its Use as a Preclinical Biomarker of Cardiac and Muscle Toxicity

Proteins involved in lipid homeostasis are often regulated through the nuclear peroxisome proliferator-activated receptors (PPAR). PPARα is the target for the fibrate-class of drugs. Fenofibrate has been approved for its lipid-lowering effects in patients with hypercholesterolemia and hypertriglyceridemia. We were interested in understanding the expression of the energy transporters in energy-utilizing tissues like liver, heart, muscle, and adipose tissues in rat with the hypothesis that the change in transporter expression would align with the known lipid-lowering effects of PPARα agonists like fenofibrate. We found that several fatty-acid transporter proteins had significantly altered levels following 8 days of fenofibrate dosing. The mRNA levels of the highly abundant Fatp2 and Fatp5 in rat liver increased approximately twofold and decreased fourfold, respectively. Several fatty-acid-binding proteins and acyl-CoA-binding proteins had a significant increase in mRNA abundance but not the major liver fatty-acid-binding protein, Fabp1. Of particular interest was the increased liver expression of Fabp3 also known as heart-fatty acid binding protein (H-FABP or FABP3). FABP3 has been proposed as a circulating clinical biomarker for cardiomyopathy and muscle toxicity, as well as a preclinical marker for PPARα-induced muscle toxicity. Here, we show that fenofibrate induces liver mRNA levels of Fabp3 ~5000-fold resulting in an approximately 50-fold increase in FABP3 protein levels in the whole liver. This increased liver expression complicates the interpretation and potential use of FABP3 as a specific biomarker for PPARα-induced muscle toxicities.

The prognostic significance of heart-type fatty acid binding protein in patients with stable coronary heart disease

To investigate the prognostic value of heart-type fatty acid binding protein (H-FABP) in patients with stable coronary heart disease (SCHD). A total of 1,071 patients with SCHD were prospectively enrolled in this Taiwan multicenter registry study, followed for 24 months. The cut-off value of H-FABP, 4.143 ng/mL, was determined using receiver operating characteristic curves. The primary cardiovascular (CV) outcome was composite CV events, defined as cardiovascular or cerebrovascular death, myocardial infarction (MI), stroke, angina related-hospitalization, PAOD-related hospitalization and heart failure. Secondary outcomes included CV or cerebrovascular death, nonfatal MI, nonfatal stroke, and acute heart failure-related hospitalization. We found that the high H-FABP group had more than a two-fold higher rate of primary CV outcomes than the low H-FABP group (32.36% vs. 15.78%, p < 0.001). Eleven patients (4.82%) of the high H-FABP group died during the 24 months of follow-up, compared to only one patient (0.12%) in the low H-FABP group. The acute heart failure-related hospitalization rate was also significantly higher in the high H-FABP group (3.5% vs. 0.95%, p < 0.005). The results remained significant after adjusting for baseline covariates. In conclusion, H-FABP was an independent predictor for CV outcomes in the patients with SCHD, mainly in CV death and acute heart failure-related hospitalization.

Novel heart failure biomarkers: why do we fail to exploit their potential?

Plasma biomarkers are useful tools in the diagnosis and prognosis of heart failure (HF). In the last decade, numerous studies have aimed to identify novel HF biomarkers that would provide superior and/or additional diagnostic, prognostic, or stratification utility. Although numerous biomarkers have been identified, their implementation in clinical practice has so far remained largely unsuccessful. Whereas cardiac-specific biomarkers, including natriuretic peptides (ANP and BNP) and high sensitivity troponins (hsTn), are widely used in clinical practice, other biomarkers have not yet proven their utility. Galectin-3 (Gal-3) and soluble suppression of tumorigenicity 2 (sST2) are the only novel HF biomarkers that are included in the ACC/AHA HF guidelines, but their clinical utility still needs to be demonstrated. In this review, we will describe natriuretic peptides, hsTn, and novel HF biomarkers, including Gal-3, sST2, human epididymis protein 4 (HE4), insulin-like growth factor-binding protein 7 (IGFBP-7), heart fatty acid-binding protein (H-FABP), soluble CD146 (sCD146), interleukin-6 (IL-6), growth differentiation factor 15 (GDF-15), procalcitonin (PCT), adrenomedullin (ADM), microRNAs (miRNAs), and metabolites like 5-oxoproline. We will discuss the biology of these HF biomarkers and conclude that most of them are markers of general pathological processes like fibrosis, cell death, and inflammation, and are not cardiac- or HF-specific. These characteristics explain to a large degree why it has been difficult to relate these biomarkers to a single disease. We propose that, in addition to clinical investigations, it will be pivotal to perform comprehensive preclinical biomarker investigations in animal models of HF in order to fully reveal the potential of these novel HF biomarkers.

Application of Large-Scale Aptamer-Based Proteomic Profiling to Planned Myocardial Infarctions

BACKGROUND

Emerging proteomic technologies using novel affinity-based reagents allow for efficient multiplexing with high-sample throughput. To identify early biomarkers of myocardial injury, we recently applied an aptamer-based proteomic profiling platform that measures 1129 proteins to samples from patients undergoing septal alcohol ablation for hypertrophic cardiomyopathy, a human model of planned myocardial injury. Here, we examined the scalability of this approach using a markedly expanded platform to study a far broader range of human proteins in the context of myocardial injury.

METHODS

We applied a highly multiplexed, expanded proteomic technique that uses single-stranded DNA aptamers to assay 4783 human proteins (4137 distinct human gene targets) to derivation and validation cohorts of planned myocardial injury, individuals with spontaneous myocardial infarction, and at-risk controls.

RESULTS

We found 376 target proteins that significantly changed in the blood after planned myocardial injury in a derivation cohort (n=20; P<1.05E-05, 1-way repeated measures analysis of variance, Bonferroni threshold). Two hundred forty-seven of these proteins were validated in an independent planned myocardial injury cohort (n=15; P<1.33E-04, 1-way repeated measures analysis of variance); >90% were directionally consistent and reached nominal significance in the validation cohort. Among the validated proteins that were increased within 1 hour after planned myocardial injury, 29 were also elevated in patients with spontaneous myocardial infarction (n=63; P<6.17E-04). Many of the novel markers identified in our study are intracellular proteins not previously identified in the peripheral circulation or have functional roles relevant to myocardial injury. For example, the cardiac LIM protein, cysteine- and glycine-rich protein 3, is thought to mediate cardiac mechanotransduction and stress responses, whereas the mitochondrial ATP synthase F0 subunit component is a vasoactive peptide on its release from cells. Last, we performed aptamer-affinity enrichment coupled with mass spectrometry to technically verify aptamer specificity for a subset of the new biomarkers.

CONCLUSIONS

Our results demonstrate the feasibility of large-scale aptamer multiplexing at a level that has not previously been reported and with sample throughput that greatly exceeds other existing proteomic methods. The expanded aptamer-based proteomic platform provides a unique opportunity for biomarker and pathway discovery after myocardial injury.

Elevated Heart-Type Fatty Acid-Binding Protein Predicts Early Myocardial Injury and Aids in the Diagnosis of Non-St Elevation Myocardial Infarction

Background

Biomarkers play an important role in the early diagnosis, risk stratification and management of patients with the acute coronary syndrome.

Objective

The objective of this study was to evaluate the clinical reliability of heart-type fatty acid-binding protein (h-FABP) in identifying patients with the acute coronary syndrome in the early hours of chest pain.

Methods

Creatine kinase (CK-MB) (in laboratory), troponin T (in laboratory) and h-FABP (with point-of-care test CardioDetect®) were performed on 791 patients who presented with chest pain with duration since onset ranging from 20 minutes to 12 hours.

Results

Data of the 791 patients were analysed. h-FABP had a higher sensitivity of 75.76% and a specificity of 96.97% compared with 58.59% and 98.84% for troponin T and 68.69% and 97.54% for CK-MB respectively (in the first 6 hours). Conclusion: h-FABP was found to be a better biomarker of cardiac necrosis in the early hours in the diagnosis of non-conclusive ECG in patients with acute myocardial infarction. (Hong Kong j.emerg.med. 2009;16:141–147)

Heart-type fatty acid-binding protein in cardiovascular disease: A systemic review

Fatty acid-binding proteins, whose clinical applications have been studied, are a family of proteins that reflect tissue injury. Heart-type fatty acid-binding protein (H-FABP) is a marker of ongoing myocardial damage and useful for early diagnosis of acute myocardial infarction (AMI). In the past decade, compared to other cardiac enzymes, H-FABP has shown more promise as an early detection marker for AMI. However, the role of H-FABP is being re-examined due to recent refinement in the search for newer biomarkers, and greater understanding of the role of high-sensitivity troponin. We discuss the current role of H-FABP as an early marker for AMI in the era of high sensitive troponin. H-FABP is highlighted as a prognostic marker for a broad spectrum of fatal diseases, viz., AMI, heart failure, arrhythmia, and pulmonary embolism that could be associated with poor clinical outcomes. Because the cut-off value of what constitutes an abnormal H-FABP potentially differs for each cardiovascular event and depends on the clinical setting, an optimal cut-off value has not been clearly established. Of note, several factors such as age, gender, and cardiovascular risk factors, which affect H-FABP levels need to be considered in this context. In this review, we discuss the clinical applications of H-FABP as a prognostic marker in various clinical settings.

Does heart-type fatty acid-binding protein predict clinical outcomes after pediatric cardiac surgery?

Introduction:

The early identification of vulnerable pediatric cardiac surgery patients can help clinicians provide them with timely support. Heart-type fatty acid-binding protein. (H-FABP) is an early biomarker of myocardial injury in acute myocardial infarction in adults. In this study, we evaluated the correlations between postoperative H-FABP, creatine kinase-myocardial band (CK-MB), troponin-I, total bypass time, and clinical outcomes.

Methods:

In 32 pediatric patients that underwent ventricular septal defect. closure we measured H-FABP, troponin-I and CK-MB preoperatively and 1, 3, and 6 h after aortic declamping. Spearman's Rho correlations were calculated between laboratory and clinical parameters including inotropic support duration, aortic cross-clamp time, total bypass time, ventilation-weaning-time, and total Intensive Care Unit stay.

Results:

H-FABP, CK-MB, troponin-I, and total bypass time have a similarly weak to moderate correlation with clinical outcome measures.

Conclusions:

The predictive value of H-FABP for clinical outcome is not stronger than that of CK-MB, Troponin-I, or bypass times.

The Prognostic Value of Serum Levels of Heart-Type Fatty Acid Binding Protein and High Sensitivity C-Reactive Protein in Patients With Increased Levels of Amino-Terminal Pro-B Type Natriuretic Peptide

Background

Amino-terminal pro-B type natriuretic peptide (NT-proBNP) is a well-established prognostic factor in heart failure (HF). However, numerous causes may lead to elevations in NT-proBNP, and thus, an increased NT-proBNP level alone is not sufficient to predict outcome. The aim of this study was to evaluate the utility of two acute response markers, high sensitivity C-reactive protein (hsCRP) and heart-type fatty acid binding protein (H-FABP), in patients with an increased NT-proBNP level.

Methods

The 278 patients were classified into three groups by etiology: 1) acute coronary syndrome (ACS) (n=62), 2) non-ACS cardiac disease (n=156), and 3) infectious disease (n=60). Survival was determined on day 1, 7, 14, 21, 28, 60, 90, 120, and 150 after enrollment.

Results

H-FABP (P<0.001), NT-proBNP (P=0.006), hsCRP (P<0.001) levels, and survival (P<0.001) were significantly different in the three disease groups. Patients were divided into three classes by using receiver operating characteristic curves for NT-proBNP, H-FABP, and hsCRP. Patients with elevated NT-proBNP (≥3,856 pg/mL) and H-FABP (≥8.8 ng/mL) levels were associated with higher hazard ratio for mortality (5.15 in NT-proBNP and 3.25 in H-FABP). Area under the receiver operating characteristic curve analysis showed H-FABP was a better predictor of 60-day mortality than NT-proBNP.

Conclusions

The combined measurement of H-FABP with NT-proBNP provides a highly reliable means of short-term mortality prediction for patients hospitalized for ACS, non-ACS cardiac disease, or infectious disease.

Novel Biomarkers of Heart Failure

Although substantial improvements have been made in majority of cardiac disorders, heart failure (HF) remains a major health problem, with both increasing incidence and prevalence over the past decades. For that reason, the number of potential biomarkers that could contribute to diagnosis and treatment of HF patients is, almost exponentially, increasing over the recent years. The biomarkers that are, at the moment, more or less ready for use in everyday clinical practice, reflect different pathophysiological processes present in HF. In this review, seven groups of biomarkers associated to myocardial stretch (mid-regional proatrial natriuretic peptide, MR-proANP), myocyte injury (high-sensitive troponins, hs-cTn; heart-type fatty acid-binding protein, H-FABP; glutathione transferase P1, GSTP1), matrix remodeling (galectin-3; soluble isoform of suppression of tumorigenicity 2, sST2), inflammation (growth differentiation factor-15, GDF-15), renal dysfunction (neutrophil gelatinase-associated lipocalin, NGAL; kidney injury molecule-1, KIM-1), neurohumoral activation (adrenomedullin, MR-proADM; copeptin), and oxidative stress (ceruloplasmin; myeloperoxidase, MPO; 8-hydroxy-2'-deoxyguanosine, 8-OHdG; thioredoxin 1, Trx1) in HF will be overviewed. It is important to note that clinical value of individual biomarkers within the single time points in both diagnosis and outcome prediction in HF is limited. Hence, the future of biomarker application in HF lies in the multimarker panel strategy, which would include specific combination of biomarkers that reflect different pathophysiological processes underlying HF.

Aptamer-Based Proteomic Profiling Reveals Novel Candidate Biomarkers and Pathways in Cardiovascular Disease

BACKGROUND

Single-stranded DNA aptamers are oligonucleotides of ≈50 base pairs in length selected for their ability to bind proteins with high specificity and affinity. Emerging DNA aptamer-based technologies may address limitations of existing proteomic techniques, including low sample throughput, which have hindered proteomic analyses of large cohorts.

METHODS

To identify early biomarkers of myocardial injury, we applied an aptamer-based proteomic platform that measures 1129 proteins to a clinically relevant perturbational model of planned myocardial infarction (PMI), patients undergoing septal ablation for hypertrophic cardiomyopathy. Blood samples were obtained before and at 10 and 60 minutes after PMI, and protein changes were assessed by repeated-measures analysis of variance. The generalizability of our PMI findings was evaluated in a spontaneous myocardial infarction cohort (Wilcoxon rank-sum). We then tested the platform's ability to detect associations between proteins and Framingham Risk Score components in the Framingham Heart Study, performing regression analyses for each protein versus each clinical trait.

RESULTS

We found 217 proteins that significantly changed in the peripheral vein blood after PMI in a derivation cohort (n=15; P<5.70E-5). Seventy-nine of these proteins were validated in an independent PMI cohort (n=15; P<2.30E-4); >85% were directionally consistent and reached nominal significance. We detected many protein changes that are novel in the context of myocardial injury, including Dickkopf-related protein 4, a WNT pathway inhibitor (peak increase 124%, P=1.29E-15) and cripto, a growth factor important in cardiac development (peak increase 64%, P=1.74E-4). Among the 40 validated proteins that increased within 1 hour after PMI, 23 were also elevated in patients with spontaneous myocardial infarction (n=46; P<0.05). Framingham Heart Study analyses revealed 156 significant protein associations with the Framingham Risk Score (n=899), including aminoacylase 1 (β=0.3386, P=2.54E-22) and trigger factor 2 (β=0.2846, P=5.71E-17). Furthermore, we developed a novel workflow integrating DNA-based immunoaffinity with mass spectrometry to analytically validate aptamer specificity.

CONCLUSIONS

Our results highlight an emerging proteomics tool capable of profiling >1000 low-abundance analytes with high sensitivity and high precision, applicable both to well-phenotyped perturbational studies and large human cohorts, as well.

Immunohistochemical detection of early myocardial infarction: a systematic review

The postmortem diagnosis of early myocardial infarction is a challenge for forensic pathologists because the routine histology is neither specific. Many authors have suggested the use of the immunohistochemistry to fill the gaps in the histological diagnosis of early myocardial infarction. This review aims to analyse advances of immunohistochemical detection of early cardiac damage due to ischaemia. To this purpose, we reviewed experimental studies that investigated immunohistochemical markers and their estimated timing of expression. The review was performed according to specific inclusion and exclusion criteria, and a total of 23 studies assessing the immunohistochemical markers for the diagnosis and timing of early myocardial infarction were identified. The literature review highlights that the analysed markers are complement components, others being inflammatory mediators, cardiac cell proteins, plasma proteins, stress or hypoxia-induced factors and proteins associated with heart failure. All studies demonstrate the effectiveness of the tested markers in the early detection of myocardial infarction in both animal and human samples.

Cytokine-like Activity of Liver Type Fatty Acid Binding Protein (L-FABP) Inducing Inflammatory Cytokine Interleukin-6

It has been reported that fatty acid binding proteins (FABPs) do not act only as intracellular mediators of lipid responses but also have extracellular functions. This study aimed to investigate whether extracellular liver type (L)-FABP has a biological activity and to determined serum L-FABP levels in patients with end-stage renal disease (ESRD). We isolated L-FABP complementary deoxyribonucleic acid (cDNA) from the Huh7 human hepatocarcinoma cell line and expressed the recombinant L-FABP protein in Escherichia coli. A549 lung carcinoma and THP-1 monocytic cells were stimulated with the human recombinant L-FABP. Human whole blood cells were also treated with the human recombinant L-FABP or interleukin (IL)-1α. IL-6 levels were measured in cell culture supernatants using IL-6 enzyme-linked immunosorbent assay (ELISA). Human recombinant L-FABP induced IL-6 in a dose-dependent manner in A549, THP-1 cells, and whole blood cells. The blood samples of healthy volunteers and patients with ESRD were taken after an overnight fast. The serum levels of L-FABP in healthy volunteers and ESRD patients were quantified with L-FABP ELISA. The values of L-FABP in patients with ESRD were significantly lower than those in the control group. Our results demonstrated the biological activity of L-FABP in human cells suggesting L-FABP can be a mediator of inflammation.

A Study on the Role of Heart Type Fatty Acid Binding Protein in the Diagnosis of Acute Myocardial Infarction

INTRODUCTION

Heart type Fatty Acid Binding Protein (H-FABP) has been proposed as an early cardiac biomarker for the diagnosis of acute myocardial Infarction (AMI) using animal models and clinical samples.

AIM

The study aimed to evaluate the role of H-FABP in early detection of AMI by comparing its sensitivity, specificity and predictive value with Creatinine Kinase-MB (CK-MB) and Cardiac Troponin I (cTnI).

MATERIALS AND METHODS

This is a cross-sectional descriptive study of 50 patients admitted with the diagnosis of AMI at a tertiary care hospital in South India. The study group was categorised in to those coming to the hospital within four hours of symptom onset and those coming in between 4 to 12 hours. H-FABP was compared with those of troponin T and myoglobin tests.

RESULTS

Among patients presenting within four hours of symptom onset, the sensitivity of H-FABP was 60% and was significantly higher than that of cardiac Troponin I (cTnI, 18.8%) and Creatinine Kinase (CK)-MB (12.5%). But specificity was only 23.53% and was less than that of cTnI (66.67%) and CK-MB (100%). In patients presenting during 4 to 12 hours of symptom onset, the sensitivity of H-FABP was 86.96% which was comparable to that of cTnI (90.9%) and CK-MB (77.3%). The specificity was 60% in the 4-12 hours group which was comparable to that of cTnI (50%) and CK-MB (50%).

CONCLUSION

The H-FABP is a sensitive biomarker for the diagnosis of AMI in the initial hours after symptom onset when the standard biomarkers may not be elevated, but it is less specific. During 4-12 hours of symptom onset it is as sensitive and specific as standard cardiac biomarkers troponin and CK-MB. Due to these factors H-FABP can be considered as a promising cardiac biomarker which can be used along with troponins and CK-MB at present.

Serum Level of Heart-Type Fatty Acid Binding Protein (H-FABP) Before and After Treatment of Congestive Heart Failure in Children

Remodeling of the heart following injury affects the morbidity and mortality in children presented with heart failure (HF). Heart-type fatty acid binding protein (H-FABP) is a novel biomarker that could be of help to predict the prognosis and risk stratification in those children. We aimed to evaluate the diagnostic and prognostic value of H-FABP in children with heart failure before and after treatment. The study was conducted as a prospective cohort study. It included 30 children with HF as a patient group and 20 healthy children matched for age and sex as a control group. Echocardiographic assessment of the heart was done using conventional Doppler echocardiography. Serum levels of (H-FABP) were measured using enzyme-linked immunosorbent assay before and after treatment of HF. All patients were observed during follow-up period of 3 months. There was a significant difference in the serum level of H-FABP in our patients before treatment (5.278 ± 3.253 ng/ml) compared with after treatment (2.089 ± 0.160 ng/ml) with significant difference compared with the control group. There was a significant increase in the serum level of H-FABP with increase in the severity of heart failure according to Ross classification. Significant increase in the H-FABP was associated with adverse outcome. Serum levels of H-FABP strongly correlated with clinical and echocardiographic assessment of LV performance of children with HF, and its levels significantly increased in children with adverse outcome suggesting its value as a useful diagnostic and prognostic predictor (with high sensitivity and specificity).

Heart-type fatty acid-binding protein (H-FABP) as an early diagnostic biomarker in patients with acute chest pain

BACKGROUND

Heart-type fatty acid-binding protein (H-FABP) is an emerging biomarker, which was found to be sensitive for the early diagnosis of acute myocardial infarction (AMI). We prospectively investigated the usefulness of H-FABP determination for the evaluation of acute chest pain in patients arriving at the emergency department.

METHODS

Fifty-four patients presenting with acute ischemic chest pain were evaluated. H-FABP was estimated at admission using latex-enhanced immunoturbidimetric assay. Serial cardiac troponin I (cTnI), creatinine kinase-MB (CK-MB) determination, ischemia workup with stress testing, and/or coronary angiogram (CAG) were performed according to standard protocols.

RESULTS

The sensitivity and specificity of H-FABP was 89.7% and 68%, for cTnI it was 62.1% and 100%, and for CK-MB it was 44.8% and 92%, respectively for diagnosis of AMI. The sensitivity of H-FABP was found to be far superior to initial cTnI and CK-MB, for those seen within 6h (100% vs. 46.1%, 33% respectively). On further evaluation of patients with positive H-FABP and negative cTnI, 71.4% of the patients had significant lesion on CAG, indicating ischemic cause of H-FABP elevation. Six patients with normal cTnI and CK-MB with high H-FABP had ST elevation on subsequent ECGs and were taken for primary angioplasty.

CONCLUSION

H-FABP is a highly sensitive biomarker for the early diagnosis of AMI. H-FABP as early marker and cTnI as late marker would be the ideal combination to cover the complete diagnostic window for AMI. Detection of myocardial injury by H-FABP may also be applied in patients with unstable angina. H-FABP can also be used as a marker for early detection of STEMI before the ECG changes become apparent.

Utility of Heart-type Fatty Acid Binding Protein as a New Biochemical Marker for the Early Diagnosis of Acute Coronary Syndrome

INTRODUCTION

Acute coronary syndrome (ACS) refers to a constellation of clinical symptoms caused by acute myocardial ischemia. Cardiovascular diseases (CVDs) are major and growing contributors to mortality and disability in India.

AIMS AND OBJECTIVES

Especially patients with non-ACS-related troponin elevations have an adverse outcome and require careful patient management. So, we look forward for another marker Heart-type Fatty Acid Binding Protein (H-FABP) that reliably detects myocardial ischemia in the absence of necrosis and would be useful for initial identification and for differentiating patients with chest pain of aetiology other than coronary ischemia.

MATERIALS AND METHODS

The study was done on 88 subjects of whom 34 subjects were with ischemic chest pain, 29 were with non-ischemic chest pain and 25 were normal subjects.

RESULTS

Receiver operating characteristic (ROC) curve analysis was done which showed that area under the curve (AUC) for H-FABP was 0.885(0.79-0.94) and that of high-sensitive Troponin T (hs-TnT) in initial six hours was 0.805(0.70-0.88). The specificity of H-FABP was higher compare to hs-TnT while sensitivity was comparable during 0-6 h of presentation of chest pain.

CONCLUSION

H-FABP can be used as an additional marker to hs-TnT in diagnosis of myocardial infarction (MI) and for exclusion of non-AMI (acute myocardial infarction) patients.

Value of heart-type fatty acid-binding protein (H-FABP) for emergency department patients with suspected acute coronary syndrome

OBJECTIVE

The aim of this study is testing the value of H-FABP in the early diagnosis of ACS alone or with routinely used biomarkers such as myoglobin, CK-MB, and cTn I in patients who admitted to emergency department (ED) with complaint of chest pain and suspected acute coronary syndrome.

MATERIAL AND METHODS

This prospective and cross-sectional study was performed at the Emergency Department of University hospital between June 2009 and September 2010. Patients who were admitted with chest pain within first 48 hours and suspected ACS were enrolled to the study. Blood samples were taken for CK-MB, myoglobin, cTnI and H-FABP The patients were divided into two groups (ACS and non ACS). Statistical analyse were used for relation of biomarkers with diagnosis of ACS.

RESULTS

A 66 patients were included to the study. H-FAPB values were positive in 15.2% patients. When H-FABP was added to routinely used biomarkers in the diagnosis of ACS, increasing was observed in all sensitivity, specificity, PPV and NPV values. However, this increase was not statistically significant.

CONCLUSION

H-FABP did not provide any significant change in early diagnosis and exclusion of ACS diagnosis when used either alone or combination with routinely used biomarkers.

Comparative study of high sensitivity troponin T and heart-type fatty acid-binding protein in STEMI patients

AIM AND BACKGROUND

Heart-type fatty acid-binding proteins (H-FABP) which are detected within 2-3 h of acute myocardial infarction are involved in uptake of free fatty acids in the myocardium. Our aim in the present study is to compare window periods of H-FABP to high sensitivity troponin T (hs-Trop T) in acute ST elevation myocardial infarction (STEMI).

METHODS

160 STEMI diagnosed patient's serum samples are analyzed for hs-Trop T and H-FABP. Different window periods of chest pain onset (<3 h, 3-6 h and >6 h) are compared with complications, in-hospital mortality and statistically analyzed.

RESULTS

From 160 patients, 53 (33%) cases are presented in <3 h, 75 (47%) in 3-6, and 32 (20%) after >6 h respectively. Accordingly sensitivity of hs-Trop T was 92%, 94% and 97% while H-FABP was 75%, 88% and 84%, respectively. Overall sensitivity was 94% and 82% respectively. Statistically significant difference between mean hs-Trop T values with respect to window period <3, 3-6 and >6 h was 0.21, 0.35 and 0.80 ng/ml respectively, p value < 0.0001. No significant difference in H-FABP values was observed. Hs-Trop T positively correlated with age (r = 0.153, P = 0.05), window period (r = 0.363, P < 0.0001), TIMI score (r = 0.208, P = 0.008), ejection fraction (r = 0.191, P = 0.008), serum H-FABP (r = 0.229, P = 0.004), and serum hs-CRP (r = 0.326, p < 0.001). There was a statistically significant difference of mean hs-Trop T values with or without in hospital mortality (0.35 vs. 0.85 ng/ml, respectively, p = 0.008). No significant correlation to age, TIMI score, ejection fraction and hs-CRP values for H-FABP was observed.

CONCLUSION

It appears that hs-Trop T is a more sensitive marker than H-FABP in early hours of AMI and higher hs-Trop T predicts increase in-hospital mortality.

The prognostic significance of the serum biomarker heart-fatty acidic binding protein in comparison with s100b in severe traumatic brain injury

The outcome after severe traumatic brain injury (TBI) is largely unfavorable, with approximately two thirds of patients suffering from severe disabilities or dying during the first 6 months. Existing predictive models displayed only limited utility for outcome prediction in individual patients. Time courses of heart-fatty acidic binding protein (H-FABP) and their association with outcome were investigated and compared with S100b. Forty-nine consecutive patients with severe TBI (sTBI; Head component of the Abbreviated Injury Scale [HAIS] >3) with mono and multiple trauma were enrolled in this study. Enzyme-linked immunosorbent assay measured blood concentrations of H-FABP and S100b at 6, 12, 24, and 48 h after TBI. Outcome measures were conscious state at 14 days (Glasgow Coma Scale), disability (Glasgow Outcome Scale Extended; GOSE), and mortality at 3 months. Univariate logistic regression analysis and receiver operating characteristic curves analysis were carried out. Maximal H-FABP and S100b concentrations were observed at 6 h after TBI (34.4±34.0 and 0.64±0.99 ng/mL, respectively). Patients with multi-trauma had significantly higher H-FABP concentrations at 24 and 48 h (22.6±25.6 and 12.4±18.2 ng/mL, respectively), compared to patients with mono trauma (6.9±5.1 and 3.7±4.2 ng/mL, respectively). In the first 48 h, H-FABP and S100b were inversely correlated with the GOSE at 3 months; H-FABP at 48 h predicted mortality with 75% sensitivity and 93% specificity. Early blood levels of H-FABP after sTBI have prognostic significance for survival and disability.

Prognostic relevance of plasma heart-type fatty acid binding protein after out-of-hospital cardiac arrest

OBJECTIVE

Heart-type fatty acid binding protein (H-FABP) is a tissue-specific protein which is rapidly released into the circulation when cardiomyocyte injury occurs. The aim of the study is to investigate the prognostic relevance of H-FABP for out-of-hospital cardiac arrest (OHCA) patients in the early post-cardiac arrest period.

DESIGN AND METHODS

This is a prospective cohort study enrolling non-traumatic resuscitated OHCA patients.

RESULTS

A total of 106 patients were enrolled. The H-FABP level at 24h was correlated to the duration from collapse to return of spontaneous circulation (p<0.001, R(2)=0.549). The outcomes of survival to discharge were worse in the patient group with the higher tertile of plasma H-FABP level at 24h after the event (p=0.011). Multivariate analysis demonstrated that the significant predictors for in-hospital mortality were APACHE II score (p=0.010), gender (p=0.025) and the tertiles of H-FABP at 24h with hazard ratios for the lowest, middle, and highest tertiles being 1.0, 1.157 (95% confidence interval 0.435-3.075, p=0.770), and 2.840 (95% confidence interval 1.137-7.092, p=0.025), respectively.

CONCLUSION

The plasma level of H-FABP at 24h after the event may be an early and independent factor associated with survival to discharge in OHCA patients.

Pathophysiological roles and clinical importance of biomarkers in acute coronary syndrome

Early diagnosis of acute coronary syndrome (ACS) is important to guide appropriate therapy at a time when it is most likely to be of value. Accurate prognostic and risk stratification will facilitate high-risk patients to have early advanced diagnostic investigations and early appropriate interventions in a cost-effective and efficient manner, while those patients at low risk of ACS complications do not need such costly diagnostic tests and unnecessary hospital admission. Recent investigations have demonstrated that elevation of biomarkers upstream from acute-phase biomarkers, biomarkers of plaque destabilization and rupture, biomarkers of myocardial ischemia, necrosis, and dysfunction may provide an earlier assessment of patient risk and identify patients with higher risk of having an adverse event. This review provides an overview of the pathophysiology and clinical characteristics of several well-established biomarkers as well as emerging biomarkers that may have potential clinical utility in patients with ACS. Such emerging biomarkers hold promise and need to be more thoroughly evaluated before utilization in routine clinical practice.

Heart type fatty acid binding protein: structure, function and biosensing applications for early detection of myocardial infarction

Heart type fatty acid binding protein (HFABP) as an early marker of cardiac injury holds a promising future with studies indicating surpassing performance as compared to myoglobin. As a plasma marker, this cytoplasmic protein owing to its small size (∼15kDa) and water solubility, appears readily in the blood-stream following cardiomyocyte damage, reaching peak levels within 6h of symptom onset. Low plasma levels of HFABP as compared to tissue levels indicate that minute amounts of the protein when released during myocardial infarction leads to a greater proportional rise. These parameters of kinetic release make it an ideal candidate for rapid assessment of acute myocardial infarction (AMI). The need for development of rapid immunoassays and immunotests so as to use HFABP as an early marker for AMI exclusion is tremendous. In the present review, we outline the various immunoassays and immunosensors developed so far for the detection of HFABP in buffer, plasma or whole blood. The principles behind the detection techniques along with their performance parameters compared to standard ELISA techniques are elucidated.

Diagnostic accuracy of heart fatty acid binding protein (H-FABP) and glycogen phosphorylase isoenzyme BB (GPBB) in diagnosis of acute myocardial infarction in patients with acute coronary syndrome

INTRODUCTION

This study aimed to assess whether heart fatty acid-binding protein (H-FABP) and glycogen phosphorylase isoenzyme BB (GPBB) could be used for the accurate diagnosis of acute myocardial infarction (AMI) in acute coronary syndrome (ACS) patients.

MATERIALS AND METHODS

The study included 108 ACS patients admitted to a coronary unit within 3 h after chest pain onset. AMI was distinguished from unstable angina (UA) using a classical cardiac troponin I (cTnI) assay. H-FABP and GPBB were measured by ELISA on admission (0 h) and at 3, 6, 12, and 24 h after admission; their accuracy to diagnose AMI was assessed using statistical methods.

RESULTS

From 92 patients with ACS; 71 had AMI. H-FABP and GPBB had higher peak value after 3 h from admission than cTnI (P = 0.001). Both markers normalized at 24 h. The area under the receiver operating characteristic curves was significantly greater for both markers in AMI patients than in UA patients at all time points tested, including admission (P < 0.001). At admission, the H-FABP (37%) and GPBB (40%) sensitivities were relatively low. They increased at 3 and 6 h after admission for both markers and decreased again after 24 h. It was 40% for H-FABP and approximately 2-times lower for GPBB (P < 0.01). In AMI patients, both biomarkers had similar specificities, positive- and negative-predictive values, positive and negative likelihood ratios, and risk ratios for AIM.

CONCLUSION

H-FABP and GPBB can contribute to early AMI diagnosis and can distinguish AMI from UA.

Heart type fatty acid binding protein in relation to pharmacologic scintigraphy in coronary artery disease

BACKGROUND

Heart-type fatty acid-binding protein (H-FABP) is a marker of myocardial necrosis, but whether it increases during myocardial ischemia is not known. This study investigated whether serum levels of H-FABP change during adenosine stress testing and nuclear imaging in patients with stable coronary artery disease.

METHODS

Thirty stable patients with established coronary artery disease on their medications were studied. Sampling was performed before the stress test, at the end of adenosine infusion, as well as 1, 2 and 3 h after the completion of the infusion.

RESULTS

No difference in H-FABP serum levels were found at the five pre-specified time points in the overall group (p=0.99); furthermore, there was no significant difference regardless of the test result--positive (p=1) or negative (p=0.98).

CONCLUSIONS

It is concluded that H-FABP does not change significantly during pharmacologic stress testing in patients with known coronary artery disease and there is no difference whether there is inducible ischemia or not.

Serum heart-type fatty acid binding protein levels in acromegaly patients

BACKGROUND

Heart-type fatty acid-binding protein (H-FABP) is a major cytoplasmic low molecular weight protein and released into the circulation when the myocardium is injured. Previous studies have demonstrated that H-FABP is closely associated with acute coronary syndrome, hypertrophic and dilated cardiomyopathy, heart failure, stroke, obstructive sleep apnea syndrome, and pulmonary embolism. The aim of this study was to investigate serum H-FABP value in patients with acromegaly.

METHODS AND RESULTS

We measured serum H-FABP levels in 30 consecutive patients with acromegaly, and 55 age-matched control subjects by using a sandwich enzymelinked immunosorbent assay. Serum H-FABP levels were significantly higher in patients with acromegaly than in control subjects (17.40 ± 10.70, and 8.30 ± 7.20, respectively) (p<0.001). A significant positive correlation was found by Spearman's correlation test between serum H-FABP levels and left ventricular end-systolic diameter (r=0.483, p=0.004).

CONCLUSION

Patients with acromegaly have increased levels of H-FABP. Serum H-FABP levels might be a marker of myocardial performance in patients with acromegaly.

Gender-specific differences in biomarkers responses to acute coronary syndromes and revascularization procedures

A growing body of gender-related research in coronary artery disease is beginning to gradually elucidate differences between women and men. In patients presenting with acute coronary syndromes (ACS), these sex differences include varying risk factor profiles, accuracy of diagnostic testing, clinical presentations, treatment practices and outcomes. There is also a differential expression of cardiac biomarkers by sex, which remains unexplained. This paper reviews all the available information on the effect of gender on cardiac biomarkers by search of MEDLINE using the terms gender differences, biomarkers, ACS and revascularization procedures. A better understanding of the sex disparities in biomarkers along with all other clinical information is essential to optimal management and patient care in the future.