The use of human heart-type fatty acid-binding protein as an early diagnostic biochemical marker of myocardial necrosis in patients with acute coronary syndrome, and its comparison with troponin-T and creatine kinase–myocardial band

Emerging biomarkers for the detection of cardiovascular diseases

Background

The prevalence of cardiovascular disease (CVD) has been continuously increasing, and this trend is projected to continue. CVD is rapidly becoming a significant public health issue. Every year there is a spike in hospital cases of CVD, a critical health concern in lower- and middle-income countries. Based on identification of novel biomarkers, it would be necessary to study and evaluate the diagnostic requirements or CVD to expedite early detection.

Main body

The literature review was written using a wide range of sources, such as well-known medical journals, electronic databases, manuscripts, texts, and other writings from the university library. After that, we analysed the specific markers of CVD and compiled a systematic review. A growing body of clinical research aims to identify people who are at risk for cardiovascular disease by looking for biomolecules. A small number of biomarkers have been shown to be useful and reliable in medicine. Biomarkers can be used for a variety of clinical applications, such as predicting heart disease risk, diagnosing disease, or predicting outcomes. As a result of the ability for a single molecule to act as a biomarker, its usefulness in medicine is expected to increase significantly.

Conclusions

Based on assessing the current trends in the application of CVD markers, we discussed and described the requirements for the application of CVD biomarkers in coronary heart disease, cerebrovascular disease, rheumatic heart disease, and other cardiovascular illnesses. Furthermore, the current review focuses on biomarkers for CVD and the procedures that should be considered to establish the comprehensive nature of the expression of biomarkers for cardiovascular illness.

Optimal cut points of N-terminal of the prohormone brain natriuretic peptide (NT-proBNP) in patients with COVID-19

Background

COVID19 patients may suffer from multiple cardiovascular complications. Recently, N-terminal of the prohormone brain natriuretic peptide (NT-proBNP) was a potentially independent risk factor for COVID-19 in-hospital death. The present study aimed to find new optimal cut points for NT-proBNP across censored survival failure time outcomes in hospitalized COVID-19 patients.

Results

This cohort study was conducted on 272 patients with COVID-19 whose initial records were recorded from March 2020 to July 2020. Demographic characteristics, clinical examinations, and laboratory measurements were collected at the beginning of the admission registered in the patient record system located in the hospital. We used the maximally selected rank statistics to determine the optimal cut points for NT-proBNP (the most significant split based on the standardized log-rank test). Survival time was defined as the days from hospital admission to discharge day. In this cohort study, two optimal cut points for NT-proBNP were 331 (pg/mL) and 11,126 (pg/mL) based on a survival model. The adjusted HR of NT-proBNP for in-hospital death was 3.41 (95% CI: 1.22–9.51, P = 0.02) for medium against low category, and 3.84 (95% CI: 1.30–11.57, P = 0.01) for high in comparison with low group.

Conclusions

We reported a dramatically increased concentration of NT-proBNP among COVID-19 patients without heart failure in both severe and non-severe cases. Moreover, our study showed that a high level of NT-proBNP was highly associated with the prolonged survival time of patients with COVID-19. NT-proBNP is a strong prognostic indicator of in-hospital death in the second week of admission.

Heart-type fatty acid-binding protein: an overlooked cardiac biomarker

Cardiac troponins (cTn) are currently the standard of care for the diagnosis of acute coronary syndromes (ACS) in patients presenting to the emergency department (ED) with chest pain (CP). However, their plasma kinetics necessitate a prolonged ED stay or overnight hospital admission, especially in those presenting early after CP onset. Moreover, ruling out ACS in low-risk patients requires prolonged ED observation or overnight hospital admission to allow serial measurements of c-Tn, adding cost. Heart-type fatty acid-binding protein (H-FABP) is a novel marker of myocardial injury with putative advantages over cTn. Being present in abundance in the myocellular cytoplasm, it is released rapidly (<1 h) after the onset of myocardial injury and could potentially play an important role in both earlier diagnosis of high-risk patients presenting early after CP onset, as well as in risk-stratifying low-risk patients rapidly. Like cTn, H-FABP also has a potential role as a prognostic marker in other conditions where the myocardial injury occurs, such as acute congestive heart failure (CHF) and acute pulmonary embolism (PE). This review provides an overview of the evidence examining the role of H-FABP in early diagnosis and risk stratification of patients with CP and in non-ACS conditions associated with myocardial injury. Key messages Heart-type fatty acid-binding protein is a biomarker that is elevated early in myocardial injury The routine use in the emergency department complements the use of troponins in ruling out acute coronary syndromes in patients presenting early with chest pain It also is useful in risk stratifying patients with other conditions such as heart failure and acute pulmonary embolism.

Post-Myocardial Infarction Ventricular Remodeling Biomarkers-The Key Link between Pathophysiology and Clinic

Studies in recent years have shown increased interest in developing new methods of evaluation, but also in limiting post infarction ventricular remodeling, hoping to improve ventricular function and the further evolution of the patient. This is the point where biomarkers have proven effective in early detection of remodeling phenomena. There are six main processes that promote the remodeling and each of them has specific biomarkers that can be used in predicting the evolution (myocardial necrosis, neurohormonal activation, inflammatory reaction, hypertrophy and fibrosis, apoptosis, mixed processes). Some of the biomarkers such as creatine kinase-myocardial band (CK-MB), troponin, and N-terminal-pro type B natriuretic peptide (NT-proBNP) were so convincing that they immediately found their place in the post infarction patient evaluation protocol. Others that are related to more complex processes such as inflammatory biomarkers, atheroma plaque destabilization biomarkers, and microRNA are still being studied, but the results so far are promising. This article aims to review the markers used so far, but also the existing data on new markers that could be considered, taking into consideration the most important studies that have been conducted so far.

Effects of Trimetazidine Pretreatment on Endothelial Dysfunction and Myocardial Injury in Unstable Angina Patients Undergoing Percutaneous Coronary Intervention

Objectives

Trimetazidine is an anti-ischemic medication licensed for the treatment of angina pectoris. However, the molecular mechanisms underlying its action remain incompletely elucidated. In this study, therefore, we examined the potential beneficial effects of trimetazidine on myocardial injury and endothelial dysfunction in patients with unstable angina in the perioperative period of percutaneous coronary intervention (PCI).

Methods

A total of 97 patients with unstable angina were randomly divided into trimetazidine (n = 48) and control (n = 49) groups. All subjects received standard medical therapy. The trimetazidine group additionally received 20 mg trimetazidine three times daily 24 hours before and after PCI. Serum levels of creatine kinase-muscle/brain (CK-MB), cardiac troponin I (cTnI), heart-type fatty acid-binding protein (h-FABP), von Willebrand factor (vWF), and nitric oxide (NO) were measured before and the morning following PCI.

Results

In the control group, levels of CK-MB, cTnI, and vWF were significantly elevated (P < 0.05) and NO level was decreased after PCI (P < 0.05). By contrast, no significant changes in the levels of these proteins were observed in the trimetazidine group after PCI (P > 0.05). Moreover, h-FABP levels were not significantly altered after PCI whether in the control or in the trimetazidine group (P > 0.05). Finally, a time-dependent increase in the levels of h-FABP from 0 to 6 hours after PCI, followed by a progressive decline, was observed (P < 0.05).

Conclusions

PCI induces endothelial dysfunction and myocardial damage in patients with unstable angina. Trimetazidine therapy in the perioperative period can reduce this damage.

The Value of Point-Of-Care Fatty Acid Binding Protein in Patients with Chest Pain in Determining Myocardial Infarction in the Emergency Setting

Introduction

Detecting patients in the early hours of acute myocardial infarction is still a challenge for emergency physicians. Fatty acid binding protein (FABP) was thought to be released into the intravascular space earlier than cardiac troponins. The aim of this study was to determine the diagnostic value of point-of-care FABP test either in diagnosing or excluding myocardial infarction during the initial admission of patients presenting with typical chest pain to the emergency department.

Methods

This study was performed in a tertiary care emergency department. Patients with typical chest pain were included into the study. Point-of-care FABP was studied during the initial admission and two hours after admission. Patients were diagnosed as myocardial infarction or not ultimately by ECG and troponin levels.

Results

A total of 224 patients were included into the study, 73 of them (32.6%) were diagnosed as acute myocardial infarction. FABP had a sensitivity and specificity of 41.0% (95%CI 29.7 to 53.2) and 100% (95%CI 97.6 to 100) and myoglobin had a sensitivity and specificity of 57.5% (95%CI 45.4 to 69.0) and 90.7% (95%CI 85.0 to 95.0) during the initial admission. Cardiac troponin T had a sensitivity of 45.2% (95%CI 33.7 to 57.2) and specificity of 100% (95%CI 97.0 to 100) during the initial admission. Two hours after admission, FABP had a sensitivity of 56.0% (95%CI 40.0 to 71.0) and specificity of 99.0% (95%CI 96.4 to 100) respectively.

Conclusions

Point-of-care FABP is good at diagnosing acute myocardial infarction in patients presenting with chest pain. However, FABP was found to be not better than either myoglobin or cardiac troponin T in excluding acute myocardial infarction in patients presenting with chest pain.

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.

Heart-Type Fatty Acid Binding Protein Level as a Tool in Identification of Early Cardiac Effects of Diabetic Ketoacidosis

OBJECTIVE

This study aimed to measure the serum levels of heart-type fatty acid binding protein (H-FABP) in patients presenting with diabetic ketoacidosis (DKA) and diabetic ketosis (DK) and to determine its role in identifying early-period cardiac ischemia.

METHODS

This prospective study included 35 patients diagnosed with DKA, 20 patients diagnosed with DK, and 20 control subjects. H-FABP, creatine kinase-MB (CK-MB), and troponin I levels were investigated at presentation in patients with DKA and DK and in the control group. H-FABP values were measured again after acidosis correction in the DKA patients.

RESULTS

No statistically significant differences were found with respect to troponin I and CK-MB within the groups. The H-FABP values of DKA patients at presentation were found to be significantly higher than those of DK patients and the control group (p=0.015). The H-FABP value of the DKA group was also found to be significantly higher than the value at hour 36 after acidosis correction (p=0.0001).

CONCLUSION

We would like to propose H-FABP as a potential marker for indicating myocardial ischemia.

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.

Comparison of a qualitative measurement of heart-type fatty acid-binding protein with other cardiac markers as an early diagnostic marker in the diagnosis of non-ST-segment elevation myocardial infarction

OBJECTIVE

Heart-type fatty acid-binding protein (H-FABP) is a novel cardiac marker used in the early diagnosis of acute myocardial infarction (AMI), which shows myocyte injury. Our study aimed to compare bedside H-FABP measurements with routine creatine kinase-MB (CK-MB) and troponin I (TnI) tests for the early diagnosis of non-ST-elevation MI (NSTEMI), as well as for determining its exclusion capacity.

METHODS

A total of 48 patients admitted to the emergency room within the first 12 hours of onset of ischaemic-type chest pain lasting more than 30 minutes and who did not have ST-segment elevation on electrocardiography (ECG) were included in the study. Definite diagnoses of NSTEMI were made in 24 patients as a result of 24-hour follow up, and the remaining 24 patients did not develop MI.

RESULTS

When various subgroups were analysed according to admission times, H-FABP was found to be a better diagnostic marker compared to CK-MB and TnI (accuracy index 85%), with a high sensitivity (79%) and specificity (93%) for early diagnosis ( ≤ six hours). The respective sensitivities of bedside H-FABP and TnI tests were 89 vs 33% (p < 0.05) for patients presenting within three hours of onset of symptoms.

CONCLUSION

Bedside H-FABP measurements may contribute to correct early diagnoses, as its levels are elevated soon following MI, and measurement is easy, with a rapid result.

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.

Beyond the Limits: Clinical Utility of Novel Cardiac Biomarkers

Preoperative assessment of cardiovascular risk is essential when it comes to extensive noncardiac surgery procedures. Therefore, accurate and timely diagnosis of myocyte damage is vital. In modern medical practice it is believed that the so-called "multimarker" approach is the most appropriate and most accurate, but new research points out that there are novel biomarkers which could be used independently. Studies that evaluate miRNA, H-FABP, and MR-PAMP give encouraging results. When it comes to miRNA clinical studies show high statistical significance, especially in the case of acute myocardial infarction (P = 0.001). Statistical significance of P = 0.007 was found in acute coronary syndrome, when H-FABP was measured. Biochemical marker MR-PAMP showed statistical significance of P < 0.0001 in most clinical studies.

Diagnostic markers of acute myocardial infarction

Acute myocardial infarction (AMI) is a major cause of morbidity and mortality worldwide. The highest risk of fatality occurs within the initial hours of onset of AMI. Thus, early diagnosis of cardiac ischemia is critical for the effective management of patients with AMI. Improper diagnosis of patients with chest pain often leads to inappropriate admission of patients without AMI and vice versa. In addition to clinical history, physical examination, accurate electrocardiogram findings and assessment of cardiac biomarkers have an important role in the early diagnosis of acute ischemia. The present review discusses in detail the various cardiac biomarkers released during the event of an AMI.

Troponin T and Heart Type Fatty Acid Binding Protein (h-Fabp) as Biomarkers in Patients Presenting with Chest Pain

Acute coronary syndrome (ACS) is a term for a range of clinical signs and symptoms suggestive of myocardial ischemia. It results in functional and structural changes and ultimately releasing protein from injured cardiomyocytes. These cardiac markers play a major role in diagnosis and prognosis of ACS. This study aims to assess the efficacy of heart type fatty acid binding protein (h-FABP) as a marker for ACS along with the routinely used hs-TropT. In our observational study, plasma h-FABP (cut-off 6.32 ng/ml) and routinely done hs-Trop T (cutoff 0.1 and 0.014 ng/ml) were estimated by immunometric laboratory assays in 88 patients with acute chest pain. Based on the clinical and laboratory test findings the patients were grouped into ACS (n = 41) and non-ACS (n = 47). The diagnostic sensitivity, specificity, NPV, PPV and ROC curve at 95 % CI were determined. Sensitivity of hs-TropT (0.1 ng/ml), hs-TropT (0.014 ng/ml) and h-FABP were 53, 86 and 78 % respectively and specificity for the same were 98, 73 and 70 % respectively. Sensitivity, specificity and NPV calculated for a cut-off combination of hs-TropT 0.014 ng/ml and h-FABP was 100, 51 and 100 % respectively. These results were substantiated by ROC analysis. Measurement of plasma h-FABP and hs-TropT together on admission appears to be more precise predictor of ACS rather than either hs-Trop T or h-FABP.

Diabetic patients have increased perioperative cardiac risk in heart-type fatty acid-binding protein-based assessment

OBJECTIVE

To test the potential role of heart-type fatty acid-binding protein (H-FABP) in detecting increased perioperative cardiac risk in comparison with cardiac troponin I (cTnI) in the early postoperative period.

SUBJECTS AND METHODS

Sixty-seven patients who had clinical risk factors and underwent elective intermediate - or high-risk noncardiac surgery were included in this study. Serum specimens were analyzed for H-FABP and cTnI levels before and at 8 h after surgery. None of the patients had chest pain; 27 had a history of ischemic heart disease, 3 of heart failure, 5 of cerebrovascular diseases, 40 of diabetes and 46 of hypertension.

RESULTS

The mean duration of the operations was 2.33 ± 1.27 h (range 1-6). In the postoperative period, 27 (40.3%) patients had increased H-FABP levels (≥7.5 ng/ml); the median preoperative serum H-FABP level was 0.13 ng/ml (<0.1-5.9) and the median postoperative H-FABP level was 6.86 ng/ml (<0.1-13.7). Only 1 (1.5%) patient had cTnI >0.1 µg/l during the postoperative period. Correlation analysis revealed that the presence of diabetes was associated with an increased H-FABP level (r = 0.30, p = 0.01). Of the 27 patients with H-FABP ≥7.5 ng/ml, 21 (87%) had diabetes. There was no significant correlation with other clinical risk factors, type or duration of surgery.

CONCLUSION

The H-FABP levels significantly increased in the postoperative period. Most patients with increased postoperative H-FABP levels were diabetic. High H-FABP levels could alert clinicians to increased perioperative cardiovascular risk and could prevent underdiagnosis, especially in diabetic 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.

Cardiac biomarkers in acute myocardial infarction

Each year, a large number of patients are seen in the Emergency Department with presentations necessitating investigation for possible acute myocardial infarction. Patients can be stratified by symptoms, risk factors and electrocardiogram results but cardiac biomarkers also have a prime role both diagnostically and prognostically. This review summarizes both the history of cardiac biomarkers as well as currently available (established and novel) assays. Cardiac troponin, our current "gold standard" biomarker criterion for the diagnosis of myocardial infarction has high sensitivity and specificity for this diagnosis and therapies instituted in patients with elevated troponin have been shown to influence outcomes. Other markers of myocardial necrosis, inflammation and neurohormonal activity have also been shown to have either diagnostic or prognostic utility, but none have been shown to be superior to troponin. The measurement of multiple biomarkers and the use of point of care markers may accelerate current diagnostic protocols for the assessment of such patients.

Heart type fatty acid binding protein is more sensitive than troponin I and creatine kinase myocardial band at early stage in determining myocardial injury caused by percutaneous coronary intervention

Measurement of circulating cardiac biomarkers has enabled early diagnosis and risk assessment of acute coronary syndrome. Heart type fatty acid binding protein (H-FABP) is a relatively novel marker for the diagnosis of myocardial injury. The purpose of the present study was to compare H-FABP with Troponin I (cTnI) and creatine kinase myocardial band (CK-MB) in determining myocardial injury in patients with early stage of percutaneous coronary intervention (PCI). Blood was withdrawn one hour before and 3 hours after PCI from 40 patients to measure H-FABP, cTnI and CKMB. H-FABP was measured qualitatively. CK-MB and cTnI were measured by a sandwich enzyme-linked immunosorbent assay. Before PCI, H-FABP was found to be negative, while cTnI and CK-MB were found to be in normal ranges. Statistical analysis of measurements 3 hours after PCI revealed that H-FABP was significantly positive in 15 (37%) patients, while cTnI was elevated in 11 (27%) patients and CKMB was elevated in 8 (20%) patients. H-FABP is statistically more sensitive than cTnI and CK-MB at detecting myocardial injury after PCI.H-FABP can be used in early stages to detect myocardial injury caused by PCI. H-FABP is more sensitive than cTnI and CK-MB in determining myocardial injury due to PCI within 3 hours. H-FABP may help us stratify a patient's risk in early stages after PCI.

Heart fatty acid-binding protein in combination with the 80-lead body surface potential map improves early detection of acute myocardial infarction in patients who are cardiac troponin T-negative at presentation

Of patients who present with ischemic-type chest pain and a negative cardiac troponin T (cTnT) at first medical contact, there are patients at a very early stage of infarction. The aim of this research was to assess heart fatty acid-binding protein (H-FABP), a novel marker of myocyte necrosis, in combination with the 80-lead body surface potential map (BSPM) in the early diagnosis of acute myocardial infarction (AMI).

METHODS

In this prospective study, consecutive patients presenting with acute ischemic-type chest pain between 2003 and 2006 were enrolled. At first medical contact, blood was sampled for cTnT and H-FABP; in addition, a 12-lead electrocardiogram (ECG) and BSPM were recorded. A second cTnT was sampled 12 hours or more after presentation. Peak cTnT 0.03 μg/L or higher diagnosed AMI. Elevated H-FABP was 5 ng/mL or higher. A cardiologist blinded to both the clinical details and 12-lead ECG interpreted the BSPM.

RESULTS

Enrolled were 407 patients (age 62 ± 13 years; 70% men). Of these 407, 180 had cTnT less than 0.03 μg/L at presentation. Acute myocardial infarction occurred in 52 (29%) of 180 patients. Of these 180 patients, 27 had ST-segment elevation (STE) on ECG, 104 had STE on BSPM (sensitivity, 88%; specificity, 55%), and 95 (53%) had H-FABP elevation. The proportion with elevated H-FABP was higher in the AMI group compared with non-AMI group (P < .001). Body surface potential map STE was significantly associated with H-FABP elevation (P < .001). Of those with initial cTnT less than 0.03 μg/L, the c-statistic for the receiver operating characteristic curve distinguishing AMI from non-AMI using H-FABP alone was 0.644 (95% confidence interval [CI], 0.521-0.771), using BSPM alone was 0.716 (95% CI, 0.638-0.793), and using the combination of BSPM and H-FABP was 0.812 (95% CI, 0.747-0.876; P < .001).

CONCLUSION

In patients with acute ischemic-type chest pain who have a normal cTnT at presentation, the combination of H-FABP and BSPM at first assessment identifies those with early AMI (c-statistic, 0.812; P < .001), thus allowing earlier triage to reperfusion therapy and secondary prevention.

Role of biomarkers in risk stratification of acute coronary syndrome

Diagnosis of acute coronary syndrome (ACS) encompasses a wide spectrum of myocardial ischaemia varying from assuredly benign to potentially fatal. Cardiac biomarkers have had a major impact on the management of this disease and are now the cornerstone in its diagnosis and prognosis. In this review we discuss both the established and the newer emerging biomarkers in ACS and their role in highlighting not only myocardial necrosis but also different facets of the pathophysiology of ACS. The future of cardiac biomarker testing may be in multimarker testing to better characterize each patient of ACS and thus tailor both short-term and long-term therapy accordingly. This novel concept, however, needs to be tested in clinical trials for its incremental value and cost-effectiveness.

Heart fatty acid binding protein (H-FABP) as a diagnostic biomarker in patients with acute coronary syndrome

AIMS AND OBJECTIVES

Diagnosis of myocardial ischaemia at an early stage in the emergency department is often difficult. A recently proposed biomarker, heart fatty acid binding protein (H-FABP) has been found to appear in the circulation superior to that of cardiac troponins in the early hours of acute coronary syndrome. We proposed to evaluate the levels of H-FABP and ascertain its utility as an early biomarker for acute coronary syndrome (ACS).

METHODS AND RESULTS

The present study was carried out in 485 subjects, of whom 297 were diagnosed as patients with ACS, 89 were diagnosed as non-cardiac chest pain (NCCP) and 99 people served as healthy controls. H-FABP levels were measured in comparison with standard markers such as troponin I and CK-MB in all subjects enrolled in the study. The levels of H-FABP were significantly raised in patients when compared to controls and NCCP (P<0.001). Receiver Operator Characteristic Curve (ROC) analysis showed H-FABP to be a good discriminator between patients with ischaemic heart disease and patients without ischaemic heart disease. The area under the curve was found to be 0.965 with 95% CI (0.945-0.979). The cut-off value above which H-FABP can be considered positive was found to be 17.7ng/ml.

CONCLUSION

H-FABP is a promising biomarker for the early detection of patients with acute coronary syndrome.

Automated heart-type fatty acid-binding protein assay for the early diagnosis of acute myocardial infarction

We compared an automated quantitative heart-type fatty acid-binding protein (H-FABP) assay with other cardiac-marker assays to examine its usefulness as an early diagnostic marker of acute myocardial infarction (AMI). Serum samples for cardiac troponin T (cTnT), creatine kinase-MB isozyme (CK-MB), myoglobin, and H-FABP were obtained from 64 patients with AMI and 53 patients with other conditions (control group). H-FABP was measured by using 2 immunoassays, the H-FABP enzyme-linked immunosorbent assay (ELISA; Biocheck, Foster City, CA) and the H-FABP latex turbidimetric immunoassay (LTIA; HBI, Anyang, Korea). Sensitivities of assays for cTnT, CK-MB, myoglobin, H-FABP (by ELISA), H-FABP (by LTIA), and electrocardiogram (ECG) for the diagnosis of AMI at hospital admission were 39.1%, 59.4%, 64.1%, 68.7%, 70.3%, and 54.7%, respectively. Specificities of cTnT, CK-MB, myoglobin, H-FABP (by ELISA), H-FABP (by LTIA), and ECG were 98.1%, 71.7%, 81.1%, 77.4%, 90.6%, and 92.5%, respectively. The automated H-FABP (by LTIA) is superior to cTnT, CK-MB, myoglobin, and H-FABP (by ELISA) tests for the diagnosis of AMI in patients admitted within 4 hours from the onset of chest pain.

Comparison of usefulness of heart-type fatty acid binding protein versus cardiac troponin T for diagnosis of acute myocardial infarction

We aimed to assess the additive diagnostic value of measuring the serum levels of soluble human heart-type fatty acid binding protein (H-FABP) in the early diagnosis of acute myocardial infarction (AMI) in unselected patients with chest pain. A total of 97 consecutive patients with acute ischemic-type chest pain were prospectively enrolled and classified according to the American Heart Association/American College of Cardiology guidelines. The test characteristics of H-FABP and cardiac troponin T serum levels at admission revealed a greater sensitivity of H-FABP in the first 4 hours of symptoms (86% vs 42%, p <0.05). Combining H-FABP and cardiac troponin T also improved the sensitivity in the detection of AMI (97% vs 71%, p <0.05) but demonstrated a greater misclassification rate (25% vs 9%, p <0.05). The specificity of H-FABP was poor (65%, 95% confidence interval 58% to 71%). Receiver operating characteristics revealed a poor performance of H-FABP in patients with non-ST-elevation myocardial infarction. Classification tree analysis demonstrated that an H-FABP-related improvement in the early definite rule-out of AMI (reduction of false-negative rate from 11% to 3%) was at the expense of an increase in the false-positive rate to 5%. In conclusion, measurement of H-FABP, in addition to cardiac troponin T, serum levels within the first 4 hours of symptoms improves the sensitivity and negative predictive value for the detection of AMI at the cost of test accuracy and precision, especially in patients with non-ST-elevation myocardial infarction.

Qualification of cardiac troponin I concentration in mouse serum using isoproterenol and implementation in pharmacology studies to accelerate drug development

Cardiac troponin I is a useful biomarker of myocardial injury, but its use in mice and application to early drug discovery are not well described. The authors investigated the relationship between cTnI concentration in serum and histologic lesions in heart tissue from mice treated with isoproterenol (ISO). Cardiac TnI concentrations in serum increased in a dose-dependant manner and remained increased twenty-four to forty-eight hours after a single administration of isoproterenol. Increased cTnI concentration was of greater magnitude and longer duration than increased fatty acid binding protein 3 concentration, aspartate aminotransferase activity, and creatine kinase activity in serum. Isoproterenol-induced increases in cTnI concentrations were both greater and more sustained in BALB/c than in CD1 mice and correlated with incidence and severity of lesions observed in heart sections from both strains. In drug development studies in BALB/c mice with novel kinase inhibitors, cTnI concentration was a reliable stand-alone biomarker of cardiac injury and was used in combination with measurements of in vivo target inhibition to demonstrate an off-target contribution to cardiotoxicity. Additional attributes, including low cost and rapid turnaround time, made cTnI concentration in serum invaluable for detecting cardiotoxicity, exploring structure-activity relationships, and prioritizing development of compounds with improved safety profiles early in drug discovery.

Intestinal fatty acid binding protein (I-FABP) as a possible biomarker of ileitis in patients with ulcerative colitis

BACKGROUND

One of nine types of FABP, intestinal fatty acid binding protein (I-FABP) is primarily limited to the mature enterocytes of the small intestine, with only trace amounts identified in the stomach and large intestine. The aim of this study was to investigate the use of I-FABP as a possible plasma marker of intestinal injury in patients with ulcerative colitis (UC).

MATERIAL AND METHODS

The study group consisted of 42 patients (11 females and 31 males) with active ulcerative colitis (UC), aged from 24 to 74 years (mean age: 41.8+/-3.5 years). Plasma I-FABP concentrations and hsCRP were compared using endoscopic pictures scored according to the system developed by Meyers et al., and analysed in the context of inflammatory process extension: pancolitis, or distal or left side colitis.

RESULTS

The mean serum I-FABP concentration /mL), whereas individuals with left-side colitis had a mean I-FABP concentration of 61.8+/-8.5 pg/mL. Significant serum I-FABP elevation was observed in UC patients with a severe form of the disease, in contrast to the serum I-FABP concentration in patients with the mild form (260.5+/-60.6 vs. 61.5+/-7.9 pg/mL).

CONCLUSION

The elevated serum I-FABP concentration in patients with UC may indicate ileitis. I-FABP may be a useful marker of the extended inflammatory process.

Circulating platelet and neutrophil activation correlates with the clinical course of unstable angina

Recent studies have suggested important roles of inflammation in the pathophysiology of unstable angina (UA). We investigated whether activation of the circulating platelets and neutrophils were implicated in inflammatory reactions associated with unstable angina Expressions of platelet P-selectin and neutrophil CD11b, and neutrophil-platelet aggregates were evaluated by flow cytometry in anticoagulated peripheral venous blood from 71 patients with UA and 22 patients with stable angina (SA). Expressions of platelet P-selectin and neutrophil CD11b, and neutrophil-platelet aggregates on the admission day were all significantly higher in 71 patients with UA than 22 with SA (median, mean fluorescence intensity [MFI]: 7.00 vs 4.51, P < 0.01, 64.68 vs 47.75, P = 0.0007; and % of 10 000 neutrophils: 7.84 vs 3.40, P = 0.0001, respectively). These three parameters in 43 patients with UA were significantly decreased (MFI: 4.23, P = 0.003, 50.82, P = 0.0003; and % of 10 000 neutrophils: 5.04, P = 0.0001, respectively) 7 days after the first measurement. These results indicate that circulating activated platelets and neutrophils are more strongly implicated in the acute phase of UA. These findings also suggest that thrombus formation after rupture of atherosclerotic plaques as well as plaque formation involves inflammatory reactions.