Heart-type Fatty acid-binding protein in Acute Myocardial infarction Evaluation (FAME): background and design of a diagnostic study in primary care

Imaging of Heart Type Fatty Acid Binding Protein Under Acute Reperfusion Ischemia Using Radio-labeled Antibody in Rat Heart Model

Purpose: Heart-type fatty acid binding protein (H-FABP) is primary transporter of free fatty acid and plays an important role in myocardial metabolism, which is characterized by high specificity and rapid appearance under ischemic condition. The objective of this study was to clarify the usefulness of imaging study of targeting H-FABP appearance using radio-labeled antibody, and correlation with myocardial fatty acid metabolism and perfusion in acute reperfusion ischemia. Method: Wistar rats were allotted to sham-operated control group (sham; n=4), ischemia non-reperfused group (IG; n=5), and ischemia-reperfusion group (RG; n=5). Ligation of left coronary artery (LCA) was performed for IG and RG. 20 min of ischemia was followed by 60min of reperfusion for RG. ¹²⁵I labeled anti H-FABP antibody (anti H-FABP), BMIPP and ^99mTc-sestamibi (MIBI) was injected intravenously. Multi-tracer digital autoradiogram was performed using µ-imager^®. The ratio of radioactivity in LCA related (culprit) area to the inferior (remote) area (target uptake ratio=TUR) was generated. Results: In sham group, no visually detectable accumulation was observed for the anti H-FABP image, and TUR_MIBI and TUR_BMIPP were equivalent to 1. In IG, TUR_MIBI and TUR_BMIPP were remarkably low (0.12±0.01, 0.24±0.07). In RG, TUR_MIBI was significantly lower (0.20±0.03, p<0.05 vs. other groups). However, TUR_BMIPP was significantly higher (2.78±1.28, p<0.05) compared to the sham and IG, whereas anti H-FABP showed markedly higher ratio in the reperfused area compared to the sham and IG (3.43±0.73 vs. 0.31±0.13 and 1.09±0.07 for IG and sham; p<0.05, and <0.01, respectively). Conclusion: Anti H-FABP accumulated specifically in reperfused area under acute ischemia, and it accorded to the area where fatty acid metabolism was activated. This study has shown the future potential for clinical application in vivo imaging of acute coronary syndrome.

Profiling thiol metabolites in myocardial infarction human serum by stable isotope labeling assisted liquid chromatography-mass spectrometry

Myocardial Infarction (MI) is one of the most common causes of deaths worldwide. Thiols have been reported to play a key role in physiological and pathological processes of MI. Comprehensive analysis of thiols would be conducive to fully elucidate the relation between thiols and MI. In the current study, we analyze the metabolomic differences of thiols in serum between MI patients (n = 30) and healthy controls (HCs, n = 30) by stable isotope labeling-dispersive solid phase extraction-liquid chromatography-full scan-Orbitrap-mass spectrometry analysis (IL-DSPE-LC-full scan-Orbitrap MS) method. We detected 300 potential thiols in serum of MI patients and HCs, among which, 67 thiols were positively or putatively identified. Furthermore, we found that the levels of 71 thiols in serum exhibited significant difference between MI patients and HCs. In the transsulfuration pathway, we observed that Cys and Hcys were upregulated, while GSH were downregulated. Our results provide a comprehensive understanding of thiols metabolome in human serum between MI patients and HCs.

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.

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.

The impact of the HEART risk score in the early assessment of patients with acute chest pain: design of a stepped wedge, cluster randomised trial

Background

Chest pain remains a diagnostic challenge: physicians do not want to miss an acute coronary syndrome (ACS), but, they also wish to avoid unnecessary additional diagnostic procedures. In approximately 75% of the patients presenting with chest pain at the emergency department (ED) there is no underlying cardiac cause. Therefore, diagnostic strategies focus on identifying patients in whom an ACS can be safely ruled out based on findings from history, physical examination and early cardiac marker measurement. The HEART score, a clinical prediction rule, was developed to provide the clinician with a simple, early and reliable predictor of cardiac risk. We set out to quantify the impact of the use of the HEART score in daily practice on patient outcomes and costs.

Methods/Design

We designed a prospective, multi-centre, stepped wedge, cluster randomised trial. Our aim is to include a total of 6600 unselected chest pain patients presenting at the ED in 10 Dutch hospitals during an 11-month period. All clusters (i.e. hospitals) start with a period of ‘usual care’ and are randomised in their timing when to switch to ‘intervention care’. The latter involves the calculation of the HEART score in each patient to guide clinical decision; notably reassurance and discharge of patients with low scores and intensive monitoring and early intervention in patients with high HEART scores. Primary outcome is occurrence of major adverse cardiac events (MACE), including acute myocardial infarction, revascularisation or death within 6 weeks after presentation. Secondary outcomes include occurrence of MACE in low-risk patients, quality of life, use of health care resources and costs.

Discussion

Stepped wedge designs are increasingly used to evaluate the real-life effectiveness of non-pharmacological interventions because of the following potential advantages: (a) each hospital has both a usual care and an intervention period, therefore, outcomes can be compared within and across hospitals; (b) each hospital will have an intervention period which enhances participation in case of a promising intervention; (c) all hospitals generate data about potential implementation problems. This large impact trial will generate evidence whether the anticipated benefits (in terms of safety and cost-effectiveness) of using the HEART score will indeed be achieved in real-life clinical practice.

Trial registration

ClinicalTrials.gov 80-82310-97-12154.

Point-of-care tests in general practice: hope or hype?

Point-of-care tests are biomedical tests on patients' specimens like blood, saliva, urine or faeces, which can be used near the patient, without interference of a laboratory. The use of these tests, many of which have been recently developed, is increasing in general practice, where they add to the GP's set of diagnostic instruments. The question is, however, whether they always contribute to an effective and high-quality diagnostic process by GPs. We present a set of criteria that can be used by guideline developers, regional primary care organizations and individual GPs to evaluate a new point-of-care test in a practice setting. These criteria do not relate only to their use and quality. A point-of-care test needs to be evaluated in the right population and for the right indications, and GPs then need to use them for the indications for which they were evaluated. Expanding the range of indications can lead to an increase in false-positive and false-negative test results.

Gender differences in pre-hospital time delay and symptom presentation in patients suspected of acute coronary syndrome in primary care

OBJECTIVE

To describe gender differences in pre-hospital delay times and symptom presentation in patients suspected of acute coronary syndrome (ACS) in a primary care setting.

METHODS

Over 150 participating GPs included 298 consecutive patients suspected of ACS (52% female, mean age 66 years, 22% eventually diagnosed with ACS according to international guidelines) in a 28-month time period. Data on time from call for help until GP consultation (doctor delay) were prospectively collected, while the time from onset of symptoms until call for help (patient delay) was recorded by the GP at the time of arrival at the patient, together with patient characteristics, including age, sex, previous medical history, chest pain, radiation of chest pain and nausea/sweating.

RESULTS

Median doctor delay was 45 [interquartile range (IQR) 20-55] minutes in women and 33 (IQR 26-72) minutes in men (P = 0.01). Median patient delay was 108 (IQR 39-348) minutes in women and 180 (IQR 48-396) minutes in men (P = 0.20). Women reported spreading chest pain more often than men (68% versus 57%, P = 0.06). Women diagnosed with ACS were older than men (mean 75 years versus 65 years, P < 0.001).

CONCLUSIONS

In patients suspected of ACS in primary care, no differences were found in patient delay, but doctor delay was longer in women than in men. Symptom presentation was largely similar between men and women, although women tended to report 'spreading' chest pain more often.

Diagnosis of coronary artery disease in persons with diabetes mellitus

Coronary heart disease (CHD) is the leading cause of morbidity and mortality in patients with diabetes. Asymptomatic CHD in these patients is elusive and carries a poor prognosis given the fact that an unheralded acute myocardial infarction or sudden cardiac death frequently constitutes its first presentation. Because effective screening for asymptomatic patients with type 2 diabetes for both the presence and severity of CHD is intuitively appealing, we have summarized the utility and prognostic value of various diagnostic modalities (both functionally and anatomically) in enhancing risk stratification and leading to improved and more aggressive management of the risk factors. There exist some evidence and recommendations for screening of asymptomatic persons with diabetes using certain modalities. More research is needed to define potential subsets of patients with diabetes who may benefit from additional testing for asymptomatic CHD.

Diagnosing acute coronary syndrome in primary care: comparison of the physicians' risk estimation and a clinical decision rule

BACKGROUND

Diagnosing acute coronary syndrome (ACS) in a primary care setting poses a diagnostic dilemma for physicians.

OBJECTIVE

We directly compared the diagnostic accuracy of a clinical decision rule (CDR) based on history taking and physical examination in suspected ACS with the risk estimates of the attending GP.

METHODS

In a prospective multicenter study, patients suspected of ACS were included by the GP. GPs were asked to estimate the probability (0%-100%) of the presence of ACS. GPs collected patient data, but they were not aware of the CDR and did not score the patient accordingly.

RESULTS

Two hundred and ninety-eight patients were included (52% female, mean age 66 years, 22% ACS). The area under the receiver operating characteristic (ROC) curve (AUC) was 0.75 [95% confidence interval (CI) 0.68-0.82] for the GP risk estimate and 0.66 (95% CI 0.58-0.73) for the CDR. There was an agreement between the risk estimation of the GP and a CDR in 51% and the prevalence of ACS in predefined low-, intermediate- and high-risk groups was similar for the GP and CDR estimates. In the low-risk group, according to the GP, four patients (8.2%) suffered an ACS. These four patients were all identified by the decision rule as high risk.

CONCLUSIONS

The GP classified patients as ACS or no ACS more adequately than the CDR, judged by the AUC. However, the use of a CDR in patients that are considered at low risk for ACS by the GP could reduce the amount of missed myocardial infarctions.

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.

Prognostic value of combination of heart-type fatty acid-binding protein and ischemia-modified albumin in patients with acute coronary syndromes and normal troponin T values

Recent studies have suggested that heart-type fatty acid-binding protein (H-FABP) may detect ongoing myocardial damage involved in the progression of acute coronary syndromes (ACS). This study was prospectively designed to examine whether the combination of H-FABP, a marker for ongoing myocardial damage, and ischemia-modified albumin (IMA), a marker for myocardial ischemia, would effectively diagnose patients with ACS. H-FABP values above 1.5 microg/l can be correctly measured via an ELISA and 6 microg/l is the currently used cut-off value (1-3). We measured serum H-FABP and IMA of 108 patients on admission within 12 hr after onset of chest pain and normal troponin T. serum samples from ACS group (n=82) had decreased capacity of ACB [64 (61-67) U/ml] compared with non-ACS ischemic chest pain group (n=26) samples [75 (71-78) U/ml] (P<0.05). The combination of IMA and H-FABP usually had better sensitivity [96.3% (92.2-100%)] (P<0.05) and accuracy [92.6 (87.7-97.5%)] (P<0.05) than when individually used. Thus, the combination of H-FABP and IMA measurements after initiation of chest pain may be highly effective for risk stratification in patients with ACS and normal cardiac troponin T.