Comparison of heart-type fatty acid binding protein and sensitive troponin for the diagnosis of early acute myocardial infarction

Evaluation of heart fatty acid-binding protein as a biomarker for canine leishmaniosis

BACKGROUND

Myocarditis frequently occurs in canine leishmaniosis (CanL). Heart fatty acid-binding protein (HFABP) is a biomarker of myocardial damage.

METHODS

This study aimed to compare HFABP concentration (HFABPc) in healthy dogs and dogs at different stages of CanL and evaluate the correlation of this biomarker with several clinicopathological and echocardiographic variables. Thirty-one dogs diagnosed with CanL and 10 healthy dogs were included.

RESULTS

HFABPc was not statistically different (p > 0.05) between groups of dogs at different LeishVet stages of CanL or between groups with high versus low to intermediate serology titres. In 70% of CanL dogs, HFABPc was within the 95% confidence interval limits of the mean of healthy dogs. A moderate negative correlation with globulin (r = -0.519; p = 0.03) and haematocrit (HCT) (r = -0.538; p = 0.02) was observed. No other significant correlation (p > 0.05) was observed with any other variable.

LIMITATIONS

Many statistical tests were performed, and therefore, type I error cannot be ruled out.

CONCLUSION

HFABPc is not consistently elevated in dogs with CanL and is not associated with the severity of the disease, or most echocardiographic or clinicopathological variables studied. The correlation with globulin and HCT was not strong and not considered clinically significant. HFABPc lacks sufficient predictive capacity in dogs with CanL, discouraging further research or clinical use of this biomarker in this disease.

FABP3 Deficiency Exacerbates Metabolic Derangement in Cardiac Hypertrophy and Heart Failure via PPARα Pathway

Background: Cardiac hypertrophy was accompanied by various cardiovascular diseases (CVDs), and due to the high global incidence and mortality of CVDs, it has become increasingly critical to characterize the pathogenesis of cardiac hypertrophy. We aimed to determine the metabolic roles of fatty acid binding protein 3 (FABP3) on transverse aortic constriction (TAC)-induced cardiac hypertrophy. Methods and Results: Transverse aortic constriction or Ang II treatment markedly upregulated Fabp3 expression. Notably, Fabp3 ablation aggravated TAC-induced cardiac hypertrophy and cardiac dysfunction. Multi-omics analysis revealed that Fabp3-deficient hearts exhibited disrupted metabolic signatures characterized by increased glycolysis, toxic lipid accumulation, and compromised fatty acid oxidation and ATP production under hypertrophic stimuli. Mechanistically, FABP3 mediated metabolic reprogramming by directly interacting with PPARα, which prevented its degradation and synergistically modulated its transcriptional activity on Mlycd and Gck. Finally, treatment with the PPARα agonist, fenofibrate, rescued the pro-hypertrophic effects of Fabp3 deficiency. Conclusions: Collectively, these findings reveal the indispensable roles of the FABP3-PPARα axis on metabolic homeostasis and the development of hypertrophy, which sheds new light on the treatment of hypertrophy.

Heart-fatty acid binding protein in dogs with degenerative valvular disease and dilated cardiomyopathy

The study objective was to investigate heart-fatty acid binding protein (HFABP) concentrations in dogs with degenerative valvular disease (MVD) and dilated cardiomyopathy (DCM), and its potential as a prognostic factor. Plasma HFABP, N-terminal pro brain natriuretic peptide (NTproBNP) and serum cardiac troponin I (cTnI) levels were measured in 21 control dogs, 23 dogs with MVD and 13 dogs with DCM, with repeated sampling at 1 and 3 months after initial presentation. All dogs were followed up after 6 and 12 months to verify survival. Heart-fatty acid binding protein concentrations were significantly higher in dogs with MVD and DCM than controls at initial presentation, and after 1 month in dogs with MVD. For dogs with DCM, a significant reduction in HFABP levels over time was observed. Comparing ACVIM stages, highest HFABP concentrations were detected in ACVIM stage C dogs compared to stage B, with the lowest levels seen in controls, and a reduction over time in stage C dogs was present. Similarly, cTnI concentrations were higher in DCM and stage C in comparison to control dogs and reduced over time, while NTproBNP concentrations were only higher in diseased dogs at 1 month. Heart-fatty acid binding protein and cTnI levels at initial presentation and ACVIM disease stage were independent predictors of survival in a univariate analysis. The elevation of HFABP in dogs with MVD and DCM in comparison to controls, its association with disease severity, and its potential in predicting reduced survival, suggest that HFABP might be useful as marker for canine MVD and DCM.

Fatty acid-binding protein 3 contributes to ischemic heart injury by regulating cardiac myocyte apoptosis and MAPK pathways

Fatty acid-binding protein 3 (FABP3), a low-molecular-weight protein, participates in lipid transportation, storage, signaling transduction, oxidation, and transcription regulation. Here, we investigated the expression and function of FABP3 in ischemic heart diseases and explored the mechanisms by which FABP3 affected remodeling after myocardial infarction (MI). We showed that ischemic or hypoxic conditions upregulated FABP3 expression in vivo and in vitro. Notably, overexpression of FABP3 induced more myocyte apoptosis in the infarction and border areas and aggravated cardiac dysfunction, with lower left ventricular ejection fraction. Meanwhile, overexpression of FABP3 drastically promoted death and apoptosis of neonatal rat ventricular cardiomyocytes under hypoxia. Furthermore, deficiency of FABP3 exerted protective effects against ischemic heart injuries by decreasing cardiac myocyte apoptosis and heart remodeling after MI. We found that overexpression of FABP3 upregulated the phosphorylation of MAPK signaling pathway and decreased phosphorylated Akt levels, which may account for the augmentation of apoptosis and remodeling after MI. To the best of our knowledge, this is the first study to demonstrate that deficiency of FABP3 would protect cardiac myocytes from apoptosis and alleviate cardiac remodeling after MI, suggesting FABP3 as a potential target to preserve cardiac function after MI. NEW & NOTEWORTHY It is an undisputable fact that myocyte apoptosis plays a crucial role in cardiac remodeling and the development of heart failure after myocardial infarction. Here, fatty acid-binding protein 3 deficiency improved myocardial structural remodeling and function by decreasing cell apoptosis and regulating MAPK signaling pathways. We suppose that fatty acid-binding protein 3 may be regarded as a potential intervention approach to preserve cardiomyocytes during myocardial infarction.

Heart-type fatty acid binding protein (H-FABP) as a biomarker for acute myocardial injury and long-term post-ischemic prognosis

Acute myocardial infarction (AMI) is a life-threatening event. Even with timely treatment, acute ischemic myocardial injury and ensuing ischemia reperfusion injury (IRI) can still be difficult issues to tackle. Apart from radiological and other auxiliary examinations, laboratory tests of applicable cardiac biomarkers are also necessary for early diagnosis and close monitoring of this disorder. Heart-type fatty acid binding protein (H-FABP), which mainly exists inside cardiomyocytes, has recently emerged as a potentially promising biomarker for myocardial injury. In this review we discuss the sensitivity and specificity of H-FABP in the assessment of myocardial injury and IRI, especially in the early stage, and its long-term prognostic value in comparison with other commonly used cardiac biomarkers, including myoglobin (Mb), cardiac troponin I (cTnI), creatine kinase MB (CK-MB), C-reactive protein (CRP), glycogen phosphorylase isoenzyme BB (GPBB), and high-sensitivity cardiac troponin T (hs-cTnT). The potential and value of combined application of H-FABP with other biomarkers are also discussed. Finally, the prospect of H-FABP is summarized; several technical issues are discussed to facilitate wider application of H-FABP in clinical practice.

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.

Early Diagnostic Performance of Heart-Type Fatty Acid Binding Protein in Suspected Acute Myocardial Infarction: Evidence From a Meta-Analysis of Contemporary Studies

BACKGROUND

Although cardiac troponin is the cornerstone in diagnosis of acute myocardial infarction (AMI), the accuracy is still suboptimal in the early hours after chest pain onset. Due to its small size, heart-type fatty acid-binding protein (H-FABP) has been reported accurate in diagnosis of AMI, however, this remains undetermined. The aim is to investigate the diagnostic performance of H-FABP alone and in conjunction with high-sensitivity troponin (hs-Tn) within 6 hours of symptom onset. Furthermore, accuracy in 0h/3h algorithm was also assessed.

METHODS

Medline and EMBASE databases were searched; sensitivity, specificity and area under ROC curve (AUC) were used as measures of the diagnostic accuracy. We pooled data on bivariate modelling, threshold effect and publication bias was applied for heterogeneity analysis.

RESULTS

Twenty-two studies with 6602 populations were included, pooled sensitivity, specificity and AUC of H-FABP were 0.75 (0.68-0.81), 0.81 (0.75-0.86) and 0.85 (0.82-0.88) within 6 hours. Similar sensitivity (0.76, 0.69-0.82), specificity (0.80, 0.71-0.87) and AUC (0.85, 0.82-0.88) of H-FABP were observed in 4185 (63%) patients in 0h/3h algorithm. The additional use of H-FABP improved the sensitivity of hs-Tn alone but worsened its specificity (all p<0.001), and resulted in no improvement of AUC (p>0.99). There was no threshold effect (p=0.18) and publication bias (p=0.31) in this study.

CONCLUSIONS

H-FABP has modest accuracy for early diagnosis of AMI within 3 and 6 hours of symptom onset. The incremental value of H-FABP seemed much smaller and was of uncertain clinical significance in addition to hs-Tn in patients with suspected AMI. Routine use of H-FABP in early presentation does not seem warranted.

High-sensitivity troponin assays for the early rule-out or diagnosis of acute myocardial infarction in people with acute chest pain: a systematic review and cost-effectiveness analysis

BACKGROUND

Early diagnosis of acute myocardial infarction (AMI) can ensure quick and effective treatment but only 20% of adults with emergency admissions for chest pain have an AMI. High-sensitivity cardiac troponin (hs-cTn) assays may allow rapid rule-out of AMI and avoidance of unnecessary hospital admissions and anxiety.

OBJECTIVE

To assess the clinical effectiveness and cost-effectiveness of hs-cTn assays for the early (within 4 hours of presentation) rule-out of AMI in adults with acute chest pain.

METHODS

Sixteen databases, including MEDLINE and EMBASE, research registers and conference proceedings, were searched to October 2013. Study quality was assessed using QUADAS-2. The bivariate model was used to estimate summary sensitivity and specificity for meta-analyses involving four or more studies, otherwise random-effects logistic regression was used. The health-economic analysis considered the long-term costs and quality-adjusted life-years (QALYs) associated with different troponin (Tn) testing methods. The de novo model consisted of a decision tree and Markov model. A lifetime time horizon (60 years) was used.

RESULTS

Eighteen studies were included in the clinical effectiveness review. The optimum strategy, based on the Roche assay, used a limit of blank (LoB) threshold in a presentation sample to rule out AMI [negative likelihood ratio (LR-) 0.10, 95% confidence interval (CI) 0.05 to 0.18]. Patients testing positive could then have a further test at 2 hours; a result above the 99th centile on either sample and a delta (Δ) of ≥ 20% has some potential for ruling in an AMI [positive likelihood ratio (LR+) 8.42, 95% CI 6.11 to 11.60], whereas a result below the 99th centile on both samples and a Δ of < 20% can be used to rule out an AMI (LR- 0.04, 95% CI 0.02 to 0.10). The optimum strategy, based on the Abbott assay, used a limit of detection (LoD) threshold in a presentation sample to rule out AMI (LR- 0.01, 95% CI 0.00 to 0.08). Patients testing positive could then have a further test at 3 hours; a result above the 99th centile on this sample has some potential for ruling in an AMI (LR+ 10.16, 95% CI 8.38 to 12.31), whereas a result below the 99th centile can be used to rule out an AMI (LR- 0.02, 95% CI 0.01 to 0.05). In the base-case analysis, standard Tn testing was both most effective and most costly. Strategies considered cost-effective depending upon incremental cost-effectiveness ratio thresholds were Abbott 99th centile (thresholds of < £6597), Beckman 99th centile (thresholds between £6597 and £30,042), Abbott optimal strategy (LoD threshold at presentation, followed by 99th centile threshold at 3 hours) (thresholds between £30,042 and £103,194) and the standard Tn test (thresholds over £103,194). The Roche 99th centile and the Roche optimal strategy [LoB threshold at presentation followed by 99th centile threshold and/or Δ20% (compared with presentation test) at 1-3 hours] were extendedly dominated in this analysis.

CONCLUSIONS

There is some evidence to suggest that hs-CTn testing may provide an effective and cost-effective approach to early rule-out of AMI. Further research is needed to clarify optimal diagnostic thresholds and testing strategies.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42013005939.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Incremental value of heart-type fatty acid-binding protein in suspected acute myocardial infarction early after symptom onset

BACKGROUND

The early diagnosis of acute myocardial infarction (AMI) very soon after symptom onset remains a major clinical challenge, even when using high-sensitivity cardiac troponin (hs-cTnT).

METHODS AND RESULTS

We investigated the incremental value of heart-type fatty acid-binding protein (hFABP) in a pre-specified subgroup analysis of patients presenting with suspected AMI within 1 h of symptom onset to the emergency department (ED) in a multicentre study. HFABP was measured in a blinded fashion. Two independent cardiologists using all available clinical information, including hs-cTnT, adjudicated the final diagnosis. Overall, 1411 patients were enrolled, of whom 105 patients presented within 1 h of symptom onset. Of these, 34 patients (32.4%) had AMI. The diagnostic accuracy as quantified by the area under the receiver-operating characteristics curve (AUC) of hFABP was high (0.84 (95% CI 0.74-0.94)). However, the additional use of hFABP only marginally increased the diagnostic accuracy of hs-cTnT (AUC 0.88 (95% CI 0.81-0.94) for hs-cTnT alone to 0.90 (95% CI 0.83-0.98) for the combination; p=ns). After the exclusion of 18 AMI patients with ST-segment elevation, similar results were obtained. Among the 16 AMI patients without ST-segment elevation, six had normal hs-cTnT at presentation. Of these, hFABP was elevated in two (33.3%) patients.

CONCLUSIONS

hFABP does not seem to significantly improve the early diagnostic accuracy of hs-cTnT in the important subgroup of patients with suspected AMI presenting to the ED very early after symptom onset.

Beyond cardiac troponin: recent advances in the development of alternative biomarkers for cardiovascular disease

Biomarkers complement clinical assessment, electrocardiogram and cardiac imaging in the diagnosis, risk stratification, triage and management of patients with suspected acute cardiovascular diseases. While there is broad consensus that cardiac troponin is the preferred biomarker in clinical practice for the detection of cardiomyocyte damage, the role of alternative biomarkers is less clear. In fact, despite high quality basic and clinical research by hundreds of groups worldwide, only a single new alternative cardiovascular biomarker (natriuretic peptides) has managed to achieve widespread clinical acceptance and inclusion in contemporary clinical practice guidelines in the last decade. This review aims to discuss the remaining unmet needs (and hence opportunities for new biomarkers) in two major clinical areas: early diagnosis of acute myocardial infarction; and early diagnosis and management of acute heart failure, and to evaluate in detail selected alternative biomarkers and recent insights gained from measuring novel biomarkers in large randomized treatment studies in patients with stable coronary artery disease, a setting in which alternative biomarkers may play a more prominent role in the future.

Point-of-care heart-type fatty acid binding protein versus high-sensitivity troponin T testing in emergency patients at high risk for acute coronary syndrome

BACKGROUND

High-sensitivity cardiac troponin testing is used to detect myocardial damage in patients with acute chest pain. Heart-type fatty acid binding protein (H-FABP) may be an alternative, available as point-of-care test.

METHODS

Patients (n=203) referred by general practitioners for suspected acute coronary syndrome or presenting with typical chest pain and one major cardiovascular risk factor at the emergency department were prospectively included in a single-centre cohort study. High-sensitivity cardiac troponin T (hs-TnT) and point-of-care H-FABP testing were concomitantly performed at admission and after 6h.

RESULTS

Maximal hs-TnT levels above the 99th percentile were observed in 152 patients (75%) with 127 (63%) fulfilling criteria for myocardial infarction. Upon admission, hs-TnT and H-FABP were associated with an area under the curve (95% CI) of 0.83 (0.77-0.89) and 0.79 (0.73-0.85), respectively, to predict myocardial infarction, which increased to 0.93 (0.90-0.97) and 0.88 (0.84-0.93), respectively, after 6h. The diagnostic accuracy for non-ST-segment elevation myocardial infarction was somewhat lower with an area under the curve (95% CI) of 0.80 (0.72-0.87), 0.90 (0.84-0.96), 0.73 (0.64-0.81) and 0.77 (0.67-0.86), respectively. When assessment was performed within 3h of chest pain onset, diagnostic accuracy of H-FABP versus hs-TnT was similar. Each standard deviation increase in admission H-FABP was associated with a 68% relative risk increase of all-cause mortality (p-value=0.027) during 666 ± 155 days of follow-up.

CONCLUSIONS

Point-of-care H-FABP testing has lower diagnostic accuracy compared with hs-TnT assessment in patients with high pre-test acute coronary syndrome probability, but might be of interest when assessment is possible early after chest pain onset.

Heart-type fatty acid binding protein in early diagnosis of myocardial infarction in the era of high-sensitivity troponin: a systematic review and meta-analysis

Introduction

Heart-type fatty acid binding protein (HT FABP) is an emerging biomarker of ischaemic myocardial necrosis. While previous studies have demonstrated its additive value when compared to contemporary troponin assays in the diagnosis of acute myocardial infarction (AMI), its utility in the era of high-sensitivity troponin (hsTn) assays remains undetermined.

Methodology

A systematic review and meta-analysis of relevant studies was performed comparing the diagnostic performance of HT FABP both alone and in conjunction with hsTn in the early diagnosis and exclusion of AMI.

Results

A systematic literature search yielded eight eligible studies including 3395 patients. Of these, 716 patients (21.1%) were eventually diagnosed with AMI. The pooled sensitivity and specificity for hsTn on admission was 82.5% (95% confidence interval [CI]: 79.8–85.0%) and 89.7% (95% CI: 88.7–90.6%), respectively, while the area under the curve (AUC) for the summary receiver operating characteristics (ROC) curve is 0.92 (SE 0.02). While the pooled specificity (84.6%, 95% CI: 83.2–85.9%) of admission HT FABP is similar to hsTn for the early diagnosis of AMI ( P = 0.07), its pooled sensitivity (63.5%, 95% CI: 59.9–67.1%, P < 0.001) is significantly worse. Accordingly, the AUC of the summary ROC curve for HT FABP (0.79, SE 0.03) is inferior to hsTn ( P < 0.0001). The addition of HT FABP to hsTn resulted in no improvement in the sensitivity ( P = 0.058) and worsened the specificity ( P = 0.001) in the early diagnosis of AMI compared to hsTn alone.

Conclusion

HT FABP does not appear to improve the diagnostic accuracy of hsTn, and consequently its routine use currently cannot not be recommended.

Cardiac biomarkers for infarct diagnosis and early exclusion of acute coronary syndrome

The acute coronary syndrome (ACS) represents a diagnostic challenge: on the one hand patients need to be quickly identified to initiate treatment and on the other hand early exclusion of patients without ACS is important to relieve patient stress as well as overcrowded emergency departments. A growing number of biomarkers are becoming available to aid physicians with this task. This review gives an overview of the current research concerning early exclusion with an emphasis on the clinically most important biomarker: cardiac troponin.

Serial measurement of hFABP and high-sensitivity troponin I post-PCI in STEMI: how fast and accurate can myocardial infarct size and no-reflow be predicted?

The objective of this study was to compare heart-specific fatty acid binding protein (hFABP) and high-sensitivity troponin I (hsTnI) via serial measurements to identify early time points to accurately quantify infarct size and no-reflow in a preclinical swine model of ST-elevated myocardial infarction (STEMI). Myocardial necrosis, usually confirmed by hsTnI or TnT, takes several hours of ischemia before plasma levels rise in the absence of reperfusion. We evaluated the fast marker hFABP compared with hsTnI to estimate infarct size and no-reflow upon reperfused (2 h occlusion) and nonreperfused (8 h occlusion) STEMI in swine. In STEMI (n = 4) and STEMI + reperfusion (n = 8) induced in swine, serial blood samples were taken for hFABP and hsTnI and compared with triphenyl tetrazolium chloride and thioflavin-S staining for infarct size and no-reflow at the time of euthanasia. hFABP increased faster than hsTnI upon occlusion (82 ± 29 vs. 180 ± 73 min, P < 0.05) and increased immediately upon reperfusion while hsTnI release was delayed 16 ± 3 min (P < 0.05). Peak hFABP and hsTnI reperfusion values were reached at 30 ± 5 and 139 ± 21 min, respectively (P < 0.05). Infarct size (containing 84 ± 0.6% no-reflow) correlated well with area under the curve for hFABP (r(2) = 0.92) but less for hsTnI (r(2) = 0.53). At 50 and 60 min reperfusion, hFABP correlated best with infarct size (r(2) = 0.94 and 0.93) and no-reflow (r(2) = 0.96 and 0.94) and showed high sensitivity for myocardial necrosis (2.3 ± 0.6 and 0.4 ± 0.6 g). hFABP rises faster and correlates better with infarct size and no-reflow than hsTnI in STEMI + reperfusion when measured early after reperfusion. The highest sensitivity detecting myocardial necrosis, 0.4 ± 0.6 g at 60 min postreperfusion, provides an accurate and early measurement of infarct size and no-reflow.