Old and newer biomarkers in heart failure: from pathophysiology to clinical significance

Current Use of Cardiac Biomarkers in Various Heart Conditions

Biomarkers are increasingly recognized to have significant clinical value in early identification and progression of various cardiovascular diseases. There are many heart conditions, such as congestive heart failure (CHF), ischemic heart diseases (IHD), and diabetic cardiomyopathy (DCM), and cardiac remodeling, in which the severity of the cardiac pathology can be mirrored through these cardiac biomarkers. From the emergency department (ED) evaluation of acute coronary syndromes (ACS) or suspected acute myocardial infarction (AMI) with cardiac marker Troponin to the diagnosis of chronic conditions like Heart Failure (HF) with natriuretic peptides, like B-type natriuretic peptide (BNP), N-terminal pro-B- type natriuretic peptide (Nt-proBNP) and mid regional pro-atrial natriuretic peptide (MR- proANP), their use is continuously increasing. Their clinical importance has led to the discovery of newer biomarkers, such as the soluble source of tumorigenicity 2 (sST2), galectin-3 (Gal-3), growth differentiation factor-15 (GDF-15), and various micro ribonucleic acids (miRNAs). Since cardiac pathophysiology involves a complex interplay between inflammatory, genetic, neurohormonal, and biochemical levels, these biomarkers could be enzymes, hormones, and biologic substances showing cardiac injury, stress, and malfunction. Therefore, multi-marker approaches with different combinations of novel cardiac biomarkers, and continual assessment of cardiac biomarkers are likely to improve cardiac risk prediction, stratification, and overall patient wellbeing. On the other hand, these biomarkers may reflect coexisting or isolated disease processes in different organ systems other than the cardiovascular system. Therefore, knowledge of cardiac biomarkers is imperative. In this article, we have reviewed the role of cardiac biomarkers and their use in the diagnosis and prognosis of various cardiovascular diseases from different investigations conducted in recent years.

Biomarkers for heart failure: small molecules with high clinical relevance

Heart failure (HF) is a rising epidemic due to the ageing population and progress in all areas of medicine. Thus, research efforts are made to ensure a timely diagnosis, to improve prognosis and treatment of the disease and to facilitate risk prediction at the population level. Because of their noninvasive determination with mostly high sensitivity and accuracy, circulating blood biomarkers are becoming increasingly important for daily clinical practice. Natriuretic peptides, especially B-type natriuretic peptide (BNP), N-terminal pro-B-type natriuretic peptide (Nt-proBNP) and midregional pro-atrial natriuretic peptide (MR-proANP) and cardiac troponins are established blood biomarkers in HF diagnosis and prognosis of HF-related outcomes. Inflammatory molecules as C-reactive protein (CRP) may have added value in anti-inflammatory therapy guidance. Next-generation biomarkers including soluble source of tumorigenicity 2 (sST2), growth differentiation factor-15 (GDF-15), galectin-3 (Gal-3) and diverse microribonucleic acids (miRNAs) may have additional benefit in assessment of cardiac remodeling or differentiation of HF subtypes. Multimarker approaches containing different combinations of established and novel biomarkers might improve HF risk prediction at the population level once they are used on top of clinical variables.

Use of biomarkers to establish potential role and function of circulating microRNAs in acute heart failure

BACKGROUND

Circulating microRNAs (miRNAs) emerge as potential heart failure biomarkers. We aimed to identify associations between acute heart failure (AHF)-specific circulating miRNAs and well-known heart failure biomarkers.

METHODS

Associations between 16 biomarkers predictive for 180day mortality and the levels of 12 AHF-specific miRNAs were determined in 100 hospitalized AHF patients, at baseline and 48hours. Patients were divided in 4 pre-defined groups, based on clinical parameters during hospitalization. Correlation analyses between miRNAs and biomarkers were performed and complemented by miRNA target prediction and pathway analysis.

RESULTS

No significant correlations were found at hospital admission. However, after 48hours, 7 miRNAs were significantly negatively correlated to biomarkers indicative for a worse clinical outcome in the patient group with the most unfavorable in-hospital course (n=21); miR-16-5p was correlated to C-reactive protein (R=-0.66, p-value=0.0027), miR-106a-5p to creatinine (R=-0.68, p-value=0.002), miR-223-3p to growth differentiation factor 15 (R=-0.69, p-value=0.0015), miR-652-3p to soluble ST-2 (R=-0.77, p-value<0.001), miR-199a-3p to procalcitonin (R=-0.72, p-value<0.001) and galectin-3 (R=-0.73, p-value<0.001) and miR-18a-5p to procalcitonin (R=-0.68, p-value=0.002). MiRNA target prediction and pathway analysis identified several pathways related to cardiac diseases, which could be linked to some of the miRNA-biomarker correlations.

CONCLUSIONS

The majority of correlations between circulating AHF-specific miRNAs were related to biomarkers predictive for a worse clinical outcome in a subgroup of worsening heart failure patients at 48hours of hospitalization. The selective findings suggest a time-dependent effect of circulating miRNAs and highlight the susceptibility to individual patient characteristics influencing potential relations between miRNAs and biomarkers.

Prognostication in Different Heart Failure Phenotypes: The Role of Circulating Biomarkers

Heart failure (HF) is multifactorial syndrome with high cardiovascular (CV) morbidity and mortality rates associated with an increasing prevalence worldwide. Measuring plasma levels of circulating biomarkers, i.e., natriuretic peptides, cardiac-specific troponins, metabolomic intermediates, Galectin-3, ST2, cardiotrophin-1, soluble endoglin and growth differentiation factor 15, may assist in the prognostication of HF development. However, the role of biomarker models in the prediction of an early stage of HF with a preserved ejection fraction (HFpEF) and HF with a reduced ejection fraction (HFrEF) is not still understood. This review explores the knowledge regarding the utility of cardiac biomarkers, aiming to reclassify patients with different phenotypes of HF. The review reports that several biomarkers reflected on subsequently alter collagen turnover, cardiac fibrosis and inflammation, which might have diagnostic and predictive value in HFpEF and HFrEF. The best candidates for determining the early stage of HF development were sST2, Galectin-3, CT-1 and GDF-15. However, increased plasma concentrations of these biomarkers were not specific to a distinct disease group of HFpEF and HFrEF. Finally, more investigations are required to determine the role of novel biomarkers in the prediction of HF and the determination of the early stages of HFpEF and HFrEF development.

Fluid Management in Patients with Chronic Heart Failure

Congestion, or fluid overload, is a classic clinical feature of patients presenting with heart failure patients, and its presence is associated with adverse outcome. However, congestion is not always clinically evident, and more objective measures of congestion than simple clinical examination may be helpful. Although diuretics are the mainstay of treatment for congestion, no randomised trials have shown the effects of diuretics on mortality in chronic heart failure patients. Furthermore, appropriate titration of diuretics in this population is unclear. Research is required to determine whether a robust method of detecting - and then treating - subclinical congestion improves outcomes.

Post-Effort Changes in Activity of Traditional Diagnostic Enzymatic Markers in Football Players' Blood

Background

Long-term and intensive physical effort causes metabolic and biochemical adaptations for both athletic and non-athletic objectives. Knowing the importance of aerobic training in football players, the aim of this study was to evaluate changes in the activity of: creatinine kinase (CK), creatine kinase MB (CKMB), lactate dehydrogenase (LDH), α-hydroxybutyrate dehydrogenase (HBDH), cholinesterase (ChE) and alkaline phosphatase (ALP) in response to a semi-long distance outdoor run under aerobic conditions among both female and male football players.

Methods

Sixteen participants aged 21.9±2 years (women) and 18.4±0.5 years (men), all of them voluntarily recruited football players, took part in an outdoor run, the women covering a distance of 7.4±0.3 km while men covered a distance of 10.7±1.0 km. Plasma activities of the studied enzymes were determined using an appropriate diagnostic assay kit.

Results

Our results indicate that total LDH activity could be a useful tool in evaluating physical fitness among athletes. We simultaneously established that ChE could not be a marker useful in assessing metabolic response to physical effort in athletes. Moreover, our results suggest that post-effort changes in ALP activity might be used to estimate early symptoms of certain vitamin deficiencies in an athlete’s diet.

Conclusions

We confirmed that the assessment of activity of selected traditional diagnostic enzymatic markers provides information about muscle state after physical effort.