The use of biomarkers for the evaluation and treatment of patients with acute coronary syndromes

A critical review on brain and heart axis response in COVID-19 patients: Molecular mechanisms, mediators, biomarkers, and therapeutics

Since the outbreak of highly virulent coronaviruses, significant interest was assessed to the brain and heart axis (BHA) in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-affected patients. The majority of clinical reports accounted for unusual symptoms associated with SARS-CoV-2 infections which are of the neurological type, such as headache, nausea, dysgeusia, anosmia, and cerebral infarction. The SARS-CoV-2 enters the cells through the angiotensin-converting enzyme (ACE-2) receptor. Patients with prior cardiovascular disease (CVD) have a higher risk of COVID-19 infection and it has related to various cardiovascular (CV) complications. Infected patients with pre-existing CVDs are also particularly exposed to critical health outcomes. Overall, COVID-19 affected patients admitted to intensive care units (ICU) and exposed to stressful environmental constraints, featured with a cluster of neurological and CV complications. In this review, we summarized the main contributions in the literature on how SARS-CoV-2 could interfere with the BHA and its role in affecting multiorgan disorders. Specifically, the central nervous system involvement, mainly in relation to CV alterations in COVID-19-affected patients, is considered. This review also emphasizes the biomarkers and therapy options for COVID-19 patients presenting with CV problems.

Novel monitoring of renal function and medication levels in saliva and capillary blood of patients with kidney disease

PURPOSE OF REVIEW

Serum creatinine, urea, and cystatin C are the main biomarkers used to estimate glomerular filtration rates in persons with and without chronic kidney disease (CKD). Frequent measurements of these assays are needed to identify patients with earlier stages of CKD, detect episodes of acute kidney injury (AKI), and monitor for CKD progression. However, the cumbersome, time-consuming nature of conventional laboratory-based kidney function assays limit more frequent monitoring and greater patient self-management.

RECENT FINDINGS

Noninvasive salivary assessments of creatinine, cystatin C, and urea make it feasible to conduct frequent monitoring of kidney function in point-of-care settings, as well as in nonclinical-care settings such as at home. Additionally, fingerstick sampling can offer an alternative route of blood testing that is suitable for home-based assessments. In this review, we provide an overview of emerging data on various salivary vs. fingerstick blood assessment methods for kidney function; their accuracy in comparison to 'gold-standard' laboratory-based methods; and their respective strengths and limitations in the clinical setting.

SUMMARY

A practical, cost-effective, minimally invasive, multimarker assessment platform has the potential to circumvent the limitation of conventional laboratory blood-based testing approaches, and thereby address a major unmet need in the management of CKD patients.

Serum CK-MB, COVID-19 severity and mortality: An updated systematic review and meta-analysis with meta-regression

OBJECTIVES

We conducted a systematic review and meta-analysis with meta-regression of creatine kinase-MB (CK-MB), a biomarker of myocardial injury, in COVID-19 patients.

METHODS

We searched PubMed, Web of Science and Scopus, for studies published between January 2020 and January 2021 that reported CK-MB, COVID-19 severity and mortality (PROSPERO registration number: CRD42021239657).

RESULTS

Fifty-five studies in 11,791 COVID-19 patients were included in the meta-analysis. The pooled results showed that CK-MB concentrations were significantly higher in patients with high disease severity or non-survivor status than patients with low severity or survivor status (standardized mean difference, SMD, 0.81, 95% CI 0.61 to 1.01, p<0.001). The rate of patients with CK-MB values above the normal range was also significantly higher in the former than the latter (60/350 vs 98/1,780; RR ​= ​2.84, 95%CI 1.89 to 4.27, p<0.001; I² ​= ​19.9, p ​= ​0.254). Extreme between-study heterogeneity was observed (I² ​= ​93.4%, p<0.001). Sensitivity analysis, performed by sequentially removing each study and re-assessing the pooled estimates, showed that the magnitude and direction of the effect size was not modified (effect size range, 0.77 to 0.84). Begg's (p ​= ​0.50) and Egger's (p ​= ​0.86) t-tests did not show publication bias. In meta-regression analysis, the SMD was significantly and positively associated with the white blood count, aspartate aminotransferase, myoglobin, troponin, brain natriuretic peptide, lactate dehydrogenase, and D-dimer.

CONCLUSIONS

Higher CK-MB concentrations were significantly associated with severe disease and mortality in COVID-19 patients. This biomarker of myocardial injury might be useful for risk stratification in this group.

Monitoring Acute Myocardial Infarction Complicated with Cardiogenic Shock — from the Emergency Room to Coronary Care Units

Cardiogenic shock remains the leading cause of death in patients hospitalized for acute myocardial infarction, despite many advances encountered in the last years in reperfusion, mechanical, and pharmacological therapies addressed to stabilization of the hemodynamic condition of these critical patients. Such patients require immediate initiation of the most effective therapy, as well as a continuous monitoring in the Coronary Care Unit. Novel biomarkers have been shown to improve diagnosis and risk stratification in patients with cardiogenic shock, and their proper use may be especially important for the identification of the critical condition, leading to prompt therapeutic interventions. The aim of this review was to evaluate the current literature data on complex biomarker assessment and monitoring of patients with acute myocardial infarction complicated with cardiogenic shock in the Coronary Care Unit.

Level of Serum Enzymes and Electrocardiogram in Healthy Rabbits after Injection of ICD-85 as an Anticancer Agent

Background:

Our previous in vivo studies confirmed that ICD-85, as an anticancer agent, was able to prevent further growth of breast tumors and expand the life expectancy of mice with breast cancer.

Methods:

Blood collection was carried out before, 1, 3, and 6 hours after ICD-85 injection. Sera were used to determinate the cardio and hepatic enzymes levels, including ALT, AST, LDH, CPK, and Ck-MB. Coagulation factors such as PT and PTT were also assayed. ECGs of all rabbits were recorded during the experiment.

Results:

ECG results showed that the injection of 50 and 100 µg/kg ICD-85 into healthy rabbits has no significant effect on heart function while the injection of 150 to 200 µg/kg ICD-85 caused ECG wave changes and mild bradycardia without toxic effects on heart. After ICD-85 injection (concentrations below 100 µg/kg), no significant increase was observed in liver and cardiac enzymes (ALT, AST, LDH, CPK, and CK-MB). However, the concentration of 150 µg/kg and above caused a rise in the enzymes. Comparison of the PT and PTT before and after ICD-85 injection showed no significant clotting time at any concentrations below 200 µg/kg.

Conclusion:

Based on the results obtained in the present study as well as our previous reports, ICD-85 at concentrations below 100 µg/kg seems to have no significant effect on the serum enzymes as indicators of hepatotoxicity and cardiotoxicity in healthy rabbits. However, to confirm this conclusion, more detailed surveys on heart and liver is needed to be carried out.

Delta troponin for the early diagnosis of AMI in emergency patients with chest pain

OBJECTIVES

In patients presenting to the Emergency Department (ED) with potential acute myocardial infarction (AMI), elevated cardiac troponin (cTn) levels are indicative of myocardial necrosis. We assessed the accuracy of 'delta cTn' at 2h or 6h compared to the cTn concentration above the 99th percentile reference value for AMI in a prospective study of adult patients presenting to ED with symptoms suggestive of possible acute coronary syndrome.

METHODS

Blood was sampled for cardiac troponin I (cTnI) on presentation, and at 2h and 6h following presentation using a sensitive assay (Beckman AccuTnI). All clinical endpoints were adjudicated by a cardiologist who was blinded to the 2h cTn assay result.

RESULTS

Of the 874 patients, 70 (8%) were diagnosed with an AMI during their index presentation. The area under the ROC curve for diagnosing AMI at 2h was 0.89 [95%CI, 0.84-0.95] for absolute delta cTn versus 0.79 [95%CI 0.73-0.85] for the relative change. Specificity and PPV at 2h were optimized using a delta cTnI ≥ 0.03 μg/L (95.8% [95%CI 94.1-97.0] and 61.4% [95%CI 50.9-70.9] respectively). Sensitivity and NPV for AMI were optimized using the 99th percentile with the addition of a delta of<0.03 μg/L (97.1% [95%CI 90.2-99.2] and 99.7% [95%CI 99-99.9] respectively).

CONCLUSIONS

An algorithm incorporating cTnI concentration and delta cTn values with a sensitive troponin assay allows accurate diagnosis of AMI within 2h from presentation and earlier rule-out of AMI in the majority of patients.

Clinical Use and Measurement of Cardiac Troponin (cTn)

Cardiac troponins are cardio-specific and are widely used for the early diagnosis and triage of patients with acute coronary syndromes in conjunction with clinical history, electrocardiographic changes and imaging. Troponin is also useful for the prediction of outcomes in acute coronary syndromes, renal failure, sepsis, and critically ill patients. New developments in assay technology, designated as high sensitivity troponins, permit detection of lower levels of troponin in most healthy individuals, earlier diagnosis of myocardial infarction, and prognosis of stable coronary disease in the community.

Biomarkers in acute myocardial injury

Acute coronary syndrome (ACS) is a significant cause of morbidity and mortality worldwide. The proper diagnosis of ACS requires reliable and accurate biomarker assays to detect evidence of myocardial necrosis. Currently, troponin is the gold standard biomarker for myocardial injury and is used commonly in conjunction with creatine kinase-MB (CK-MB) and myoglobin to enable a more rapid diagnosis of ACS. A new generation of highly sensitive troponin assays with improved accuracy in the early detection of ACS is now available, but the correct interpretation of assay results will require a careful consideration of assay characteristics and the clinical setting prior to incorporation into routine practice. B-type natriuretic peptides, copeptin, ischemia-modified albumin, heart-type fatty-acid-binding protein, myeloperoxidase, C-reactive protein, choline, placental growth factor, and growth-differentiation factor-15 make up a promising group of other biomarkers that have shown the ability to improve prognosis and diagnosis of ACS compared with traditional markers.

Release of tissue-specific proteins into coronary perfusate as a model for biomarker discovery in myocardial ischemia/reperfusion injury

Diagnosis of acute coronary syndromes is based on protein biomarkers, such as the cardiac troponins (cTnI/cTnT) and creatine kinase (CK-MB) that are released into the circulation. Biomarker discovery is focused on identifying very low abundance tissue-derived analytes from within albumin-rich plasma, in which the wide dynamic range of the native protein complement hinders classical proteomic investigations. We employed an ex vivo rabbit model of myocardial ischemia/reperfusion (I/R) injury using Langendorff buffer perfusion. Nonrecirculating perfusate was collected over a temporal profile of 60 min reperfusion following brief, reversible ischemia (15 min; 15I/60R) for comparison with irreversible I/R (60I/60R). Perfusate proteins were separated using two-dimensional gel electrophoresis (2-DE) and identified by mass spectrometry (MS), revealing 26 tissue-specific proteins released during reperfusion post-15I. Proteins released during irreversible I/R (60I/60R) were profiled using gel-based (2-DE and one-dimensional gel electrophoresis coupled to liquid chromatography and tandem mass spectrometry; geLC-MS) and gel-free (LC-MS/MS) methods. A total of 192 tissue-specific proteins were identified during reperfusion post-60I. Identified proteins included those previously associated with I/R (myoglobin, CK-MB, cTnI, and cTnT), in addition to examples currently under investigation in large cohort studies (heart-type fatty acid binding protein; FABPH). The postischemic release profile of a novel cardiac-specific protein, cysteine and glycine-rich protein 3 (Csrp3; cardiac LIM domain protein) was validated by Western blot analysis. We also identified Csrp3 in serum from 6 of 8 patients postreperfusion following acute myocardial infarction. These studies indicate that animal modeling of biomarker release using ex vivo buffer perfused tissue to limit the presence of obfuscating plasma proteins may identify candidates for further study in humans.

Clinical Use of Natriuretic Peptides

Either B-type natriuretic peptide (BNP) or NT-proBNP may be used as a diagnostic, screening, prognostic and therapeutic tool for CHF. The Food and Drug Administration (FDA) cleared the cut-off point for BNP at 100 pg/mL, and that of NT-proBNP at 125 pg/mL for patients <75 years and 450 pg/mL for those >75. A steadily rising titre even below the cut-off value should be raised as a concern as heart failure is progressive if left untreated and may result in cardiac death. Both biomarkers are also featured in lab investigations for patients with acute coronary syndrome (ACS).

Troponin measurements during drug development--considerations for monitoring and management of potential cardiotoxicity: an educational collaboration among the Cardiac Safety Research Consortium, the Duke Clinical Research Institute, and the US Food and Drug Administration

Drug-induced cardiac toxicity is a recognized challenge in development and implementation of pharmacotherapy. Appropriate biomarkers are needed to detect these abnormalities early in development and to manage the risk of potentially cardiotoxic drugs or biologic agents. Circulating cardiac troponin (cTn) is the most widely used biomarker for detection of myocardial injury. Although most commonly used to detect myonecrosis in the setting of ischemia, cTns are also elevated with other acute and chronic disease processes, including heart failure, renal failure, sepsis, pulmonary embolic disease, and many others. High-sensitivity assays for both cTnI and cTnT are now available that achieve acceptable imprecision (coefficient of variation <10%) at the 99th percentile of a normal reference population. Even more sensitive assays are being developed that detect cTn in ranges that are near the level of normal cellular turnover (apoptosis). These properties of cTn and the continuing evolution of highly sensitive assays position cTn as a potentially uniquely informative marker for early detection of cardiac toxicity. This article summarizes collaborative discussions among key stakeholders in the Cardiac Safety Research Consortium about the use of cTn monitoring in drug development.

Correlation between serum cardiac markers and myocardial infarct size quantified by myocardial perfusion imaging in patients with hypertrophic cardiomyopathy after alcohol septal ablation

Myocardial infarct (MI) size is a well-established prognostic marker but the association of serum markers with MI size, as measured by myocardial perfusion imaging (MPI), has not been well studied in patients with hypertrophic cardiomyopathy (HC) after alcohol septal ablation (ASA). Creatine kinase (CK), CK-MB, troponin I, and brain natriuretic peptide were measured before and at multiple points after ASA in patients with HC and were correlated with MI size measured by MPI. MPI at rest was performed in 54 patients with HC at a median of 2 days after ASA. CK, CK-MB, and troponin I increased after ASA to peak levels at 12 hours and their cumulative levels (area under the curve) showed significant correlation with size of MI by MPI (r = 0.544, 0.408, and 0.477, p <0.001, 0.003, and 0.001, respectively). The best marker was level of CK at 12 hours (r = 0.609, p <0.0001) after ASA. Brain natriuretic peptide level did not change significantly after ASA (p = 1.0) and only weakly correlated with MI size by MPI (r = 0.130, p = 0.007). In conclusion, CK, CK-MB, and troponin I measured at 12 hours, at peak, and as the area under the curve correlated well with infarct size, but CK level at 12 hours was the best marker. CK continues to be a useful marker of MI size despite the introduction of newer, more specific markers, especially when infarct onset is known with certainty as in patients with HC undergoing ASA.