Revisiting myocardial necrosis biomarkers: assessment of the effect of conditioning therapies on infarct size by kinetic modelling

Population pharmacokinetics of mycophenolate in patients treated for interstitial lung disease (EVER-ILD study)

BACKGROUND

Mycophenolate mofetil (MMF) has been used to treat interstitial lung disease (ILD), but mycophenolate (MPA) pharmacokinetics was not reported for this use. This ancillary study of the EVER-ILD protocol aimed at describing the pharmacokinetic variability of MPA using population modelling in ILD.

METHODS

Concentrations of MPA were measured during an 8-h course for 27 ILD patients treated with 1000 mg MMF b.i.d. Absorption, distribution and elimination of MPA were described using population compartment models with first-order transfer and elimination rate constants, while accounting for both absorption peaks using gamma absorption models.

RESULTS

The pharmacokinetics of MPA was best described using a two-compartment model and two gamma absorption models, model performances of this model were still similar to those of a one gamma absorption model. This pharmacokinetics seemed to be notably influenced by body weight, renal function and inflammatory status. The distribubtion value area under the concentration curve between two administrations of MMF was AUC12 = 52.5 mg.h/L in median (interquartile range: 42.2-58.0 mg.h/L).

CONCLUSION

This is the first study reporting MPA pharmacokinetics in ILD. This pharmacokinetics appears to be similar to other indications and should be further investigated in future studies.

Importance of H-FABP in Early Diagnosis of Acute Myocardial Infarction

Background

Over the years, troponins have aced the para-clinical tests for confirming the diagnosis of acute myocardial infarction. However, the rise in their levels is entirely time-dependent, which can cause a delay in the initiation of treatment protocols. Heart fatty acid binding protein (H-FABP) can serve comparatively as a better biological marker for overcoming this flaw of troponins, as it is quickly released into the bloodstream once the myocardial injury occurs due to decreased blood supply. This study aimed to evaluate the usefulness of this marker as well as establish the specificity and sensitivity of testing the H-FABP, if it adds to early diagnosis and can be relied upon in the future.

Material and Methods

We evaluated 83 patients and their H-FABP levels, along with the standard cardiac markers like hsTni and CK-MB, in patients presenting with symptoms indicating an ongoing coronary event, who had presented to our hospital between August 2020 and June 2021. The patients were divided into two groups: group 1 comprised patients who had first medical contact within 4 hours of the onset of chest pain, and group 2 patients who had first medical contact after 4 hours of the appearance of symptoms. Statistical analysis was performed using MedCalc v20.023, considering statistical significance values of p <0.05. Results for targeted variables are presented using descriptive statistics (mean, standard deviation, range, median, and associated interquartile range) for continuous data, and counts with associated percentages for categorical data.

Results

H-FABP was found to have better sensitivity and specificity of 89.67 and 95.65 in group 1 patients and 86.73 and 49.84, respectively, in group 2 patients. The other two cardiac biomarkers evaluated had lower values in response to H-FABP in the first 4 hours of presentation. Results for group 2 showed that specificitivity for hsTni is higher than that of H-FABP, that is, 69.98.

Conclusion

Heart fatty acid binding protein (H-FABP) should be included in the protocol for biochemical evaluation of all patients presenting to the emergency services with a suspicion of possible myocardial infarction. Early detection of this protein can help in effective and timely management of myocardial infarction, thus further decreasing mortality rates and the financial burden on healthcare systems worldwide.

SARS-CoV-2 infection and multi-organ system damage: A review

The SARS-CoV-2 infection causes COVID-19, which has affected approximately six hundred million people globally as of August 2022. Organs and cells harboring angiotensin-converting enzyme 2 (ACE2) surface receptors are the primary targets of the virus. However, once it enters the body through the respiratory system, the virus can spread hematogenously to infect other body organs. Therefore, COVID-19 affects many organs, causing severe and long-term complications, even after the disease has ended, thus worsening the quality of life. Although it is known that the respiratory system is most affected by the SARS-CoV-2 infection, many organs/systems are affected in the short and long term. Since the COVID-19 disease simultaneously affects many organs, redesigning diagnostic and therapy policies to fit the damaged organs is strongly recommended. Even though the pathophysiology of many problems the infection causes is unknown, the frequency of COVID-19 cases rises with age and the existence of preexisting symptoms. This study aims to update our knowledge of SARS-CoV-2 infection and multi-organ dysfunction interaction based on clinical and theoretical evidence. For this purpose, the study comprehensively elucidates the most recent studies on the effects of SARS-CoV-2 infection on multiple organs and systems, including respiratory, cardiovascular, gastrointestinal, renal, nervous, endocrine, reproductive, immune, and parts of the integumentary system. Understanding the range of atypical COVID-19 symptoms could improve disease surveillance, limit transmission, and avoid additional multi-organ-system problems.

The IC-D score for predicting prophylactic cardioverter-defibrillator implantation following acute myocardial infarction

BACKGROUND

A reduced left ventricular ejection fraction (LVEF) ≤35% ≥6 weeks following an acute myocardial infarction (MI) may indicate prophylactic implantation of a cardioverter-defibrillator (ICD). We sought to find predictors of absence of significant left ventricular (LV) remodeling post-MI.

METHODS

All consecutive patients hospitalized for acute MI with an LVEF ≤35% at discharge in our institution from 2010 were retrospectively included. Patients were assigned to two groups according to the persistence of an LVEF ≤35% (ICD+) or a recovery >35% (ICD-). Logistic regression was performed to build a predictive score, which was then externally validated.

RESULTS

Among a total of 1533 consecutive MI patients, 150 met inclusion criteria, 53 (35%) in the ICD+ group and 97 in the ICD group. After multivariable analyses, an LVEF ≤25% at discharge (adjusted OR 6.23 [2.47 to 17.0], p < .0001) and a CPK peak at the MI acute phase >4600 UI/L (adjusted OR 9.99 [4.27 to 25.3], p < .0001) both independently predicted non-recovery at 6 weeks. The IC-D (Increased Cpk-LV Dysfunction) score predicted persistent LVEF ≤35% with areas under curve of 0.83 and 0.73, in the study population and in a multicenter validation cohort of 150 patients, respectively (p < .0001).

CONCLUSIONS

The association of a severely reduced LVEF and a major release of myocardial necrosis biomarkers at the acute phase of MI predict unfavorable remodeling, and prophylactic ICD implantation.

COVID-19 and multiorgan failure: A narrative review on potential mechanisms

The outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) in December 2019 form Wuhan, China leads to coronavirus disease 2019 (COVID-19) pandemic. While the common cold symptoms are observed in mild cases, COVID-19 is accompanied by multiorgan failure in severe patients. The involvement of different organs in severe patients results in lengthening the hospitalization duration and increasing the mortality rate. In this review, we aimed to investigate the involvement of different organs in COVID-19 patients, particularly in severe cases. Also, we tried to define the potential underlying mechanisms of SARS-CoV2 induced multiorgan failure. The multi-organ dysfunction is characterized by acute lung failure, acute liver failure, acute kidney injury, cardiovascular disease, and as well as a wide spectrum of hematological abnormalities and neurological disorders. The most important mechanisms are related to the direct and indirect pathogenic features of SARS-CoV2. Although the presence of angiotensin-converting enzyme 2, a receptor of SARS-CoV2 in the lung, heart, kidney, testis, liver, lymphocytes, and nervous system was confirmed, there are controversial findings to about the observation of SARS-CoV2 RNA in these organs. Moreover, the organ failure may be induced by the cytokine storm, a result of increased levels of inflammatory mediators, endothelial dysfunction, coagulation abnormalities, and infiltration of inflammatory cells into the organs. Therefore, further investigations are needed to detect the exact mechanisms of pathogenesis. Since the involvement of several organs in COVID-19 patients is important for clinicians, increasing their knowledge may help to improve the outcomes and decrease the rate of mortality and morbidity.

Association of influenza infection and vaccination with cardiac biomarkers and left ventricular ejection fraction in patients with acute myocardial infarction

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We examined the association of influenza infection and vaccination with cardiac biomarkers and LVEF .

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Mean and median CK-MB levels were significantly higher among unvaccinated cases .

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Large size infarcts were more frequent in influenza positive cases and less frequent in vaccinated cases.

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Influenza vaccine may have a protective effect against large infarcts .

Aims

The aim of this study was to examine the association of influenza infection and vaccination with extent of cardiac damage during acute myocardial infarctions (AMIs) as measured by serum biomarkers and left ventricular ejection function (LVEF) in patients.

Methods

Post-hoc analysis was performed on data from a prospective case-control study of influenza and AMI, conducted in a tertiary care hospital in Sydney, Australia. We included 275 cases of AMI, aged ≥ 40 years admitted to the cardiology during the study period.

Results

Mean and median CK-MB levels were significantly higher among unvaccinated group compared to vaccinated group (p value < 0.05). Troponin levels were also higher among unvaccinated group compared to vaccinated group; although not statistically significant. Troponin and CKMB values were not statistically different among influenza positive cases and influenza negative cases. Large size infarcts were less frequent among vaccinated cases compared to unvaccinated cases (25% vs 35.5%) and were more frequent among influenza positive cases compared to influenza negative cases (35.3% vs 31.5%), however differences were not statistically significant. LVEF was lower among vaccinated cases compared to unvaccinated cases (62.5% vs. 52.8%) and influenza positive cases compared to influenza negative cases (58.8% vs 55.4), however differences were not significant.

Conclusion

Lower CKMB levels among vaccinated groups showed that influenza vaccine may have a protective effect against large infarcts, therefore influenza vaccination should be recommended for high risk groups. The study suggests an association of larger infarcts with influenza infection, but larger studies are required to confirm this.

A general model for cell death and biomarker release from injured tissues

Cellular response to insults may result in the initiation of different cell death processes. For many cases the cell death process will result in an acute release of cellular material that in some circumstances provides valuable information about the process (i.e. may represent a biomarker). The characteristics of the biomarker release is often informative and plays critical roles in clinical practice and toxicology research. The aim of this study is to develop a general, semi-mechanistic model to describe cell turnover and biomarker release by injured tissue that can be used for estimation in pharmacokinetic and (toxicokinetic)-pharmacodynamic studies. The model included three components: (1) natural tissue turnover, (2) biomarker release from cell death and its movement from the cell through the tissue into the blood, (3) different target insult mechanisms of cell death. We applied the general model to biomarker release profiles for four different cell insult causes. Our model simulations showed good agreements with reported data under both delayed release and rapid release cases. Additionally, we illustrate the use of the model to provide different biomarker profiles. We also provided details on interpreting parameters and their values for other researchers to customize its use. In conclusion, our general model provides a basic structure to study the kinetic behaviour of biomarker release and disposition after cellular insult.

Cardioprotection for Acute MI in Light of the CONDI2/ERIC-PPCI Trial: New Targets Needed

Protection against ischaemia-reperfusion injury after revascularisation in acute myocardial infarction remains an enigma. Many targets have been identified, but after the failure of the recent Effect of Remote Ischaemic Conditioning on Clinical Outcomes in ST-elevation Myocardial Infarction Patients Undergoing Primary Percutaneous Coronary Intervention (CONDI2/ERIC-PPCI) trial to show translation to clinical benefit, there is still no pharmacological or mechanical strategy that has translated to clinical practice. This article addresses the results of the CONDI2/ERIC-PPCI trial in the context of previous studies of ischaemic conditioning, and then considers the prospects for other potential targets of cardioprotection. Finally, the authors examine the pitfalls and challenges in trial design for future investigation of cardioprotective strategies. In particular, this article highlights the need for careful endpoint and patient selection, as well as the need to pay attention to the biology of cardioprotection during the study.

Kinetic modelling of myocardial necrosis biomarkers offers an easier, reliable and more acceptable assessment of infarct size

Infarct size is a major prognostic factor in ST-segment elevation myocardial infarction (STEMI). It is often assessed using repeated blood sampling and the estimation of biomarker area under the concentration versus time curve (AUC) in translational research. We aimed at developing limited sampling strategies (LSS) to accurately estimate biomarker AUC using only a limited number of blood samples in STEMI patients. This retrospective study was carried out on pooled data from five clinical trials of STEMI patients (TIMI blood flow 0/1) studies where repeated blood samples were collected within 72 h after admission to assess creatine kinase (CK), cardiac troponin I (cTnI) and muscle-brain CK (CK-MB). Biomarker kinetics was assessed using previously described biomarker kinetic models. A number of LSS models including combinations of 1 to 3 samples were developed to identify sampling times leading to the best estimation of AUC. Patients were randomly assigned to either learning (2/3) or validation (1/3) subsets. Descriptive and predictive performances of LSS models were compared using learning and validation subsets, respectively. An external validation cohort was used to validate the model and its applicability to different cTnI assays, including high-sensitive (hs) cTnI. 132 patients had full CK and cTnI dataset, 49 patients had CK-MB. For each biomarker, 180 LSS models were tested. Best LSS models were obtained for the following sampling times: T4-16 for CK, T8-T20 for cTnI and T8-T16 for CK-MB for 2-sample LSS; and T4-T16-T24 for CK, T4-T12-T20 for cTnI and T8-T16-T20 for CK-MB for 3-sample LSS. External validation was achieved on 103 anterior STEMI patients (TIMI flow 0/1), and the cTnI model applicability to recommended hs cTnI confirmed. Biomarker kinetics can be assessed with a limited number of samples using kinetic modelling. This opens the way for substantial simplification of future cardioprotection studies, more acceptable for the patients.

Relationship between high sensitivity C-reactive protein and angiographic severity of coronary artery disease

Background

Coronary artery disease (CAD) remains a leading cause of morbidity and mortality. Cytokines play a potential role in atherosclerosis pathogenesis and progression. We investigated the association between high sensitive C-reactive protein (hsCRP) and severity of CAD.

Methods

CAD patients were stratified according to hsCRP cut-off value into high levels hsCRP group (≥ 8.4 mg/L) and low levels hsCRP group (< 8.4 mg/L). Severity of CAD was assessed according to artery stenosis degree and the number of vessel involved. Statistical analysis was performed using Statistical Package for the Social Sciences (SPSS, version 23.0).

Results

The mean age was 60.3 ± 11.0 years. The level of hsCRP was increased and ranged from 0.2 to 1020.0 mg/L. Biochemical risk factors and severity of CAD didn't show significant differences between the two groups. In multivariate linear analysis, cardiac troponin I (cTnI) and serum amyloid A (SAA) were predictors of hsCRP. As shown in receiver operating characteristic (ROC) curve analysis performed in patients with ST-segment elevation myocardial infarction (STEMI) and compared to myonecrosis biomarkers, hsCRP (area under the curve (AUC): 0.905; 95%CI: 0.844-0.966; P < 0.001) could be a powerful predictor marker in evaluating the infarct size after myocardial infarction but not better than cTnI.

Conclusions

HsCRP levels were not associated with the severity of CAD but could be useful in the evaluation of myocardial necrosis in patients with STEMI.

Whole blood transcriptome profile at hospital admission discriminates between patients with ST-segment elevation and non-ST-segment elevation acute myocardial infarction

Whether ST-segment (STEMI) and non-ST-segment elevation myocardial infarction (NSTEMI) should be regarded as distinct pathophysiological entities is a matter of debate. We tested the hypothesis that peripheral blood gene-expression profiles at presentation distinguish STEMI from NSTEMI. We performed a case-control study collecting whole-blood from 60 STEMI and 58 NSTEMI (defined according to the third universal definition of MI) consecutive patients on hospital admission. We used RNA-sequencing for the discovery phase, comparing 15 STEMI vs. 15 NSTEMI patients, matched for age, sex, and cardiovascular risk factors, and quantitative PCR in the remaining unmatched patients for validating top-significant genes. Gene-level differential expression analysis identified significant differences in the expression of 323 genes: 153 genes withstood correction for admission cardiac troponin I (cTnI), differentiating the two conditions independently of myocardial necrosis extent. Functional annotation analysis uncovered divergent modulation in leukocyte and platelet activation, cell migration, and mitochondrial respiratory processes. Linear regression analysis revealed gene expression patterns on admission predicting infarct size, as indexed by cTnI peak (R² = 0.58–0.75). Our results unveil distinctive pathological traits for these two MI subtypes and provide insights into the early assessment of injury extent. This could translate into RNA-based disease-specific biomarkers for precision diagnosis and risk stratification.

Cardiovascular Risk Assessment for Noncardiac Surgery: Are We Ready for Biomarkers?

Biomarkers aided perioperative cardiac assessment is a relatively new concept. Cardiac biomarkers with historical significance (aspartate transaminase, dehydrogenase, creatinine kinase and myoglobin) have paved the way for traditional biomarkers (cardiac troponin, C-reactive protein, lipoprotein). Contemporary biomarkers like natriuretic peptides (BNP and ProBNP) are validated risk markers in both acute and chronic cardiac diseases and are showing remarkable promise in predicting serious cardiovascular complications after non-cardiac surgery. This review is intended to provide a critical overview of traditional and contemporary biomarkers for perioperative cardiovascular assessment and management. This review also discusses the potential utility of newer biomarkers like galectin-3, sST-2, GDF-15, TNF-alpha, MiRNAs and many others that can predict inflammation, cardiac remodeling, injury and endogenous stress and need further investigations to establish their clinical utility. Though promising, biomarker led perioperative care is still in infancy and it has not been determined that it can improve clinical outcomes.

Complement activation in acute myocardial infarction: An early marker of inflammation and tissue injury?

BACKGROUND

Acute myocardial infarction (AMI) is a potentially fatal condition, being a major cause of death worldwide. Ischemia suffered during AMI causes tissue damage, leading to an inflammatory process. Moreover, myocardial injury can generate damage-associated molecular patterns that activate pattern recognition molecules including some complement proteins.

METHODS

Here we investigated products of complement activation, C3d and soluble C5b9 (sC5b9), as potential biomarkers for myocardial injury and inflammation, as well as serum cytokines (IL-6 and TNF-alpha), alpha-1-acid glycoprotein (AGP), and classical markers of myocardial necrosis (creatine kinase, creatine kinase-MB isoform, myoglobin and troponin-I) in a longitudinal study of patients with AMI (from admission, 6 h and 12 h post admission, and at discharge from hospital). Individuals undergoing cardiac catheterization (CC) with normal coronary arteries and asymptomatics with no history of cardiovascular disease or invasive procedures were included as controls.

RESULTS

Plasma C3d was higher in AMI at admission, 6 h, 12 h, and discharge vs CC (p < 0.0001; p = 0.0061; p = 0.0081; p = 0.044) and asymptomatic (p = 0.0001 for admission, 6 h and 12 h; p = 0.0002 for discharge). Moreover, sC5b9 was higher only at admission and 6 h vs asymptomatic (p = 0.0031 and p = 0.0019). Additionally, AGP levels were elevated at admission, 6 h, 12 h, and discharge vs asymptomatic (p = 0.0003; p = 0.0289; p = 0.0009, p = 0.0017). IL-6 concentration was low at admission and 6 h and reached a peak at 12 h (p < 0.0001 for all groups). All classical markers of myocardial necrosis presented higher concentration at 6 h.

CONCLUSIONS

Our results showed that complement activation is an early event in AMI occurring before the elevation of classical markers of myocardial necrosis such as creatine kinase, creatine kinase-MB isoform, myoglobin and troponin-I. These findings indicated C3d and sC5b9 as possible biomarkers for inflammation and tissue damage in AMI.

Region of Interest analysis using mass spectrometry imaging of mitochondrial and sarcomeric proteins in acute cardiac infarction tissue

Matrix-assisted laser desorption ionization image mass spectrometry (MALDI-IMS) has been developed for the identification of peptides in various tissues. The MALDI-IMS signal distribution patterns and quantification of the signal intensities of the regions of interest (ROI) with healthy regions were compared for identification of the disease specific biomarkers. We performed a new ROI analysis using the conventional t-test and data number independent Cohen’s d-value analysis. Using these techniques, we analysed heart tissues after acute myocardial infarction (AMI). As a result, IMS signals of mitochondrial adenosine triphosphate synthase alpha subunit (ATP5A), myosin-6/7(MYH6/7), aortic actin, and the myosin light chain 3 (MYL3) were identified in the infarcted region. In particular, the signals of MYH7 are significantly greater in the infarcted region using ROI analysis. ROI analysis using MALDI-IMS may be a promising technique for the identification of biomarkers for pathological studies that involve the comparison of diseased and control areas.