Adverse Cardiac Remodelling after Acute Myocardial Infarction: Old and New Biomarkers

Left Ventricular Remodeling after Myocardial Infarction: From Physiopathology to Treatment

Myocardial infarction (MI) is the leading cause of death and morbidity worldwide, with an incidence relatively high in developed countries and rapidly growing in developing countries. The most common cause of MI is the rupture of an atherosclerotic plaque with subsequent thrombotic occlusion in the coronary circulation. This causes cardiomyocyte death and myocardial necrosis, with subsequent inflammation and fibrosis. Current therapies aim to restore coronary flow by thrombus dissolution with pharmaceutical treatment and/or intravascular stent implantation and to counteract neurohormonal activation. Despite these therapies, the injury caused by myocardial ischemia leads to left ventricular remodeling; this process involves changes in cardiac geometry, dimension and function and eventually progression to heart failure (HF). This review describes the pathophysiological mechanism that leads to cardiac remodeling and the therapeutic strategies with a role in slowing the progression of remodeling and improving cardiac structure and function.

Lipid Levels and New-Onset Atrial Fibrillation in Patients with Acute Myocardial Infarction

AIM

In acute myocardial fraction (AMI) patients, the association between lipid parameters and new-onset atrial fibrillation (NOAF) remains unclear due to limited evidence.

METHODS

A total of 4282 participants free from atrial fibrillation (AF) at baseline were identified in Beijing Friendship Hospital. Fasting levels of total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) were measured at baseline. The study population was stratified based on tertiles of lipid profile and lipid ratios. Incidence of NOAF was observed at the follow-up visits. The associations between different lipid parameters and the incidence of NOAF were assessed by multivariate Cox regression analysis.

RESULTS

Over a median follow-up period of 42.0 months (IQR: 18.7, 67.3 months), 3.1% (N=132) AMI patients developed NOAF. After multivariable adjustment, higher TC (hazard ratios (HR): 0.205, 95% confidence intervals (CI): 0.061-0.696) levels were inversely associated with NOAF development. However, higher HDL-C (HR: 1.892, 95% CI: 1.133-3.159) levels were positively associated with NOAF development. LDL-C levels, TG levels, non-HDL-C levels, and lipid ratios showed no association with NOAF development.

CONCLUSION

TC levels were inversely associated with incidence of NOAF; this was mainly reflected in the subgroups of male gender and older patients (65 years or older). HDL-C levels were positively associated with incidence of NOAF; this was mainly reflected in the subgroups of male gender and younger patients (age ＜65 years). There was no significant association of NOAF with LDL-C, TG, or non-HDL-C levels.

Advantages of long-term combination pharmacotherapy with a beta-blocker and eplerenone in patients with ST-segment elevation acute coronary syndrome

Aim. To conduct a comparative analysis of the effect of long-term pharmacotherapy (12 months) using a β-blocker (nebivolol) and its combination with eplerenone in patients after ST-segment elevation acute coronary syndrome (STE-ACS) with heart failure with mildly reduced ejection fraction (EF) (HFmrEF) on the structural and functional cardiac parameters.

Material and methods. We examined 130 patients with STE-ACS and HFmrEF after successful myocardial revascularization by percutaneous coronary intervention. The mean age of patients was 53,6 [46;57] years. Ten patients withdrew from the study due to personal reasons. Subsequently, patients were randomly divided into 2 treatment groups as follows: 60 patients received nebivolol; 60 patients received nebivolol and eplerenone. Patients were examined at two stages: 1st day of the disease before PCI and 12 months later. All patients underwent a clinical examination, echocardiography, followed by assessment of left ventricular (LV) EF, LV end-diastolic volume index (EDVI), LV endsystolic volume index (ESVI), LV myocardial index (LVMI), LV wall motion score index (WMSI), the ratio of peak early diastolic flow over peak late diastolic flow (E/A), the ratio of early diastolic transmitral flow velocity to the mitral annular velocity (E/e´).

Results. Twelve-month pharmacotherapy with nebivolol in patients after STE-ACS showed an increase in LVEF by 7,2% (p<0,05), a decrease in WMSI by 13,0% (p<0,05), an increase in the E/A ratio by 11,1% (р<0,05), decrease in the E/e’ ratio by 7,2% (р<0,05). LV EDVI increased by 4,6% (p>0,05). Twelve-month combined pharmacotherapy with nebivolol and eplerenone showed an increase in LVEF by 16,0% (p<0,01), a decrease in LV ESVI by 17,9% (p<0,05), and a decrease in WMSI by 26,7% (p<0,01), LVMI — by 23,8% (р<0,01). At the same time, LV EDVI decreased by 0,7% (p>0,05). The E/A ratio increased significantly by 22,2% (<0,01), E/e’ decreased by 29,6% (р<0,01). Comparative analysis also found that combination therapy had a more pronounced positive effect on LVEF (p<0,05), ESVI (p<0,05), WMSI (p<0,05), LVMI (p<0,01), as well as diastolic function in the form of a significant increase in E/A (p<0,05) and E/e’ (p<0,01), which recovered to normal values.

Conclusion. The advantages of long-term combination pharmacotherapy of nebivolol and eplerenone in HFmrEF patients after STE-ACS on both structural and functional cardiac parameters were established.

Podocan and Adverse Clinical Outcome in Patients Admitted With Suspected Acute Coronary Syndromes

Background

Markers of bone and extracellular matrix (ECM) remodeling may be associated with adverse outcomes in atherosclerotic cardiovascular disease. Podocan is a newly discovered ECM glycoprotein, previously not studied in a chest pain population. We wanted to study the association between Podocan levels on admission and the risk of adverse outcomes in a chest pain population with suspected acute coronary syndromes.

Methods

A total of 815 patients from the Risk markers in Acute Coronary Syndrome (RACS) trial with suspected coronary chest pain were followed for 7 years. Blood samples were taken immediately after inclusion and stored in the biobank. Associations between Podocan and endpoints were assessed with Cox proportional hazards analyses.

Results

The median admission level of Podocan was 0.674 ng/ml (0.566–0.908 ng/ml). No significant association was found between Podocan quartile levels and all-cause death, neither at 1 year nor 2- or 7-years follow-up (p > 0.05 for all). Furthermore, no significant association could be shown between Podocan and cardiac death, myocardial infarction (MI), stroke, or the composites of all-cause death/MI/stroke or cardiac death/MI/stroke (p > 0.05 for all). Similarly, in a subgroup of patients with Troponin T-positive (n = 432) there was no significant association between Podocan and any of the outcome measures (p > 0.05 for all endpoints and points in time).

Conclusion

Podocan, a novel ECM biomarker, is not associated with all-cause mortality or other major cardiovascular adverse events in patients admitted with acute chest pain suspected to be of coronary origin.

Clinical Trials.gov Identifier:

NCT00521976.

PINK1/Parkin-mediated mitophagy in cardiovascular disease: From pathogenesis to novel therapy

Cardiovascular disease(CVD)is one of the predominant causes of death and morbidity. Mitochondria play a key role in maintaining cardiac energy metabolism. However, mitochondrial dysfunction leads to excessive production of ROS, resulting in oxidative damage to cardiomyocytes and contributing to a variety of cardiovascular diseases. In such a case, the clearance of impaired mitochondria is necessary. Currently, most studies have indicated an essential role for mitophagy in maintaining cardiac homeostasis and regulating CVD-related metabolic transition. Recent studies have implicated that PTEN-induced putative kinase 1 (PINK1)/Parkin-mediated mitophagy has been implicated in maintaining cardiomyocyte homeostasis. Here, we discuss the physiological and pathological roles of PINK1/Parkin-mediated mitophagy in the cardiovascular system, as well as potential therapeutic strategies based on PINK1/Parkin-mediated mitophagy modulation, which are of great significance for the prevention and treatment of cardiovascular diseases.

Mitochondrial Damage in Myocardial Ischemia/Reperfusion Injury and Application of Natural Plant Products

Ischemic heart disease (IHD) is currently one of the leading causes of death among cardiovascular diseases worldwide. In addition, blood reflow and reperfusion paradoxically also lead to further death of cardiomyocytes and increase the infarct size. Multiple evidences indicated that mitochondrial function and structural disorders were the basic driving force of IHD. We summed up the latest evidence of the basic associations and underlying mechanisms of mitochondrial damage in the event of ischemia/reperfusion (I/R) injury. This review then reviewed natural plant products (NPPs) which have been demonstrated to mitochondria-targeted therapeutic effects during I/R injury and the potential pathways involved. We realized that NPPs mainly maintained the integrality of mitochondria membrane and ameliorated dysfunction, such as improving abnormal mitochondrial calcium handling and inhibiting oxidative stress, so as to protect cardiomyocytes during I/R injury. This information will improve our knowledge of mitochondrial biology and I/R-induced injury's pathogenesis and exhibit that NPPs hold promise for translation into potential therapies that target mitochondria.

PRKAR1A and SDCBP Serve as Potential Predictors of Heart Failure Following Acute Myocardial Infarction

Background and Objectives

Early diagnosis of patients with acute myocardial infarction (AMI) who are at a high risk of heart failure (HF) progression remains controversial. This study aimed at identifying new predictive biomarkers of post-AMI HF and at revealing the pathogenesis of HF involving these marker genes.

Methods and Results

A transcriptomic dataset of whole blood cells from AMI patients with HF progression (post-AMI HF, n = 16) and without progression (post-AMI non-HF, n = 16) was analyzed using the weighted gene co-expression network analysis (WGCNA). The results indicated that one module consisting of 720 hub genes was significantly correlated with post-AMI HF. The hub genes were validated in another transcriptomic dataset of peripheral blood mononuclear cells (post-AMI HF, n = 9; post-AMI non-HF, n = 8). PRKAR1A, SDCBP, SPRED2, and VAMP3 were upregulated in the two datasets. Based on a single-cell RNA sequencing dataset of leukocytes from heart tissues of normal and infarcted mice, PRKAR1A was further verified to be upregulated in monocytes/macrophages on day 2, while SDCBP was highly expressed in neutrophils on day 2 and in monocytes/macrophages on day 3 after AMI. Cell-cell communication analysis via the "CellChat" package showed that, based on the interaction of ligand-receptor (L-R) pairs, there were increased autocrine/paracrine cross-talk networks of monocytes/macrophages and neutrophils in the acute stage of MI. Functional enrichment analysis of the abovementioned L-R genes together with PRKAR1A and SDCBP performed through the Metascape platform suggested that PRKAR1A and SDCBP were mainly involved in inflammation, apoptosis, and angiogenesis. The receiver operating characteristic (ROC) curve analysis demonstrated that PRKAR1A and SDCBP, as well as their combination, had a promising prognostic value in the identification of AMI patients who were at a high risk of HF progression.

Conclusion

This study identified that PRKAR1A and SDCBP may serve as novel biomarkers for the early diagnosis of post-AMI HF and also revealed their potentially regulatory mechanism during HF progression.

Protective effects of natural products against myocardial ischemia/reperfusion: Mitochondria-targeted therapeutics

Patients with ischemic heart disease receiving reperfusion therapy still need to face left ventricular remodeling and heart failure after myocardial infarction. Reperfusion itself paradoxically leads to further cardiomyocyte death and systolic dysfunction. Ischemia/reperfusion (I/R) injury can eliminate the benefits of reperfusion therapy in patients and causes secondary myocardial injury. Mitochondrial dysfunction and structural disorder are the basic driving force of I/R injury. We summarized the basic relationship and potential mechanisms of mitochondrial injury in the development of I/R injury. Subsequently, this review summarized the natural products (NPs) that have been proven to targeting mitochondrial therapeutic effects during I/R injury in recent years and related cellular signal transduction pathways. We found that these NPs mainly protected the structural integrity of mitochondria and improve dysfunction, such as reducing mitochondrial division and fusion abnormalities, improving mitochondrial Ca²⁺ overload and inhibiting reactive oxygen species overproduction, thereby playing a role in protecting cardiomyocytes during I/R injury. This data would deepen the understanding of I/R-induced mitochondrial pathological process and suggested that NPs are expected to be transformed into potential therapies targeting mitochondria.

IGFBP-6: At the Crossroads of Immunity, Tissue Repair and Fibrosis

Insulin-like growth factors binding protein-6 (IGFBP-6) is involved in a relevant number of cellular activities and represents an important factor in the immune response, particularly in human dendritic cells (DCs). Over the past several years, significant insights into the IGF-independent effects of IGFBP-6 were discovered, such as the induction of chemotaxis, capacity to increase oxidative burst and neutrophils degranulation, ability to induce metabolic changes in DCs, and, more recently, the regulation of the Sonic Hedgehog (SHH) signaling pathway during fibrosis. IGFBP-6 has been implicated in different human diseases, and it plays a rather controversial role in the biology of tumors. Notably, well established relationships between immunity, stroma activity, and fibrosis are prognostic and predictive of response to cancer immunotherapy. This review aims at describing the current understanding of mechanisms that link IGFBP-6 and fibrosis development and at highlighting the multiple roles of IGFBP-6 to provide an insight into evolutionarily conserved mechanisms that can be relevant for inflammation, tumor immunity, and immunological diseases.

Dapagliflozin Improves Cardiac Function, Remodeling, Myocardial Apoptosis, and Inflammatory Cytokines in Mice with Myocardial Infarction

Dapagliflozin (DAPA) exerts cardioprotective effects in non-diabetic patients. Nonetheless, the protective mechanism remains unknown. This study aims to evaluate the performance of DAPA on cardiac function and remodeling as well as its potential mechanism in mice with myocardial infarction (MI). Here, a MI mice model was established. One week after MI, mice were treated with saline or DAPA (1.5 mg/kg/day) for 4 weeks. At the end of this study, echocardiography was performed to assess cardiac structure and function. Myocardial apoptosis was analyzed by Western blot and immunofluorescence. Inflammatory cytokines and cardiac fibrosis were analyzed by real-time PCR and Masson's trichrome stain, respectively. Results showed that DAPA improved cardiac structure and function, attenuated cardiac fibrosis, and inhibited inflammatory cytokines and myocardial apoptosis. Moreover, the inhibition of PI3K/AKT/mTOR pathway might be related to the cardioprotective role of DAPA. These findings reveal that dapagliflozin is a potential therapeutic agent for MI patients without diabetes.

Deep Learning Analyses to Delineate the Molecular Remodeling Process after Myocardial Infarction

Specific proteins and processes have been identified in post-myocardial infarction (MI) pathological remodeling, but a comprehensive understanding of the complete molecular evolution is lacking. We generated microarray data from swine heart biopsies at baseline and 6, 30, and 45 days after infarction to feed machine-learning algorithms. We cross-validated the results using available clinical and experimental information. MI progression was accompanied by the regulation of adipogenesis, fatty acid metabolism, and epithelial-mesenchymal transition. The infarct core region was enriched in processes related to muscle contraction and membrane depolarization. Angiogenesis was among the first morphogenic responses detected as being sustained over time, but other processes suggesting post-ischemic recapitulation of embryogenic processes were also observed. Finally, protein-triggering analysis established the key genes mediating each process at each time point, as well as the complete adverse remodeling response. We modeled the behaviors of these genes, generating a description of the integrative mechanism of action for MI progression. This mechanistic analysis overlapped at different time points; the common pathways between the source proteins and cardiac remodeling involved IGF1R, RAF1, KPCA, JUN, and PTN11 as modulators. Thus, our data delineate a structured and comprehensive picture of the molecular remodeling process, identify new potential biomarkers or therapeutic targets, and establish therapeutic windows during disease progression.

Aldosterone Blockade in Acute Myocardial Infarction: A Systematic Review and Meta-Analysis

Background

A comprehensive evaluation of the benefits of mineralocorticoid receptor antagonists (MRA) in acute myocardial infarction (AMI) patients is lacking.

Objective

To summarize the evidence on the efficacy and safety of MRA in patients admitted for AMI.

Methods

Articles were identified through PubMed, Embase, Cochrane Library, Ovid (Medline1946-2021), and ClinicalTrials.gov databases from their inception to December 31, 2020.

Results

15 articles with a total of 11,861 patients were included. MRA reduced the risk of all-cause mortality by 16% (relative ratio (RR): 0.84; 95% confidence interval (CI) (0.76, 0.94); P = 0.002) and the incidence of cardiovascular adverse events by 12% (RR: 0.88, 95% CI (0.83, 0.93), P < 0.00001) in post-AMI patients, and further analysis demonstrated that early administration of MRA within 7 days after AMI resulted in a greater reduction in all-cause mortality (RR: 0.72, 95% CI (0.61, 0.85), P < 0.0001). Subgroup analyses showed that post-STEMI patients without left ventricular systolic dysfunction (LVSD) treated with MRA had a 36% reduction in all-cause mortality (RR: 0.64, 95% CI (0.46, 0.89), P = 0.007) and a 22% reduction in cardiovascular adverse events (RR: 0.78, 95% CI (0.67, 0.91), P = 0.002). Meanwhile, post-STEMI patients without LVSD treated with MRA get significant improvements in left ventricular ejection fraction (mean difference (MD): 2.69, 95% CI (2.44, 2.93), P < 0.00001), left ventricular end-systolic index (MD: -4.52 ml/m², 95% CI (-8.21, -0.83), P = 0.02), and left ventricular end-diastolic diameter (MD: -0.11 cm, 95% CI (-0.22, 0.00), P = 0.05). The corresponding RR were 1.72 (95% CI (1.43, 2.07), P < 0.00001) for considered common adverse events (hyperkalemia, gynecomastia, and renal dysfunction).

Conclusions

Our findings suggest that MRA treatment reduces all-cause mortality and cardiovascular adverse events in post-AMI patients, which is more significant in patients after STEMI without LVSD. In addition, MRA treatment may exert beneficial effects on the reversal of cardiac remodeling in patients after STEMI without LVSD.

The Value of Three-Dimensional Speckle-Tracking Echocardiography in the Prediction of Cardiovascular Events in Patients with Hypertension Complicated by Acute Myocardial Infarction: A Long-Term Follow-Up Study

Background

Patients with hypertension complicated by acute myocardial infarction (AMI) have a generally poor prognosis. The identification of powerful predictors for recurring cardiovascular events (RCEs) is vital. This study seeks to evaluate the predictive value of three-dimensional (3D) strain parameters for RCEs in patients with hypertension complicated by AMI.

Methods

We successfully followed up patients with hypertension and AMI from April 2015 to December 2015 in this retrospective study. Participants previously underwent 3D echocardiography, one week, and one month after percutaneous coronary intervention (PCI). The left ventricular structural function parameters, as well as 3D strain parameters including 3D global longitudinal strain (3D-GLS), 3D global circumferential strain, 3D global radial strain, and 3D global area strain (3D-GAS), were acquired. A Cox model was used to determine the relationships between these parameters and RCEs.

Results

In total, 62 patients were enrolled in the analysis. During follow-up (41.27 ± 20.45 months), 20 patients (32.3%) had RCEs that were independently predicted one month after PCI by 3D-GLS (HR: 1.481, 95% CI: 1.202–1.824, P < 0.001) and 3D-GAS (HR: 1.254, 95% CI: 1.093–1.440, P = 0.001). The optimal cutoffs for 3D-GLS and 3D-GAS in predicting cardiac events were ≥12.5% (area under the receiver operating characteristic curve [AUC]: 0.736, 95% CI: 0.611–0.862, P = 0.003), and >20.5% (AUC: 0.685, 95% CI: 0.551–0.818, P = 0.020), respectively.

Conclusion

The assessed values of 3D-GLS and 3D-GAS one month after PCI can predict RCEs in patients with hypertension complicated by AMI.

Identification of candidate genes and pathways in limonin-mediated cardiac repair after myocardial infarction

BACKGROUND

Myocardial infarction (MI) resulting from acute coronary ischemia may cause significant morbidity and mortality, and microRNAs play a vital role in this pathophysiology. Limonin (LIM) is a natural medicine from citrus fruit that protects organs against ischemic diseases, but the candidate genes and pathways associated with cardioprotection are unknown.

METHODS

MI was induced by ligating the left anterior descending coronary in male Sprague-Dawley rats. LIM was orally administered for 7 days after the induction of MI. Subsequently, the hearts were collected to examine significant changes in microRNAs and mRNAs among the control (CON), MI, and LIM + MI groups. Gene Ontology (GO) terms, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, and protein-protein interaction (PPI) networks were used to identify the biological functions and signaling pathways of differentially expressed mRNAs. Candidate genes were validated by RT-qPCR.

RESULTS

Compared to the CON group, MI caused significant changes in the expression of 26 microRNAs and 1979 mRNAs. The bioinformatics analysis showed that inflammation, apoptosis, and oxidation were enriched in GO terms, while RAP1, PI3K/AKT, RAS, and cGMP-PKG were enriched in KEGG pathways. In addition, compared to the MI group, LIM induced significant changes in the expression of 4 microRNAs and 173 mRNAs. The differentially expressed mRNAs were related to collagen biosynthesis, the immune response, extrinsic apoptosis, and tight junctions. One microRNA (rno-miR-10a-5p) and 2 mRNAs (IGLON5 and LMX1A) were differentially expressed among the CON, MI, and LIM + MI groups.

CONCLUSIONS

Our results suggest that the rno-miR-10a-5p-IGLON5/LMX1A axis may be a candidate pathway and promising target through which LIM alleviates MI-induced cardiac dysfunction.

Communication Between Cardiomyocytes and Fibroblasts During Cardiac Ischemia/Reperfusion and Remodeling: Roles of TGF-β, CTGF, the Renin Angiotensin Axis, and Non-coding RNA Molecules

Communication between cells is a foundational concept for understanding the physiology and pathology of biological systems. Paracrine/autocrine signaling, direct cell-to-cell interplay, and extracellular matrix interactions are three types of cell communication that regulate responses to different stimuli. In the heart, cardiomyocytes, fibroblasts, and endothelial cells interact to form the cardiac tissue. Under pathological conditions, such as myocardial infarction, humoral factors released by these cells may induce tissue damage or protection, depending on the type and concentration of molecules secreted. Cardiac remodeling is also mediated by the factors secreted by cardiomyocytes and fibroblasts that are involved in the extensive reciprocal interactions between these cells. Identifying the molecules and cellular signal pathways implicated in these processes will be crucial for creating effective tissue-preserving treatments during or after reperfusion. Numerous therapies to protect cardiac tissue from reperfusion-induced injury have been explored, and ample pre-clinical research has attempted to identify drugs or techniques to mitigate cardiac damage. However, despite great success in animal models, it has not been possible to completely translate these cardioprotective effects to human applications. This review provides a current summary of the principal molecules, pathways, and mechanisms underlying cardiomyocyte and cardiac fibroblast crosstalk during ischemia/reperfusion injury. We also discuss pre-clinical molecules proposed as treatments for myocardial infarction and provide a clinical perspective on these potential therapeutic agents.

Changes in the Biomarkers of Oxidative/Nitrosative Stress and Endothelial Dysfunction Are Associated with Cardiovascular Risk in Periodontitis Patients

Patients with cardiovascular disease (CVD) and periodontitis (PT) show shared risk factors as result of the altered molecular mechanisms associated with pathological conditions. The aim of our study was to evaluate if the plasma biomarkers associated with endothelial dysfunction may also be related to alterations in the inflammatory status in peripheral blood mononuclear cells (PBMC). Patients with PT, coronary heart disease (CHD), or both diseases as well as controls were enrolled. Plasma levels of coenzyme Q10 (CoQ10), 3-nitrotyrosine (NT), and asymmetric dimethylarginine (ADMA) were assessed using HPLC. mRNA levels of caspase-1 (CASP1), NLR family pyrin domain containing 3 (NLRP3), and tumor necrosis factor-α (TNF-α) in PBMC from the recruited subjects were quantified using real-time PCR. Patients with PT + CHD showed lower CoQ10 plasma levels and increased concentrations of NT in comparison to healthy subjects. ADMA levels were higher in CHD and PT + CHD patients compared to controls. Transcript levels of CASP1, NLRP3, and TNF-α were up-regulated in PBMC from all patient groups when compared to healthy subjects. Our results suggest a possible causal link between oxidative stress, high levels of NT and ADMA, and inflammasome activation, which may be involved in the endothelial inflammatory dysfunction leading to the pathogenesis and progression of CHD in PT patients.

Past, Present, and Future of Blood Biomarkers for the Diagnosis of Acute Myocardial Infarction-Promises and Challenges

Despite important advancements in acute myocardial infarction (AMI) management, it continues to represent a leading cause of mortality worldwide. Fast and reliable AMI diagnosis can significantly reduce mortality in this high-risk population. Diagnosis of AMI has relied on biomarker evaluation for more than 50 years. The upturn of high-sensitivity cardiac troponin testing provided extremely sensitive means to detect cardiac myocyte necrosis, but this increased sensitivity came at the cost of a decrease in diagnostic specificity. In addition, although cardiac troponins increase relatively early after the onset of AMI, they still leave a time gap between the onset of myocardial ischemia and our ability to detect it, thus precluding very early management of AMI. Newer biomarkers detected in processes such as inflammation, neurohormonal activation, or myocardial stress occur much earlier than myocyte necrosis and the diagnostic rise of cardiac troponins, allowing us to expand biomarker research in these areas. Increased understanding of the complex AMI pathophysiology has spurred the search of new biomarkers that could overcome these shortcomings, whereas multi-omic and multi-biomarker approaches promise to be game changers in AMI biomarker assessment. In this review, we discuss the evolution, current application, and emerging blood biomarkers for the diagnosis of AMI; we address their advantages and promises to improve patient care, as well as their challenges, limitations, and technical and diagnostic pitfalls. Questions that remain to be answered and hotspots for future research are also emphasized.

Circulating biomarkers as predictors of left ventricular remodeling after myocardial infarction

INTRODUCTION

The main impact of myocardial infarction is shifting from acute mortality to adverse remodeling and chronic left ventricle dysfunction. Several circulating biomarkers are explored for better risk stratification of these patients. Biomarker testing is a very attractive idea, since it is non-invasive, not operator-dependent and widely available.

AIM

In the present paper we analyze data from the years 2005-2020 about circulating biomarkers of remodeling after myocardial infarction.

MATERIAL AND METHODS

We assessed 53 articles, which examined 160 relations between biomarkers and remodeling. We analyze inclusion criteria for individual studies, time points of serum collection and remodeling assessment as well as imaging methods.

RESULTS

The main groups of assessed biomarkers included B-type natriuretic peptides, markers of cardiomyocyte injury and necrosis, markers of inflammatory response, markers of extracellular matrix turnover, microRNAs and hormones. The most common method of remodeling assessment was echocardiography and the most frequent time point for remodeling evaluation was 6 months.

CONCLUSIONS

The present analysis shows that although a relatively large number biomarkers were tested, selecting one ideal marker is still a challenge. A combination of biomarkers from different groups might be appropriate for predicting remodeling. Data presented in this analysis might be helpful for designing future studies, evaluating clinical use of an individual biomarker or a combination of different biomarkers.

Identification of monocyte-associated genes as predictive biomarkers of heart failure after acute myocardial infarction

BACKGROUND

Acute myocardial infarction (AMI) is a major contributor of heart failure (HF). Peripheral blood mononuclear cells (PBMCs), mainly monocytes, are the essential initiators of AMI-induced HF. The powerful biomarkers for early identification of AMI patients at risk of HF remain elusive. We aimed to identify monocyte-related critical genes as predictive biomarkers for post-AMI HF.

METHODS

We performed weighted gene co-expression network analysis (WGCNA) on transcriptomics of PBMCs from AMI patients who developed HF or did not. Functional enrichment analysis of genes in significant modules was performed via Metascape. Then we obtained the single-cell RNA-sequencing data of recruited monocytes/macrophages from AMI and control mice using the Scanpy and screened 381 differentially expressed genes (DEGs) between the two groups. We validated the expression changes of the 25 genes in cardiac macrophages from AMI mice based on bulk RNA-sequencing data and PBMCs data mentioned above.

RESULTS

In our study, the results of WGCNA showed that two modules containing 827 hub genes were most significantly associated with post-AMI HF, which mainly participated in cell migration, inflammation, immunity, and apoptosis. There were 25 common genes between DEGs and hub genes, showing close relationship with inflammation and collagen metabolism. CUX1, CTSD and ADD3 exhibited consistent changes in three independent studies. Receiver operating characteristic curve analysis showed that each of the three genes had excellent performance in recognizing post-AMI HF patients.

CONCLUSION

Our findings provided a set of three monocyte-related biomarkers for the early prediction of HF development after AMI as well as potential therapeutic targets of post-AMI HF.

Obstructive sleep apnea during acute coronary syndrome is related to myocardial necrosis and wall stress

BACKGROUND

The relative contribution of pathophysiological mechanisms in acute coronary syndrome (ACS) towards obstructive sleep apnea (OSA) is not well-studied. We examined the correlation between severity of OSA and inflammation, myocardial necrosis, wall stress, and fibrosis.

METHODS

A total of 89 patients admitted with ACS underwent a sleep study during index admission. Plasma levels of high-sensitivity C-reactive protein (hs-CRP), troponin I, N-terminal pro-brain natriuretic peptide (NT-proBNP), and suppression of tumorigenicity 2 (ST2) were prospectively analyzed. Two patients diagnosed with central sleep apnea were excluded.

RESULTS

The recruited patients were divided into no (AHI <5 events/hour, 9.2%), mild (5-<15, 27.6%), moderate (15-<30, 21.8%), and severe (≥30, 41.4%) OSA. Compared to the no, mild and moderate OSA groups, the severe OSA group had a higher body mass index (p = 0.005). They were also more likely to present with ST-segment elevation ACS (versus non-ST-segment elevation ACS) (p = 0.041), have undergone previous coronary artery bypass grafting (p = 0.013), demonstrate complete coronary occlusion during baseline coronary angiography (p = 0.049), and have a larger left atrial diameter measured on echocardiography (p = 0.029). Likewise, the severe OSA group had higher plasma levels of hs-CRP (p = 0.004), troponin I (p = 0.017), and NT-proBNP (p = 0.004), but not ST2 (p = 0.10). After adjustment for the effects of confounding variables, OSA was independently associated with troponin I (ie, myocardial necrosis; p = 0.001) and NT-proBNP (ie, myocardial wall stress; p = 0.008).

CONCLUSION

Severe OSA during the acute phase of ACS was associated with extensive myocardial necrosis and high myocardial wall stress, but not with inflammation and myocardial fibrosis.

Post-Myocardial Infarction Ventricular Remodeling Biomarkers-The Key Link between Pathophysiology and Clinic

Studies in recent years have shown increased interest in developing new methods of evaluation, but also in limiting post infarction ventricular remodeling, hoping to improve ventricular function and the further evolution of the patient. This is the point where biomarkers have proven effective in early detection of remodeling phenomena. There are six main processes that promote the remodeling and each of them has specific biomarkers that can be used in predicting the evolution (myocardial necrosis, neurohormonal activation, inflammatory reaction, hypertrophy and fibrosis, apoptosis, mixed processes). Some of the biomarkers such as creatine kinase-myocardial band (CK-MB), troponin, and N-terminal-pro type B natriuretic peptide (NT-proBNP) were so convincing that they immediately found their place in the post infarction patient evaluation protocol. Others that are related to more complex processes such as inflammatory biomarkers, atheroma plaque destabilization biomarkers, and microRNA are still being studied, but the results so far are promising. This article aims to review the markers used so far, but also the existing data on new markers that could be considered, taking into consideration the most important studies that have been conducted so far.