The Role of Microvascular Obstruction and Intra-Myocardial Hemorrhage in Reperfusion Cardiac Injury. Analysis of Clinical Data.

Microvascular obstruction (MVO) of coronary arteries promotes an increase in mortality and major adverse cardiac events in patients with acute myocardial infarction (AMI) and percutaneous coronary intervention (PCI). Intramyocardial hemorrhage (IMH) is observed in 41-50% of patients with ST-segment elevation myocardial infarction and PCI. The occurrence of IMH is accompanied by inflammation. There is evidence that microthrombi are not involved in the development of MVO. The appearance of MVO is associated with infarct size, the duration of ischemia of the heart, and myocardial edema. However, there is no conclusive evidence that myocardial edema plays an important role in the development of MVO. There is evidence that platelets, inflammation, Ca 2 + overload, neuropeptide Y, and endothelin-1 could be involved in the pathogenesis of MVO. The role of endothelial cell damage in MVO formation remains unclear in patients with AMI and PCI. It is unclear whether nitric oxide production is reduced in patients with MVO. Only indirect evidence on the involvement of inflammation in the development of MVO has been obtained. The role of reactive oxygen species (ROS) in the pathogenesis of MVO is not studied. The role of necroptosis and pyroptosis in the pathogenesis of MVO in patients with AMI and PCI is also not studied. The significance of the balance of thromboxane A2, vasopressin, angiotensin II, and prostacyclin in the formation of MVO is currently unknown. Conclusive evidence regarding the role of coronary artery spasm in the development of MVhasn't been established. Correlation analysis of the neuropeptide Y, endothelin-1 levels and the MVO size in patients with AMI and PCI has not previously been performed. It is unclear whether epinephrine aggravates reperfusion necrosis of cardiomyocytes. Dual antiplatelet therapy improves the efficacy of PCI in prevention of MVO. It is unknown whether epinephrine or L-type Ca 2 + channel blockers result in the long-term improvement of coronary blood flow in patients with MVO.

Ferroptosis, a Regulated Form of Cell Death, as a Target for the Development of Novel Drugs Preventing Ischemia/Reperfusion of Cardiac Injury, Cardiomyopathy and Stress-Induced Cardiac Injury.

The hospital mortality in patients with ST-segment elevation myocardial infarction (STEMI) is about 6% and has not decreased in recent years. The leading cause of death of these patients is ischemia/reperfusion (I/R) cardiac injury. It is quite obvious that there is an urgent need to create new drugs for the treatment of STEMI based on knowledge about the pathogenesis of I/R cardiac injury, in particular, based on knowledge about the molecular mechanism of ferroptosis. In this study, it was demonstrated that ferroptosis is involved in the development of I/R cardiac injury, antitumor drug-induced cardiomyopathy, diabetic cardiomyopathy, septic cardiomyopathy, and inflammation. There is indirect evidence that ferroptosis participates in stress-induced cardiac injury. The activation of AMPK, PKC, ERK1/2, PI3K, and Akt prevents myocardial ferroptosis. The inhibition of HO-1 alleviates myocardial ferroptosis. The roles of GSK-3ß and NOS in the regulation of ferroptosis require further study. The stimulation of Nrf2, STAT3 prevents ferroptosis. The activation of TLR4 and NF-κB promotes ferroptosis of cardiomyocytes. MiR-450b-5p and miR-210-3p can increase the tolerance of cardiomyocytes to hypoxia/reoxygenation through the inhibition of ferroptosis. Circ_0091761 RNA, miR-214-3p, miR-199a-5p, miR-208a/b, miR-375-3p, miR-26b-5p and miR-15a-5p can aggravate myocardial ferroptosis.

Potential utility of SPECT/CT with 99mTc-Tektrotyd for imaging of post-myocardial infarction inflammation.

BACKGROUND: There is a need to develop methods for post-myocardial infarction (MI) inflammation monitoring. Scintigraphy with somatostatin receptor targeted radiotracers has potential in this field. The purpose was to study the association of 99mTc-Tektrotyd uptake intensity in MI area with heart contractility indices over 6-month follow-up. METHODS: Fourteen patients with acute ST-segment elevation anterior MI (STEMI) were examined with 99mTc-Tektrotyd SPECT/CT, myocardial perfusion scintigraphy (MPS) at rest, cardiac magnetic resonance imaging (cMRI) and transthoracic echocardiography (TTE). Scintigraphic results were compared with 6-month TTE indices. RESULTS: On the 7th day after a MI onset, cardiac 99mTc-Tektrotyd uptake was found in 7 of 14 patients. Median of 99mTc-Tektrotyd SUVmax was 1.59 (1.38; 2.83), the summed rest score (SRS) was 11 (5; 18), infarct size (by cMRI)-13.15 (3.3; 32.2) %. 99mTc-Tektrotyd SUVmax strongly correlated with 6-month heart contractility indices (r = 0.81, P < 0.05 for the end diastolic volume; r = 0.61 P < 0.05 for Δ end diastolic volume), with SRS (r = 0.85, P < 0.05) and infarct size (by cMRI) (r = 0.79, P < 0.05). CONCLUSION: The intensity (SUVmax) of 99mTc-Tektrotyd uptake in the area of recent MI directly depends on the size of ischemic myocardial injury and correlates with changes of heart contractility indexes over the 6 month follow-up.

Relationships between indicators of prothrombotic activity and coronary microvascular dysfunction in patients with myocardial infarction with obstructive and non-obstructive coronary artery disease.

The relationship between prothrombotic activity and coronary microvascular dysfunction (MVD) is limited. This study aimed to perform a comparative analysis of the relationship between prothrombotic activity and MVD in patients with myocardial infarction without obstructive coronary artery disease (MINOCA) and myocardial infarction with obstructive coronary artery disease (MI-CAD). MATERIAL AND METHODS: A total of 37 patients were enrolled in the study; the main group included 16 MINOCA patients, and 21 MI-CAD patients were included in the control group. Blood samples for protein C, antithrombin, WF, plasminogen, and homocysteine were performed on the 4th ± 1 day of admission. CZT-SPECT data were used to determine the standard indices of myocardial perfusion dis-orders (SSS, SRS, and SDS), as well as stress and rest myocardial blood flow (MBF), myocardial flow reserve (MFR), and difference flows (DF). MVD was defined as MFR (≤ 1.91 ml/min); coronary slow flow (CSF) was defined as corrected TIMI frame count (21 ± 3). RESULTS: We performed a step-by-step analysis of prothrombotic activity of the hemostasis system in binary logistic regression for MINOCA patients to identify factors associated with MVD (MFR ≤ 1.91 ml/min). A predictive model was developed to estimate the probability of reduced MFR. A low MFR is related to only plasminogen in MINOCA patients, whereas only wall motion score index (WMSI) in MI-CAD group was associated with a low MFR. CONCLUSION: This small-scale study revealed the relationship between indicators of prothrombotic activity and MVD. The key factors that affect MVD in MINOCA patients was plasminogen, whereas, in patients with MI-CAD, WMSI was the key factor. Measurements of MVD may enhance the risk stratification and facilitate future targeting of adjunctive antithrombotic therapies in MINOCA and MI-CAD patients.

Macrophage activation and polarization in post-infarction cardiac remodeling.

Adverse cardiac remodeling leads to impaired ventricular function and heart failure, remaining a major cause of mortality and morbidity in patients with acute myocardial infarction. It have been shown that, even if all the recommended therapies for ST-segment elevation myocardial infarction are performed, one third of patients undergoes progressive cardiac remodeling that represents morphological basis for following heart failure. The need to extend our knowledge about factors leading to different clinical scenarios of myocardial infarction and following complications has resulted in a research of immuno-inflammatory pathways and molecular activities as the basis for post-infarction remodeling. Recently, macrophages (cells of the innate immune system) have become a subject of scientific interest under both normal and pathological conditions. Macrophages, besides their role in host protection and tissue homeostasis, play an important role in pathophysiological processes induced by myocardial infarction. In this article we summarize data about the function of monocytes and macrophages plasticity in myocardial infarction and outline potential role of these cells as effective targets to control processes of inflammation, cardiac remodeling and healing following acute coronary event.

The Role of Inflammation in the Pathogenesis of Cardiogenic Shock Secondary to Acute Myocardial Infarction: A Narrative Review.

Cardiogenic shock (CS) is one of the most serious complications of myocardial infarction (MI) with a high mortality rate. The timely and effective prevention and early suppression of this adverse event may influence the prognosis and outcome in patients with MI complicated by CS (MI CS). Despite the use of existing pharmaco-invasive options for maintaining an optimal pumping function of the heart in patients with MI CS, its mortality remains high, prompting the search for new approaches to pathogenetic therapy. This review considers the role of the systemic inflammatory response in the pathogenesis of MI CS. The primary processes involved in its initiation are described, including the progression from the onset of MI to the generalization of the inflammatory response and the development of multiple organ dysfunction. The approaches to anti-inflammatory therapy in patients with CS are discussed, and further promising research directions are outlined. In this review, we updated and summarized information on the inflammatory component of MI CS pathogenesis with a particular focus on its foundational aspects. This will facilitate the identification of specific inflammatory phenotypes and endotypes in MI CS and the development of targeted therapeutic strategies for this MI complication.

Efficiency and Safety of Intracoronary Epinephrine Administration in Patients With ST-Elevation Myocardial Infarction With Refractory Coronary No-Reflow.

Studies assessing the treatment of refractory no-reflow in patients with ST-elevation myocardial infarction (STEMI) are limited to clinical cases and pilot studies. This study aimed to evaluate the efficacy and safety of intracoronary adrenaline administration in such patients. Ninety consecutive patients with refractory coronary no-reflow during percutaneous coronary intervention (PCI) were prospectively included after the initial failure of conventional treatment. They were randomized into 2 groups: 45 patients in Group 1 received adrenaline, and 45 patients in Group 2 (control) received conventional treatments alone. After intracoronary drug administration, the adrenaline group demonstrated significantly higher rates of coronary flow restoration in the infarct-related artery to the level of thrombolysis in myocardial infarction grade 3 (56% vs 29% [p = 0.01]) and resolution of STEMI >50% after PCI (78% vs 36% [p <0.001]). Additionally, the adrenaline group showed a lower indexed microvascular obstruction (MVO) volume compared with the control group (0.9 [0.3; 3.1] % vs 1.9 [0.6; 7.9] % [p = 0.048]). A significant improvement in ejection fraction (EF) was observed in the adrenaline group (p = 0.025). Intracoronary adrenaline administration during PCI in patients with STEMI with refractory no-reflow is more effective compared with conventional treatments. This approach improves coronary flow in the infarct-related artery, facilitates a faster resolution of STEMI, enhances EF, and reduces MVO volume. Intracoronary adrenaline administration demonstrates a comparable safety profile to conventional treatment strategies in terms of life-threatening arrhythmias occurrence. The study suggests that intracoronary adrenaline administration during PCI could be an effective treatment strategy for patients with STEMI with refractory no-reflow.

Do platelets protect the heart against ischemia/reperfusion injury or exacerbate cardiac ischemia/reperfusion injury? The role of PDGF, VEGF, and PAF.

BACKGROUND: Acute myocardial infarction (AMI) is one of the main causes of death. It is quite obvious that there is an urgent need to develop new approaches for treatment of AMI. OBJECTIVE: This review analyzes data on the role of platelets in the regulation of cardiac tolerance to ischemia/reperfusion (I/R). METHODS: It was performed a search of topical articles using PubMed databases. FINDINGS: Platelets activated by a cholesterol-enriched diet, thrombin, and myocardial ischemia exacerbate I/R injury of the heart. The P2Y12 receptor antagonists, remote ischemic postconditioning and conditioning alter the properties of platelets. Platelets acquire the ability to increase cardiac tolerance to I/R. Platelet-derived growth factors (PDGFs) increase tolerance of cardiomyocytes and endothelial cells to I/R. PDGF receptors (PDGFRs) were found in cardiomyocytes and endothelial cells. PDGFs decrease infarct size and partially abrogate adverse postinfarction remodeling. Protein kinase C, phosphoinositide 3-kinase, and Akt involved in the cytoprotective effect of PDGFs. Vascular endothelial growth factor increased cardiac tolerance to I/R and alleviated adverse postinfarction remodeling. The platelet-activating factor (PAF) receptor inhibitors increase cardiac tolerance to I/R in vivo. PAF enhances cardiac tolerance to I/R in vitro. It is possible that PAF receptor inhibitors could protect the heart by blocking PAF receptor localized outside the heart. PAF protects the heart through activation of PAF receptor localized in cardiomyocytes or endothelial cells. Reactive oxygen species and kinases are involved in the cardioprotective effect of PAF. CONCLUSION: Platelets play an important role in the regulation of cardiac tolerance to I/R.

Somatostatin Receptor Type 2 as a Potential Marker of Local Myocardial Inflammation in Myocardial Infarction: Morphologic Data on Distribution in Infarcted and Normal Human Myocardium.

Nuclear imaging modalities can detect somatostatin receptor type 2 (SSTR2) in vivo as a potential marker of local post-MI inflammation. SSTR2+ macrophages are thought to be the main substrate for SSTR-targeted radioimaging. However, the distribution of SSTR2+ cells in the MI patients' myocardium is unknown. Using immunohistochemistry, we investigated the distribution of SSTR2+ cells in the myocardium of patients who died during the MI inflammatory phase (n = 7) compared to the control group of individuals with fatal trauma (n = 3). Inflammatory cellular landscapes evolve in a wave front-like pattern, so we divided the myocardium into histological zones: the infarct core (IC), the border zone (BZ), the remote zone (RZ), and the peri-scar zone (PSZ). The number of SSTR2+ neutrophils (NPs), SSTR2+ monocytes/macrophages (Mos/MPs), and SSTR2+ vessels were counted. In the myocardium of the control group, SSTR2+ NPs and SSTR2+ Mos/MPs were occasional, SSTR2+ vessels were absent. In the RZ, the picture was similar to the control group, but there was a lower number of SSTR2+ Mos/MPs in the RZ. In the PSZ, SSTR2+ vessel numbers were highest in the myocardium. In the IC, the median number of SSTR2+ NPs was 200 times higher compared to the RZ or control group myocardium, which may explain the selective uptake of SSTR-targeted radiotracers in the MI area during the inflammatory phase of MI.

The role of ß-adrenergic receptors in the regulation of cardiac tolerance to ischemia/reperfusion. Why do ß-adrenergic receptor agonists and antagonists protect the heart?

BACKGROUND: Catecholamines and ß-adrenergic receptors (ß-ARs) play an important role in the regulation of cardiac tolerance to the impact of ischemia and reperfusion. This systematic review analyzed the molecular mechanisms of the cardioprotective activity of ß-AR ligands. METHODS: We performed an electronic search of topical articles using PubMed databases from 1966 to 2023. We cited original in vitro and in vivo studies and review articles that documented the cardioprotective properties of ß-AR agonists and antagonists. RESULTS: The infarct-reducing effect of ß-AR antagonists did not depend on a decrease in the heart rate. The target for ß-blockers is not only cardiomyocytes but also neutrophils. ß1-blockers (metoprolol, propranolol, timolol) and the selective ß2-AR agonist arformoterol have an infarct-reducing effect in coronary artery occlusion (CAO) in animals. Antagonists of ß1- and ß2-АR (metoprolol, propranolol, nadolol, carvedilol, bisoprolol, esmolol) are able to prevent reperfusion cardiac injury. All ß-AR ligands that reduced infarct size are the selective or nonselective ß1-blockers. It was hypothesized that ß1-AR blocking promotes an increase in cardiac tolerance to I/R. The activation of ß1-AR, ß2-AR, and ß3-AR can increase cardiac tolerance to I/R. The cardioprotective effect of ß-AR agonists is mediated via the activation of kinases and reactive oxygen species production. CONCLUSIONS: It is unclear why ß-blockers with the similar receptor selectivity have the infarct-sparing effect while other ß-blockers with the same selectivity do not affect infarct size. What is the molecular mechanism of the infarct-reducing effect of ß-blockers in reperfusion? Why did in early studies ß-blockers decrease the mortality rate in patients with acute myocardial infarction (AMI) and without reperfusion and in more recent studies ß-blockers had no effect on the mortality rate in patients with AMI and reperfusion? The creation of more effective ß-AR ligands depends on the answers to these questions.

Macrophages of the Cardiorenal Axis and Myocardial Infarction.

The aim of our study was to compare the features of macrophage (mf) composition of the kidneys in patients with fatal myocardial infarction (MI) and in patients without cardiovascular diseases (CVD). We used kidney fragments taken during autopsy. Macrophage infiltration was assessed by immunohistochemistry: antibodies CD68 were used as a common mf marker, CD80-M1 type mf marker, CD163, CD206, and stabilin-1-M2 type. Macrophage composition of the kidneys in patients with fatal MI was characterized by the predominance of CD163+ cells among studied cells, and the control group was characterized by the predominance of CD163+, CD206+, and CD68+. In patients with MI, biphasic response from kidney cells was characterized for CD80+ and CD206+: their number decreased by the long-term period of MI; other cells did not show any dynamics. The exact number of CD80+ cells in kidneys of individuals without CVD was slightly higher than in patients with MI, and the number of CD206+-strikingly predominant. Subsequent analysis of CD80+ and CD206+ cells in a larger sample, as well as comparison of data with results obtained from survivors of MI, may bring us closer to understanding whether the influence on these cells can serve as a new target in personalized therapy in postinfarction complications.

Pro-Inflammatory Biomarkers and Progression of Atherosclerosis in Patients with Myocardial Infarction with Non-Obstructive Coronary Artery Disease: 1-Year Follow-Up.

The objective of our study was to evaluate the concentrations of pro-inflammatory biomarkers in patients with acute myocardial infarction with non-obstructive coronary arteries (MINOCA) compared to patients with acute myocardial infarction with obstructive coronary arteries (MI-CAD) in the early post-infarction period and after 1 year and to perform a comparative analysis of the relationship between laboratory biomarkers and atherosclerosis progression in patients with MINOCA and MI-CAD. METHODS: Samples of peripheral venous blood were collected upon admission and on days 2, 4, and 7 of hospitalization and after 1 year. An extended multiplex analysis was performed in blood serum. Multidetector-computed tomography coronary angiography was performed on day 7 and 1 year after acute myocardial infarction to assess the progression of atherosclerosis. RESULTS: The level of high-sensitive C-reactive protein (hsCRP) was elevated upon admission in MINOCA patients compared to MI-CAD patients (p = 0.05), but it was comparable in two groups at other time points and did not exceed the reference range after 1 year. Despite comparable levels of cytokines CXCL-6, LIGHT, CCL-8, and endocan-1 in patients in both groups, MINOCA patients had a greater increase in pro-inflammatory cytokines PlGF, oncostatin M, IL-20, and CCL-15 sVCAM-1 in the early post-infarction period and in CCL-21, sVCAM-1, oncostatin M, and PlGF after 1 year. We observed significant differences in the dynamics of the following biomarkers between patients with MI-CAD and MINOCA: the dynamics of concentrations of CCL21 (p = 0.002), LIGHT (p = 0.03), and endocan-1 (p = 0.03) after 1 year compared to day 1 in MI-CAD and MINOCA patients was opposite, while the dynamics of CXCL6 (p = 0.04) and endocan-1 (p = 0.02) differed between groups when evaluated after 1 year compared to day 7 of the early post-infarction period. In the MINOCA group, factors associated with atherosclerosis progression were concentrations of sVCAM-1 and CCL-21, while in the MI-CAD group, concentrations of CCL-8 and CXCL6 were the main determinants of atherosclerosis progression. CONCLUSIONS: This small study showed that MINOCA and MI-CAD patients exhibited differences in a pro-inflammatory biomarker profile in the early post-infarction period and after 1-year follow-up, which implies distinct inflammatory pathways involved in atherogenesis during MINOCA. The key factors that were associated with atherosclerosis progression in MINOCA patients are sVCAM-1 and CCL-21, which may suggest a complex genesis of atherosclerosis progression due to structurally altered plaques and changes in the microcirculatory bed. In MI-CAD patients, CCL-8 and CXCL-6 were the key biomarkers associated with atherosclerosis progression. Further large-scale studies are required to confirm our data.

Microarray Analysis for Transcriptomic Profiling of Myocardium in Patients with Fatal Myocardial Infarction.

Transcriptomic evidence from human myocardium in myocardial infarction (MI) is still not sufficient. Thus, there is a need for studies on human cardiac samples in relation to the clinical data of patients. The purpose of our pilot study was to investigate the transcriptomic profile of myocardium in the infarct zone, in comparison to the remote myocardium, in patients with fatal MI, via microarray analysis. This study included four patients with fatal MI type 1. We selected histologically verified samples from within the infarct area (n = 4) and remote myocardium (n = 4). The whole transcriptome was evaluated using microarray analysis. Differentially expressed genes (DEGs) clustered in the infarct area and in the remote myocardium allowed their differentiation. We identified a total of 1785 DEGs (8.32%) in the infarct area, including 1692 up-regulated (94.79%) and 93 down-regulated (5.21%) genes. The top 10 up-regulated genes were TRAIL, SUCLA2, NAE1, PDCL3, OSBPL5, FCGR2C, SELE, CEP63, ST3GAL3 and C4orf3. In the infarct area, we found up-regulation of seventeen apoptosis-related genes, eleven necroptosis-related, and six necrosis-related genes. Transcriptome profiling of the myocardium in patients with MI remains a relevant area of research for the formation of new scientific hypotheses and a potential way to increase the translational significance of studies into myocardial infarction.

The Signaling Mechanism of Remote Postconditioning of the Heart: Prospects of the Use of Remote Postconditioning for the Treatment of Acute Myocardial Infarction.

Acute myocardial infarction (AMI) remains the leading cause of mortality in the world, highlighting an urgent need for the development of novel, more effective approaches for the treatment of AMI. Remote postconditioning (RPost) of the heart could be a useful approach. It was demonstrated that RPost triggers infarct size reduction, improves contractile function of the heart in reperfusion, mitigates apoptosis, and stimulates autophagy in animals with coronary artery occlusion and reperfusion. Endogenous opioid peptides and adenosine could be involved in RPost. It was found that kinases and NO-synthase participate in RPost. KATP channels, MPT pore, and STAT3 could be hypothetical end-effectors of RPost. Metabolic syndrome and old age abolish the cardioprotective effect of RPost in rats. The data on the efficacy of RPost in clinical practice are inconsistent. These data are discussed in the review.

SCAI Staging Application for Acute Myocardial Infarction-Related Cardiogenic Shock at a Single-Center Russian Registry.

AIM: To access the features of the course of myocardial infarction (MI) in patients with different stages of MI complicated by cardiogenic shock (MI CS) according to the SCAI scale. METHODS: We retrospectively described the portrait of CS MI (n = 117) at different stages of SCAI from the hospital MI registry (n = 1253). RESULTS: Hospital mortality increased from stage to stage (p ≤ 0.001). Significant differences in biochemical parameters were found both for indicators characterizing intensive care measures, such as the presence of mechanical lung ventilation or an intra-aortic balloon pump, and for indicators of organ hypoperfusion such as lactate level, pHv (7.39 (7.36; 7.44) at stage A-B; 7.14 (7.06; 7.18) at stage E), creatinine, and glomerular filtration rate. Parameters related to MI characteristics, such as instrumental and laboratory data, anamnesis of ischemia, and performed treatment, did not differ between groups. Polynomial logistic regression showed that lactate level, mechanical ventilation, and monocyte count upon admission (1.15 (0.96; 1.23) at stage A-B; 0.78 (0.49; 0.94) at stage E, p = 0.005) correlated with CS severity. CONCLUSION: The characteristics of MI at different stages of SCAI do not have differences and do not determine the severity of shock. We revealed a high discriminatory potential of the pH level in predicting refractory shock. The value of monocytes at admission may be a promising predictor of the severity of MI CS. The question of the causes of heterogeneity of MI CS, taking into account the homogeneity of MI characteristics, remains open and promising.

A historical literature review of coronary microvascular obstruction and intra-myocardial hemorrhage as functional/structural phenomena.

The analysis of experimental data demonstrates that platelets and neutrophils are involved in the no-reflow phenomenon, also known as microvascular obstruction (MVO). However, studies performed in the isolated perfused hearts subjected to ischemia/reperfusion (I/R) do not suggest the involvement of microembolization and microthrombi in this phenomenon. The intracoronary administration of alteplase has been found to have no effect on the occurrence of MVO in patients with acute myocardial infarction. Consequently, the major events preceding the appearance of MVO in coronary arteries are independent of microthrombi, platelets, and neutrophils. Endothelial cells appear to be the target where ischemia can disrupt the endothelium-dependent vasodilation of coronary arteries. However, reperfusion triggers more pronounced damage, possibly mediated by pyroptosis. MVO and intra-myocardial hemorrhage contribute to the adverse post-infarction myocardial remodeling. Therefore, pharmacological agents used to treat MVO should prevent endothelial injury and induce relaxation of smooth muscles. Ischemic conditioning protocols have been shown to prevent MVO, with L-type Ca 2+ channel blockers appearing the most effective in treating MVO.

Characteristics of the Cardiosplenic Axis in Patients with Fatal Myocardial Infarction.

Myocardial ischemia triggers neurohumoral activation of the cardiosplenic axis. In rodents, adverse outcomes occur upon prolonged entrance of mononuclear cells from the spleen into myocardial tissue. The purpose of this study is to assess the features of spleen structure in patients with fatal myocardial infarction (MI), the dynamics of macrophage infiltration of the spleen and its relationship with cardiac macrophage infiltration and unfavorable outcomes. Using immunohistochemistry techniques, we analyzed the macrophage infiltration of the spleen and myocardium sections collected from patients (n = 30) with fatal MI. The spleen of the patients was decreased and showed a predominance of red pulp with a high concentration of CD68+ and stabilin-1+ cells. The white pulp contained many medium and small follicles and a lower concentration of CD68+ and stabilin-1+ cells, which was comparable to that in the infarct area of the myocardium. The concentration of CD68+ and stabilin-1+ cells increased in the myocardium in the late period of MI, but did not show any dynamics in the spleen. A high number of CD68+ cells in the red pulp and reduced concentration of stabilin-1+ cells in the white pulp were associated with unfavorable post-infarction outcomes. These fundamental findings could be a basis for the development of new personalized therapeutic and diagnostic approaches for the treatment of MI and its complications.

Macrophages of the "Heart-Kidney" Axis: Their Dynamics and Correlations with Clinical Data and Outcomes in Patients with Myocardial Infarction.

Changes in the macrophage infiltration of kidneys in rodents under ischemic conditions may affect cardiac macrophages and lead to development of adaptive cardiac remodeling. The aim of our study was to translate experimental findings into clinically relevant applications and assess the features of macrophage infiltration of the kidney and its correlations with changes in macrophage infiltration of the myocardium and with clinical data in patients who experienced a fatal myocardial infarction (MI). We examined fragments of both organs taken from patients (n = 30) who suffered from fatal MI. Macrophage infiltration was assessed by immunohistochemistry. Macrophage infiltration of the kidneys in patients with fatal MI is heterogeneous. The early period of MI was shown to be characterized by the prevalence of CD163+ and CD68+ cells, and in the long-term period by only CD163+ cells. However, only the level of CD206+ cells in the kidneys showed the dynamics representing the late MI period. Its decrease accompanied increase in the numbers of cardiac CD68+, CD163+, CD206+, and stabilin-1+ cells in the infarct area. Kidney CD206+ cells had more correlations with cardiac macrophages than other cells, and the presence of these cells also correlated with impairment of renal function and early death.

Association of increased oncostatin M with adverse left ventricular remodeling in patients with myocardial infarction.

Background: The study of laboratory biomarkers that reflect the development of adverse cardiovascular events in the postinfarction period is of current relevance. The aim of the present study was evaluation of oncostatin M (OSM) concentration changes in the early and late stages of myocardial infarction and evaluation of the possibility of its use in prediction of adverse left ventricular (LV) remodeling in patients with myocardial infarction with ST-elevated segment (STEMI). Methods: The study involved 31 patients with STEMI admitted in the first 24 hours after the onset of MI and 30 patients with chronic coronary artery disease as a control group. Echocardiographic study was performed on day 3 and in 6 months after STEMI. The serum levels of biomarkers were evaluated on the day of hospital admission and 6 months after MI using multiplex immunoassay. Results: OSM level increased during the first 24 h after the onset of the disease, with the following decrease in 6 months. OSM concentration at admission had correlated with echocardiography parameters and Nt-proBNP, troponin I, CK-MB levels. Our study has demonstrated association of the increased levels of OSM at the early stages of STEMI with development of the adverse LV remodeling in 6 months after the event. Conclusions: Elevation of OSM levels in the first 24 h after STEMI is associated with the development of the adverse LV remodeling in the long-term post-infarction period.

Pharmacological Approaches to Limit Ischemic and Reperfusion Injuries of the Heart: Analysis of Experimental and Clinical Data on P2Y12 Receptor Antagonists.

Ischemic and reperfusion injuries of the heart underlie the pathogenesis of acute myocardial infarction (AMI) and sudden cardiac death. The mortality rate is still high and is 5-7% in patients with ST-segment elevation myocardial infarction. The review is devoted to pharmacological approaches to limitation of ischemic and reperfusion injuries of the heart. The article analyzes experimental evidence and the clinical data on the effects of P2Y12 receptor antagonists on the heart's tolerance to ischemia/reperfusion in animals with coronary artery occlusion and reperfusion and also in patients with AMI. Chronic administration of ticagrelor prevented adverse remodeling of the heart. There is evidence that sphingosine-1-phosphate is the molecule that mediates the infarct-reducing effect of P2Y12 receptor antagonists. It was discussed a role of adenosine in the cardioprotective effect of ticagrelor.