Infliximab Limits Injury in Myocardial Infarction.

BACKGROUND: The purpose of this study was to investigate a therapeutic approach targeting the inflammatory response and consequent remodeling from ischemic myocardial injury. METHODS AND RESULTS: Coronary thrombus aspirates were collected from patients at the time of ST-segment-elevation myocardial infarction and subjected to array-based proteome analysis. Clinically indistinguishable at myocardial infarction (MI), patients were stratified into vulnerable and resilient on the basis of 1-year left ventricular ejection fraction and death. Network analysis from coronary aspirates revealed prioritization of tumor necrosis factor-α signaling in patients with worse clinical outcomes. Infliximab, a tumor necrosis factor-α inhibitor, was infused intravenously at reperfusion in a porcine MI model to assess whether infliximab-mediated immune modulation impacts post-MI injury. At 3 days after MI (n=7), infliximab infusion increased proregenerative M2 macrophages in the myocardial border zone as quantified by immunofluorescence (24.1%±23.3% in infliximab versus 9.29%±8.7% in sham; P<0.01). Concomitantly, immunoassays of coronary sinus samples quantified lower troponin I levels (41.72±7.34 pg/mL versus 58.11±10.75 pg/mL; P<0.05) and secreted protein analysis revealed upregulation of injury-modifying interleukin-2, -4, -10, -12, and -18 cytokines in the infliximab-treated cohort. At 4 weeks (n=12), infliximab treatment resulted in significant protective influence, improving left ventricular ejection fraction (53.9%±5.4% versus 36.2%±5.3%; P<0.001) and reducing scar size (8.31%±10.9% versus 17.41%±12.5%; P<0.05). CONCLUSIONS: Profiling of coronary thrombus aspirates in patients with ST-segment-elevation MI revealed highest association for tumor necrosis factor-α in injury risk. Infliximab-mediated immune modulation offers an actionable pathway to alter MI-induced inflammatory response, preserving contractility and limiting adverse structural remodeling.

Quantitative Analysis of Innate Lymphoid Cells in Patients with ST-Segment Elevation Myocardial Infarction.

BACKGROUND: Acute myocardial infarction (AMI) is one of the principal causes of death in Mexico and worldwide. AMI triggers an acute inflammatory process that induces the activation of different populations of the innate immune system. Innate lymphoid cells (ILCs) are an innate immunity, highly pleiotropic population, which have been observed to participate in tissue repair and polarization of the adaptive immune response. OBJECTIVE: We aimed to analyze the levels of subsets of ILCs in patients with ST-segment elevation myocardial infarction (STEMI), immediately 3 and 6 months post-AMI, and analyze their correlation with clinical parameters. RESULTS: We evaluated 29 STEMI patients and 15 healthy controls and analyzed the different subsets of circulating ILCs, immediately 3 and 6 months post-AMI. We observed higher levels of circulating ILCs in STEMI patients compared to control subjects and a significant correlation between ILC levels and cardiac function. We also found increased production of the cytokines interleukin 5 (IL-5) and interleukin 17A (IL-17A), produced by ILC2 cells and by ILC3 cells, respectively, in the STEMI patients. CONCLUSION: This study shows new evidence of the role of ILCs in the pathophysiology of AMI and their possible involvement in the maintenance of cardiac function.

Systemic immune- inflammation index predicts post-MI left ventricular remodeling.

AIMS: Previous studies demonstrated that remodeling after successful percutaneous coronary intervention (PCI) depends on the inflammatory response triggered by myocardial infarction (MI). The systemic immune-inflammation index (SII) is a novel inflammation index strongly associated with coronary artery disease. In our study, we sought to determine whether SII could predict Post-MI LV remodeling. METHODS AND RESULTS: The study population included 528 patients (mean age 62.5 ± 10.2, 73% male) diagnosed with STEMI. Based on the increase in LVEDV within the first 12 months after STEMI, patients were divided into two groups. We categorized the ≥ 20% increase in LVEDV among remodelers (257 patients, 49%), and the other 271 patients (51%), as non-remodelers. To determine the relationship between laboratory parameters and LV remodeling, univariate and multivariate logistic regression models were used. In a univariate model, higher hs-CRP and SII values were associated with increased LVEDV. In a multivariate analysis, SII independently correlated with LV remodeling A cut-off value of 613.3 or higher for SII was significantly correlated with LV remodeling based on ROC analysis. CONCLUSION: SII provides an easy-to-calculate and affordable biomarker for cardiovascular diseases. It may be used as a new biomarker to predict LV remodeling in patients with STEMI.

Impact of Age on Systemic Inflammatory Profile of Patients With ST-Segment-Elevation Myocardial Infarction and Acute Ischemic Stroke.

BACKGROUND: Aging is associated with a chronic low-grade inflammatory state. This condition may affect the acute inflammatory response involved in ST-segment-elevation myocardial infarction (STEMI) or acute ischemic stroke (AIS). We sought to compare the profile of a set of circulating inflammatory markers between young and older patients admitted for STEMI or AIS. METHODS: HIBISCUS-STEMI (Cohort of Patients to Identify Biological and Imaging Markers of Cardiovascular Outcomes in ST Elevation Myocardial Infarction) and HIBISCUS-STROKE (Cohort of Patients to Identify Biological and Imaging Markers of Cardiovascular Outcomes in Stroke) are 2 cohort studies that enrolled patients with STEMI treated with primary percutaneous coronary intervention in the cardiac intensive care unit of Lyon and patients with AIS treated with mechanical thrombectomy in the Lyon Stroke Center, respectively from 2016 to 2019. Patients were classified as older if they were ≥65 years and as young if they were <65 years. In both cohorts, CRP (C-reactive protein), IL (interleukin)-6, IL-8, IL-10, MCP (monocyte chemoattractant protein), sTNF-RI (soluble tumor necrosis factor receptor I), sST2 (soluble form suppression of tumorigenicity 2), and VCAM-1 (vascular cellular adhesion molecule-1) were measured on serum collected at 5 time points using enzyme-linked immunosorbent assay. A multiple logistic regression model was performed to detect an association between area under the curve of circulating inflammatory markers within the first 48 hours and older age. RESULTS: A total of 260 patients with STEMI and 164 patients with AIS were included. Of them, there were 76 (29%) and 105 (64%) older patients with STEMI and AIS, respectively. Following multivariable analysis, a high area under the curve of IL-6 and sTNF-RI, a low lymphocyte count, and a high neutrophil-lymphocyte ratio at 24 hours were associated with older age in patients with STEMI and AIS. CONCLUSIONS: Older patients had higher IL-6 and sTFN-RI levels within the first 48 hours associated with a lower lymphocyte count and a higher neutrophil-lymphocyte ratio at 24 hours in both cohorts.

Immunoglobulin E Sensitization to Mammalian Oligosaccharide Galactose-α-1,3 (α-Gal) Is Associated With Noncalcified Plaque, Obstructive Coronary Artery Disease, and ST-Segment-Elevated Myocardial Infarction.

BACKGROUND: Treating known risk factors for coronary artery disease (CAD) has substantially reduced CAD morbidity and mortality. However, a significant burden of CAD remains unexplained. Immunoglobulin E sensitization to mammalian oligosaccharide galactose-α-1,3-galactose (α-Gal) was recently associated with CAD in a small observational study. We sought to confirm that α-Gal sensitization is associated with CAD burden, in particular noncalcified plaque. Additionally, we sort to assess whether that α-Gal sensitization is associated with ST-segment-elevated myocardial infarction (STEMI) Methods: We performed a cross-sectional analysis of participants enrolled in the BioHEART cohort study. We measured α-Gal specific-immunoglobulin E antibodies in serum of 1056 patients referred for CT coronary angiography for suspected CAD and 100 selected patients presenting with STEMI, enriched for patients without standard modifiable risk factors. CT coronary angiograms were assessed using coronary artery calcium scores and segmental plaque scores. RESULTS: α-Gal sensitization was associated with presence of noncalcified plaque (odds ratio, 1.62 [95% CI, 1.04-2.53], P=0.03) and obstructive CAD (odds ratio, 2.05 [95% CI, 1.29-3.25], P=0.002), independent of age, sex, and traditional risk factors. The α-Gal sensitization rate was 12.8-fold higher in patients with STEMI compared with matched healthy controls and 2.2-fold higher in the patients with STEMI compared with matched stable CAD patients (17% versus 1.3%, P=0.01 and 20% versus 9%, P=0.03, respectively). CONCLUSIONS: α-Gal sensitization is independently associated with noncalcified plaque burden and obstructive CAD and occurs at higher frequency in patients with STEMI than those with stable or no CAD. These findings may have implications for individuals exposed to ticks, as well as public health policy. Registration: URL: https://www.anzctr.org.au; Unique identifier: ACTRN12618001322224.

Basophils balance healing after myocardial infarction via IL-4/IL-13.

The inflammatory response after myocardial infarction (MI) is a precisely regulated process that greatly affects subsequent remodeling. Here, we show that basophil granulocytes infiltrated infarcted murine hearts, with a peak occurring between days 3 and 7. Antibody-mediated and genetic depletion of basophils deteriorated cardiac function and resulted in enhanced scar thinning after MI. Mechanistically, we found that basophil depletion was associated with a shift from reparative Ly6Clo macrophages toward increased numbers of inflammatory Ly6Chi monocytes in the infarcted myocardium. Restoration of basophils in basophil-deficient mice by adoptive transfer reversed this proinflammatory phenotype. Cellular alterations in the absence of basophils were accompanied by lower cardiac levels of IL-4 and IL-13, two major cytokines secreted by basophils. Mice with basophil-specific IL-4/IL-13 deficiency exhibited a similarly altered myeloid response with an increased fraction of Ly6Chi monocytes and aggravated cardiac function after MI. In contrast, IL-4 induction in basophils via administration of the glycoprotein IPSE/α-1 led to improved post-MI healing. These results in mice were corroborated by the finding that initially low counts of blood basophils in patients with acute MI were associated with a worse cardiac outcome after 1 year, characterized by a larger scar size. In conclusion, we show that basophils promoted tissue repair after MI by increasing cardiac IL-4 and IL-13 levels.

Unraveling the thread of uncontrolled immune response in COVID-19 and STEMI: an emerging need for knowledge sharing.

The outbreak of severe acute respiratory syndrome coronavirus 2 that first emerged in Wuhan in December 2019 has resulted in the devastating pandemic of coronavirus disease 2019, creating an emerging need for knowledge sharing. Meanwhile, myocardial infarction is and will probably remain the foremost cause of death in the Western world throughout the coming decades. Severe deregulation of the immune system can unnecessarily expand the inflammatory response and participate in target and multiple organ failure, in infection but also in critical illness. Indeed, the course and fate of inflammatory cells observed in severe ST-elevation myocardial infarction (neutrophilia, monocytosis, and lymphopenia) almost perfectly mirror those recently reported in severe coronavirus disease 2019. A pleiotropic proinflammatory imbalance hampers adaptive immunity in favor of uncontrolled innate immunity and is associated with poorer structural and clinical outcomes. The goal of the present review is to gain greater insight into the cellular and molecular mechanisms underlying this canonical activation and downregulation of the two arms of the immune response in both entities, to better understand their pathophysiology and to open the door to innovative therapeutic options. Knowledge sharing can pave the way for therapies with the potential to significantly reduce mortality in both infectious and noninfectious scenarios.

A DARPin targeting activated Mac-1 is a novel diagnostic tool and potential anti-inflammatory agent in myocarditis, sepsis and myocardial infarction.

The monocyte ß2-integrin Mac-1 is crucial for leukocyte-endothelium interaction, rendering it an attractive therapeutic target for acute and chronic inflammation. Using phage display, a Designed-Ankyrin-Repeat-Protein (DARPin) was selected as a novel binding protein targeting and blocking the αM I-domain, an activation-specific epitope of Mac-1. This DARPin, named F7, specifically binds to activated Mac-1 on mouse and human monocytes as determined by flow cytometry. Homology modelling and docking studies defined distinct interaction sites which were verified by mutagenesis. Intravital microscopy showed reduced leukocyte-endothelium adhesion in mice treated with this DARPin. Using mouse models of sepsis, myocarditis and ischaemia/reperfusion injury, we demonstrate therapeutic anti-inflammatory effects. Finally, the activated Mac-1-specific DARPin is established as a tool to detect monocyte activation in patients receiving extra-corporeal membrane oxygenation, as well as suffering from sepsis and ST-elevation myocardial infarction. The activated Mac-1-specific DARPin F7 binds preferentially to activated monocytes, detects inflammation in critically ill patients, and inhibits monocyte and neutrophil function as an efficient new anti-inflammatory agent.

Overexpression of genes involved in lymphocyte activation and regulation are associated with reduced CRM-derived cardiac remodelling after STEMI.

AIMS: Lymphopenia after ST-segment elevation myocardial infarction (STEMI) correlates with deleterious cardiac consequences and worse prognosis. An in-depth examination of genes implicated in lymphocyte proliferation, activation and regulation and their association with short- and long-term cardiac structure and function is therefore of great interest. METHODS: Peripheral blood mononuclear cells were isolated from 10 control subjects and 64 patients with a first STEMI treated with primary percutaneous coronary intervention and submitted to cardiac magnetic resonance after 1 week and 6 months. mRNA expression of genes implicated in lymphocyte activation (CD25 and CD69) and regulation [programmed death (PD)-1 and cytotoxic T-lymphocyte antigen (CTLA)-4] were determined by qRT-PCR. RESULTS: In comparison to controls, STEMI patients showed heightened mRNA expression of CD25 and lower PD-1 and CTLA-4 96 h after coronary reperfusion. Patients with extensive infarctions (>30% of left ventricular mass) at 1 week displayed a notable reduction in CD25, CD69, PD-1, and CTLA-4 expression (p < 0.05). However, CD25 was the only predictor of 1-week extensive infarct size in multivariate logistic regression analysis (odds ratio 0.019; 95% confidence interval [0.001-0.505]; p = 0.018). Regarding long-term ventricular function, mRNA expression of CD25 under the mean value was associated with worse ventricular function and more adverse remodelling. CONCLUSIONS: Following STEMI, heightened expression of genes expressed in regulatory T cells (CD25 and CD69) and immune checkpoints (PD-1 and CTLA-4) correlates with a better short- and long-term cardiac structure and function. Advancing understanding of the pathophysiology of lymphopenia and evaluating novel immunomodulatory therapies will help translate these results into future clinical trials.

Extracellular vesicles derived from Krüppel-Like Factor 2-overexpressing endothelial cells attenuate myocardial ischemia-reperfusion injury by preventing Ly6Chigh monocyte recruitment.

Background: The ischemia/reperfusion (I/R) process in patients with ST-segment elevation myocardial infarction (STEMI) triggers an immune response, resulting in myocyte death. Krüppel-Like Factor 2 (KLF2), which is highly expressed in endothelial cells (ECs) under laminar flow, exerts anti-inflammatory effects. In this study, we explored the role of small extracellular vesicles (EVs) from KLF2-overexpressing ECs (KLF2-EVs) in the immunomodulation and its implications in myocardial I/R injury. Methods and Results: The small EVs were isolated from KLF2-overexpressing ECs' supernatant using gradient centrifugation. Mice were subjected to 45 min of ischemia followed by reperfusion, and KLF2-EVs were administrated through intravenous injection. KLF2-EVs ameliorated I/R injury and alleviated inflammation level in the serum and heart. We employed the macrophage depletion model and splenectomy and showed that Ly6Chigh monocyte recruitment from bone marrow was the main target of KLF2-EVs. miRNA-sequencing of KLF2-EVs and bioinformatics analysis implicated miRNA-24-3p (miR-24-3p) as a potent candidate mediator of monocyte recruitment and CCR2 as a downstream target. miR-24-3p mimic inhibited the migration of Ly6Chigh monocytes, and miR-24-3p antagomir reversed the effect of KLF2-EVs in myocardial I/R. Conclusion: Our data demonstrated that KLF2-EVs attenuated myocardial I/R injury in mice via shuttling miR-24-3p that restrained the Ly6Chigh monocyte recruitment. Thus, KLF2-EVs could be a potential therapeutic agent for myocardial I/R injury.

Concomitant myopericarditis and takotsubo syndrome following immune checkpoint inhibitor therapy.

A 62-year-old man with metastatic hepatocellular carcinoma presented with ST elevation myocardial infarction had received one dose of nivolumab 3 weeks prior. Cardiac catheterisation was negative for obstructive coronary artery disease. He was transferred to the cardiac intensive care unit due to ventricular arrhythmias and markedly elevated troponin T levels. Transthoracic echocardiogram showed severely depressed left ventricular ejection fraction of 18% (normal 55%-70%) with mid and apical ballooning consistent with takotsubo syndrome (TTS). Intravenous glucocorticoids were administered due to suspicion for superimposed myocarditis. Cardiac MRI 3 days later showed mid-myocardial and subepicardial delayed enhancement in the inferior and lateral walls as well as apex indicative of myopericarditis. He clinically improved on steroids and was discharged with outpatient follow-up. This case highlights major cardiac complications that may arise with immune checkpoint inhibitor therapy. In addition, it emphasises the importance of assessing for concomitant myocarditis even when initial imaging suggests TTS.

Assessment of neutrophil and neutrophil/lymphocyte ratio in coronary collateral developed patients with acute coronary syndrome.

OBJECTIVE Inflammation-related markers provide diagnostic and prognostic information for coronary artery disease and acute coronary syndrome. We aimed to compare neutrophil count and neutrophil/lymphocyte ratio (NLR) in acute coronary syndrome patients with coronary collateral development in our study. METHODS A total of 426 patients (102 unstable angina pectoris (USAP), 223 non-ST-elevation myocardial infarction (non-STEMI), 103 ST-elevation myocardial infarction (STEMI) were compared regarding hemoglobin, platelet, lymphocyte, neutrophil count, and NLR. RESULTS Neutrophil count and NLR were significantly lower in USAP patients and higher in STEMI patients; 5.14± 1.79 vs. 7.21± 3.05 vs. 9.93±4.67 and 2.92±2.39 vs. 5.19±4.80 vs. 7.93±6.38, p <0.001. Other parameters, i.e., hemoglobin, platelet, and lymphocyte count, were not significantly different between the groups. CONCLUSIONS In our study, it was concluded that there may be a statistically significant difference in the number of neutrophil counts and NLR among the types of acute coronary syndromes with coronary collateral development.

Admission Low-Density Lipoprotein Cholesterol Stratified by Circulating CD14++CD16+ Monocytes and Risk for Recurrent Cardiovascular Events Following ST Elevation Myocardial Infarction: Lipid Paradox Revised.

Lower level of low-density lipoprotein cholesterol (LDL-C) is paradoxically associated with increased mortality in ST elevation myocardial infarction (STEMI) patients. The underlying mechanism remains unclear. In a cohort of 220 de novo STEMI patients receiving timely primary percutaneous coronary intervention, admission LDL-C was negatively associated with circulating CD14++CD16+ monocyte counts. Moreover, admission LDL-C < 85 mg/dL was associated with increased risk for major adverse cardiovascular events (MACE) during a median follow-up of 2.7 years. After categorizing the patients according to the cutoff values of 85 mg/dL for LDL-C and the median for CD14++CD16+ monocytes, low LDL-C-associated MACE risk was only observed in those with high CD14++CD16+ monocyte counts (low LDL-C/high CD14++CD16+ monocytes vs. low LDL-C/low CD14++CD16+ monocytes: hazard ratio 5.38, 95% confidence interval 1.52 to 19.06, P = 0.009). This work provided the proof-of-principle evidence indicating a role of CD14++CD16+ monocytes in risk stratification of STEMI patients presenting with low LDL-C level. Graphical abstract.

Dynamic changes of innate lymphoid cells in acute ST-segment elevation myocardial infarction and its association with clinical outcomes.

An increasing body of evidence has implicated the innate immune system in the causation of acute ST-segment elevation myocardial infarction (STEMI). Innate lymphoid cells (ILCs) are newly identified members of the lymphoid lineage that are important effectors of innate immunity. The role of ILCs in STEMI has not been explored. We characterized the ILCs present in peripheral blood of 176 STEMI patients and 52 controls. Patients were followed up for up to 23 months. Flow cytometry showed that the proportion of total ILCs and ILC1s were significantly increased compared with controls; contrary to ILC1s, the proportion of ILC2s among total ILCs decreased significantly during the acute phase of STEMI. ILC1s percentage was an independent predictor of major adverse cardiovascular events (MACE). On multivariate Cox regression, the 3rd tertile of ILC1s was associated with a higher MACE rate compared with the 1st tertile (hazard ratio: 2.26; 95% confidence interval 1.56-3.27; P = 0.014). RNA-sequencing (RNA-Seq) revealed increased expressions of interferon-γ, tumor necrosis factor-α, vascular cell adhesion molecule 1 (VCAM1), and matrix metallopeptidase 9. Moreover, as active factors secreted by ILC1s, levels of interleukin (IL)-12 and IL-18 were significantly increased in STEMI patients. Increased ILC1s in patients with STEMI was associated with poor outcomes. Our findings suggest that ILC1s may play an important role in STEMI.

Monocyte Subsets Are Differently Associated with Infarct Size, Left Ventricular Function, and the Formation of a Potentially Arrhythmogenic Scar in Patients with Acute Myocardial Infarction.

To investigate the role of classical (CLM, CD14++CD16-), intermediate (INTM, CD14++CD16+), and non-classical (Non-CLM, CD14+CD16++) monocytes in scar formation after ST-elevation myocardial infarction (STEMI), evaluated with cardiac magnetic resonance (CMR). One hundred two patients with a first STEMI had serial blood analyses after 1, 3, and 7 days. A CMR was performed at 7 days and 6 months, depicting scar core (CO), border zone (BZ), and the presence of BZ channels. CLM and INTM levels progressively decreased, correlated with the scar mass, CO, and BZ at 7 days and 6 months (p < 0.05), and inversely with left ventricular ejection fraction (LVEF, p < 0.01). Non-CLM levels gradually increased, correlated with BZ mass and the presence of BZ channels at 7 days and 6 months (p < 0.001).CLM and INTM are associated with infarct size and inversely with LVEF, whereas Non-CLM are associated with BZ mass and the presence of potentially arrhythmogenic substrate.

Assessment of neutrophil and neutrophil/lymphocyte ratio in coronary collateral developed patients with acute coronary syndrome

SUMMARY OBJECTIVE Inflammation-related markers provide diagnostic and prognostic information for coronary artery disease and acute coronary syndrome. We aimed to compare neutrophil count and neutrophil/lymphocyte ratio (NLR) in acute coronary syndrome patients with coronary collateral development in our study. METHODS A total of 426 patients (102 unstable angina pectoris (USAP), 223 non-ST-elevation myocardial infarction (non-STEMI), 103 ST-elevation myocardial infarction (STEMI) were compared regarding hemoglobin, platelet, lymphocyte, neutrophil count, and NLR. RESULTS Neutrophil count and NLR were significantly lower in USAP patients and higher in STEMI patients; 5.14± 1.79 vs. 7.21± 3.05 vs. 9.93±4.67 and 2.92±2.39 vs. 5.19±4.80 vs. 7.93±6.38, p <0.001. Other parameters, i.e., hemoglobin, platelet, and lymphocyte count, were not significantly different between the groups. CONCLUSIONS In our study, it was concluded that there may be a statistically significant difference in the number of neutrophil counts and NLR among the types of acute coronary syndromes with coronary collateral development.

RESUMO OBJETIVO Marcadores relacionados a inflamação fornecem informações de diagnóstico e prognóstico para doença arterial coronariana e síndrome coronariana aguda. Nosso objetivo foi comparar o número de neutrófilos e razão neutrófilos/linfócitos (RNL) em pacientes com síndrome coronariana aguda com desenvolvimento de circulação colateral. MÉTODOS Um total de 426 pacientes [102 com angina de peito instável (APIN), 223 com infarto do miocárdio sem supradesnível de ST (IMSS), 103 com infarto do miocárdio com supradesnível de ST (IMCS)] foram comparados em relação a hemoglobina, plaquetas, linfócitos, neutrófilos e RNL. RESULTADOS O número de neutrófilos e RNL estavam significativamente mais baixos em pacientes com APIN e mais altos nos pacientes com IMCS; 5,14± 1,79 vs. 7,21± 3,05 vs. 9,93±4,67 and 2,92±2,39 vs. 5,19±4,80 vs. 7,93±6,38, p <0,001. Os outros parâmetros (hemoglobina, contagem de linfócitos e plaquetas) não foram significativamente diferentes entre os grupos. CONCLUSÃO No nosso estudo, concluiu-se que pode haver uma diferença significativa no número de neutrófilos e RNL entre os tipos de síndromes coronarianas agudas com desenvolvimento de circulação colateral.

Neutrophil extracellular traps and fibrocytes in ST-segment elevation myocardial infarction.

Leukocyte-mediated inflammation is central in atherothrombosis and ST-segment elevation myocardial infarction (STEMI). Neutrophil extracellular traps (NETs) have been shown to enhance atherothrombosis and stimulate fibroblast function. We analyzed the effects of NETs on cardiac remodeling after STEMI. We measured double-stranded (ds)DNA and citrullinated histone H3 (citH3) as NET surrogate markers in human culprit site and femoral blood collected during primary percutaneous coronary intervention (n = 50). Fibrocytes were characterized in whole blood by flow cytometry, and in culprit site thrombi and myocardium by immunofluorescence. To investigate mechanisms of fibrocyte activation, isolated NETs were used to induce fibrocyte responses in vitro. Enzymatic infarct size was assessed using creatine-phosphokinase isoform MB area under the curve. Left ventricular function was measured by transthoracic echocardiography. NET surrogate markers were increased at the culprit site compared to the femoral site and were positively correlated with infarct size and left ventricular dysfunction at follow-up. In vitro, NETs promoted fibrocyte differentiation from monocytes and induced fibrocyte activation. Highly activated fibrocytes accumulated at the culprit site and in the infarct transition zone. Our data suggest that NETs might be important mediators of fibrotic remodeling after STEMI, possibly by stimulating fibrocytes.

Impact of inflammation-mediated response on pan-coronary plaque vulnerability, myocardial viability and ventricular remodeling in the postinfarction period - the VIABILITY study: Protocol for a non-randomized prospective clinical study.

INTRODUCTION: While the role of inflammation in acute coronary events is well established, the impact of inflammatory-mediated vulnerability of coronary plaques from the entire coronary tree, on the extension of ventricular remodeling and scaring, has not been clarified yet. MATERIALS AND METHODS: The present manuscript describes the procedures of the VIABILITY trial, a descriptive prospective single-center cohort study. The main purpose of this trial is to assess the link between systemic inflammation, pan-coronary plaque vulnerability (referring to the plaque vulnerability within the entire coronary tree), myocardial viability and ventricular remodeling in patients who had suffered a recent ST-segment elevation acute myocardial infarction (STEMI). One hundred patients with STEMI who underwent successful revascularization of the culprit lesion in the first 12 hours after the onset of symptoms will be enrolled in the study. The level of systemic inflammation will be evaluated based on the serum biomarker levels (hs-CRP, matrix metalloproteinases, interleukin-6) in the acute phase of the myocardial infarction (MI) and at 1 month. Pan-coronary plaque vulnerability will be assessed based on serum biomarkers known to be associated with increased plaque vulnerability (V-CAM or I-CAM) and at 1 month after infarction, based on computed tomographic angiography analysis of vulnerability features of all coronary plaques. Myocardial viability and remodeling will be assessed based on 3D speckle tracking echocardiography associated with dobutamine infusion and LGE-CMR associated with post-processing imaging methods. The study population will be categorized in 2 subgroups: subgroup 1 - subjects with STEMI and increased inflammatory response at 7 days after the acute event (hs-CRP ≥ 3 mg/dl), and subgroup 2 - subjects with STEMI and no increased inflammatory response at 7 days (hs-CRP < 3 mg/dl). Study outcomes will consist in the rate of post-infarction heart failure development and the major adverse events (MACE) rate. CONCLUSION: VIABILITY is the first prospective study designed to evaluate the influence of infarct-related inflammatory response on several major determinants of post-infarction outcomes, such as coronary plaque vulnerability, myocardial viability, and ventricular remodeling.

Loss of Regulatory Immune Function in Coronary Artery Disease Patients from the Indian Population.

The pathogenic roles of inflammatory T cells and monocytes subsets have not been explored in different manifestations of coronary artery disease. We studied the frequency of these cells, their response to autoantigens, regulatory cell functional assay, foam cell formation and macrophage differentiation in 181 patients (stable angina, ST-elevated myocardial infarction (STEMI), NSTEMI, and unstable angina), and 34 controls and in samples collected during recurrent cardiac events and from patients showing clinical improvement. The proportion of Th17 cells and monocytes gradually increased in patients with stable angina at one end of the spectrum followed by NSTEMI, STEMI, and unstable angina at other end. Inflammatory cells were positively and inversely associated with recurrent events and clinical improvement, respectively. Patients showed expansion of Th17 cells in response to autoantigen (HSP60) and compromised Treg function. Our results suggest that stress-induced activation of inflammatory cells expands in the absence of regulatory control in CAD patients.

Effect of Oral N-Acetylcysteine Supplementation on the Immunity System in Patients with Acute Myocardial Infarction.

BACKGROUND: inflammation, oxidative stress, and fibrosis play important roles after an acute myocardial infarction (AMI) event. The most studied inflammatory biomarker in cardiovascular disease is C-reactive protein (CRP). It has been demonstrated that myeloperoxidase (MPO) and Galectin-3 (Gal-3) have some essential roles on immune system when an AMI event occurs. We aimed to determine the effect of oral N-acetylcysteine (NAC) supplementation at the dose of 600 mg 3 times daily for 3 consecutive days on the immune system of AMI patients. METHODS: our randomized single-blinded experimental study using pre- and post-treatment evaluations was performed at Dr. Moewardi Hospital, Indonesia, from May to August 2018. Thirty-two patients with AMI and ST segment elevation (STEMI) who received fibrinolytic therapy were included. There were 17 patients received standard therapy plus 600 mg oral NAC supplementation every 8 h for 3 days and 15 patients received standard therapy, which served as the control group. High-sensitivity C-reactive protein (HsCRP), MPO, and Gal-3 levels of both groups were evaluated at admission and after 72 h receiving treatment. RESULTS: HsCRP, MPO, and Gal-3 levels between NAC and control groups at admission were not significantly different; while intergroup differences after 72 h of NAC supplementation were significant (p values of HsCRP, MPO, and Gal-3 levels were 0.0001, 0.001, and 0.017, respectively). Furthermore, in the NAC group, HsCRP, MPO, and Gal-3 levels at 72 h after treatment were significantly different from the corresponding levels at admission (p values: 0.0001, 0.0001, and 0.0001, respectively); the control group did not show these differences. There were also significant intergroup differences between the NAC and control groups regarding HsCRP, MPO, and Gal-3 levels (p values: 0.011, 0.022, and 0.014, respectively). CONCLUSION: oral supplementation of 600 mg NAC every 8 h for 72 h can reduce HsCRP, MPO, and Gal-3 levels in AMI patients receiving fibrinolytic therapy. Results of our study will provide more options for supplementation therapy to improve management of IMA patients.