Anti-inflammatory strategies for ventricular remodeling following ST-segment elevation acute myocardial infarction

Ozone protects from myocardial ischemia-reperfusion injury via inhibition of the NLRP3 inflammasome

Ischemic heart disease (IHD) is a leading cause of morbidity and mortality worldwide. Myocardial ischemia/reperfusion injury (MIRI) is the primary cause of myocardial injury triggered by post-myocardial infarction reperfusion therapy. Its pathogenesis involves Ca2+ overload, the production of large amounts of oxygen-free radicals, inflammation, and cell necrosis. Growing evidence suggests that the NLRP3 inflammasome significantly contributes to the sterile inflammatory response and pyroptosis in MIRI, linking damage sensing to the initiation and amplification of the inflammatory response. Reportedly, ozone exerts anti-inflammatory and anti-infection effects by activating the antioxidant system. Additional evidence suggests that ozone inhibits NLRP3 inflammasome expression to relieve ischemic injury. In this study, we aimed to explore whether pretreating the myocardium with ozone protects it from MIRI by inhibiting the NLRP3 inflammasome. Rats were subjected to rectal infusion of ozone for 5 consecutive days, followed by ligation of the left anterior descending coronary artery for 30 min and reperfusion for 120 min to induce MIRI. Experimental results were obtained using echocardiography, triphenyltetrazolium chloride and hematoxylin and eosin staining, western blotting, and enzyme-linked immunosorbent assay. The results showed that ozone significantly improved the diastolic function of the heart, reduced the area of myocardial infarction, and decreased the expression levels of NLRP3, pro-caspase-1, ASC, and the secretion of caspase-1, interleukin (IL)-1β, and IL-18. In summary, these findings reveal that ozone pretreatment can alleviate the damage that occurs during MIRI by inhibiting the NLRP3 Inflammasome.

The Role of MCPIP1 in Macrophage Polarization and Cardiac Function Post-Myocardial Infarction

Macrophages play a critical role in both initiating and resolving inflammation following MI (myocardial infarction). Their polarization is essential for maintaining cardiac function. This study aims to explore the role of MCPIP1(Monocyte chemotactic protein-induced protein 1) in regulating macrophage polarization and its impact on heart-spleen interactions during MI recovery. The role of MCPIP1 was investigated using histological staining, RNA sequencing of bone marrow-derived macrophages, co-culture experiments, and validated by western blot. Compared to controls, myeloid MCPIP1-deficient mice had lower survival rates, larger infarction areas, and more severe inflammatory responses after MI. This was due to increased M1 polarization and impaired conversion to the M2 phenotype. Ferroptosis activation in MCPIP1-deficient macrophages was inhibited by Fer-1 and PFT-α, which promoted M2 polarization and fibroblast activation into myofibroblasts. MCPIP1-deficient MI mice also showed splenomegaly and elevated levels of circulating macrophages, indicating excessive extramedullary hematopoiesis. Splenectomy improved survival rates and reduced infarction size in MCPIP1-deficient mice. MCPIP1 suppresses the P53/ferroptosis pathway to regulate macrophage polarization and TGF-β/SMAD3-mediated fibroblast activation. Its deficiency exacerbates inflammation through abnormal splenic macrophage output, impairing cardiac repair. MCPIP1 is a promising therapeutic target for modulating ferroptosis and heart-spleen communication to protect cardiac function following MI.

Association between mild renal insufficiency, inflammatory status on initial admission, and 1-year mortality following ST-segment elevation myocardial infarction

The systemic inflammation tends to increase progressively as kidney function deteriorates. However, it remains unknown whether mild renal insufficiency affects inflammatory response at admission and subsequent clinical outcomes following ST-segment elevation myocardial infarction (STEMI). This study aimed to evaluate the joint, interactive, and mediating effects of estimated glomerular filtration rate (eGFR) and neutrophil-lymphocyte ratio (NLR) at admission on 1-year mortality in STEMI patients. Data were collected from 5,594 consecutive STEMI patients at seven centers (NCT04996901). Mildly reduced eGFR (60-89 mL/min/1.73m2) was associated with both elevated NLR and increased 1-year mortality (β 0.55, 95%CI [0.07-1.02], P = 0.024; HR 2.18, 95%CI [1.55-3.08], P < 0.001; respectively). Inflammation at admission mediated a small but significant proportion of the association between mildly reduced eGFR and mortality risk (1.7%, P = 0.030). Incorporating eGFR and NLR into a predictive model significantly improved mortality prediction following STEMI compared with clinical risk factors alone (C-index, 0.799 vs. 0.730, P < 0.001; net reclassification index 0.334, P < 0.001). These findings support the identification of patients at risk who may benefit from intensive kidney function monitoring and early adjuvant intervention, while also highlighting the need for developing anti-inflammatory therapies for STEMI patients with renal insufficiency.

Myeloid-derived suppressor cells alleviate adverse ventricular remodeling after acute myocardial infarction

The fundamental pathophysiological mechanism in the progression of chronic heart failure following acute myocardial infarction (AMI) is ventricular remodeling, in which innate and adaptive immunity both play critical roles. Myeloid-derived suppressor cells (MDSCs) have been demonstrated to function in a range of pathological conditions, such as infections, inflammation, autoimmune diseases, and tumors. However, it is unclear how MDSCs contribute to cardiac remodeling following AMI. This study aimed to identify the function and underlying mechanism of MDSCs in controlling cardiac remodeling following AMI. Following AMI in mice, MDSCs frequencies changed dynamically, considerably increased on day 7 in blood, spleens, lymph nodes and hearts, and decreased afterwards. Consistently, mice with AMI displayed enhanced cardiac function on day 14 post-AMI, reduced infract size and higher survival rates on day 28 post-AMI following the adoptive transfer of MDSCs. Furthermore, MDSCs inhibited the inflammatory response by decreasing pro-inflammatory cytokine (TNF-α, IL-17, Cxcl-1, and Cxcl-2) expression, up-regulating anti-inflammatory cytokine (TGF-β1, IL-10, IL-4, and IL-13) expression, reducing CD3+ T cell infiltration in the infarcted heart and enhancing M2 macrophage polarization. Mechanistically, MDSCs improved the release of anti-inflammatory factors (TGF-β1 and IL-10) and decreased the injury of LPS-induced cardiomyocytes in vitro in a manner dependent on cell-cell contact. Importantly, blockade of IL-10 partially abolished the cardioprotective role of MDSCs. This study found that MDSCs contributed to the restoration of cardiac function and alleviation of adverse cardiac remodeling after AMI possibly by inhibiting inflammation.

Association of Intramyocardial Hemorrhage With Inflammatory Biomarkers in Patients With ST-Segment Elevation Myocardial Infarction

BACKGROUND

Ischemia-reperfusion (I/R) injury patterns detected by cardiac magnetic resonance imaging after percutaneous coronary intervention (PCI) have important prognostic implications and trigger inflammatory processes that can further enhance myocardial tissue damage.

OBJECTIVES

The authors aimed to investigate the association of circulating inflammatory markers and I/R injury patterns in patients with ST-segment elevation myocardial infarction (STEMI).

METHODS

This observational study included 456 STEMI patients. Peripheral venous blood samples were drawn 48 hours after PCI for analysis of high-sensitivity C-reactive protein (hs-CRP), white blood cell count (WBCc), and interleukin (IL)-6. The presence of I/R injury was defined by the detection of intramyocardial hemorrhage (IMH) according to cardiac magnetic resonance T2∗. Clinical endpoint was the occurrence of major adverse cardiac events, defined as composite of all-cause death, nonfatal reinfarction, and new congestive heart failure.

RESULTS

IMH was present in 150 (33%) patients. Hs-CRP (OR: 2.89; 95% CI: 1.96-4.26; P < 0.001), WBCc (OR: 1.32; 95% CI: 1.04-1.67; P = 0.021), and IL-6 (OR: 1.86; 95% CI: 1.38-2.51; P < 0.001) were associated with presence of IMH. Only hs-CRP was independently associated with IMH (OR: 1.95; 95% CI: 1.30-2.93; P = 0.001) after adjustment for other clinical parameters. Furthermore, patients with hs-CRP levels above the median (>26.4 mg/L) were more likely to experience major adverse cardiac events (12% vs 4%, P = 0.002) during a median follow-up of 12 (Q1-Q3: 12-13) months.

CONCLUSIONS

In patients with STEMI treated with primary PCI, inflammatory parameters including hs-CRP, WBCc, and IL-6 were significantly associated with I/R injury as defined by IMH. After adjustment for other factors, hs-CRP was the only independent inflammatory biomarker associated with IMH.

A novel indicator of all-cause mortality in acute coronary syndrome: the CALLY index

AIMS

This study aimed to identify the prognostic significance of the C-reactive protein-albumin-lymphocyte (CALLY) index for predicting all-cause mortality in acute coronary syndrome (ACS) patients who have undergone primary percutaneous coronary intervention (pPCI) for revascularization.

MATERIALS AND METHODS

505 patients who presented with ACS and underwent pPCI were retrospectively included in this single center study. CALLY index and other five prognostic scores were calculated. The median follow-up was 40 months. All-cause mortality was defined as the primary endpoint.

RESULTS

The median age of the patients was 59 years, 23.4% were female. The CALLY index was categorized into low (<0.7) and high (≥0.7). Age (p = 0.038), concomitant atrial fibrillation (p = 0.023), previous CABG (p = 0.001), ACE-I/ARB/ARNI use (p = 0.015), diuretic use (p = 0.021), and a low-CALLY index (p < 0.001) were identified as independent predictors of all-cause mortality in multivariate cox regression analysis. When compared to other prognostic scores according to AUC in ROC analysis, the CALLY index demonstrated the best ability to predict all-cause mortality. Additionally, patients with a high-CALLY index exhibited significantly better survival outcomes compared to those with a low-CALLY index (log-rank:p < 0.001).

CONCLUSIONS

CALLY index can be utilized as a novel prognostic score for predicting all-cause mortality in ACS patients who have undergone pPCI.

Interleukin-1 Blockade in Patients With ST-Segment Elevation Myocardial Infarction Across the Spectrum of Coronary Artery Disease Complexity

ABSTRACT

Patients with ST-segment elevation myocardial infarction (STEMI) and complex coronary artery disease (CAD) face a poor prognosis, including increased heart failure (HF) risk. Phase 2 clinical trials of anakinra have shown inhibition of the acute inflammatory response and prevention of HF after STEMI, but data on its effects based on CAD complexity are lacking. We performed a pooled secondary analysis of 139 patients with STEMI. The SYNTAX (Synergy Between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery), SYNTAX II, and Gensini scores were calculated, and patients were divided into 2 groups below and above the median. We evaluated the effect of anakinra on the area-under-the-curve of high-sensitivity C-reactive protein (hsCRP-AUC) at 14 days, and the composite endpoint of new-onset HF, HF hospitalization, or all-cause death at 1-year follow-up using Kaplan-Meier survival curves, Cox regression analysis for hazard ratios (HRs), and tested interactions between subgroups. All 3 CAD complexity scores (SYNTAX, SYNTAX II, and Gensini) were associated with an increased risk of adverse events (HR 1.02-1.06, all P-values ≤0.025). We found no statistically significant interactions between CAD extent, measured as single-vessel or multivessel CAD, SYNTAX score ≤9 or >9, SYNTAX II score ≤24 or >24, Gensini score ≤32 or >32, and treatment effect of anakinra on hsCRP-AUC or the composite clinical endpoint (all P - values for interaction >0.05). In conclusion, among patients with STEMI, IL-1 blockade with anakinra significantly attenuated the acute inflammatory response and reduced the risk of HF-related events regardless of the spectrum of CAD complexity.

Inhibition of mir-155-5p alleviates cardiomyocyte pyroptosis induced by hypoxia/reoxygenation via targeting SIRT1-mediated activation of the NLRP3 inflammasome

OBJECTIVE

The hypoxia/reoxygenation (H/R)-induced pyroptosis of cardiomyocytes plays a crucial role in the pathogenesis of myocardial infarction (MI). miR-155-5p represents a promising target for MI therapy. However, its involvement in H/R-induced pyroptosis remains unclear.

METHODS

The H/R exposed rat cardiomyocyte H9c2 was utilized as in vitro model, and the expression levels of miR-155-5p and SIRT1 in cells were modulated through cell transfection experiments. Cell proliferative activity was assessed using the Cell counting kit-8 assay. Supernatant lactate dehydrogenase (LDH) activity was determined through colorimetry. The levels of living and dead cell were observed via Calcin-AM/PI staining. Levels of supernatant interleukin (IL)-1β and IL-18 were measured using ELISA assay. The expression levels of miR-155-5p and silent information regulator 1 (SIRT1) mRNA were detected by qRT-PCR. The protein expression levels of SIRT1, NLRP3, N-terminal gasdermin D (GSDMD-N), and Cleaved caspase-1 were evaluated using Western blot analysis. The targeted regulatory relationship between miR-155-5p and SIRT1 was verified using dual luciferase reporter gene assay.

RESULTS

The proliferation activity of H9c2 cells induced by H/R was attenuated, accompanied by severe injury, increased cell death, and the release of a substantial amount of pro-inflammatory cytokines IL-1β and IL-18. In addition, H/R stimulation resulted in the upregulation of miR-155-5p expression and downregulation of SIRT1 expression in H9c2 cells. Suppression of miR-155-5p or overexpression of SIRT1 exhibited ameliorative effects on H/R-induced cellular injury in H9c2 cells and inhibited NLRP3 inflammasome-mediated pyroptosis. The dual-luciferase assay confirmed the direct targeting of SIRT1 by miR-155-5p in H9c2 cells. Furthermore, partial reversal of the inhibitory effect of miR-155-5p inhibitor on H/R-induced NLRP3 inflammasome-mediated pyroptosis in H9c2 cells was observed upon interference with SIRT1 expression.

CONCLUSION

Inhibition of miR-155-5p alleviates cardiomyocyte pyroptosis induced by H/R via targeting SIRT1-mediated activation of the NLRP3 inflammasome.

Assembly of ceria-Nrf2 nanoparticles as macrophage-targeting ROS scavengers protects against myocardial infarction

Myocardial infarction (MI) is a leading cause of morbidity and mortality worldwide, and mitigating oxidative stress is crucial in managing MI. Nuclear factor erythroid 2-related factor 2 (Nrf2) plays a critical role in combating oxidative stress and facilitating cardiac remodeling post-MI. Here, we engineered Cerium oxide (CeO2) nanoparticle-guided assemblies of ceria/Nrf2 nanocomposites to deliver Nrf2 plasmids. The CeO2/Nrf2 nanocomposites effectively activated the Nrf2/antioxidant response element (ARE) signaling pathway both in vivo and in vitro. In a mouse MI model induced by permanent ligation of the left anterior descending artery (LAD), CeO2/Nrf2 nanocomposites were administered via tail vein injection, predominantly targeting circulating monocytes and macrophages which will be recruited to the heart post MI due to the acute inflammatory response. We demonstrated that CeO2/Nrf2 nanocomposites alleviated cardiac systolic dysfunction and significantly reduced infarct size and scar fibrosis post-MI. Furthermore, CeO2/Nrf2 nanocomposites effectively mitigated MI-induced oxidative stress and downregulated Nrf2-regulated inflammatory genes (tumor necrosis factor-α, IL-6, and inducible nitric oxide synthase), thereby reducing cardiomyocyte apoptosis. These findings indicate that CeO2/Nrf2 nanocomposites significantly enhance Nrf2 signaling activation and confer protection against MI. This study identifies CeO2/Nrf2 nanocomposites as a promising strategy for post-MI therapy.

Endothelial progenitor cells have high predictive value for ventricular remodeling after percutaneous coronary intervention in acute myocardial infarction

OBJECTIVE

Acute myocardial infarction (AMI) and the following heart failure are main causes of disability and death across the globe. Endothelial progenitor cell (EPC) levels are linked to AMI. Herein, we assessed the predictive value of EPCs for post-percutaneous coronary intervention (PCI) ventricular remodeling in AMI patients.

METHODS

This study retrospectively analyzed 215 AMI patients receiving PCI, who were then categorized into the VR ( n  = 66) and N-VR ( n  = 149) groups as per whether they developed post-PCI ventricular remodeling. Left ventricular ejection fraction (LVEF), N-terminal pro-brain natriuretic peptide (NT-pro-BNP), and EPCs were measured. The correlations of LVEF and NT-pro-BNP with EPCs, the predictive value of EPCs for post-PCI ventricular remodeling, and the risk of post-PCI ventricular remodeling in AMI patients with different EPC levels were analyzed by Spearman's analysis, receiver-operating characteristic curve, and Kaplan-Meier curve.

RESULTS

LVEF and EPC levels were lower and NT-pro-BNP level was higher in the VR group than the N-VR group. EPC levels in the class III-IV group were lower than those in the class I-II group. EPC levels in AMI patients correlated positively with LVEF ( r  = 0.683) and negatively with NT-pro-BNP ( r  = -0.761). EPCs exhibited high predictive value for post-PCI ventricular remodeling in AMI [area under the curve (AUC) of 0.822] and anterior MI (AUC = 0.941) patients. AMI and anterior MI patients with low EPC levels had a higher risk of post-PCI ventricular remodeling.

CONCLUSION

Low EPC levels have high predictive value for post-PCI ventricular remodeling, and increase the risk of post-PCI ventricular remodeling in AMI patients.

Bone Morphogenetic Protein 9 Protects Against Myocardial Infarction by Improving Lymphatic Drainage Function and Triggering DECR1-Mediated Mitochondrial Bioenergetics

BACKGROUND

BMP9 (bone morphogenetic protein 9) is a member of the TGF-β (transforming growth factor β) family of cytokines with pleiotropic effects on glucose metabolism, fibrosis, and lymphatic development. However, the role of BMP9 in myocardial infarction (MI) remains elusive.

METHODS

The expressional profiles of BMP9 in cardiac tissues and plasma samples of subjects with MI were determined by immunoassay or immunoblot. The role of BMP9 in MI was determined by evaluating the impact of BMP9 deficiency and replenishment with adeno-associated virus-mediated BMP9 expression or recombinant human BMP9 protein in mice.

RESULTS

We show that circulating BMP9 and its cardiac levels are markedly increased in humans and mice with MI and are negatively associated with cardiac function. It is important to note that BMP9 deficiency exacerbates left ventricular dysfunction, increases infarct size, and augments cardiac fibrosis in mice with MI. In contrast, replenishment of BMP9 significantly attenuates these adverse effects. We further demonstrate that BMP9 improves lymphatic drainage function, thereby leading to a decrease of cardiac edema. In addition, BMP9 increases the expression of mitochondrial DECR1 (2,4-dienoyl-CoA [coenzyme A] reductase 1), a rate-limiting enzyme involved in β-oxidation, which, in turn, promotes cardiac mitochondrial bioenergetics and mitigates MI-induced cardiomyocyte injury. Moreover, DECR1 deficiency exacerbates MI-induced cardiac damage in mice, whereas this adverse effect is restored by the treatment of adeno-associated virus-mediated DECR1. Consistently, DECR1 deletion abrogates the beneficial effect of BMP9 against MI-induced cardiomyopathy and cardiac damage in mice.

CONCLUSIONS

These results suggest that BMP9 protects against MI by fine-tuning the multiorgan cross-talk among the liver, lymph, and the heart.

Prognostic significance of C-reactive protein-albumin-lymphocyte (CALLY) index after primary percutaneous coronary intervention in patients with ST-segment elevation myocardial infarction

BACKGROUND

In this study, the relationship between C-reactive protein-albumin-lymphocyte (CALLY) index, a novel composite indicator based on inflammation and nutrition, and major adverse cardiovascular events (MACEs) was investigated in patients with ST-segment elevation myocardial infarction (STEMI).

MATERIALS AND METHODS

This retrospective study included 438 patients with STEMI who were treated at a single center between January 2017 and December 2020. The CALLY index was calculated for each patient on admission. The predictive value of the CALLY index for short- and long-term MACEs was evaluated using the area under the curve (AUC) analysis, and the corresponding AUC values were calculated. Clinical characteristics were analyzed after categorizing the population based on the optimal cut-off value of the CALLY index. Multivariate Cox regression analysis was used to determine factors independently associated with MACEs, while logistic regression analysis was used to identify factors independently associated with the severity of coronary artery lesions. Kaplan-Meier estimation and log-rank test were used to assess event-free survival rates among different CALLY index groups. Additionally, Spearman's correlation test was used to determine the association between the CALLY index and the Gensini score.

RESULTS

The AUC for predicting short-term MACEs in STEMI patients using the CALLY index was 0.758, while the AUC for predicting long-term MACEs was 0.740. Similarly, the AUC values were 0.815 and 0.819, respectively, when evaluating the short- and long-term mortality rates using the CALLY index. Multivariable Cox regression analysis revealed that a high CALLY index (threshold of 1.50) independently reduced the risk of short-term MACEs in patients with STEMI (hazard ratio [HR] = 0.274, 95 % confidence interval [CI] = 0.121-0.621, P=0.002). Multivariable Cox regression also demonstrated that a high CALLY index (threshold > 0.91) independently reduced the occurrence of long-term MACEs during follow-up in STEMI patients (HR=0.439, 95 % CI=0.292-0.659, P<0.001). Furthermore, multivariate logistic regression analysis revealed that a high CALLY index (threshold > 1.13) independently reduced the risk of severe coronary artery lesions in patients with STEMI (odds ratio = 0.299 [95 % CI=184-0.485], P<0.001). A positive correlation was observed between the CALLY index and the Gensini score (P<0.001).

CONCLUSION

The CALLY index is a novel, convenient, and valuable prognostic indicator exhibiting a protective effect against both short- and long-term MACEs in patients with STEMI, emphasizing the significance of inflammation/nutrition in this patient population.

Non-coding RNAs and angiogenesis in cardiovascular diseases: a comprehensive review

Non-coding RNAs (ncRNAs) have key roles in the etiology of many illnesses, including heart failure, myocardial infarction, stroke, and in physiological processes like angiogenesis. In transcriptional regulatory circuits that control heart growth, signaling, and stress response, as well as remodeling in cardiac disease, ncRNAs have become important players. Studies on ncRNAs and cardiovascular disease have made great progress recently. Here, we go through the functions of non-coding RNAs (ncRNAs) like circular RNAs (circRNAs), and microRNAs (miRNAs) as well as long non-coding RNAs (lncRNAs) in modulating cardiovascular disorders.

IL-1 blockade in cardiovascular disease: an appraisal of the evidence across different inflammatory paradigms

Pre-clinical and clinical studies suggest a role for inflammation in the pathophysiology of cardiovascular (CV) diseases. The NLRP3 (NACHT, leucine-rich repeat, and pyrin domain-containing protein 3) inflammasome is activated during tissue injury and releases interleukin-1β (IL-1β). We describe three paradigms in which the NLRP3 inflammasome and IL-1β contribute to CV diseases. During acute myocardial infarction (AMI), necrotic cell debris, including IL-1α, induce NLRP3 inflammasome activation and further damage the myocardium contributing to heart failure (HF) (acute injury paradigm). In chronic HF, IL-1β is induced by persistent myocardial overload and injury, neurohumoral activation and systemic comorbidities favoring infiltration and activation of immune cells into the myocardium, microvascular inflammation, and a pro-fibrotic response (chronic inflammation paradigm). In recurrent pericarditis, an autoinflammatory response triggered by cell injury and maintained by the NLRP3 inflammasome/IL-1β axis is present (autoinflammatory disease paradigm). Anakinra, recombinant IL-1 receptor antagonist, inhibits the acute inflammatory response in patients with ST elevation myocardial infarction (STEMI) and acute HF. Canakinumab, IL-1β antibody, blunts systemic inflammation and prevents complications of atherosclerosis in stable patients with prior AMI. In chronic HF, anakinra reduces systemic inflammation and improves cardiorespiratory fitness. In recurrent pericarditis, anakinra and rilonacept, a soluble IL-1 receptor chimeric fusion protein blocking IL-1α and IL-1β, treat and prevent acute flares. In conclusion, the NLRP3 inflammasome and IL-1 contribute to the pathophysiology of CV diseases, and IL-1 blockade is beneficial with different roles in the acute injury, chronic inflammation and autoinflammatory disease paradigms. Further research is needed to guide the optimal use of IL-1 blockers in clinical practice.

Prehospital Pulse-Dose Glucocorticoid in ST-Segment Elevation Myocardial Infarction: The PULSE-MI Randomized Clinical Trial

Importance

In patients with ST-segment elevation myocardial infarction (STEMI), acute inflammation is related to the extent of myocardial damage and may increase infarct size. Thus, administration of pulse-dose glucocorticoid in the very early phase of infarction may reduce infarct size.

Objective

To determine the cardioprotective effect of prehospital pulse-dose glucocorticoid in patients with STEMI.

Design, Setting, and Participants

This was a 1:1 investigator-initiated, blinded, placebo-controlled, randomized clinical trial conducted between November 14, 2022, and October 17, 2023, with last follow-up on January 17, 2024. Patients 18 years and older with less than 12 hours of acute chest pain and STEMI were included in the prehospital setting throughout the Region Zealand and Capital Region of Denmark and transferred to Rigshospitalet, Denmark.

Intervention

Patients were randomly allocated to intravenous glucocorticoid (methylprednisolone, 250 mg) or placebo in the prehospital setting.

Main Outcomes and Measures

The primary outcome was final infarct size on cardiac magnetic resonance (CMR) at 3 months. The power calculation was based on an anticipated final infarct size of 13%. Secondary outcomes included CMR outcomes on acute scan and at 3 months, peak of cardiac biomarkers, clinical end points at 3 months, and adverse events.

Results

Of 530 included patients (median [IQR] age, 65 [56-75] years; 418 male [78.9%]) with STEMI, 401 (76%) were assessed for the primary outcome, with 198 patients treated with glucocorticoid and 203 with placebo. Median final infarct size was similar in the treatment groups (glucocorticoid, 5%; IQR, 2%-11% vs placebo, 6%; IQR, 2%-13%; P = .24). Compared with placebo, the glucocorticoid group had smaller acute infarct size (odds ratio, 0.78; 95% CI, 0.61-1.00), less microvascular obstruction (relative risk ratio, 0.83; 95% CI, 0.71-0.99), and greater acute left ventricular ejection fraction (mean difference, 4.44%; 95% CI, 2.01%-6.87%). Other secondary outcomes were similar in both groups.

Conclusions and Relevance

In patients with STEMI, treatment with prehospital pulse-dose glucocorticoid did not reduce final infarct size after 3 months. However, the trial was likely underpowered as the final infarct size was smaller than anticipated. The glucocorticoid group had improved acute parameters compared with placebo.

Trial Registration

ClinicalTrials.gov Identifier: NCT05462730.

The impact of aging on cardiac repair and regeneration

In contrast to neonates and lower organisms, the adult mammalian heart lacks any capacity to regenerate following injury. The vast majority of our understanding of cardiac regeneration is based on research in young animals. Research in aged individuals is rare. This is unfortunate as aging induces many changes in the heart. The first part of this review covers the main technologies being pursued in the cardiac regeneration field and how they are impacted by the aging processes. The second part of the review covers the significant amount of aging-related research that could be used to aid cardiac regeneration. Finally, a perspective is provided to suggest how cardiac regenerative technologies can be improved by addressing aging-related effects.

RNF149 Destabilizes IFNGR1 in Macrophages to Favor Postinfarction Cardiac Repair

BACKGROUND

Macrophage-driven inflammation critically involves in cardiac injury and repair following myocardial infarction (MI). However, the intrinsic mechanisms that halt the immune response of macrophages, which is critical to preserve homeostasis and effective infarct repair, remain to be fully defined. Here, we aimed to determine the ubiquitination-mediated regulatory effects on averting exaggerated inflammatory responses in cardiac macrophages.

METHODS

We used transcriptome analysis of mouse cardiac macrophages and bone marrow-derived macrophages to identify the E3 ubiquitin ligase RNF149 (ring finger protein 149) as a modulator of macrophage response to MI. Employing loss-of-function methodologies, bone marrow transplantation approaches, and adenovirus-mediated RNF149 overexpression in macrophages, we elucidated the functional role of RNF149 in MI. We explored the underlying mechanisms through flow cytometry, transcriptome analysis, immunoprecipitation/mass spectrometry analysis, and functional experiments. RNF149 expression was measured in the cardiac tissues of patients with acute MI and healthy controls.

RESULTS

RNF149 was highly expressed in murine and human cardiac macrophages at the early phase of MI. Knockout of RNF149, transplantation of Rnf149-/- bone marrow, and bone marrow macrophage-specific RNF149-knockdown markedly exacerbated cardiac dysfunction in murine MI models. Conversely, overexpression of RNF149 in macrophages attenuated the ischemia-induced decline in cardiac contractile function. RNF149 deletion increased infiltration of proinflammatory monocytes/macrophages, accompanied by a hastened decline in reparative subsets, leading to aggravation of myocardial apoptosis and impairment of infarct healing. Our data revealed that RNF149 in infiltrated macrophages restricted inflammation by promoting ubiquitylation-dependent proteasomal degradation of IFNGR1 (interferon gamma receptor 1). Loss of IFNGR1 rescued deleterious effects of RNF149 deficiency on MI. We further demonstrated that STAT1 (signal transducer and activator of transcription 1) activation induced Rnf149 transcription, which, in turn, destabilized the IFNGR1 protein to counteract type-II IFN (interferon) signaling, creating a feedback control mechanism to fine-tune macrophage-driven inflammation.

CONCLUSIONS

These findings highlight the significance of RNF149 as a molecular brake on macrophage response to MI and uncover a macrophage-intrinsic posttranslational mechanism essential for maintaining immune homeostasis and facilitating cardiac repair following MI.

Repair of the Infarcted Heart: Cellular Effectors, Molecular Mechanisms and Therapeutic Opportunities

The adult mammalian heart has limited endogenous regenerative capacity and heals through the activation of inflammatory and fibrogenic cascades that ultimately result in the formation of a scar. After infarction, massive cardiomyocyte death releases a broad range of damage-associated molecular patterns that initiate both myocardial and systemic inflammatory responses. TLRs (toll-like receptors) and NLRs (NOD-like receptors) recognize damage-associated molecular patterns (DAMPs) and transduce downstream proinflammatory signals, leading to upregulation of cytokines (such as interleukin-1, TNF-α [tumor necrosis factor-α], and interleukin-6) and chemokines (such as CCL2 [CC chemokine ligand 2]) and recruitment of neutrophils, monocytes, and lymphocytes. Expansion and diversification of cardiac macrophages in the infarcted heart play a major role in the clearance of the infarct from dead cells and the subsequent stimulation of reparative pathways. Efferocytosis triggers the induction and release of anti-inflammatory mediators that restrain the inflammatory reaction and set the stage for the activation of reparative fibroblasts and vascular cells. Growth factor-mediated pathways, neurohumoral cascades, and matricellular proteins deposited in the provisional matrix stimulate fibroblast activation and proliferation and myofibroblast conversion. Deposition of a well-organized collagen-based extracellular matrix network protects the heart from catastrophic rupture and attenuates ventricular dilation. Scar maturation requires stimulation of endogenous signals that inhibit fibroblast activity and prevent excessive fibrosis. Moreover, in the mature scar, infarct neovessels acquire a mural cell coat that contributes to the stabilization of the microvascular network. Excessive, prolonged, or dysregulated inflammatory or fibrogenic cascades accentuate adverse remodeling and dysfunction. Moreover, inflammatory leukocytes and fibroblasts can contribute to arrhythmogenesis. Inflammatory and fibrogenic pathways may be promising therapeutic targets to attenuate heart failure progression and inhibit arrhythmia generation in patients surviving myocardial infarction.

A review of therapeutic approaches for post-infarction left ventricular remodeling

Left ventricular remodeling is an adaptive process initially developed in response to acute myocardial infarction (AMI), but it ends up with negative adverse outcomes such as infarcted wall thinning, ventricular dilation, and cardiac dysfunction. A prolonged excessive inflammatory reaction to cardiomyocytes death and necrosis plays the crucial role in the pathophysiological mechanisms. The pharmacological treatment includes nitroglycerine, β-blockers, ACEi/ARBs, SGLT2i, mineralocorticoid receptor antagonists, and some miscellaneous aspects. Stem cells therapy, CD34+ cells transplantation and gene therapy constitute the promissing therapeutic approaches for post AMI cardiac remodeling, thereby enhancing angiogenesis, cardiomyocytes differenciation and left ventricular function on top of inhibiting apoptosis, inflammation, and collagen deposition. All these lead to reduce infarct size, scar formation and myocardial fibrosis.

Acute Response of the Noninfarcted Myocardium and Surrounding Tissue Assessed by T2 Mapping After STEMI

BACKGROUND

ST-segment elevation myocardial infarction (STEMI) is associated with a systemic and local inflammatory response with edema. However, their role at the tissue level is poorly characterized.

OBJECTIVES

This study aims to characterize T2 values of the noninfarcted myocardium (NIM) and surrounding tissue and to investigate prognostic relevance of higher NIM T2 values after STEMI.

METHODS

A total of 171 consecutive patients with STEMI without prior cardiovascular events who underwent cardiac magnetic resonance after primary percutaneous coronary intervention were analyzed in terms of standard infarct characteristics. Edema of the NIM, liver, spleen, and pectoralis muscle was assessed based on T2 mapping. Follow-up was available for 130 patients. The primary endpoint was major adverse cardiac events (MACE), defined as cardiovascular death, myocardial infarction, unplanned coronary revascularization or rehospitalization for heart failure. The median time from primary percutaneous coronary intervention to cardiac magnetic resonance was 3 days (IQR: 2-5 days).

RESULTS

Higher (above the median value of 45 ms) T2 values in the NIM area were associated with larger infarct size, microvascular obstruction, and left ventricular dysfunction and did not correlate with C-reactive protein, white blood cells, or T2 values of the pectoralis muscle, liver, and spleen. At a median follow-up of 17 months, patients with higher (>45 ms) NIM T2 values had increased risk of MACE (P < 0.001) compared with subjects with NIM T2 values ≤45 ms, mainly caused by a higher rate of myocardial reinfarction (26.3% vs 1.4%; P < 0.001). At multivariable analysis, higher NIM T2 values independently predicted MACE (HR: 2.824 [95% CI: 1.254-6.361]; P = 0.012).

CONCLUSIONS

Higher NIM T2 values after STEMI are independently associated with worse cardiovascular outcomes, mainly because of higher risk of myocardial infarction.

Chronic systemic glucocorticoid therapy is associated with increased risk of major vascular complications and cardiac tamponade after transcatheter aortic valve implantation: a systematic review and meta-analysis

INTRODUCTION

TAVI-related complications, such as conduction disturbances, vascular complications or death may be related to increased inflammatory response. The aim of this study was to elucidate the efficacy and safety of the systemic glucocorticoid therapy regarding the adverse events after TAVI deployment.

EVIDENCE ACQUISITION

We conducted a systemic search of PubMed, a reference list of relevant articles, and Medline. The main efficacy outcomes of interest were all-cause death, cardiac and non-cardiac death, permanent pacemaker implantation (PPM), new left bundle branch block (LBBB), stroke, and myocardial infarction (MI). Safety endpoints were major vascular complications, major bleeding events, and cardiac tamponade.

EVIDENCE SYNTHESIS

A total of 7 studies including data from 3439 patients with a median follow-up was 30 days. Systemic glucocorticoid compared to the control group were associated with an increased risk of non-cardiac death (Relative Risk [RR] 5.90 95%CI [2.95; 11.80], P<0.001) major vascular complications (RR 1.78, 95%CI [1.22 - 2.61], P=0.003) and cardiac tamponade (RR 3.42, 95%CI [1.69 - 6.92], P<0.001). However, there were no differences in all-cause death, cardiac death, new LBBB, stroke, MI, or major bleeding events (all P values >0.05).

CONCLUSIONS

Glucocorticoid therapy before the TAVI procedure was associated with an increase in non-cardiac death, major vascular events and cardiac tamponade. There were no differences in the risk of all-cause death, cardiac death, PPM or LBBB, stroke, or MI.

The role of the NLRP3 inflammasome and pyroptosis in cardiovascular diseases

An intense, stereotyped inflammatory response occurs in response to ischaemic and non-ischaemic injury to the myocardium. The NACHT, LRR and PYD domains-containing protein 3 (NLRP3) inflammasome is a finely regulated macromolecular protein complex that senses the injury and triggers and amplifies the inflammatory response by activation of caspase 1; cleavage of pro-inflammatory cytokines, such as pro-IL-1β and pro-IL-18, to their mature forms; and induction of inflammatory cell death (pyroptosis). Inhibitors of the NLRP3 inflammasome and blockers of IL-1β and IL-18 activity have been shown to reduce injury to the myocardium and pericardium, favour resolution of the inflammation and preserve cardiac function. In this Review, we discuss the components of the NLRP3 inflammasome and how it is formed and activated in various ischaemic and non-ischaemic cardiac pathologies (acute myocardial infarction, cardiac dysfunction and remodelling, atherothrombosis, myocarditis and pericarditis, cardiotoxicity and cardiac sarcoidosis). We also summarize current preclinical and clinical evidence from studies of agents that target the NLRP3 inflammasome and related cytokines.

Circadian Influences on Myocardial Ischemia-Reperfusion Injury and Heart Failure

The impact of circadian rhythms on cardiovascular function and disease development is well established, with numerous studies in genetically modified animals emphasizing the circadian molecular clock's significance in the pathogenesis and pathophysiology of myocardial ischemia and heart failure progression. However, translational preclinical studies targeting the heart's circadian biology are just now emerging and are leading to the development of a novel field of medicine termed circadian medicine. In this review, we explore circadian molecular mechanisms and novel therapies, including (1) intense light, (2) small molecules modulating the circadian mechanism, and (3) chronotherapies such as cardiovascular drugs and meal timings. These promise significant clinical translation in circadian medicine for cardiovascular disease. (4) Additionally, we address the differential functioning of the circadian mechanism in males versus females, emphasizing the consideration of biological sex, gender, and aging in circadian therapies for cardiovascular disease.

Impact of C-reactive protein levels and role of anakinra in patients with ST-elevation myocardial infarction

BACKGROUND

Interleukin-1 blockade with anakinra reduces C-reactive protein (CRP) levels and prevents heart failure (HF) events after ST-segment myocardial infarction (STEMI). The effectiveness of anakinra according to the degree of systemic inflammation in STEMI has not been addressed.

METHODS

We analyzed 139 patients from three Virginia Commonwealth University Anakinra Response Trial randomized clinical trials to assess whether CRP levels predicted HF hospitalization or death in patients with STEMI, and if CRP levels influenced the effects of treatment with anakinra.

RESULTS

CRP cut-off levels for prediction of the composite of death or HF hospitalization for CRP at admission, 3 and 14 days were, respectively 6.45 mg/L (100% of sensitivity and 66.1% specificity), 26 mg/L (100% of sensitivity and 78% specificity) and 9.56 mg/L (100% of sensitivity and 80% specificity). More patients with elevated CRP levels died or had a HF hospitalization (5/47 [11%] vs 0/82 [0%], p = 0.004 for CRP at admission; 5/32 [15.6%] vs 0/92 [0%], p < 0.001 for day 3 and 5/26 [19%] vs 0/89 [0%], p < 0.001 for day 14). A greater number of patients treated with anakinra had low CRP levels at 3 and 14 days compared to placebo (Odds Ratio 0.11 [95% IC 0.04-0.28], p < 0.0001 and OR 0.35 [95% CI 0.14-0.86], p = 0.02, respectively). Anakinra significantly prevented death or HF hospitalization in patients with high inflammatory burden (p = 0.04 for admission, p = 0.24 for day 3, and p = 0.05 for day 14).

CONCLUSION

Patients with elevated CRP had higher incidence of HF hospitalization or death. Anakinra reduced the number of patients with elevated CRP levels and prevented death or HF hospitalization in patients with elevated CRP levels.

Transplantation of induced pluripotent stem cells-derived cardiomyocytes combined with modified Taohong Siwu decoction improved heart repair after myocardial infarction

Objective

This study aimed to study whether modified Taohong Siwu decoction (MTHSWD) combined with human induced pluripotent stem cells-derived cardiomyocytes (iPS-CMs) transplantation can promote cardiac function in myocardial infarction (MI) nude mouse model and explore its possible mechanism.

Methods

The MI mouse model was established by the ligation of left anterior descending coronary artery. After 4 weeks of gavage of MTHSWD combined with iPS-CMs transplantation, the changes in heart function of mice were examined by echocardiography. The histological changes were observed by Masson's trichrome staining. The survival and differentiation of transplanted cells were detected by double immunofluorescence staining of human nuclear antigen (HNA) and cardiac troponin T (cTnT). The number of c-kit-positive cells in the infarct area were evaluated by immunofluorescent staining. The levels of stromal cell-derived factor 1 (SDF-1), stem cell factor (SCF), vascular endothelial growth factor (VEGF) and basic fibroblast growth factor in infarcted myocardium tissues were detected by ELISA.

Results

MTHSWD combined with iPS-CMs transplantation can improve the heart function of MI mice, reduce the infarct size and collagen deposition in infarct area. By immunofluorescence double-label detection of HNA and cTnT, it was found that MTHSWD combined with iPS-CMs transplantation can improve the survival and maturation of iPS-CMs. In addition, MTHSWD combined with iPS-CMs transplantation can activate more endogenous c-kit positive cardiac mesenchymal cells, and significantly increase the content of SDF-1, SCF and VEGF in myocardial tissues.

Conclusions

The combination of MTHSWD with iPS-CMs transplantation promoted cardiac function of nude mice with MI by improving the survival and maturation of iPS-CMs in the infarct area, activating the endogenous c-kit positive cardiac mesenchymal cells, and increasing paracrine.

Response to interleukin-1 blockade with anakinra in women and men with ST-segment elevation myocardial infarction

BACKGROUND

Interleukin-1 blockade with anakinra reduces high-sensitivity C-reactive protein (hsCRP) levels and prevents heart failure (HF) events after ST-segment myocardial infarction (STEMI). Sex-based differences in STEMI patients have been reported, but no data are available regarding response to anakinra.

METHODS

We analyzed the systemic inflammation and composite end-point of new-onset HF or death in women and men with STEMI treated with anakinra from three different Virginia Commonwealth University Anakinra Response Trial (VCUART) randomized clinical trials.

RESULTS

We analyzed 139 patients, 29 (21%) were women while 110 (79%) were men. Baseline hsCRP was higher in women compared to men (8.9 [5.2-13.5] vs. 4.2 [2.1-7.7] mg/L, P<0.001). Eighty-four patients were treated with anakinra (22 [75%] women and 62 [56%] men). The area under the curve of hsCRP (hsCRP-AUC) after 14 days was numerically lower in patients receiving anakinra versus placebo both in men (86 [37-130] vs. 223 [119-374] mg day/L) and in women (73 [46-313] vs. 242 [102-988] mg day/L) (P<0.001 for multiple groups, P for interaction 0.22). The incidence of the composite endpoint was also numerically lower in the anakinra group compared to placebo, both in men (4 [6.4%] vs. 14 [29.1%]) and in women (3 [13.6%] vs. 2 [28.5%]) (P=0.019 for multiple groups, P for interaction 0.44). There were no statistically significant differences between women and men in hsCRP-AUC and death or HF events when comparing separately the anakinra and placebo groups (all P>0.05).

CONCLUSIONS

Women were underrepresented in the VCUART trials, they appeared to have higher hsCRP levels at time of presentation, yet to benefit similar to men by treatment with anakinra in STEMI.

Protective effect of human epicardial adipose-derived stem cells on myocardial injury driven by poly-lactic acid nanopillar array

We investigated if poly-lactic acid (PLA) nanopillar array can trigger the differentiation of human epicardial (ADSCs) (heADSCs) into cardiomyocyte-like cells and explored the effects of these cardiomyocyte-like cells on myocardial infarction (MI) in vivo. PLA nanopillar array (200 nm diameter) and plain PLA film (PLA planar) induced heADSCs were marked with carboxyfluorescein. After 7 days, the expressions of myocardiocyte-specific genes were significantly enhanced in cells seeded on PLA nanopillar array compared with that on PLA planar, especially CACNA1C, KCNH2, and MYL2 genes (p < 0.05). However, the expressions of cardiac troponin T (cTNT), KCNQ1, and KCNA5 were lower than those in PLA planar-induced heADSCs (p < 0.05), whereas GATA4 tended to increase with time. The cells with positively stained α-actinin and cTNT were elevated in heADSCs induced by PLA nanopillar array compared with those induced by PLA planar only (p < 0.05). In vivo experiments showed that cardiac function was improved after injecting PLA-nanopillar array-induced heADSCs into the ischemic heart (p < 0.05, compared with PLA planar + MI group). Furthermore, tyrosine hydroxylase density was significantly lower (p < 0.05). PLA nanopillar array directly drives the differentiation of heADSCs into cardiomyocyte-like cells, and the induced heADSCs exhibit a protective effect on ischemic myocardium by improving cardiac function in MI rats.

Ischemic cardiomyopathy: epidemiology, pathophysiology, outcomes, and therapeutic options

Ischemic cardiomyopathy (ICM) is the most prevalent cause of heart failure (HF) in developed countries, with significant morbidity and mortality, despite constant improvements in the management of coronary artery disease. Current literature on this topic remains fragmented. Therefore, this review aimed to summarize the most recent data on ICM, focusing on its definition, epidemiology, outcomes, and therapeutic options. The most widely accepted definition is represented by a left ventricular dysfunction in the presence of significant coronary artery disease. The prevalence of ICM is largely influenced by age and sex, with older individuals and males being more affected. Its pathophysiology is characterized by plaque buildup, thrombus formation, hypoperfusion, ischemic cell death, and left ventricular remodeling. Despite improvements in therapy, ICM still represents a public health burden, with a 1-year mortality rate of 16% and a 5-year mortality rate of approximately 40% in the USA and Europe. Therefore, optimization of cardiovascular function, prevention of progressive remodeling, reduction of HF symptoms, and improved survival are the main goals of treatment. Therapeutic options for ICM include lifestyle changes, optimal medical therapy, revascularization, device therapy, mechanical circulatory support, and cardiac transplantation. Personalized management strategies and tailored patient care are needed to improve the outcomes of patients with ICM.

An eNAMPT-neutralizing mAb reduces post-infarct myocardial fibrosis and left ventricular dysfunction

Myocardial infarction (MI) triggers adverse ventricular remodeling (VR), cardiac fibrosis, and subsequent heart failure. Extracellular nicotinamide phosphoribosyltransferase (eNAMPT) is postulated to play a significant role in VR processing via activation of the TLR4 inflammatory pathway. We hypothesized that an eNAMPT specific monoclonal antibody (mAb) could target and neutralize overexpressed eNAMPT post-MI and attenuate chronic cardiac inflammation and fibrosis. We investigated humanized ALT-100 and ALT-300 mAb with high eNAMPT-neutralizing capacity in an infarct rat model to test our hypothesis. ALT-300 was 99mTc-labeled to generate 99mTc-ALT-300 for imaging myocardial eNAMPT expression at 2 hours, 1 week, and 4 weeks post-IRI. The eNAMPT-neutralizing ALT-100 mAb (0.4 mg/kg) or saline was administered intraperitoneally at 1 hour and 24 hours post-reperfusion and twice a week for 4 weeks. Cardiac function changes were determined by echocardiography at 3 days and 4 weeks post-IRI. 99mTc-ALT-300 uptake was initially localized to the ischemic area at risk (IAR) of the left ventricle (LV) and subsequently extended to adjacent non-ischemic areas 2 hours to 4 weeks post-IRI. Radioactive uptake (%ID/g) of 99mTc-ALT-300 in the IAR increased from 1 week to 4 weeks (0.54 ± 0.16 vs. 0.78 ± 0.13, P < 0.01). Rats receiving ALT-100 mAb exhibited significantly improved myocardial histopathology and cardiac function at 4 weeks, with a significant reduction in the collagen volume fraction (%LV) compared to controls (21.5 ± 6.1% vs. 29.5 ± 9.9%, P < 0.05). Neutralization of the eNAMPT/TLR4 inflammatory cascade is a promising therapeutic strategy for MI by reducing chronic inflammation, fibrosis, and preserving cardiac function.

Pre-hospital pulse glucocorticoid therapy in patients with ST-segment elevation myocardial infarction transferred for primary percutaneous coronary intervention: a randomized controlled trial (PULSE-MI)

BACKGROUND

Inflammation in ST-segment elevation myocardial infarction (STEMI) is an important contributor to both acute myocardial ischemia and reperfusion injury after primary percutaneous coronary intervention (PCI). Methylprednisolone is a glucocorticoid with potent anti-inflammatory properties with an acute effect and is used as an effective and safe treatment of a wide range of acute diseases. The trial aims to investigate the cardioprotective effects of pulse-dose methylprednisolone administered in the pre-hospital setting in patients with STEMI transferred for primary PCI.

METHODS

This trial is a randomized, blinded, placebo-controlled prospective clinical phase II trial. Inclusion will continue until 378 patients with STEMI have been evaluated for the primary endpoint. Patients will be randomized 1:1 to a bolus of 250 mg methylprednisolone intravenous or matching placebo over a period of 5 min in the pre-hospital setting. All patients with STEMI transferred for primary PCI at Rigshospitalet, Copenhagen University Hospital, Denmark, will be screened for eligibility. The main eligibility criteria are age ≥ 18 years, acute onset of chest pain with < 12 h duration, STEMI on electrocardiogram, no known allergy to glucocorticoids or no previous coronary artery bypass grafting, previous acute myocardial infarction in assumed culprit, or a history with previous maniac/psychotic episodes. Primary outcome is final infarct size measured by late gadolinium enhancement on cardiac magnetic resonance (CMR) 3 months after STEMI. Secondary outcomes comprise key CMR efficacy parameters, clinical endpoints at 3 months, the peak of cardiac biomarkers, and safety.

DISCUSSION

We hypothesize that pulse-dose methylprednisolone administrated in the pre-hospital setting decreases inflammation and thus reduces final infarct size in patients with STEMI treated with primary PCI.

TRIAL REGISTRATION

EU-CT number: 2022-500762-10-00; Submitted May 5, 2022.

CLINICALTRIALS

gov Identifier: NCT05462730; Submitted July 7, 2022, first posted July 18, 2022.

Implications of Activating the ANT2/mTOR/PGC-1α Feedback Loop: Insights into Mitochondria-Mediated Injury in Hypoxic Myocardial Cells

Mitochondrial dysfunction is known to play a critical role in the development of cardiomyocyte death during acute myocardial infarction (AMI). However, the exact mechanisms underlying this dysfunction are still under investigation. Adenine nucleotide translocase 2 (ANT2) is a key functional protein in mitochondria. We aimed at exploring the potential benefits of ANT2 inhibition against AMI. We utilized an oxygen-glucose deprivation (OGD) cell model and an AMI mice model to detect cardiomyocyte injury. We observed elevated levels of reactive oxygen species (ROS), disrupted mitochondrial membrane potential (MMP), and increased apoptosis due to the overexpression of ANT2. Additionally, we discovered that ANT2 is involved in myocardial apoptosis by activating the mTOR (mechanistic target of rapamycin kinase)-dependent PGC-1α (PPARG coactivator 1 alpha) pathway, establishing a novel feedback loop during AMI. In our experiments with AC16 cells under OGD conditions, we observed protective effects when transfected with ANT2 siRNA and miR-1203. Importantly, the overexpression of ANT2 counteracted the protective effect resulting from miR-1203 upregulation in OGD-induced AC16 cells. All these results supported that the inhibition of ANT2 could alleviate myocardial cell injury under OGD conditions. Based on these findings, we propose that RNA interference (RNAi) technology, specifically miRNA and siRNA, holds therapeutic potential by activating the ANT2/mTOR/PGC-1α feedback loop. This activation could help mitigate mitochondria-mediated injury in the context of AMI. These insights may contribute to the development of future clinical strategies for AMI.

Downregulation of apoptotic repressor AVEN exacerbates cardiac injury after myocardial infarction

Myocardial infarction (MI) is a leading cause of heart failure (HF), associated with morbidity and mortality worldwide. As an essential part of gene expression regulation, the role of alternative polyadenylation (APA) in post-MI HF remains elusive. Here, we revealed a global, APA-mediated, 3' untranslated region (3' UTR)-lengthening pattern in both human and murine post-MI HF samples. Furthermore, the 3' UTR of apoptotic repressor gene, AVEN, is lengthened after MI, contributing to its downregulation. AVEN knockdown increased cardiomyocyte apoptosis, whereas restoration of AVEN expression substantially improved cardiac function. Mechanistically, AVEN 3' UTR lengthening provides additional binding sites for miR-30b-5p and miR-30c-5p, thus reducing AVEN expression. Additionally, PABPN1 (poly(A)-binding protein 1) was identified as a potential regulator of AVEN 3' UTR lengthening after MI. Altogether, our findings revealed APA as a unique mechanism regulating cardiac injury in response to MI and also indicated that the APA-regulated gene, AVEN, holds great potential as a critical therapeutic target for treating post-MI HF.

Progranulin deficiency exacerbates cardiac remodeling after myocardial infarction

Myocardial infarction (MI) is a lethal disease that causes irreversible cardiomyocyte death and subsequent cardiovascular remodeling. We have previously shown that the administration of recombinant progranulin (PGRN) protects against myocardial ischemia and reperfusion injury. However, the post-MI role of PGRN remains unclear. In the present study, we investigated the effects of PGRN deficiency on cardiac remodeling after MI. Wild-type and PGRN-knockout mice were subjected to MI by ligation of the left coronary artery for histological, electrophysiological, and protein expression analysis. Cardiac macrophage subpopulations were analyzed by flow cytometry. Bone marrow-derived macrophages (BMDMs) were acquired and treated with LPS + IFN-γ and IL-4 to evaluate mRNA levels and phagocytic ability. PGRN expression was gradually increased in the whole heart at 1, 3, and 7 days after MI. Macrophages abundantly expressed PGRN at the border areas at 3 days post-MI. PGRN-knockout mice showed higher mortality, increased LV fibrosis, and severe arrhythmia following MI. PGRN deficiency increased the levels of CD206 and MerTK expression and macrophage infiltration in the infarcted myocardium, which was attributed to a larger subpopulation of cardiac CCR2+ Ly6Clow CD11b+ macrophages. PGRN-deficient BMDMs exhibited higher TGF-β, IL-4R, and lower IL-1β, IL-10 and increased acute phagocytosis following stimulation of LPS and IFN-γ. PGRN deficiency reduced survival and increased cardiac fibrosis following MI with the induction of abnormal subpopulation of cardiac macrophages early after MI, thereby providing insight into the relationship between properly initiating cardiac repair and macrophage polarization after MI.

The role of miR1 and miR133a in new-onset atrial fibrillation after acute myocardial infarction

BACKGROUND

The development of new-onset atrial fibrillation (NOAF) after acute myocardial infarction (AMI) is a clinical complication that requires a better understanding of the causative risk factors. This study aimed to explore the risk factors and the expression and function of miR-1 and miR-133a in new atrial fibrillation after AMI.

METHODS

We collected clinical data from 172 patients with AMI treated with emergency percutaneous coronary intervention (PCI) between October 2021 and October 2022. Independent predictors of NOAF were determined using binary logistic univariate and multivariate regression analyses. The predictive value of NOAF was assessed using the area under the receiver operating characteristic (ROC) curve for related risk factors. In total, 172 venous blood samples were collected preoperatively and on the first day postoperatively; the expression levels of miR-1 and miR-133a were determined using the polymerase chain reaction. The clinical significance of miR-1 and miR-133a expression levels was determined by Spearman correlation analysis.

RESULTS

The Glasgow prognostic score, left atrial diameter, and infarct area were significant independent risk factors for NOAF after AMI. We observed that the expression levels of miR-1 and miR-133a were significantly higher in the NOAF group than in the non-NOAF group. On postoperative day 1, strong associations were found between miR-133a expression levels and the neutrophil ratio and between miR-1 expression levels and an increased left atrial diameter.

CONCLUSIONS

Our findings indicate that the mechanism of NOAF after AMI may include an inflammatory response associated with an increased miR-1-related mechanism. Conversely, miR-133a could play a protective role in this clinical condition.

Promising Therapeutic Treatments for Cardiac Fibrosis: Herbal Plants and Their Extracts

Cardiac fibrosis is closely associated with multiple heart diseases, which are a prominent health issue in the global world. Neurohormones and cytokines play indispensable roles in cardiac fibrosis. Many signaling pathways participate in cardiac fibrosis as well. Cardiac fibrosis is due to impaired degradation of collagen and impaired fibroblast activation, and collagen accumulation results in increasing heart stiffness and inharmonious activity, leading to structure alterations and finally cardiac function decline. Herbal plants have been applied in traditional medicines for thousands of years. Because of their naturality, they have attracted much attention for use in resisting cardiac fibrosis in recent years. This review sheds light on several extracts from herbal plants, which are promising therapeutics for reversing cardiac fibrosis.

Phloretin ameliorates heart function after myocardial infarction via NLRP3/Caspase-1/IL-1β signaling

OBJECTIVES/AIMS

Inflammation is crucial in structural and electrical remodeling after myocardial infarction (MI), affecting cardiac pump function and conduction pathways. Phloretin possesses an anti-inflammation role by inhibiting the NLRP3/Caspase-1/IL-1β pathway. However, the effects of Phloretin on cardiac contractile and electrical conduction function after MI remained unclear. Therefore, we aimed to investigate the potential role of Phloretin in a rat model of MI.

METHODS

Rats were assigned into four groups: Sham, Sham+Phloretin, MI and MI+Phloretin, with ad libitum food and water. In the MI and MI+Phloretin groups, the left anterior descending coronary artery was occluded for 4 weeks, while the Sham and Sham+Phloretin groups received sham operation. The Sham+Phloretin group and the MI+Phloretin group received oral administration of Phloretin. In vitro, H9c2 cells were subjected to hypoxic conditions to simulate an MI model, with Phloretin for 24 h. Cardiac electrophysiological properties were assessed following MI, including the effective refractory period (ERP), action potential duration (APD)90 and ventricular fibrillation (VF) incidence. Echocardiography evaluated left ventricular ejection fraction (LVEF), left ventricular fraction shortening (LVFS), left ventricular internal diameter at end-diastole (LVIDd), left ventricular internal diameter at end-systole (LVIDs), left ventricular end-systolic volume (LVESV) and left ventricular end-diastolic volume (LVEDV) to assess cardiac function. Serum type B natriuretic peptide (BNP) level was applied to evaluate the degree of Heart failure (HF). The fibrosis area and severity were assessed by Masson staining and protein expression levels of collagen 3, collagen 1, TGF-β and α-SMA. Western blot analysis estimated the protein expression levels of NLRP3, Pro Caspase-1, Caspase-1, ASC, IL-18, IL-1β, pp38, p38, and Connexin43(Cx43) to elucidate the influence of inflammation on electrical remodeling after MI.

RESULTS

Our findings demonstrate that Phloretin inhibits the NLRP3/Caspase-1/IL-1β pathway, leading to the upregulation of Cx43 by limiting p38 phosphorylation, which further decreases susceptibility to ventricular arrhythmias (VAs). Additionally, Phloretin attenuated fibrosis by inhibiting inflammation to prevent HF. In vitro experiments also provided strong evidence supporting the inhibitory effects of Phloretin on the NLRP3/Caspase-1/IL-1β pathway.

CONCLUSION

Our results suggest that Phloretin could suppress the NLRP3/Caspase-1/IL-1β pathway to reverse structural and electrical remodeling after MI to prevent the occurrence of VAs and HF.

Extracellular Matrix/Glycopeptide Hybrid Hydrogel as an Immunomodulatory Niche for Endogenous Cardiac Repair after Myocardial Infarction

The treatment of myocardial infarction (MI) remains a substantial challenge due to excessive inflammation, massive cell death, and restricted regenerative potential, leading to maladaptive healing process and eventually heart failure. Current strategies of regulating inflammation or improving cardiac tissue regeneration have limited success. Herein, a hybrid hydrogel coassembled by acellular cardiac extracellular matrix (ECM) and immunomodulatory glycopeptide is developed for endogenous tissue regeneration after MI. The hydrogel constructs a niche recapitulating the architecture of native ECM for attracting host cell homing, controlling macrophage differentiation via glycopeptide unit, and promoting endotheliocyte proliferation by enhancing the macrophage-endotheliocyte crosstalk, which coordinate the innate healing mechanism for cardiac tissue regeneration. In a rodent MI model, the hybrid hydrogel successfully orchestrates a proreparative response indicated by enhanced M2 macrophage polarization, increased angiogenesis, and improved cardiomyocyte survival, which alleviates infarct size, improves wall thicknesses, and enhances cardiac contractility. Furthermore, the safety and effectiveness of the hydrogel are demonstrated in a porcine MI model, wherein proteomics verifies the regulation of immune response, proangiogenesis, and accelerated healing process. Collectively, the injectable composite hydrogel serving as an immunomodulatory niche for promoting cell homing and proliferation, inflammation modulation, tissue remodeling, and function restoration provides an effective strategy for endogenous cardiac repair.

Potential diagnostic biomarkers: 6 cuproptosis- and ferroptosis-related genes linking immune infiltration in acute myocardial infarction

The current diagnostic biomarkers of acute myocardial infarction (AMI), troponins, lack specificity and exist as false positives in other non-cardiac diseases. Previous studies revealed that cuproptosis, ferroptosis, and immune infiltration are all involved in the development of AMI. We hypothesize that combining the analysis of cuproptosis, ferroptosis, and immune infiltration in AMI will help identify more precise diagnostic biomarkers. The results showed that a total of 19 cuproptosis- and ferroptosis-related genes (CFRGs) were differentially expressed between the healthy and AMI groups. Functional enrichment analysis showed that the differential CFRGs were mostly enriched in biological processes related to oxidative stress and the inflammatory response. The immune infiltration status analyzed by ssGSEA found elevated levels of macrophages, neutrophils, and CCR in AMI. Then, we screened 6 immune-related CFRGs (CXCL2, DDIT3, DUSP1, CDKN1A, TLR4, STAT3) to construct a nomogram for predicting AMI and validated it in the GSE109048 dataset. Moreover, we also identified 5 pivotal miRNAs and 10 candidate drugs that target the 6 feature genes. Finally, RT-qPCR analysis verified that all 6 feature genes were upregulated in both animals and patients. In conclusion, our study reveals the significance of immune-related CFRGs in AMI and provides new insights for AMI diagnosis and treatment.

Comparison of Safety and Biological Efficacy of Anakinra (Kineret) Dispensed in Polycarbonate Plastic versus Borosilicate Glass Syringes: A Patient-Level Analysis of VCUART2 and VCUART3 Clinical Trials

Anakinra is a recombinant human interleukin-1 receptor antagonist approved for the treatment of inflammatory diseases. Kineret is available as a solution prepared in a borosilicate glass syringe. For implementing a placebo-controlled double-blind randomized clinical trial, anakinra is commonly transferred into plastic syringes. However, there is limited data on anakinra's stability in polycarbonate syringes. We described the results of our previous studies on the use of anakinra in glass (VCUART3) versus plastic syringes (VCUART2) compared with placebo. These studies were conducted in patients with ST-segment elevation myocardial infarction (STEMI), and we assessed the anti-inflammatory effects of anakinra versus placebo by comparing the area under the curve for high-sensitivity cardiac reactive protein (AUC-CRP) levels during the first 14 days of STEMI, its clinical effects on heart failure (HF) hospitalization, cardiovascular death, or new diagnosis of HF as well as adverse events profile between groups. The levels of AUC-CRP were 75 (50-255 mg·day/l) for anakinra in plastic syringes versus 255 (116-592 mg·day/l) in placebo and 60 (24-139 mg·day/l) and 86 (43-123 mg·day/l) for anakinra once and twice daily in glass syringes, respectively, compared with placebo 214 (131-394 mg·day/l). The rate of adverse events was also comparable between groups. There were no differences in the rate of HF hospitalization or cardiovascular death in patients who received anakinra in plastic or glass syringes. Fewer cases of new-onset heart failure occurred in patients receiving anakinra in plastic or glass syringes compared with placebo. Anakinra stored in plastic (polycarbonate) syringes provides comparable biologic and clinical effect to glass (borosilicate) syringes. SIGNIFICANCE STATEMENT: Anakinra (Kineret) 100 mg administered subcutaneously in patients with ST-segment elevation myocardial infarction (STEMI) for a duration of up to 14 days appears to have comparable safety and biological efficacy signals when delivered in prefilled glass or transferred into plastic polycarbonate syringes. This may have important implications for the feasibility of designing clinical trials in STEMI and other clinical conditions.

Clinical and Pharmacological Implications of Time to Treatment with Interleukin-1 Blockade in ST-Segment Elevation Myocardial Infarction

Interleukin-1 (IL-1) blockade with anakinra given within 12 hours from reperfusion has been shown to reduce the inflammatory response as well as prevent heart failure (HF) events in patients with STEMI. We sought to determine whether time-to-treatment influences the efficacy of anakinra on systemic inflammation and incidence of HF events in patients with STEMI. We divided the cohort in two groups base6d on the median time from percutaneous coronary intervention (PCI) to investigational drug, and analyzed the effects of anakinra on the area-under-the-curve for C reactive protein (AUC-CRP) and on incidence of the composite endpoint of death or new onset HF. We analyzed data from 139 patients: 84 (60%) treated with anakinra and 55 (40%) with placebo. The median time from PCI to investigational treatment was 271 (182-391) minutes. The AUC-CRP was significantly higher in patients receiving placebo versus anakinra both in those with time from PCI to treatment <271 minutes (222.6 [103.9-325.2] vs. 78.4 [44.3-131.2], P < 0.001) and those with time from PCI to treatment ≥271 minute (235.2 [131.4-603.4] vs. 75.5 [38.9-171.9], P < 0.001) (P > 0.05 for interaction). Anakinra significantly reduced the combined endpoint of death or new onset HF in patients with time from PCI to treatment <271 minutes (5 [11%] vs. 9n[36%], log-rank χ 2 5.985, P = 0.014) as well as in patients with time from PCI to drug ≥271 minutes (2n[5%] vs. 7 [23%], log-rank χ 2 3.995, P = 0.046) (P > 0.05 for interaction). IL-1 blockade with anakinra blunts the acute systemic inflammatory response and prevents HF events independent of time-to-treatment. SIGNIFICANCE STATEMENT: In patients with ST segment elevation presenting within 12 hours of pain onset and treated within 12 hours of reperfusion, interleukin-1 blockade with anakinra blunts the acute systemic inflammatory response, a surrogate of interleukin-1 activity, and prevents heart failure events independent of time-to-treatment.

The relationship between C-reactive protein to lymphocyte ratio and the prevalence of myocardial infarction in US adults: A cross-sectional study

Objective

C-reactive protein to lymphocyte ratio (CLR) has been identified as a novel inflammatory biomarker. However, the role of CLR in myocardial infarction is unclear. Thus, this study designs to investigate the association of CLR with the prevalence of myocardial infarction in a large multiracial population in the United States.

Methods

Participants from the National Health and Nutrition Examination Survey (NHANES) 2017-March 2020 Pre-pandemic were included in this cross-sectional study. Multivariable regression and subgroup analyses, controlling for demographic variables, were performed to examine the association between CLR and its quintiles and myocardial infarction. A smooth curve fitting was used to model the non-linear relationship between them.

Results

A total of 12,615 participants aged ≥18 years were recruited, of whom 609 (4.83%) self-reported a history of myocardial infarction. Compared to those in the lowest quartile of ln-transformed CLR (Q1), the myocardial infarction risks for subjects in Q2, Q3, and Q4 were 1.64, 1.71, and 1.79 times, respectively. Obvious upward trends were observed when ln-transformed CLR increased (P for trend <0.01). In continuous analyses, the fully adjusted odds ratios (OR) for myocardial infarction prevalence per ln-transformed increment in CLR was 1.46 (95% CI: 1.16-1.84, P < 0.01). Furthermore, a linear association was detected for ln-transformed CLR with the risk of myocardial infarction. Interaction test showed that the effect of CLR on myocardial infarction was significantly affected by age (P for interaction = 0.04).

Conclusions

Data from a large, cross-sectional cohort program show that CLR is positively associated with myocardial infarction prevalence. Our findings highlight that CLR may be a novel inflammation warning biomarker for myocardial infarction.

Effects of atorvastatin and rosuvastatin on dysfunctional coronary circulation in patients with ST-segment elevation myocardial infarction

OBJECTIVE

Evidence of therapy for dysfunctional coronary circulation in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (pPCI) is limited. This study was performed to compare the effects of atorvastatin and rosuvastatin on dysfunctional coronary circulation.

METHODS

This retrospective study enrolled 597 consecutive patients with STEMI who underwent pPCI in 3 centers from June 2016 to December 2019. Dysfunctional coronary circulation was defined by the thrombolysis in myocardial infarction (TIMI) grade and the TIMI myocardial perfusion grade (TMPG). Logistic regression analysis was used to evaluate the impact of different statin types on dysfunctional coronary circulation.

RESULTS

The incidence of TIMI no/slow reflow did not differ between the two groups, but the incidence of TMPG no/slow reflow was significantly lower in the atorvastatin than rosuvastatin group (44.58% vs. 57.69%, respectively). After multivariate adjustment, the odds ratio with 95% confidence interval of rosuvastatin was 1.72 (1.17-2.52) for after pretreatment TMPG no/slow reflow and 1.73 (1.16-2.58) for after stenting TMPG no/slow reflow. Atorvastatin and rosuvastatin showed no significant differences in clinical outcomes during hospitalization.

CONCLUSIONS

Compared with rosuvastatin, atorvastatin was associated with better coronary microcirculatory perfusion in patients with STEMI who underwent pPCI.

Prognostic significance of non-infarcted myocardium correlated with microvascular impairment evaluated dynamically by native T1 mapping

OBJECTIVES

This study aimed to investigate the influence of microvascular impairment on myocardial characteristic alterations in remote myocardium at multiple time points, and its prognostic significance after acute ST-segment elevation myocardial infarction (STEMI).

METHODS

Patients were enrolled prospectively and performed CMR at baseline, 30 days, and 6 months. The primary endpoint was major adverse cardiac events (MACE): death, myocardial reinfarction, malignant arrhythmia, and hospitalization for heart failure. Cox proportional hazards regression modeling was analyzed to estimate the correlation between T1 mapping of remote myocardium and MACE in patients with and without microvascular obstruction (MVO).

RESULTS

A total of 135 patients (mean age 60.72 years; 12.70% female, median follow-up 510 days) were included, of whom 86 (63.70%) had MVO and 26 (19.26%) with MACE occurred in patients. Native T1 values of remote myocardium changed dynamically. At 1 week and 30 days, T1 values of remote myocardium in the group with MVO were higher than those without MVO (p = 0.030 and p = 0.001, respectively). In multivariable cox regression analysis of 135 patients, native_1w T1 (HR 1.03, 95%CI 1.01-1.04, p = 0.002), native_30D T1 (HR 1.05, 95%CI 1.03-1.07, p < 0.001) and LGE (HR 1.10, 95%CI 1.05-1.15, p < 0.001) were joint independent predictors of MACE. In multivariable cox regression analysis of 86 patients with MVO, native_30D T1 (HR 1.05, 95%CI 1.04-1.07, p < 0.001) and LGE (HR 1.10, 95%CI 1.05-1.15, p < 0.001) were joint independent predictors of MACE.

CONCLUSIONS

The evolution of native T1 in remote myocardium was associated with the extent of microvascular impairment after reperfusion injury. In patients with MVO, native_30D T1 and LGE were joint independent predictors of MACE.

Effects of sacubitril/valsartan on cardiac reverse remodeling and cardiac resynchronization in patients with acute myocardial infarction

INTRODUCTION

In 2014, the PARADIGM-HF trial (Prospective Comparison of ARNI with ACEI to Determine Impact on Global Mortality and Morbidity in Heart Failure) has shown that sacubitril/valsartan can reduce the risk of hospitalization and death from cardiovascular causes more effectively than enalapril (an ACEI) in heart failure patients with reduced ejection fraction (HFrEF). Similarly, the PARADIGM-HF trial (Comparison of Sacubitril-Valsartan vs. Enalapril on Effect on NT-proBNP in Patients Stabilized from an Acute Heart Failure Episode) came to similar conclusions and extended the PARADIGM-HF trial results in 2019. Since then, numerous new studies have provided further insight in HFrEF, sacubitril/valsartan can reduce N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels, increase left ventricular ejection fraction (LVEF), reverse ventricular remodeling, and reduce other non-fatal manifestations of clinical deterioration as compared to ACEI/ARB. However, few trials have compared the effects of these drugs in patients shortly after AMI. Therefore, it is necessary to further explore the clinical efficacy and safety of sacubitril/valsartan vs. valsartan in patients with AMI.

METHODS

We conducted an open-label, prospective, randomized controlled trial to determine the superiority in ameliorating ventricular remodeling and preventing of heart failure in patients with AMI after percutaneous coronary intervention (PCI), 148 patients were randomly assigned (85 to sacubitril/valsartan and 63 to valsartan).

RESULTS

LAV, LVDV, and LVSV were all decreased in the sacubitril/valsartan group when compared with before treatment, but there was no difference between the sacubitril/valsartan group and the valsartan group. In addition, compared with before treatment in the sacubitril/valsartan group, the heart global work index (GWI) and the global work efficiency (GWE) increased, while the heart global wasted work (GWW) decreased. Patients in the sacubitril/valsartan group have similar MACE and adverse side effects to those in the valsartan group.

CONCLUSION

Sacubitril/valsartan has the same performance as valsartan in inhibiting ventricular remodeling and preventing heart failure after PCI in patients with AMI, and its clinical application is safe. It provides a clinical foundation for the application of sacubitril/valsartan in patients with AMI.

Adenosine kinase promotes post-infarction cardiac repair by epigenetically maintaining reparative macrophage phenotype

Pro-inflammatory and reparative macrophages are crucial in clearing necrotic myocardium and promoting cardiac repair after myocardial infarction (MI), respectively. Extracellular adenosine has been demonstrated to modulate macrophage polarization through adenosine receptors. However, the role of intracellular adenosine in macrophage polarization has not been explored and adenosine kinase (ADK) is a major enzyme regulating intracellular adenosine levels. Here, we aimed to elucidate the role of ADK in macrophage polarization and its subsequent impact on MI. We demonstrated that ADK was upregulated in bone marrow-derived macrophages (BMDMs) after IL-4 treatment and was highly expressed in the infarct area at day 7 post-MI, especially in macrophages. Compared with wild-type mice, myeloid-specific Adk knockout mice showed increased infarct size, limited myofibroblast differentiation, reduced collagen deposition and more severe cardiac dysfunction after MI, which was related to impaired reparative macrophage phenotype in MI tissue. We found that ADK deletion or inhibition significantly decreased the expression of reparative genes, such as Arg1, Ym1, Fizz1, and Cd206 in BMDMs after IL-4 treatment. The increased intracellular adenosine due to Adk deletion inhibited transmethylation reactions and decreased the trimethylation of H3K4 in BMDMs after IL-4 treatment. Mechanistically, we demonstrated that Adk deletion suppressed reparative macrophage phenotype through decreased IRF4 expression, which resulted from reduced levels of H3K4me3 on the Irf4 promotor. Together, our study reveals that ADK exerts a protective effect against MI by promoting reparative macrophage polarization through epigenetic mechanisms.

Targeting regulatory T cells for cardiovascular diseases

Cardiovascular diseases (CVDs) are the leading cause of death and disability worldwide. The CVDs are accompanied by inflammatory progression, resulting in innate and adaptive immune responses. Regulatory T cells (Tregs) have an immunosuppressive function and are one of the subsets of CD4⁺T cells that play a crucial role in inflammatory diseases. Whether using Tregs as a biomarker for CVDs or targeting Tregs to exert cardioprotective functions by regulating immune balance, suppressing inflammation, suppressing cardiac and vascular remodeling, mediating immune tolerance, and promoting cardiac regeneration in the treatment of CVDs has become an emerging research focus. However, Tregs have plasticity, and this plastic Tregs lose immunosuppressive function and produce toxic effects on target organs in some diseases. This review aims to provide an overview of Tregs' role and related mechanisms in CVDs, and reports on the research of plasticity Tregs in CVDs, to lay a foundation for further studies targeting Tregs in the prevention and treatment of CVDs.

Device-Based Approaches Targeting Cardioprotection in Myocardial Infarction: The Expanding Armamentarium of Innovative Strategies

Coronary reperfusion therapy has played a pivotal role for reducing mortality and heart failure after acute myocardial infarction. Although several adjunctive approaches have been studied for reducing infarct size further, both ischemia-reperfusion injury and microvascular obstruction are still major contributors to both early and late clinical events after acute myocardial infarction. The progress in the field of cardioprotection has found several promising proof-of-concept preclinical studies. However, translation from bench to bedside has not been very successful. This comprehensive review discusses the importance of infarct size as a driver of clinical outcomes post-acute myocardial infarction and summarizes recent novel device-based approaches for infarct size reduction. Device-based interventions including mechanical cardiac unloading, myocardial cooling, coronary sinus interventions, supersaturated oxygen therapy, and vagal stimulation are discussed. Many of these approaches can modify ischemic myocardial biology before reperfusion and offer unique opportunities to target ischemia-reperfusion injury.

Suppression of lysosomal-associated protein transmembrane 5 ameliorates cardiac function and inflammatory response by inhibiting the nuclear factor-kappa B (NF-κB) pathway after myocardial infarction in mice

Myocardial infarction (MI) as the remarkable presentation of coronary artery disease is still a reason for morbidity and mortality in worldwide. Lysosomal-associated protein transmembrane 5 (LAPTM5) is a lysosomal-related protein found in hematopoietic tissues and has been confirmed as a positive regulator of pro-inflammatory pathways in macrophages. However, the role of LAPTM5 in MI remains unknown. In this study, we found that both mRNA and protein expression levels of LAPTM5 were significantly elevated in MI mice. Suppression of LAPTM5 in myocardial tissues decreased cardiac fibrosis and improved cardiac function after MI. At the molecular level, downregulated LAPTM5 dramatically suppressed the macrophage activation and inflammatory response via inhibiting the activation of the nuclear factor-kappa B (NF-κB) pathway. Collectively, suppression of LAPTM5 in myocardial tissues inhibits the pro-inflammatory response and the cardiac dysfunction caused by MI. This study indicated that LAPTM5 as a pro-inflammatory factor plays a crucial role in MI disease.

Stress hyperglycemia ratio and neutrophil to lymphocyte ratio are reliable predictors of new-onset atrial fibrillation in patients with acute myocardial infarction

Background

The occurrence of new-onset atrial fibrillation (NOAF) post-acute myocardial infarction (AMI) is associated with worse outcomes. In this study, we sought to assess the predictive effect of stress hyperglycemia ratio (SHR) and neutrophil to lymphocyte ratio (NLR) to predict NOAF in patients with AMI.

Materials and methods

We recruited 3,194 individuals with AMI but free of atrial fibrillation (AF). AMI cases were stratified into groups according to SHR and NLR quartiles and were further categorized based on diabetes status. High SHR and high NLR were defined as the highest quartile of SHR and NLR. A nomogram incorporating risk factors for NOAF was constructed using multivariate logistic regression analyses. The performance of the novel nomogram was tested for predictive performance, agreement between the actual and predicted probability, and clinical utility using area under the curve (AUC), bootstrapped calibration curves, and decision curve analysis, respectively.

Result

A total of 245 (7.67%) patients developed NOAF post-AMI. The NOAF cases had higher values of SHR and NLR than non-NOAF patients after AMI regardless of diabetes status. After adjusting for potential confounders, high SHR and NLR were independently associated with NOAF post-AMI. Moreover, the novel nomogram incorporating high NLR and high SHR for NOAF risk estimation in patients with AMI showed satisfactory performance assessed by the AUC, calibration curves, decision curve analysis.

Conclusion

SHR and NLR were independently associated with NOAF in AMI patients. The constructed novel nomogram that incorporates SHR and NLR might assist in NOAF risk stratification post-AMI.

Clinical characteristics and risk factors of in-hospital gastrointestinal bleeding in patients with acute myocardial infarction

Background

Gastrointestinal bleeding (GIB) is one of the most serious complications of acute myocardial infarction (AMI) and is correlated with poor outcomes.

Objective

To evaluate the prevalence, risk factors and in-hospital mortality of GIB in patients with AMI.

Methods

This observational case-control study retrospectively enrolled consecutive patients with AMI from the Department of Cardiovascular Medicine and Cardiovascular Surgery of the First Affiliated Hospital of Xi'an Jiaotong University from January 2015 to December 2020. GIB after AMI was identified by International Classification of Diseases (ICD) codes from inpatient medical settings and validated by medical record review. AMI patients without GIB were accordingly classified as the control group. Propensity score matching (PSM) was used to match with the GIB group and the control group. All anonymized clinical data were provided by the Biobank of the First Affiliated Hospital of Xi'an Jiaotong University.

Results

A total of 5,868 AMI patients were enrolled, 0.87% (51/5,868) of whom developed GIB after AMI. On the univariate analysis, history of diabetes, chronic kidney disease, Killip IV, a lower hemoglobin concentration, a higher serum level of creatinine, blood urea nitrogen and D-dimer were closely associated with the risk of GIB (P < 0.05). On the multivariable analysis, a lower hemoglobin concentration (OR: 0.93, 95% CI: 0.89–0.96, P < 0.001) was independently associated with the risk of GIB. Patients with GIB had a much higher in-hospital mortality rate than those without GIB (14.3 vs. 2.1%, P = 0.047). In-hospital mortality among patients with GIB after AMI appeared to be associated with a decreased hemoglobin concentration (OR: 0.93, 95% CI: 0.86–0.99, P = 0.045) and Killip IV (OR: 51.59, 95% CI: 2.65–1,005.30, P = 0.009).

Conclusion

The history of diabetes, poor renal function and heart failure were associated with the high risk of GIB in patients experiencing AMI. The in-hospital mortality in patients with AMI complicating GIB was higher than that in patients without GIB and was associated with a decreased hemoglobin concentration and high Killip classification.