Advances in Nanoparticles in the Prevention and Treatment of Myocardial Infarction.

Myocardial infarction (MI) is one of the most prevalent types of cardiovascular disease. During MI, myocardial cells become ischemic and necrotic due to inadequate blood perfusion, leading to irreversible damage to the heart. Despite the development of therapeutic strategies for the prevention and treatment of MI, their effects are still unsatisfactory. Nanoparticles represent a new strategy for the pre-treatment and treatment of MI, and novel multifunctional nanoparticles with preventive and therapeutic capabilities hold promise for the prevention and treatment of this disease. This review summarizes the common types and properties of nanoparticles, and focuses on the research progress of nanoparticles for the prevention and treatment of MI.

Pharmacological inhibition of RUNX1 reduces infarct size after acute myocardial infarction in rats and underlying mechanism revealed by proteomics implicates repressed cathepsin levels.

Myocardial infarction (MI) results in prolonged ischemia and the subsequent cell death leads to heart failure which is linked to increased deaths or hospitalizations. New therapeutic targets are urgently needed to prevent cell death and reduce infarct size among patients with MI. Runt-related transcription factor-1 (RUNX1) is a master-regulator transcription factor intensively studied in the hematopoietic field. Recent evidence showed that RUNX1 has a critical role in cardiomyocytes post-MI. The increased RUNX1 expression in the border zone of the infarct heart contributes to decreased cardiac contractile function and can be therapeutically targeted to protect against adverse cardiac remodelling. This study sought to investigate whether pharmacological inhibition of RUNX1 function has an impact on infarct size following MI. In this work we demonstrate that inhibiting RUNX1 with a small molecule inhibitor (Ro5-3335) reduces infarct size in an in vivo rat model of acute MI. Proteomics study using data-independent acquisition method identified increased cathepsin levels in the border zone myocardium following MI, whereas heart samples treated by RUNX1 inhibitor present decreased cathepsin levels. Cathepsins are lysosomal proteases which have been shown to orchestrate multiple cell death pathways. Our data illustrate that inhibition of RUNX1 leads to reduced infarct size which is associated with the suppression of cathepsin expression. This study demonstrates that pharmacologically antagonizing RUNX1 reduces infarct size in a rat model of acute MI and unveils a link between RUNX1 and cathepsin-mediated cell death, suggesting that RUNX1 is a novel therapeutic target that could be exploited clinically to limit infarct size after an acute MI.

Effects of genetically proxied lipid-lowering drugs on acute myocardial infarction: a drug-target mendelian randomization study.

OBJECTIVE: High low-density-lipoprotein (LDL) cholesterol has been associated with an increased risk of coronary artery diseases (CAD) including acute myocardial infarction (AMI). However, whether lipids lowering drug treatment is causally associated with decreased risk of AMI remains largely unknown. We used Mendelian randomization (MR) to evaluate the influence of genetic variation affecting the function of lipid-lowering drug targets on AMI. METHODS: Single-nucleotide polymorphisms (SNPs) associated with lipids as instruments were extracted from the Global Lipids Genetics Consortium (GLGC). The genome-wide association study (GWAS) data for AMI were obtained from UK Biobank. Two sample MR analysis was used to study the associations between high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, and triglycerides (TG) with AMI (n = 3,927). Genetic variants associated with LDL cholesterol at or near drug target gene were used to mimic drug effects on the AMI events in drug target MR. RESULTS: Genetically predicted higher LDL-C (per one SD increase in LDL-C of 38.67 mg/dL, OR 1.006, 95% CI 1.004-1.007) and TG (per one SD increase in TG of 90.72 mg/dL, 1.004, 1.002-1.006) was associated with increased risk of AMI, but decreased risk for higher HDL-C (per one SD increase in HDL-C of 15.51 mg/dL, 0.997, 0.995-0.999) in univariable MR. Association remained significant for LDL-C, but attenuated toward the null for HDL-C and TG in multivariable MR. Genetically proxied lower LDL-C with genetic variants at or near the PCSK9 region (drug target of evolocumab) and NPC1L1 (drug target of ezetimibe) were associated with decreased risk of AMI (0.997, 0.994-0.999 and 0.986, 0.975-0.998, respectively), whereas genetic variants at HMGCR region (drug target of statin) showed marginal association with AMI (0.995, 0.990-1.000). After excluding drug target-related SNPs, LDL-C related SNPs outside the drug target region remained a causal effect on AMI (0.994, 0.993-0.996). CONCLUSIONS: The findings suggest that genetically predicted LDL-C may play a predominant role in the development of AMI. The drug MR results imply that ezetimibe and evolocumab may decrease the risk of AMI due to their LDL-C lowering effect, and there are other non-drug related lipid lowering pathways that may be causally linked to AMI.

A novel anti-inflammatory strategy for myocardial ischemia-reperfusion in rats with cinnamamide derivative compound 7.

Reperfusion after myocardial ischemia would aggravate myocardial structural and functional damage, known as myocardial ischemia-reperfusion (MI/R) injury. Cinnamamide derivatives have been reported to exert cardioprotective effects, and we have previously reported that compound 7 played a role in cardioprotection against MI/R via anti-inflammatory effect. However, exact mechanism underlying such beneficial action of compound 7 is still unclear. The protective effect of compound 7 was determined in H9c2 cells under H2O2 stimulation with or without nigerin (NLRP3 activator). Electrocardiogram, echocardiography, myocardial infarction size, histopathology and serum biochemical assay were performed in MI/R rats. Metabolomics in vivo and mRNA or protein levels of NLRP3, ASC, cleaved caspase-1 and its downstream IL-18 and IL-1ß were detected both in vitro and in vivo. Compound 7 significantly ameliorate H2O2-induced cardiomyocyte damage, which was supported by in vivo data determined by improved left ventricular systolic function and histopathological changes, reduced myocardial infarction area and cellular apoptosis in heart tissue. Cardiac differential metabolites demonstrated that compound 7 indeed altered the cardiac reprogramming of inflammation-related metabolites, which was evidenced by down-regulated cardiac inflammation by compound 7. Additionally, compound 7 alleviated myocardial injury by inhibiting the NLRP3 pathway rather than other members of the inflammasome both in vitro and in vivo, which was further evidenced by CETSA assay. Whereas, nigerin blocked the inhibitory activity of compound 7 against NLRP3. Cinnamamide derivative compound 7 ameliorated MI/R injury by inhibiting inflammation via NLRP3.

Research of the dynamic regulatory mechanism of Compound Danshen Dripping Pills on myocardial infarction based on metabolic trajectory analysis.

BACKGROUND: Myocardial infarction (MI) is a serious cardiovascular disease, which presents different pathophysiological changes with the prolongation of the disease. Compound danshen dripping pills (CDDP) has obvious advantages in MI treatment and widely used in the clinic. However, the current studies were mostly focused on the endpoint of CDDP intervention, lacking the dynamic attention to the disease process. It is of great value to establish a dynamic research strategy focused on the changes in pharmacodynamic substances for guiding clinical medication more precisely. PURPOSE: It is aimed to explore the dynamic regulating pattern of CDDP on MI based on metabolic trajectory analysis, and then clarify the variation characteristic biomarkers and pharmacodynamic substances in the intervention process. METHODS: The MI model was successfully prepared by coronary artery left anterior descending branch ligation, and then CDDP intervention was given for 28 days. Endogenous metabolites and the components of CDDP in serum were measured by LC/MS technique simultaneously to identify dynamic the metabolic trajectory and screen the characteristic pharmacodynamic substances at different points. Finally, network pharmacology and molecular docking techniques were used to simulate the core pharmacodynamic substances and core target binding, then validated at the genetic and protein level by Q-PCR and western blotting technology. RESULTS: CDDP performed typical dynamic regulation features on metabolite distribution, biological processes, and pharmacodynamic substances. During 1-7 days, it mainly regulated lipid metabolism and inflammation, the Phosphatidylcholine (PC(18:1(9Z/18:1(9Z)) and Sphingomyelin (SM(d18:1/23:1(9Z)), SM(d18:1/24:1(15Z)), SM(d18:0/16:1(9Z))) were the main characteristic biomarkers. Lipid metabolism was the mainly regulation pathway during 14-21 days, and the characteristic biomarkers were the Lysophosphatidylethanolamine (LysoPE(0:0/20:0), PE-NMe2(22:1(13Z)/15:0)) and Sphingomyelin (SM(d18:1/23:1(9Z))). At 28 days, in addition to inflammatory response and lipid metabolism, fatty acid metabolism also played the most important role. Correspondingly, Lysophosphatidylcholine (LysoPC(20:0/0:0)), Lysophosphatidylserine (LPS(18:0/0:0)) and Fatty acids (Linoelaidic acid) were the characteristic biomarkers. Based on the results of metabolite distribution and biological process, the characteristic pharmacodynamic substances during the intervention were further identified. The results showed that various kinds of Saponins and Tanshinones as the important active ingredients performed a long-range regulating effect on MI. And the other components, such as Tanshinol and Salvianolic acid B affected Phosphatidylcholine and Sphingomyelin through Relaxin Signaling pathway during the early intervention. Protocatechualdehyde and Rosmarinic acid affected Lysophosphatidylethanolamine and Sphingomyelin through EGFR Tyrosine kinase inhibitor resistance during the late intervention. Tanshinone IIB and Isocryptotanshinone via PPAR signaling pathway affected Lysophosphatidylcholine, Lysophosphatidylserine, and Fatty acids. CONCLUSION: The dynamic regulating pattern was taken as the entry point and constructs the dynamic network based on metabolic trajectory analysis, establishes the dynamic correlation between the drug-derived components and the endogenous metabolites, and elucidates the characteristic biomarkers affecting the changes of the pharmacodynamic indexes, systematically and deeply elucidate the pharmacodynamic substance and mechanism of CDDP on MI. It also enriched the understanding of CDDP and provided a methodological reference for the dynamic analysis of complex systems of TCM.

Platelet-targeted thromboprophylaxis with a human serum albumin fusion drug: Preventing thrombosis and reducing cardiac ischemia/reperfusion injurywithout bleeding complications.

Background: Myocardial infarction (MI) as a consequence of atherosclerosis-associated acute thrombosis is a leading cause of death and disability globally. Antiplatelet and anticoagulant drugs are standard therapies in preventing and treating MI. However, all clinically used drugs are associated with bleeding complications, which ultimately limits their use in patients with a high risk of bleeding. We have developed a new recombinant drug, targ-HSA-TAP, that combines targeting and specific inhibition of activated platelets as well as anticoagulation. This drug is designed and tested for a prolonged circulating half-life, enabling unique thromboprophylaxis without bleeding complications. Methods: Targ-HSA-TAP combines a single-chain antibody (scFv) that targets activated glycoprotein IIb/IIIa on activated platelets, human serum albumin (HSA) for prolonged circulation, and tick anticoagulant peptide (TAP) for coagulation FX inhibition. A non-binding scFv is employed as a non-targeting control (non-targ-HSA-TAP). Its efficacy was investigated in vivo using murine models of acute thrombosis and cardiac ischemia-reperfusion (I/R) injury. Results: Our experiments confirmed the targeting specificity of targ-HSA-TAP to activated platelets and demonstrated effective prevention of platelet aggregation and thrombus formation, as well as FXa inhibition in vitro. Thromboprophylactic administration of targ-HSA-TAP subcutaneously in mice prevented occlusion of the carotid artery after ferric chloride injury as compared to non-targ-HSA-TAP and PBS-control treated mice. By comparing the therapeutic outcomes between targ-TAP and targ-HSA-TAP, we demonstrate the significant improvements brought by the HSA fusion in extending the drug's half-life and enhancing its therapeutic window for up to 16 h post-administration. Importantly, tail bleeding time was not prolonged with targ-HSA-TAP in contrast to the clinically used anticoagulant enoxaparin. Furthermore, in a murine model of cardiac I/R injury, mice administered targ-HSA-TAP 10 h before injury demonstrated preserved cardiac function, with significantly higher ejection fraction and fractional shortening, as compared to the non-targ-HSA-TAP and PBS control groups. Advanced strain analysis revealed reduced myocardial deformation and histology confirmed a reduced infarct size in targ-HSA-TAP treated mice compared to control groups. Conclusion: The inclusion of HSA represents a significant advancement in the design of targeted therapeutic agents for thromboprophylaxis. Our activated platelet-targeted targ-HSA-TAP is a highly effective antithrombotic drug with both anticoagulant and antiplatelet effects while retaining normal hemostasis. The long half-life of targ-HSA-TAP provides the unique opportunity to use this antithrombotic drug for more effective, long-lasting and safer anti-thrombotic prophylaxis. In cases where MI occurs, this prophylactic strategy reduces thrombus burden and effectively reduces cardiac I/R injury.

Activation of Cardiac δ2-Opioid Receptors Increases Heart Tolerance to Reperfusion.

Coronary occlusion (45 min) and reperfusion (120 min) in male Wistar rats in vivo, as well as total ischemia (45 min) of an isolated rat heart followed by reperfusion (30 min) were reproduced. The selective δ2-opioid receptor agonist deltorphin II (0.12 mg/kg and 152 nmol/liter) was administered intravenously 5 min before reperfusion in vivo or added to the perfusion solution at the beginning of reperfusion of the isolated heart. The peripheral opioid receptor antagonist naloxone methiodide and δ2-opioid receptor antagonist naltriben were used in doses of 5 and 0.3 mg/kg, respectively. It was found that the infarct-limiting effect of deltorphin II is associated with the activation of δ2-opioid receptors. We have demonstrated that deltorphin II can improve the recovery of the contractility of the isolated heart after total ischemia.

Poricoic acid A promotes angiogenesis and myocardial regeneration by inducing autophagy in myocardial infarction.

Myocardial infarction (MI) is a kind of cardiovascular diseases with high morbidity and mortality. Poricoic acid A (PAA) is the main active substance in Poria cocos, which has been discovered to exhibit an ameliorative role in the progression of many diseases. However, no report has been focused on the regulatory effects of PAA on MI progression. In this study, at first, oxygen glucose deprivation (OGD) treatment was performed in human cardiac microvascular endothelial cells (HCMECs) to mimic MI cell model. Our findings demonstrated that cell proliferation was reduced post OGD treatment, but which was reversed by PAA treatment. Moreover, PAA suppressed cell apoptosis in OGD-triggered HCMEC cells. Next, it revealed that PAA induced autophagy in OGD-treated HCMEC cells through enhancing LC3-II/LC3-I level and reducing P62 level. In addition, PAA strengthened the angiogenesis ability and migration ability in OGD-induced HCMEC cells. Lastly, it was uncovered that PAA modulated the AMPK/mTOR signaling pathway through affecting the p-mTOR/mTOR and p-AMPK/AMPK levels. In conclusion, PAA can promote angiogenesis and myocardial regeneration after MI by inducing autophagy through modulating the AMPK/mTOR pathway. This work suggested that PAA may be a potential and useful drug for MI treatment.

Melatonin alleviates myocardial dysfunction through inhibition of endothelial-to-mesenchymal transition via the NF-κB pathway.

Endothelial-to-mesenchymal transition (EndMT) is a complex biological process of cellular transdifferentiation by which endothelial cells (ECs) lose their characteristics and acquire mesenchymal properties, leading to cardiovascular remodeling and complications in the adult cardiovascular diseases environment. Melatonin is involved in numerous physiological and pathological processes, including aging, and has anti-inflammatory and antioxidant activities. This molecule is an effective therapeutic candidate for preventing oxidative stress, regulating endothelial function, and maintaining the EndMT balance to provide cardiovascular protection. Although recent studies have documented improved cardiac function by melatonin, the mechanism of action of melatonin on EndMT remains unclear. The present study investigated the effects of melatonin on induced EndMT by transforming growth factor-ß2/interleukin-1ß in both in vivo and in vitro models. The results revealed that melatonin reduced the migratory ability and reactive oxygen species levels of the cells and ameliorated mitochondrial dysfunction in vitro. Our findings indicate that melatonin prevents endothelial dysfunction and inhibits EndMT by activating related pathways, including nuclear factor kappa B and Smad. We also demonstrated that this molecule plays a crucial role in restoring cardiac function by regulating the EndMT process in the ischemic myocardial condition, both in vessel organoids and myocardial infarction (MI) animal models. In conclusion, melatonin is a promising agent that attenuates EC dysfunction and ameliorates cardiac damage compromising the EndMT process after MI.

Magnesium implantation as a continuous hydrogen production generator for the treatment of myocardial infarction in rats.

Molecular hydrogen is an emerging broad-spectrum antioxidant molecule that can be used to treat myocardial infarction (MI). However, with hydrogen inhalation, the concentration that can be reached within target organs is low and the duration of action is short, which makes it difficult to achieve high dose targeted delivery of hydrogen to the heart, seriously limiting the therapeutic potential of hydrogen for MI. As a result of reactions with the internal environment of the body, subcutaneous implantation of magnesium slices leads to continuous endogenous hydrogen production, leading to a higher hydrogen concentration and a longer duration of action in target organs. In this study, we propose magnesium implant-based hydrogen therapy for MI. After subcutaneous implantation of magnesium slices in the dorsum of rats, we measured hydrogen production and efficiency, and evaluated the safety of this approach. Compared with hydrogen inhalation, it significantly improved cardiac function in rats with MI. Magnesium implantation also cleared free radicals that were released as a result of mitochondrial dysfunction, as well as suppressing cardiomyocyte apoptosis.

Exploring T-cell exhaustion features in Acute myocardial infarction for a Novel Diagnostic model and new therapeutic targets by bio-informatics and machine learning.

BACKGROUND: T-cell exhaustion (TEX), a condition characterized by impaired T-cell function, has been implicated in numerous pathological conditions, but its role in acute myocardial Infarction (AMI) remains largely unexplored. This research aims to identify and characterize all TEX-related genes for AMI diagnosis. METHODS: By integrating gene expression profiles, differential expression analysis, gene set enrichment analysis, protein-protein interaction networks, and machine learning algorithms, we were able to decipher the molecular mechanisms underlying TEX and its significant association with AMI. In addition, we investigated the diagnostic validity of the leading TEX-related genes and their interactions with immune cell profiles. Different types of candidate small molecule compounds were ultimately matched with TEX-featured genes in the "DrugBank" database to serve as potential therapeutic medications for future TEX-AMI basic research. RESULTS: We screened 1725 differentially expressed genes (DEGs) from 80 AMI samples and 71 control samples, identifying 39 differential TEX-related transcripts in total. Functional enrichment analysis identified potential biological functions and signaling pathways associated with the aforementioned genes. We constructed a TEX signature containing five hub genes with favorable prognostic performance using machine learning algorithms. In addition, the prognostic performance of the nomogram of these five hub genes was adequate (AUC between 0.815 and 0.995). Several dysregulated immune cells were also observed. Finally, six small molecule compounds which could be the future therapeutic for TEX in AMI were discovered. CONCLUSION: Five TEX diagnostic feature genes, CD48, CD247, FCER1G, TNFAIP3, and FCGRA, were screened in AMI. Combining these genes may aid in the early diagnosis and risk prediction of AMI, as well as the evaluation of immune cell infiltration and the discovery of new therapeutics.

Improving therapeutic effects of exosomes encapsulated gelatin methacryloyl/hyaluronic acid blended and oxygen releasing injectable hydrogel by cardiomyocytes induction and vascularization in rat myocardial infarction model.

Acute myocardial infarction (AMI) causes acute cardiac cell death when oxygen supply is disrupted. Improving oxygen flow to the damaged area could potentially achieve the to prevent cell death and provide cardiac regeneration. Here, we describe the production of oxygen-producing injectable bio-macromolecular hydrogels from natural polymeric components including gelatin methacryloyl (GelMA), hyaluronic acid (HA) loaded with catalase (CAT). Under hypoxic conditions, the O2-generating hydrogels (O2 (+) hydrogel) encapsulated with Mesenchymal stem cells (MSCs)-derived-exosomes (Exo- O2 (+) hydrogel) released substantial amounts of oxygen for >5 days. We demonstrated that after 7 days of in vitro cell culture, exhibits identical production of paracrine factors compared to those of culture of rat cardiac fibroblasts (RCFs), rat neonatal cardiomyocytes (RNCs) and Human Umbilical Vein Endothelial Cells (HUVECs), demonstrating its ability to replicate the natural architecture and function of capillaries. Four weeks after treatment with Exo-O2 (+) hydrogel, cardiomyocytes in the peri-infarct area of an in vivo rat model of AMI displayed substantial mitotic activity. In contrast with infarcted hearts treated with O2 (-) hydrogel, Exo- O2 (+) hydrogel infarcted hearts showed a considerable increase in myocardial capillary density. The outstanding therapeutic advantages and quick, easy fabrication of Exo- O2 (+) hydrogel has provided promise favourably for potential cardiac treatment applications.

Comparative effectiveness of myocardial patches and intramyocardial injections in treating myocardial infarction with a MitoQ/hydrogel system.

In cardiac tissue engineering, myocardial surface patches and hydrogel intramyocardial injections represent the two primary hydrogel-based strategies for myocardial infarction (MI) treatment. However, the comparative effectiveness of these two treatments remains uncertain. Therefore, this study aimed to compare the effects of the two treatment modalities by designing a simple and reproducible hydrogel cross-linked with γ-PGA and 4-arm-PEG-SG. To improve mitochondrial damage in cardiomyocytes (CMs) during early MI, we incorporated the mitochondria-targeting antioxidant MitoQ into the hydrogel network. The hydrogel exhibited excellent biodegradability, biocompatibility, adhesion, and injectability in vitro. The hydrogel was utilized for rat MI treatment through both patch adhesion and intramyocardial injections. In vivo results demonstrated that the slow release of MitoQ peptide from the hydrogel hindered ROS production in CM, alleviated mitochondrial damage, and enhanced CM activity within 7 days, effectively inhibiting MI progression. Both hydrogel intramyocardial injections and patches exhibited positive therapeutic effects, with intramyocardial injections demonstrating superior efficacy in terms of cardiac function and structure in equivalent treatment cycles. In conclusion, we developed a MitoQ/hydrogel system that is easily prepared and can serve as both a myocardial patch and an intramyocardial injection for MI treatment, showing significant potential for clinical applications.

Cardiovascular outcomes of sodium-glucose Co-transporter 2 inhibitors use after myocardial infarction: A systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Patients who had acute myocardial infarction are at high risk of negative cardiac outcomes and previous SGLT2i landmark trials excluded these patients. It therefore remains unclear if SGLT2i is safe and confers beneficial cardiovascular outcomes after acute myocardial infarction. METHODS: We systematically reviewed randomized controlled trials that evaluated the outcomes of adding SGLT2i to conventional post-myocardial infarction care. Random-effects model meta-analysis via RevMan 5.4 was done on data extracted from pooled 11,204 patients. RESULTS: SGLT2i use after acute myocardial infarction was significantly associated with reduced heart failure hospitalization (OR: 0.77, 95%CI: 0.62-0.96, p=0.02), but was not associated with a reduction in all-cause mortality (OR: 1.05, 95%CI: 0.77-1.43, p=0.75), cardiac-related death (OR: 1.04, 95%CI: 0.83-1.30, p=0.76), or major adverse cardiac events (OR: 0.90, 95%CI: 0.77-1.05, p=0.18). CONCLUSION: SGLT2 inhibitor therapy after acute myocardial infarction is safe and is associated with a reduced risk of heart failure hospitalization, but not with all-cause mortality.

Chlorthalidone vs Hydrochlorothiazide for Hypertension Treatment After Myocardial Infarction or Stroke: A Secondary Analysis of a Randomized Clinical Trial.

Importance: Patients with prior myocardial infarction (MI) or stroke have a greater risk of recurrent cardiovascular (CV) events. Objective: To evaluate the association of chlorthalidone (CTD) vs hydrochlorothiazide (HCTZ) with CV outcomes and noncancer deaths in participants with and without prior MI or stroke. Design, Setting, and Participants: This was a prespecified secondary analysis of the Diuretic Comparison Project (DCP), a pragmatic randomized clinical trial conducted within 72 participating Veterans Affairs health care systems from June 2016 to June 2021, in which patients aged 65 years or older with hypertension taking HCTZ at baseline were randomized to continue HCTZ or switch to CTD at pharmacologically comparable doses. This secondary analysis was performed from January 3, 2023, to February 29, 2024. Exposures: Pharmacologically comparable daily dose of HCTZ or CTD and history of MI or stroke. Main Outcomes and Measures: Outcome ascertainment was performed from randomization to the end of the study. The primary outcome consisted of a composite of stroke, MI, urgent coronary revascularization because of unstable angina, acute heart failure hospitalization, or noncancer death. Additional outcomes included achieved blood pressure and hypokalemia (potassium level <3.1 mEq/L; to convert to mmol/L, multiply by 1.0). Results: The DCP randomized 13 523 participants to CTD or HCTZ, with a mean (SD) study duration of 2.4 (1.4) years. At baseline, median age was 72 years (IQR, 69-75 years), and 96.8% were male. Treatment effect was evaluated in subgroups of participants with (n = 1455) and without (n = 12 068) prior MI or stroke at baseline. There was a significant adjusted interaction between treatment group and history of MI or stroke. Participants with prior MI or stroke randomized to CTD had a lower risk of the primary outcome than those receiving HCTZ (105 of 733 [14.3%] vs 140 of 722 [19.4%]; hazard ratio [HR], 0.73; 95% CI, 0.57-0.94; P = .01) compared with participants without prior MI or stroke, among whom incidence of the primary outcome was slightly higher in the CTD arm compared with the HCTZ arm (597 of 6023 [9.9%] vs 535 of 6045 [8.9%]; HR, 1.12; 95% CI, 1.00-1.26; P = .054) (P = .01 for interaction). The incidence of a nadir potassium level less than 3.1 mEq/L and hospitalization for hypokalemia differed among those with and without prior MI or stroke when comparing those randomized to CTD vs HCTZ, with a difference only among those without prior MI or stroke (potassium level <3.1 mEq/L: prior MI or stroke, 43 of 733 [5.9%] vs 37 of 722 [5.1%] [P = .57]; no prior MI or stroke, 292 of 6023 [4.9%] vs 206 of 6045 [3.4%] [P < .001]; hospitalization for hypokalemia: prior MI or stroke, 14 of 733 [1.9%] vs 16 of 722 [2.2%] [P = .72]; no prior MI or stroke: 84 of 6023 [1.4%] vs 57 of 6045 [0.9%] [P = .02]). Conclusions and Relevance: Results of this secondary analysis of the DCP trial suggest that CTD may be associated with reduced major adverse CV events and noncancer deaths in patients with prior MI or stroke compared with HCTZ. Trial Registration: ClinicalTrials.gov Identifier: NCT02185417.

Progresses and perspectives on natural polysaccharide based hydrogels for repair of infarcted myocardium.

Myocardial infarction (MI) is serious health threat and impairs the quality of life. It is a major causative factor of morbidity and mortality. MI leads to the necrosis of cardio-myocytes, cardiac remodelling and dysfunction, eventually leading to heart failure. The limitations of conventional therapeutic and surgical interventions and lack of heart donors have necessitated the evolution of alternate treatment approaches for MI. Polysaccharide hydrogel based repair of infarcted myocardium have surfaced as viable option for MI treatment. Polysaccharide hydrogels may be injectable hydrogels or cardiac patches. Injectable hydrogels can in situ deliver cells and bio-actives, facilitating in situ cardiac regeneration and repair. Polysaccharide hydrogel cardiac patches reduce cardiac wall stress, and inhibit ventricular expansion and promote angiogenesis. Herein, we discuss about MI pathophysiology and myocardial microenvironment and how polysaccharide hydrogels are designed to mimic and support the microenvironment for cardiac repair. We also put forward the versatility of the different polysaccharide hydrogels in mimicking diverse cardiac properties, and acting as a medium for delivery of cells, and therapeutics for promoting angiogenesis and cardiac repair. The objectives of this review is to summarize the factors leading to MI and to put forward how polysaccharide based hydrogels promote cardiac repair. This review is written to enable researchers understand the factors promoting MI so that they can undertake and design novel hydrogels for cardiac regeneration.

ß-Blocker Use and Clinical Outcomes in Patients With COPD Following Acute Myocardial Infarction.

Importance: While ß-blockers are associated with decreased mortality in cardiovascular disease (CVD), exacerbation-prone patients with chronic obstructive pulmonary disease (COPD) who received metoprolol in the Beta-Blockers for the Prevention of Acute Exacerbations of Chronic Obstructive Pulmonary Disease (BLOCK-COPD) trial experienced increased risk of exacerbations requiring hospitalization. However, the study excluded individuals with established indications for the drug, raising questions about the overall risk and benefit in patients with COPD following acute myocardial infarction (AMI). Objective: To investigate whether ß-blocker prescription at hospital discharge is associated with increased risk of mortality or adverse cardiopulmonary outcomes in patients with COPD and AMI. Design, Setting, and Participants: This prospective, longitudinal cohort study with 6 months of follow-up enrolled patients aged 35 years or older with COPD who underwent cardiac catheterization for AMI at 18 BLOCK-COPD network hospitals in the US from June 2020 through May 2022. Exposure: Prescription for any ß-blocker at hospital discharge. Main Outcomes and Measures: The primary outcome was time to the composite outcome of death or all-cause hospitalization or revascularization. Secondary outcomes included death, hospitalization, or revascularization for CVD events, death or hospitalization for COPD or respiratory events, and treatment for COPD exacerbations. Results: Among 3531 patients who underwent cardiac catheterization for AMI, prevalence of COPD was 17.1% (95% CI, 15.8%-18.4%). Of 579 total patients with COPD and AMI, 502 (86.7%) were prescribed a ß-blocker at discharge. Among the 562 patients with COPD included in the final analysis, median age was 70.0 years (range, 38.0-94.0 years) and 329 (58.5%) were male; 553 of the 579 patients (95.5%) had follow-up information. Among those discharged with ß-blockers, there was no increased risk of the primary end point of all-cause mortality, revascularization, or hospitalization (hazard ratio [HR], 1.01; 95% CI, 0.66-1.54; P = .96) or of cardiovascular events (HR, 1.11; 95% CI, 0.65-1.92; P = .69), COPD-related or respiratory events (HR, 0.75; 95% CI, 0.34-1.66; P = .48), or treatment for COPD exacerbations (rate ratio, 1.01; 95% CI, 0.53-1.91; P = .98). Conclusions and Relevance: In this cohort study, ß-blocker prescription at hospital discharge was not associated with increased risk of adverse outcomes in patients with COPD and AMI. These findings support use of ß-blockers in patients with COPD and recent AMI.