Cardiac hypertrophy is characterized by cardiac structural remodeling, fibrosis, microvascular rarefaction, and chronic inflammation. The heart is structurally organized by different cell types, including cardiomyocytes, fibroblasts, endothelial cells, and immune cells. These cells highly interact with each other by a number of paracrine or autocrine factors. Cell-cell communication is indispensable for cardiac development, but also plays a vital role in regulating cardiac response to damage. Although cardiomyocytes and fibroblasts are deemed as key regulators of hypertrophic stimulation, other cells, including endothelial cells, also exert important effects on cardiac hypertrophy. More particularly, endothelial cells are the most abundant cells in the heart, which make up the basic structure of blood vessels and are widespread around other cells in the heart, implicating the great and inbuilt advantage of intercellular crosstalk. Cardiac microvascular plexuses are essential for transport of liquids, nutrients, molecules and cells within the heart. Meanwhile, endothelial cell-mediated paracrine signals have multiple positive or negative influences on cardiac hypertrophy. However, a comprehensive discussion of these influences and consequences is required. This review aims to summarize the basic function of endothelial cells in angiogenesis, with an emphasis on angiogenic molecules under hypertrophic conditions. The secondary objective of the research is to fully discuss the key molecules involved in the intercellular crosstalk and the endothelial cell-mediated protective or detrimental effects on other cardiac cells. This review provides a more comprehensive understanding of the overall role of endothelial cells in cardiac hypertrophy and guides the therapeutic approaches and drug development of cardiac hypertrophy.

The APOA1/C3/A4/A5 cluster is an essential component in regulating lipoprotein metabolism and maintaining plasma lipid homeostasis. A genome-wide association analysis and Mendelian randomization have revealed potential associations between genetic variants within this cluster and lipid metabolism disorders, including hyperlipidemia and cardiovascular events. An enhanced understanding of the complexity of gene regulation has led to growing recognition regarding the role of epigenetic variation in modulating APOA1/C3/A4/A5 gene expression. Intensive research into the epigenetic regulatory patterns of the APOA1/C3/A4/A5 cluster will help increase our understanding of the pathogenesis of lipid metabolism disorders and facilitate the development of new therapeutic approaches. This review discusses the biology of how the APOA1/C3/A4/A5 cluster affects circulating lipoproteins and the current progress in the epigenetic regulation of the APOA1/C3/A4/A5 cluster.

Fulminant myocarditis (FM) is an acute and severe form of myocarditis with rapid progression and poor clinical outcomes in the absence of acute or chronic coronary artery disease. Electrocardiogram (ECG) abnormalities can provide preliminary clues for diagnosis; however, there is a lack of systemic descriptions on ECG changes in FM populations. Thus, a retrospective analysis of 150 consecutive FM patients and 300 healthy controls was performed to determine the characteristic ECG findings in FM. All patients included had markedly abnormal ECG findings. Specifically, 83 (55.33%) patients had significantly lower voltage with remarkably decreased QRS amplitudes in all leads compared with healthy controls (p < 0.01), and 77 (51.33%) patients had a variety of arrhythmias with lethality ventricular tachycardia/ventricular fibrillation in 21 (14.00%) patients and third-degree atrioventricular block in 21 (14.00%) patients, whereas sinus tachycardia was only found in 43 (28.67%) patients with the median heart rate (HR; 88.00 bpm, IQR: 76.00–113.50) higher than that of controls (73.00 bpm, IQR: 68.00–80.00) (p = 0.000). Conduction and repolarization abnormalities were common in patients. A longer QTc interval (452.00 ms, IQR: 419.00–489.50) and QRS duration (94.00 ms, IQR: 84.00–119.00) were observed in patients compared to controls (QTc interval = 399.00 ms, IQR: 386.00–414.00; QRS duration = 90.00 ms, IQR: 86.00–98.00) (p < 0.05). Additionally, HR > 86.50 bpm, QTc > 431.50 ms, and RV5 + SV1 < 1.715 mV can be used to predict FM. Thus, marked and severe ECG abnormalities provide preliminary clues for the diagnosis of FM.

Transfer RNA-derived small RNAs (tsRNAs) have emerged as potential biomarkers of various human diseases. However, the clinical utility and biological functions of tsRNA in acute coronary syndrome (ACS) remain poorly understood. To investigate this, we performed high-throughput small RNA sequencing on peripheral blood monocyte cells (PBMCs) from 24 ACS patients and 12 healthy controls. Our analysis revealed distinct and characteristic expression patterns of tsRNAs in response to ACS, highlighting their potential as disease signatures in human PBMCs. Differentially expressed tsRNAs were validated using RT-qPCR in two independent case-control sets. Among these, tRF-Gly-GCC-06 was significantly upregulated in volunteers with unstable angina (UA) and acute myocardial infarction (AMI) (p < 0.05) and showed a statistically significant positive correlation with the Gensini score (r = 0.353, p < 0.001). Moreover, this tsRNA was independently associated with an increased risk of ACS after adjusting for conventional cardiovascular risk factors (odds ratio (OR) = 1.58, 95% confidence interval (CI): 1.37–1.83, p < 0.001). A series of functional studies showed that tRF-Gly-GCC-06 significantly facilitated macrophage proliferation and migration and modulated inflammation-related gene expression in vitro. This study identified a novel functional gene associated with ACS, tRF-Gly-GCC-06, as a potential clinical biomarker and therapeutic target.

Heart failure with preserved ejection fraction (HFpEF) represents a complex clinical syndrome characterized by limited therapeutic options, which are largely due to its intricate pathophysiology. The role of mechanical stress is pivotal in maintaining cardiovascular homeostasis; conversely, its dysregulation may precipitate the progression of cardiovascular diseases. In HFpEF, both macroscopic structural alterations and intricate molecular processes might be influenced by mechanical stress. This review examines the potential associations between mechanical stress and HFpEF, exploring the pathophysiological underpinnings to the effects of mechanotransduction effectors on cardiac remodeling and the progression of heart failure, providing novel insights into the pathological mechanisms of HFpEF. Therapeutic strategies targeting these mechanotransduction effectors have shown promise in mitigating pathological cardiac remodeling in models of metabolic-associated heart failure, underscoring their potential as innovative treatments for HFpEF. Considering the clinical heterogeneity of HFpEF, it is imperative to pursue phenotype-specific personalized treatments to optimize therapeutic efficacy.

BACKGROUND: Premature atrial contractions (PACs) are independently associated with atrial fibrillation, stroke, and heart failure, yet no pharmacological therapy is approved for PAC suppression. Experimental studies have identified a functional cardiac glutamatergic system in which N-methyl-D-aspartate receptors regulate atrial electrophysiology. Preclinical studies show that pharmacological antagonism of N-methyl-D-aspartate receptors with memantine suppresses atrial arrhythmias. METHODS: We conducted an investigator-initiated, phase 2, multicenter, randomized, double-blind, placebo-controlled trial. Symptomatic adults with frequent PACs (≥1000/24 h) were randomly assigned to receive memantine or placebo for 6 weeks. The primary end point was the percentage change in mean 24-hour PAC count from baseline to the end of treatment. The primary analysis was performed in the intention-to-treat population. Prespecified secondary end points included the responder rate (≥50% PAC reduction), percentage change in nonsustained atrial tachycardia burden, and cumulative incidence of new-onset atrial fibrillation. RESULTS: Among 241 patients included in the efficacy analysis, memantine resulted in a greater reduction in PAC count than placebo (between-group difference, 47.1 percentage points; P =0.0045). The responder rate was higher with memantine than with placebo (52.4% versus 23.1%; P <0.0001). Memantine also reduced nonsustained atrial tachycardia burden (between-group difference, 30.98 percentage points; P =0.0043) and was associated with a lower cumulative incidence of new-onset atrial fibrillation (4.8% versus 23.9%; P <0.0001). No clinically meaningful differences were observed in electrocardiographic intervals or left ventricular function, and no drug-related serious adverse events occurred. CONCLUSIONS: In patients with frequent symptomatic PACs, memantine reduced atrial ectopy and atrial tachyarrhythmia burden and demonstrated a favorable safety profile. These findings provide proof of concept for a novel, non–ion channel–based therapeutic strategy targeting the cardiac glutamatergic system. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT06501638.