Myocardial fibrosis in congenital heart disease

AI-enhanced computational discovery of promising ALK5 inhibitors in a ultra-large chemical space library for cardiovascular Disease therapy

Cardiac fibrosis, characterized by excessive extracellular matrix deposition, is a critical contributor to cardiovascular diseases, including heart failure. Transforming growth factor-beta 1 signaling, especially through activin receptor-like kinase 5 (ALK5), plays a key role in cardiac fibroblast activation and fibrosis. Traditional drug discovery approaches face challenges in identifying ALK5 inhibitors. This study leverages computational methods to expedite the discovery of potential ALK5 inhibitors. An active learning model was trained to screen a vast compound library, resulting in the selection of promising candidates. Molecular fingerprint clustering analysis and the absorption, distribution, metabolism, excretion, toxicity evaluation further characterized these compounds. Machine learning-based quantitative structure - activity relationship models predicted their activity. Molecular dynamics simulations assessed binding stability in different environments. DE50349483 and DE21377883 emerged as promising candidates with potential inhibitory effects. This study showcases the power of computational methods in drug discovery, offering hope for innovative therapies in cardiac fibrosis.

Dual inhibition of TGFβ and PDGF improves RV remodeling and function in response to RV pressure or volume-loading

Right ventricular (RV) pressure and volume loading induce RV fibrosis in association with RV dysfunction, morbidity, and mortality in repaired tetralogy of Fallot. Transforming-growth factor-β1 (TGFβ1) and platelet-derived growth factor (PDGF) activate common downstream signaling pathways via TGFβ canonical and non-canonical signaling to promote increased fibroblast activation, proliferation, and fibrosis in other organs. However, the role of PDGF and TGFβ canonical and non-canonical signaling in RV fibrosis is incompletely characterized. Here, we investigate whether dual inhibition of TGFβ and PDGF, using Tranilast (TRN), improves RV remodeling in response to pulmonary artery banding (PAB) or pulmonary regurgitation (PR). TRN reduced TGFβ canonical signaling in PAB rats associated with improved RV fibrosis, hypertrophy, and RV function. In response to PR, TRN reduced PDGFRβ expression and normalized ERK1/2 activity, which were associated with reduced RV hypertrophy and improved diastolic relaxation. We identify that PDGF drives RV fibroblast proliferation and activation via SMAD2/3, JNK, and β-catenin signaling. Our studies suggest that TGFβ and PDGF are interconnected drivers of RV fibrosis and hence synergistic targets to improve RV remodeling in RV pressure and volume loading.

Novel Therapies for Patients With Systemic Right Ventricle

Systemic RV dysfunction is a significant prognostic factor in congenital heart disease, particularly affecting patients with transposition of the great arteries post-atrial switch and congenitally corrected transposition of the great arteries. These patients often experience chronic pressure loading conditions, leading to structural, mechanical, and electrical adaptations that can result in heart failure. This article reviews novel therapeutic approaches for managing systemic right ventricular failure in patients with adult congenital heart disease, focusing on pharmacologic, device-based, and advanced heart failure therapies. Traditional heart failure medications such as angiotensin converting enzyme inhibitors, angiotensin II receptor blockers, β-blockers, and mineralocorticoid receptor antagonists have shown mixed results in systemic right ventricular failure. However, newer agents like angiotensin receptor-neprilysin inhibitors and sodium-glucose cotransporter 2 inhibitors have demonstrated promising outcomes in improving cardiac remodeling and function. Cardiac resynchronization therapy has shown benefits in selected patients, particularly those with prior ventricular pacing. Mechanical circulatory support and heart transplantation remain viable options for advanced heart failure, with recent studies indicating favourable long-term outcomes. The management of systemic right ventricular failure requires a personalized approach, considering the unique anatomic and physiological characteristics of each patient. Although traditional therapies have limited efficacy, novel pharmacologic and device-based treatments might offer new hope for this patient population. Further research is needed to refine these strategies and identify new therapeutic targets.

The interplay of senescence and MMPs in myocardial infarction: implications for cardiac aging and therapeutics

Aging is associated with a marked increase in cardiovascular diseases, such as myocardial infarction (MI). Cellular senescence is also a crucial factor in the development of age-related MI. Matrix metalloproteinases (MMPs) interaction with cellular senescence is a critical determinant of MI development and outcomes, most notably in the aged heart. After experiencing a heart attack, senescent cells exhibit a Senescence-Associated Secretory Phenotype (SASP) and are involved in tissue regeneration and chronic inflammation. MMPs are necessary for extracellular matrix proteolysis and have a biphasic effect, promoting early heart healing and detrimental change if overexpressed shortly. This review analyses the complex connection between senescence and MMPs in MI and how it influences elderly cardiac performance. Critical findings suggest that increasing cellular senescence in aged hearts elevates MMP activity and aggravates extended ventricular remodeling and dysfunction. Additionally, we explore potential therapeutics that address MMPs and senescence to enhance old MI patient myocardial performance and regeneration.

Impact of cardiovascular magnetic resonance in single ventricle physiology: a narrative review

Background and Objective

Cardiovascular magnetic resonance (CMR) is a routine cross-sectional imaging modality in adults with congenital heart disease. Developing CMR techniques and the knowledge that CMR is well suited to assess long-term complications and to provide prognostic information for single ventricle (SV) patients makes CMR the ideal assessment tool for this patient cohort. Nevertheless, many of the techniques have not yet been incorporated into day-to-day practice. The aim of this review is to provide a comprehensive overview of CMR applications in SV patients together with recent scientific findings.

Methods

Articles from 2009 to August 2024 retrieved from PubMed on CMR in SV patients were included. Case reports and non-English literature were excluded.

Key Content and Findings

CMR is essential for serial follow-up of SV patients and CMR-derived standard markers can improve patient management and prognosis assessment. Advanced CMR techniques likely will enhance our understanding of Fontan hemodynamics and are promising tools for a comprehensive patient evaluation and care.

Conclusions

There is increasing research that shows the advantages of CMR in Fontan patients. However, further research about the prognostic role of CMR in older Fontan patients and how new methods such as modeling and deep learning pipelines can be clinically implemented is warranted.

Enrichment of Ginseng Rare Sapogenin 25-OH-PPT and Its Protective Effect on Myocardial Fibrosis

Ginseng (Panax ginseng C. A. Meyer), a traditional Chinese medicine, and the rare ginsenosides contained in it have various physiological activities. 25-OH-PPT (T19) is a rare natural dammarane-type ginseng sapogenin. Pharmacological studies have shown that T19 has good hypoglycemic, antioxidant, and anti-inflammatory activities. In the research, we optimized the T19 enrichment process and explored the potential mechanism of T19 in myocardial oxidative stress. Firstly, we studied a hydrolysis process on ginseng stems and leaves ginsenosides. Optimization factors include acid types, acid concentrations, ultrasound time, and ultrasound temperature. To develop safer preparation conditions more suitable for production scaleup, we studied the difference in hydrolysis between inorganic acid and food acids. The results show that using hydrochloric acid to hydrolyze ginsenosides in ginseng stems and leaves can increase the content of T19 to 12.16%. When using edible citric acid, the maximum content of T19 is 1.9%. However, using citric acid for hydrolysis has higher safety and non-toxic properties. Meanwhile, the myocardial protective effect of T19 was evaluated, indicating that T19 could effectively reduce isoproterenol (ISO)-induced oxidative stress injury by reducing the levels of LDH and CK-MB and regulating the contents of antioxidant enzymes SOD, lipid peroxidation product MDA, and non-enzymatic antioxidant GSH in cardiomyocytes. Further study demonstrated that regulation of fibrosis markers Collagen I, Collagen III, and α-SMA was involved in the potential mechanism of T19 efficiency.

Pathology of explanted pediatric hearts: An 11-year study. Population characteristics and implications for outcomes

BACKGROUND

As more pediatric patients become candidates for heart transplantation (HT), understanding pathological predictors of outcome and the accuracy of the pretransplantation evaluation are important to optimize utilization of scarce donor organs and improve outcomes. The authors aimed to investigate explanted heart specimens to identify pathologic predictors that may affect cardiac allograft survival after HT.

METHODS

Explanted pediatric hearts obtained over an 11-year period were analyzed to understand the patient demographics, indications for transplant, and the clinical-pathological factors.

RESULTS

In this study, 149 explanted hearts, 46% congenital heart defects (CHD), were studied. CHD patients were younger and mean pulmonary artery pressure and resistance were significantly lower than in cardiomyopathy patients. Twenty-one died or underwent retransplantation (14.1%). Survival was significantly higher in the cardiomyopathy group at all follow-up intervals. There were more deaths and the 1-, 5- and 7-year survival was lower in patients ≤10 years of age at HT. Early rejection was significantly higher in CHD patients exposed to homograft tissue, but not late rejection. Mortality/retransplantation rate was significantly higher and allograft survival lower in CHD hearts with excessive fibrosis of one or both ventricles. Anatomic diagnosis at pathologic examination differed from the clinical diagnosis in eight cases.

CONCLUSIONS

Survival was better for the cardiomyopathy group and patients >10 years at HT. Prior homograft use was associated with a higher prevalence of early rejection. Ventricular fibrosis (of explant) was a strong predictor of outcome in the CHD group. We presented several pathologic findings in explanted pediatric hearts.

Epidemiology and Definition of Heart Failure in Adult Congenital Heart Disease

Adults with congenital heart disease (ACHD) are facing lifelong complications, notably heart failure (HF). This review focuses on classifications, incidence, prevalence, and mortality of HF related to ACHD. Diagnosing HF in ACHD is intricate due to anatomic variations, necessitating comprehensive clinical evaluations. Hospitalizations and resource consumption for ACHD HF have significantly risen compared with non-ACHD HF patients. With more than 30% prevalence in complex cases, HF has become the leading cause of death in ACHD. These alarming trends underscore the insufficient understanding of ACHD-related HF manifestations and management challenges within the context of aging, complexity, and comorbidity.

Essentials of Imaging the Repaired Tetralogy of Fallot Patient

Tetralogy of Fallot is one of the commoner forms of congenital heart disease (CHD) with an incidence estimated at around 1 in 3000 live births. Its prevalence is roughly 5%-10% of all forms of CHD. Although it is a cyanotic disorder at presentation, early surgical repair has led to survival to adulthood in the overwhelming majority of cases. However-as with most repaired CHD-such patients are fixed, not cured, and will inevitably come to the attention of the imaging specialist. This article attempts to describe and summarize the main forms of repaired tetralogy that may be encountered in tertiary hospital imaging practice. The anatomy of different forms of tetralogy is reviewed, and relevant pathophysiology is discussed. Reference is made to 22q11 syndrome, which is often missed or not considered by even specialist congenital physicians, and the alerting features of this condition are reviewed. The benefits and challenges of computed tomography and magnetic resonance imaging in the congenital population are covered, and there is discussion regarding the various approaches to imaging available using these techniques.