Ischemic heart disease (IHD) remains a leading cause of global morbidity and mortality despite advances in prevention, diagnosis, and therapy. Traditional clinical risk scores and biomarkers often fail to fully capture the complex molecular processes underlying atherosclerosis, myocardial infarction, and ischemic cardiomyopathy, leaving substantial residual risk. MicroRNAs have emerged as promising regulators and biomarkers of cardiovascular disease, among which microRNA-21 (miR-21) has attracted particular attention. MiR-21 is deeply involved in key pathophysiological mechanisms of IHD, including endothelial dysfunction, vascular inflammation, vascular smooth muscle cell proliferation, plaque development and vulnerability, cardiomyocyte survival, and myocardial fibrosis. Accumulating clinical evidence suggests that circulating miR-21 holds diagnostic value across the ischemic continuum, from stable coronary artery disease to acute coronary syndromes, myocardial infarction, and ischemic heart failure. Moreover, miR-21 demonstrates prognostic relevance, correlating with plaque instability, adverse remodeling, heart failure progression, and long-term cardiovascular outcomes. Preclinical studies further indicate that miR-21 represents a double-edged therapeutic target, offering cardio protection in acute ischemic injury while contributing to fibrosis and maladaptive remodeling if dysregulated. This narrative review summarizes current evidence on the diagnostic, prognostic, and therapeutic utility of miR-21 in IHD, highlighting its clinical promise as well as key limitations and future translational challenges.

Transthyretin (TTR) amyloidosis is a systemic, progressive, and fatal disease. TTR is integral in vitamin A (retinol) transport via its binding to retinol binding protein 4 (RBP4). Current and emerging therapies for TTR amyloid cardiomyopathy (ATTR-CM), including RNAi therapies and potentially CRISPR-based therapies, reduce hepatic transthyretin production and hence decrease serum RBP4, which decreases circulating vitamin A levels. However, despite these reductions in circulating vitamin A, hepatic reserves and alternative delivery mechanisms may prevent clinical manifestations of vitamin A deficiency. Vitamin A functions as a key regulator of immunity, antioxidant function, cell growth and differentiation and vision. This paper aims to serve as a comprehensive review of vitamin A and its metabolites, their transport, and their function in human health and disease. Additionally, we seek to synthesize the relevant outcomes and safety data of TTR silencing therapies and how they relate to circulating vitamin A levels and vitamin A-related clinical outcomes in a manner that is relevant to the cardiac amyloidosis specialist.

Coronary microvascular dysfunction (CMD) is an important cause of angina and myocardial ischemia in patients without obstructive coronary artery disease and contributes substantially to the clinical spectrum of angina with non-obstructive coronary arteries (ANOCA) and ischemia with non-obstructive coronary arteries (INOCA). These conditions represent a heterogeneous group of coronary vasomotor disorders in which structural and functional abnormalities of the coronary microcirculation, endothelial dysfunction, coronary vasospasm, and diffuse non-obstructive atherosclerosis may occur alone or in combination. This review summarizes current knowledge on the pathophysiology, diagnosis, and management of CMD in patients with ANOCA and INOCA. We discuss the distinction between ANOCA and INOCA, the principal coronary functional endotypes, and the mechanisms responsible for impaired coronary microvascular function. We also review contemporary diagnostic approaches, including non-invasive imaging and invasive coronary function testing, with emphasis on their complementary roles in identifying the underlying mechanism of ischemia. Current management strategies are presented from a mechanism-based perspective, including lifestyle modification, pharmacological therapy, endotype-guided treatment, and emerging therapeutic approaches. Improved understanding of coronary functional abnormalities has shifted clinical evaluation beyond the exclusion of obstructive coronary artery disease toward identification of the mechanism responsible for persistent symptoms and ischemia. Continued advances in disease phenotyping, coronary function testing, and targeted therapies are expected to support more individualized management and improve outcomes in this diverse patient population.

Pediatric chronic kidney disease (CKD) is traditionally viewed as a disorder of impaired renal function, yet its effects extend far beyond the kidneys. Growing evidence indicates that CKD may disrupt brain development through interconnected biological, vascular, inflammatory, and psychosocial mechanisms, with lasting consequences for cognition, mental health, and educational attainment. In this perspective, we propose the kidney-brain axis as a neuro-renal framework for understanding these neurological consequences of pediatric CKD. We discuss current evidence linking CKD with neurocognitive impairment, structural brain abnormalities, psychosocial burden, and adverse educational outcomes, while examining the biological mechanisms that may underlie these associations. We also consider the role of kidney transplantation, emphasizing that restoration of renal function does not necessarily restore normal neurodevelopmental trajectories. Finally, we outline the clinical implications of integrating routine neurodevelopmental assessment into pediatric nephrology care and highlight priorities for future research. Recognizing neurodevelopment as a core component of pediatric CKD may help redefine disease burden and support more comprehensive, lifelong care for affected children.

Cardiovascular toxicity is an important complication of treatment for hematologic malignancies, but it is often discussed mainly in terms of direct myocardial injury. Endothelial injury may provide a common link between several cardiovascular complications seen in these patients. Endothelial dysfunction may already be present because of the malignancy itself and can be further increased by anticancer treatment, immune activation and haematopoietic stem cell transplantation. Oxidative stress, reduced nitric oxide availability, inflammation, increased vascular permeability and activation of coagulation can shift the endothelium from a protective to a pro-inflammatory and prothrombotic state. These changes could contribute to hypertension, thrombosis, atherosclerotic disease, coronary microvascular dysfunction, arterial stiffness and myocardial dysfunction. The role of endothelial injury is particularly relevant with BCR-ABL inhibitors, proteasome inhibitors, CAR-T-cell therapy, bispecific antibodies and transplantation, although the mechanisms and strength of evidence differ between treatments. Several circulating biomarkers and tools, including angiopoietin-2, von Willebrand factor, soluble thrombomodulin, adhesion molecules and the Endothelial Activation and Stress Index, may help identify endothelial injury, but their clinical roles still remain unclear. This review examines endothelial injury across hematologic malignancies and their treatments and discusses its role in cardiovascular toxicity, current approaches to vascular protection and the main gaps that need to be addressed before endothelial assessment can become part of routine cardio-oncology care.