Search Results (858)

Background: Recent advancements in heart failure (HF) therapy have significantly enhanced the management of patients across all phenotypes of left ventricular ejection fraction. However, these multidrug regimens frequently induce alterations in renal function by influencing intrarenal hemodynamics, thereby modifying glomerular capillary pressure. This phenomenon could result in a mild to moderate decline in estimated glomerular filtration rate (eGFR), often classified as “worsening kidney function.” This nomenclature stems from consistent observations of eGFR reductions recorded during HF treatment in clinical trials. This narrative review aims to elucidate why the observed eGFR declines in clinical practice may represent either loss of functioning glomeruli or pharmacologically mediated reductions in intraglomerular pressure that ultimately safeguards long-term renal and cardiovascular outcomes. Methods: By a comprehensive re-examination of data from HF clinical trials conducted with various classes of medications, all affecting eGFR, we sought to provide evidence that the decline in eGFR is associated with the activation of specific mechanisms that collectively contribute to a reduction in glomerular filtration pressure, a prominent factor in maladaptive neurohormonal responses. Results: From the investigation of angiotensin-converting enzyme inhibitors to the more recent non-steroidal mineralocorticoid receptor antagonist, the renal effects of these therapeutic regimens correlate with improvements in patient outcomes. The data consistently indicate that an early decline in eGFR, when coupled with an enhancement in HF outcomes, is associated with a more gradual decline in eGFR during long-term follow-up. Conclusions: Clinicians should recognize early declines in eGFR as indicators of favorable intraglomerular hemodynamic adjustments that mitigate maladaptive neurohormonal responses and contribute to improved long-term outcomes in patients with HF. Full article

Background: Vascular compression syndromes are increasingly recognized as underdiagnosed contributors to morbidity in patients exhibiting dysautonomia. Underlying vascular compression syndromes affecting the head and neck, abdomen, pelvis, and lower extremities may influence venous return, neurohormonal signaling, and autonomic regulation. There is considerable clinical overlap among these syndromes, as well as between hypermobility spectrum disorders (HSD) and dysautonomia, indicating possible shared or interacting pathophysiological mechanisms. Purpose/Aims: This hypothesis-generating narrative review synthesizes current evidence linking vascular compression syndromes with dysautonomia, highlights potential mechanistic pathways, identifies patterns of syndromic overlap, and emphasizes the importance of systematic evaluation in affected patient populations. Key Findings: Evidence from retrospective studies, case series, and clinical observations indicates that vascular compression syndromes may be prevalent among patients with dysautonomia, particularly postural orthostatic tachycardia syndrome (POTS) and HSD, yet are often unrecognized. Proposed mechanisms based on limited data include impaired venous capacitance and preload reserve, increased intracranial pressure, altered renin–aldosterone and cortisol signaling, underlying autoimmune and systemic diseases, and sympathetic ganglion irritation. Several compression syndromes show symptom overlap and frequent co-occurrence, especially in patients with connective tissue disorders. Emerging data suggest that targeted interventions, such as surgical decompression or venous stenting, may improve orthostatic intolerance and quality-of-life measures in selected patients, though high-quality prospective data remain limited. Conclusions: Vascular compression syndromes may be an important yet underappreciated contributor to dysautonomia. Increased clinical awareness and systematic screening may reduce diagnostic delays and morbidity in this underserved population. Prospective studies are needed to clarify prevalence, establish causal relationships, and determine the impact of targeted treatments on autonomic outcomes. Full article

Background: Obstructive sleep apnea (OSA) is associated with lower urinary tract symptoms (LUTS), particularly nocturia, though mechanisms including hypoxia, intrathoracic pressure changes, and hormonal alterations. While age and severity may influence these associations, stratified analyses remain limited. This study examined polysomnographic (PSG) parameters, International Prostate Symptom Score (IPSS) components, and hormonal/electrolyte markers in age- and severity-stratified men with suspected OSA. Methods: In this cross-sectional study, 104 men (mean age 60.8 ± 9.8 years) underwent PSG. Analyses were stratified by age (<60 vs. ≥60 years) and respiratory disturbance index (RDI) severity. Correlations were used to assess PSG indices, IPSS subdomains (irritative, obstructive, quality of life [QoL]), and markers including antidiuretic hormone [ADH], aldosterone, plasma renin activity [PRA], sodium, potassium. Nocturnal polyuria index (NPI ≥ 33%) was calculated in a subset of participants. Pearson correlations, ANOVA, and Kruskal–Wallis tests were used (p < 0.05), with adjustments for multiple comparisons. Results: Moderate OSA predominated (RDI 27.2 ± 20.4 events/h); nocturia affected 61.5% of the cohort. In those <60 years (n = 48), mild RDI correlated with nocturia (r = 0.42, p = 0.028), while severe RDI correlated strongly with the obstructive subscore (r = 0.96, p = 0.009). In those ≥60 years (n = 56), QoL correlated with sleep efficiency (r = 0.48, p = 0.012) and total sleep time (r = 0.46, p = 0.015). Severe RDI was associated with higher IPSS (14.5 ± 6.2 vs. 10.5 ± 4.8, p = 0.028) and nocturia (3.5 ± 1.7 vs. 2.4 ± 1.1, p = 0.02). ADH was significantly lower in severe OSA (1.4 ± 0.8 vs. 2.7 ± 1.1 pg/mL, p = 0.03). Conclusions: Age and OSA severity modulate PSG–LUTS–hormonal associations. Younger men exhibit hypoxia-linked obstructive symptoms, whereas older men experience sleep fragmentation that impacts QoL. ADH suppression is associated with severe OSA. Full article

Heart failure with preserved ejection fraction (HFpEF) represents the predominant form of heart failure, affecting over 50% of all heart failure patients with increasing prevalence in aging populations. Despite significant advances in cardiovascular medicine, HFpEF remains a complex clinical syndrome with poorly understood pathophysiology and limited treatment options. While most studies have traditionally focused on the renin–angiotensin–aldosterone system (RAAS) and other related mechanisms, emerging evidence has unveiled a critical bidirectional relationship between dysregulation of gut microbiota and HFpEF development. This phenomenon, mediated through microbiome-driven inflammation and endothelial dysfunction, introduces a novel concept and potential emerging conceptual framework in understanding HFpEF. This comprehensive review explores this novel gut–heart axis by synthesizing the latest evidence from original studies and clinical trials. We discuss novel mechanisms involving bacterial metabolites, including short-chain fatty acids (SCFAs), trimethylamine N-oxide (TMAO), bile acids, and amino acid derivatives. We also examine how gut dysbiosis may contribute to systemic inflammation through lipopolysaccharide translocation, NLRP3 inflammasome activation, and endothelial dysfunction. Furthermore, clinical trials investigating microbiome-targeted interventions, including probiotics, fecal microbiota transplantation, metabolite supplementation, and precision medicine approaches, are critically evaluated for their therapeutic potential. This review provides a framework for hypothesis generation and future research directions about therapeutic strategies targeting the gut–heart axis in HFpEF management. Full article

Hypertension-induced renal injury is a major cause of chronic kidney disease and end-stage renal disease. Increasing evidence indicates that disease progression is not driven solely by hemodynamic stress but results from the interplay of multiple molecular mechanisms. In this review, we propose a stage-structured and network-based framework to systematically integrate current mechanistic insights into hypertension-induced renal injury. Early events, mainly including endothelial dysfunction and renal hypoxia, establish a permissive microenvironment for disease progression. These insults activate amplifying pathways such as the renin–angiotensin–aldosterone system (RAAS) overactivation, oxidative stress, immune and inflammatory responses, and sympathetic nervous system hyperactivity, which interact through cross-talk and positive feedback loops. Ultimately, these signals converge on fibrotic programs characterized by epithelial–mesenchymal transition (EMT), fibroblast activation, and extracellular matrix deposition, leading to irreversible structural remodeling and functional decline. Furthermore, epigenetics, the gut–kidney axis, autophagy dysfunction and renal aging also contribute to this process. We highlight two critical and underappreciated aspects: the existence of a permissive ‘early-window’ dominated by endothelial dysfunction and hypoxia, which sets the stage for later amplification; and the hierarchical interplay between amplifying mechanisms where cross talk creates self-reinforcing loops that may explain therapeutic resistance. In addition, this review highlights emerging biomarkers for early diagnosis and disease monitoring, and discusses therapeutic advances that extend beyond blood pressure control to disease-modifying interventions that confer renoprotective effects. By integrating molecular mechanisms with diagnostic and therapeutic perspectives, this review provides a comprehensive framework for early detection and precision intervention in hypertension-induced renal injury. Full article

Diabetic kidney disease (DKD) is a major complication of diabetes mellitus that contributes substantially to chronic kidney failure and increased cardiovascular risk. Beyond progressive deterioration of renal function, DKD is associated with disturbances in endocrine and vascular regulation. Among these, alterations in vitamin D homeostasis and blood pressure (BP) control represent clinically relevant, yet incompletely integrated aspects of DKD pathophysiology. This narrative review synthesizes current evidence on the multidirectional relationships between DKD, vitamin D deficiency, and arterial hypertension (AH). Attention is given to renal mechanisms responsible for reduced vitamin D availability in DKD, including proteinuria-related loss of vitamin D-binding proteins, impaired proximal tubular reabsorption, decreased renal activation of vitamin D, and hormonal regulators such as fibroblast growth factor-23. It further discusses how insufficient vitamin D signaling may influence renal and vascular pathways involved in BP regulation. Mechanistic links between vitamin D deficiency and AH in DKD are discussed, with emphasis on maladaptive activation of the renin–angiotensin–aldosterone system (RAAS), persistent inflammation, oxidative stress, endothelial dysfunction, and insulin resistance. These interdependent processes promote both renal injury progression and sustained elevations in BP, forming a self-reinforcing pathogenic loop. Finally, available data on vitamin D-based therapeutic strategies in DKD are reviewed, including native vitamin D supplementation, active vitamin D metabolites, and vitamin D receptor agonists. Although experimental and observational studies suggest potential nephroprotective and vasculoprotective effects, evidence from randomized clinical trials remains heterogeneous. Further well-designed prospective studies are required to clarify the clinical utility of vitamin D interventions in patients with DKD and coexisting AH. Full article

Cardiac fibrosis represents a final common pathway in a wide range of cardiac disorders, leading to structural remodeling, diastolic dysfunction, and heart failure. From a pathologist’s viewpoint, fibrotic remodeling displays distinctive morphologic patterns such as interstitial, perivascular, and replacement fibrosis, which mirror specific cellular and molecular mechanisms. Central to this process is the activation of cardiac fibroblasts into myofibroblasts, driven by profibrotic signaling cascades such as transforming growth factor beta (TGF-β)/mothers against decapentaplegic homolog proteins (SMAD), Wingless/Integrated signaling pathway (Wnt)/βeta-catenin, and Hippo-Yes-associated protein (YAP)/transcriptional coactivator with PDZ-binding motif (TAZ) pathways. Neurohumoral mediators, including angiotensin II and aldosterone, further amplify extracellular matrix synthesis and tissue stiffness. Epigenetic modulators and non-coding RNAs (n-c RNAs) orchestrate transcriptional programs that perpetuate fibroblast activation. Histopathological correlates of these molecular events, collagen deposition, alpha-smooth muscle actin (α-SMA) expression, and extracellular matrix (ECM) cross-linking, can be demonstrated through immunohistochemistry and digital morphometry. This review integrates molecular signaling and morphologic evidence to delineate the mechanisms of cardiac fibrosis, emphasizing the pathologist’s role as a link between molecular insight and diagnostic interpretation. Understanding these intertwined processes provides the foundation for novel antifibrotic therapies targeting key molecular nodes of fibroblast activation and matrix remodeling. Full article

Background/Objectives: Primary aldosteronism (PA), the leading cause of secondary hypertension, results from autonomous aldosterone hypersecretion. It is characterized by increased extracellular volume, elevated cardiac output, and greater arterial stiffness compared with essential hypertension, reflecting aldosterone-mediated hemodynamic dysregulation. The prevalence and morbidity of PA are increasingly acknowledged; however, PA continues to be underdiagnosed because of limited screening and diagnostic complexity. Methods: A narrative review was conducted using PubMed (2015–2025), with terms targeting PA epidemiology, excluding treatment-focused studies. From 971 articles, 133 relevant studies (original research studies, reviews, meta-analyses) were included, addressing prevalence, risk factors, comorbidities, genetics, and diagnostic issues. Results: PA prevalence in hypertensive populations is 5–10%, rising to 17.8% in young-onset and 20–30% in resistant hypertension. Screening indications include resistant/severe hypertension, hypokalemia, adrenal incidentaloma, young-onset disease, obstructive sleep apnea (59.8% comorbidity in hypertensive PA), and familial history, while a link may exist with papillary thyroid cancer. The aldosterone–renin ratio (ARR) is the primary screening tool, limited by assay variability and confounders (e.g., sodium intake). Confirmatory testing (such as with the saline infusion test) is often challenging to perform in routine practice. Adrenal venous sampling (AVS) is useful for subtyping unilateral (aldosterone-producing adenoma; APA; ~35–50%) vs. bilateral (idiopathic hyperaldosteronism; IHA) disease, despite technical challenges. Somatic mutations (e.g., KCNJ5, more frequent in Asians) and rare familial forms drive PA. Complications include cardiovascular events (Major Adverse Cardiovascular Events; MACE: 13.6% at 5.8 years), stroke, renal impairment (decreased eGFR, proteinuria), metabolic disorders (diabetes, obesity), and novel associations (vertebral fractures, renal stones, normal-tension glaucoma). Psychiatric comorbidities (depression/anxiety in 30–70% of patients) have been associated with central mineralocorticoid receptor effects, with sleep disturbances being prominent in females. Subclinical PA predicts hypertension and arterial stiffness. Conclusion: Improved screening protocols, standardized ARR cutoffs, and advanced imaging and genetic analyses are needed to enhance PA detection. Future research should validate cost-effective screening and clarify psychiatric-metabolic links for optimized management. Full article

Background: Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) can cause persistent, multisystem complications collectively termed long COVID. Cardiovascular sequelae are among the most clinically significant yet remain incompletely characterized. This review aimed to synthesize current evidence on objective cardiovascular outcomes in long COVID and explore underlying mechanisms. Methods: A systematic review was conducted using PubMed, Scopus, and Web of Science for studies published between January 2020 and March 2024. Search terms included “COVID-19,” “long COVID,” “post-acute sequelae,” “cardiovascular,” “echocardiography,” “biomarkers,” and “imaging.” Only studies reporting at least one cardiovascular outcome, defined as either objectively measured parameters (e.g., echocardiography, cardiac biomarkers, ECG findings, or vascular function indices) or clinically relevant cardiovascular symptoms during follow-up, were included. From 412 identified records, ten recent, high-quality studies with a primary cardiovascular focus were selected. This systematic review was conducted in accordance with the PRISMA 2020 guidelines. Results: Long COVID is associated with subclinical myocardial dysfunction, arrhythmias, endothelial injury, vascular stiffness, and a prothrombotic state. Reported findings included reduced left ventricular ejection fraction, impaired global longitudinal strain, increased arterial stiffness, elevated cardiac biomarkers, new-onset hypertension, and persistent ECG changes, even in non-hospitalized patients without prior cardiovascular disease. Proposed mechanisms include myocardial inflammation, endothelial dysfunction, renin–angiotensin–aldosterone system dysregulation, autonomic imbalance, and chronic inflammation. Secondary bacterial and fungal infections were noted in critically ill survivors but did not fully explain the breadth or persistence of symptoms. Conclusions: Long COVID is a heterogeneous entity with substantial cardiovascular implications across all levels of acute disease severity. Early detection through longitudinal monitoring, standardized definitions, and multidisciplinary care is essential to reduce long-term cardiovascular risk. Full article

Heart failure (HF) is a global health challenge characterized by the heart’s inability to satisfy metabolic demands, driven by renin–angiotensin–aldosterone system (RAAS) overactivation, a neurohormonal imbalance, and emerging mechanisms like the gut–heart axis and mitochondrial dysfunction. Affecting over 6 million adults in the US alone, HF incurs a 5-year mortality rate of 50% and escalating costs projected to double by 2030. This review examines HF’s molecular paradigms, integrating established pathways with advances in omics, stem cell therapy, genetic modification, and personalized medicine. The RAAS blockade remains central, yet its efficacy is limited in HF with preserved ejection fraction (HFpEF). Stem cell therapies (mesenchymal and induced pluripotent stem cells) show regenerative potential but face poor retention (<10% survival at 30 days). CRISPR/Cas9 offers precision, though off-target effects persist. The gut microbiome, via trimethylamine N-oxide, exacerbates inflammation, while omics technologies promise biomarkers for tailored treatments. Challenges include translating these innovations into practice, particularly for HFpEF. Future directions involve novel HFpEF therapies, enhanced stem cell delivery, precise genetic tools, and microbiome interventions, supported with artificial intelligence. By 2030, these advances could shift HF management toward regeneration, contingent on overcoming translational barriers through global collaboration. Full article

Hypertension (HTN) remains a leading modifiable risk factor for cardiovascular disease, and non-pharmacological strategies combining exercise training with plant-derived bioactive supplementation are increasingly recognized as promising adjuncts for blood pressure (BP) management. This evidence-based review synthesizes findings from 31 clinical studies investigating selected plant-based supplements with the strongest available clinical evidence, namely beetroot juice (BRJ), green tea (GT), curcumin (CN), resveratrol (RSV), and garlic, administered alone or in combination with different exercise modalities across acute, short-term, and long-term interventions. Collectively, the evidence indicates that BRJ exerts the most consistent BP-lowering effects, particularly during aerobic training performed at ~50% heart rate reserve (HRR), or ~60% peak oxygen consumption (VO_2peak) in individuals with early-stage vascular dysfunction. CN and garlic also enhance exercise-induced BP reductions, especially in older or metabolically compromised populations. GT shows variable outcomes depending on caffeine content, exercise modality, and participant health status, while RSV provides modest vascular support, often contingent on concurrent training. Mechanistically, these botanicals and exercise converge on key vascular-regulatory pathways, including enhanced nitric oxide (NO) bioavailability, reduced oxidative stress and inflammation, attenuated renin–angiotensin–aldosterone system (RAAS) and sympathetic activity, and improved mitochondrial function through Sirtuin 1 (SIRT1)/AMP-activated protein kinase (AMPK) signaling. Together, these integrated mechanisms improve endothelial function, lower vascular resistance, and ultimately reduce BP. From a translational standpoint, combining exercise with targeted plant-based supplementation offers a safe, accessible, and physiologically synergistic strategy for BP control in clinical populations. Future research should define optimal dosing, timing relative to exercise, and population-specific efficacy to inform precision-based, integrative interventions for HTN management. Full article

Background/Objectives: Losartan, an angiotensin II receptor blocker (ARB) used to treat hypertension and heart failure, shows significant variability in pharmacokinetics (PK) and pharmacodynamics (PD) among individuals. Methods: In this study, we developed a physiologically based pharmacokinetic/pharmacodynamic (PBPK/PD) model of losartan and its active metabolite, E3174, using curated data from 25 clinical trials. The model mechanistically describes the processes of absorption, hepatic metabolism, renal and fecal excretion, and pharmacodynamic blood pressure regulation. Simulation studies examined the effects of dose, hepatic and renal impairment, and genetic polymorphisms in cytochrome p450 2C9 (CYP2C9) and P-glycoprotein 1, also known as multidrug resistance protein 1 (MDR1) or ATP-binding cassette sub-family B member 1 (ABCB1), on the model. Results: The model successfully reproduced key PK/PD observations, including dose-dependent receptor blockade, attenuated responses with hepatic impairment, modest enhancement with renal impairment, and substantial variability in E3174 formation dependent on CYP2C9; the effects of ABCB1 were minimal. Specifically, dose dependency simulations confirmed the saturable nature of CYP2C9 metabolism, predicting a decreasing E3174-to-losartan ratio and a stronger, sustained suppression of blood pressure and aldosterone at higher doses. Hepatic impairment was predicted to lead to elevated losartan plasma concentrations (increased AUC) and attenuated metabolite formation, confirming the clinical need for dose reduction. Renal impairment simulations predicted stable losartan AUC but showed an overestimation of E3174 accumulation compared to observed data, where E3174 exposure remained stable. Genetic variability (CYP2C9) was the major determinant of response, with simulations confirming that reduced-function alleles lead to a 1.6- to 3-fold increase in losartan AUC and diminished blood pressure reduction. ABCB1 variability resulted in only minor modulation of systemic exposure and blood pressure effects. Conclusions: This mechanistic digital twin framework provides a quantitative basis for understanding variability in losartan therapy and supports its application in individualized dosing strategies. Full article

Feline chronic kidney disease is a leading cause of mortality in geriatric cats, characterized by a progressive and irreversible loss of renal function. Despite its high prevalence, early diagnosis remains challenging due to nephron compensatory mechanisms and the limited sensitivity of traditional biomarkers, creating a diagnostic gap that necessitates the exploration of novel biomarkers for earlier detection. This review examines the complex pathophysiology of the disease, including renin–angiotensin–aldosterone system activation, tubulointerstitial fibrosis, and mineral metabolism disturbances. By analyzing recent scientific literature, this work evaluates current diagnostic landscape and clinical relevance of emerging biomarkers. Evidence indicates that symmetric dimethylarginine and fibroblast growth factor-23 improve detection of early metabolic and filtration changes, while urinary biomarkers like cystatin B and retinol-binding protein provide specific insights into tubular injury. Bridging the diagnostic gap requires a transition from a reactive, azotemia-based framework to a multi-parametric diagnostic approach that integrates novel biomarkers with serial clinical and laboratory monitoring. Although financial constraints and limited availability restrict widespread clinical implementation, incorporating these advances is essential for earlier prognostic stratification and timely therapeutic decision-making. This integrated strategy has the potential to slow disease progression and improve survival and quality of life in cats with chronic kidney disease. Full article

Hypertension has traditionally been viewed as a hemodynamic disorder leading to cardiac and renal injury; however, growing evidence suggests that, in many individuals, elevated blood pressure is instead the earliest clinical expression of subtle cardiorenal dysfunction. Early abnormalities—such as low-grade albuminuria, increased renal resistive index, arterial stiffness, and masked or nocturnal hypertension—can appear before estimated glomerular filtration rate decline or elevated office blood pressure, indicating early impairment of pressure–natriuresis, heightened tissue renin–angiotensin–aldosterone system (RAAS) activity, and increased renal microvascular impedance. The aim of this review is to summarize mechanistic, clinical, and phenotypic evidence supporting the concept that hypertension functions as an early biomarker along the cardiorenal continuum. Incorporating vascular and renal biomarkers, ambulatory blood pressure phenotyping, and targeted laboratory indices into routine assessment may identify individuals transitioning from functional disturbances to structural organ damage. These abnormalities reflect a mechanistic triad of arterial stiffening, salt-sensitive RAAS activation, and circadian blood pressure disruption, collectively defining the early cardiorenal–hypertensive phenotype. Viewing hypertension through a cardiorenal lens underscores a critical opportunity for earlier detection and mechanism-oriented intervention, which may modify disease trajectory and prevent progression to overt chronic kidney disease and heart failure. Full article

Hypertension is highly prevalent among patients with chronic kidney disease (CKD), contributing significantly to cardiovascular morbidity and progressive renal decline. This overview explores the intricate pathophysiologic mechanisms driving hypertension in renal insufficiency, including volume overload, renin–angiotensin–aldosterone system (RAAS) activation, sympathetic overactivity, and vascular dysfunction. Diagnostic challenges such as white-coat hypertension and the underuse of ambulatory monitoring are discussed, along with the importance of volume assessment and target organ evaluation. We also emphasize individualized management strategies combining lifestyle modification, pharmacotherapy—including RAAS inhibitors, diuretics, and novel agents—and the growing role of device-based interventions. In particular, renal denervation (RDN) has emerged as a potential adjunctive option for selected patients with resistant hypertension in CKD, with preliminary evidence suggesting blood pressure reduction in selected and carefully studied populations, including dialysis-dependent patients. Special considerations for transplant recipients, elderly individuals, and those on dialysis are highlighted, underscoring the need for nuanced, patient-centered care. Misconceptions surrounding RAAS blockade, dialysis hypotension, and therapeutic inertia are critically appraised. Finally, future directions point to biomarker-driven approaches, digital health integration, and large-scale trials on RDN to refine treatment paradigms. This comprehensive synthesis offers a pragmatic framework for clinicians managing hypertension in CKD, aligning mechanistic insights with emerging evidence and clinical realities. Full article