Cardiorenal Syndrome and Inflammation: A Forgotten Frontier Resolved by Sorbents?

Cardiorenal syndrome (CRS) describes the maladaptive relationship between heart and kidney dysfunction, with different pathways perpetuating the pathophysiology. Inflammation is one of these mechanisms. It contributes to the final nonhemodynamic pathways of organ dysfunction in the heart-kidney cross-talk. It may be a mediator and amplifier of this pathological communication, playing a vital role in both acute and chronic cardiorenal dysfunction. Current therapeutic strategies are not satisfactory in mitigating the inflammatory pathway in CRS. Hemoadsorption overcomes this limitation, and the soluble mediators of inflammation are potentially amenable to removal by hemoadsorption. This perspective article describes the inflammatory mechanisms in CRS and the rationality of using hemoadsorption in this scenario.

Rising to the challenge of cardio-renal-metabolic disease in the 21st century: Translating evidence into best clinical practice to prevent and manage atherosclerosis.

Rising rates of obesity-associated cardiometabolic disorders allied to ageing populations are driving increases in cardiovascular morbidity and mortality. These adverse trends present challenges for healthcare systems that are struggling to prevent and manage the burgeoning cardiometabolic nexus of multiple long-term conditions. While potent new medications and non-pharmacological interventions have ushered in a promising new therapeutic era, translating clinical trial data to real-world clinical practice is often suboptimal. Postgraduate training and narrowly focused clinical specialisations reflect the traditional siloed approach to managing cardiovascular-metabolic disease that appears increasingly outmoded in the 21st century. It is our contention that greater inter-disciplinary collaboration allied to increased awareness of the continuum of cardiometabolic disease should enable clinicians to address this global public health threat more effectively. With this aim in mind, we have established an International Cardiometabolic Working Group. It is our hope to stimulate the interest of clinicians and clinical researchers across a range of medical specialties who share the vision of better care for people living with cardiometabolic diseases.

A new animal model of cardiorenal syndrome could be established by inducing heart failure through coronary artery ligation in spontaneously hypertensive rats.

In rats with unilateral nephrectomy and cardiac dysfunction, renal function deteriorates at an accelerated rate, as evidenced by increased proteinuria. Whether myocardial infarct-induced heart failure (HF) exacerbates renal injury in hypertensive rats with mild renal injury has not been reported. Rats underwent either coronary ligation or sham surgery. Thirty spontaneously hypertensive rats (SHRs) aged 8 weeks were randomly divided into two groups. Group 1 was the sham group, in which the rats underwent thoracotomy without ligation of the coronary artery. Group 2 underwent coronary artery ligation. The rats in group 2 underwent coronary artery ligation on week 0. The experiment lasted 12 weeks. Urine was collected in metabolic cages over a 24-h period. Urine was collected from the rats 2 days before the end of the experiment, and the ratio of urinary protein to urinary creatinine was measured in the clinical laboratory. All rats were examined by echocardiogram one day before the end of the experiment. On the last day of the experiment, blood was collected and sent to the laboratory for analysis. Hematoxylin-eosin (HE) and periodic acid-Schiff (PAS) staining were performed on heart and kidney sections. The ejection fraction in group 2 was lower than that in group 1 (P < 0.001). The urinary albumin to creatinine ratio in group 2 was greater than that in group 1 (P < 0.001). The urea and creatinine levels in group 1 were significantly lower than those in group 2 (P < 0.01). The levels of brain natriuretic peptide (BNP), neutrophil gelatinase-associated lipocalin (NGAL) and cystatin C were greater in the second group than in the first group (P < 0.05). The interleukin-1ß (IL-1ß) and interleukin-6 (IL-6) levels in group 2 were significantly greater than those in group 1 (P < 0.001). The malondialdehyde (MDA) levels in Group 2 were greater than those in Group 1 (P < 0.01). The glutathione peroxidase (GSH-Px) levels in Group 2 were lower than those in Group 1 (P < 0.05). The level of angiotensin II (AT-II) in group 1 was lower than that in group 2 (P < 0.001). Cardiac dysfunction secondary to myocardial infarction could induce cardiorenal interactions in SHRs. It could be interpreted by the activation of oxidative stress, changes in inflammation and alteration of renin-angiotensin-aldosterone system.

The Need to Identify Novel Markers for Early Renal Injury in Cardiorenal Syndrome.

The term "Cardiorenal Syndrome" (CRS) refers to the complex interplay between heart and kidney dysfunction. First described by Robert Bright in 1836, CRS was brought to its modern view by Ronco et al. in 2008, who defined it as one organ's primary dysfunction leading to secondary dysfunction in the other, a view that led to the distinction of five different types depending on the organ of primary dysfunction and the temporal pattern (acute vs. chronic). Their pathophysiology is intricate, involving various hemodynamic, neurohormonal, and inflammatory processes that result in damage to both organs. While traditional biomarkers have been utilized for diagnosing and prognosticating CRS, they are inadequate for the early detection of acute renal damage. Hence, there is a pressing need to discover new biomarkers to enhance clinical outcomes and treatment approaches.

Exploring the nexus: The place of kidney diseases within the cardiovascular-kidney-metabolic syndrome spectrum.

Cardiovascular-kidney-metabolic (CKM) syndrome and chronic kidney disease (CKD) are two significant comorbidities affecting a large proportion of the general population with considerable crosstalk. In addition to substantial co-incidence of CKD and CKM syndrome in epidemiological studies, clinical and pre-clinical studies have identified similar pathophysiological pathways leading to both entities. Patients with CKM syndrome are more prone to develop acute kidney injury and CKD, while therapeutic alternatives and their success rates are considerably lower in such patient groups. Nevertheless, the association between CKM syndrome and CKD or ESKD is bidirectional rather than being a cause-effect relationship as patients with CKD are also prone to develop peripheral insulin resistance, high blood pressure, and dyslipidemia. Furthermore, such patients are less likely to receive kidney transplantation in addition to the higher allograft dysfunction risk. We hereby aim to evaluate the association in-between kidney diseases and CKM syndrome, including epidemiological data, pre-clinical studies with pathophysiological pathways, and potential therapeutic perspectives.

Blood Volume Analysis and Cardiorenal Syndrome: From Bench to Bedside.

BACKGROUND: This review delves into the intricate landscape of cardiorenal syndrome (CRS) and highlights the pivotal role of blood volume analysis (BVA) in improving patient care and outcomes. SUMMARY: BVA offers a direct and highly accurate quantification of intravascular volume, red blood cell volume, and plasma volume, complete with patient-specific norms. This diagnostic tool enhances the precision of diuretic and red cell therapies, significantly elevating the effectiveness of conventional care. KEY MESSAGES: Our objectives encompass a comprehensive understanding of how BVA informs the evaluation and treatment of CRS, including its subtypes, pathophysiology, and clinical significance. We delve into BVA principles, techniques, and measurements, elucidating its diagnostic potential and advantages compared to commonly used surrogate measures. We dissect the clinical relevance of BVA in various CRS scenarios, emphasizing its unique contributions to each subtype. By assessing the tangible impact of BVA on patient outcomes through meticulous analysis of relevant clinical studies, we unveil its potential to enhance health outcomes and optimize resource utilization. Acknowledging the challenges and limitations associated with BVA's clinical implementation, we underscore the importance of multidisciplinary collaboration among cardiologists, nephrologists, and other clinicians. Finally, we identify research gaps and propose future directions for BVA and CRS, contributing to ongoing advancements in this field and patients affected by this complicated clinical syndrome.

Accelerated idioventricular rhythm as a manifestation of chronic renocardiac syndrome: A case report.

In this case report, we describe a patient who presented with chronic symptoms and signs of uremia and persistent accelerated idioventricular rhythm (AIVR) on electrocardiogram. Findings from blood tests, echocardiography, renal ultrasound, and renal scan were suggestive of heart failure with reduced ejection fraction and chronic kidney disease, and attendance of daily hemodialysis sessions led to the restoration of sinus rhythm. Typically, AIVR has a favorable prognosis and, if necessary, medical intervention focuses on addressing the underlying responsible causes. Accumulation of uremic toxins has the potential to trigger the formation of AIVR and clearance of small solutes through conventional hemodialysis may contribute to sinus rhythm restoration.

Cardiac Devices and Kidney Disease.

A growing variety of cardiac devices are available to monitor or support cardiovascular function. The entwined nature of cardiovascular disease and kidney disease makes the relationship of these devices with kidney disease a multifaceted question relating to the use of these devices in individuals with kidney disease and to the effects of the devices and device placement on kidney health. Cardiac devices can be categorized broadly into cardiac implantable electronic devices, structural devices, and circulatory assist devices. Cardiac implantable electronic devices include devices for monitoring and managing cardiac electrical activity and devices for monitoring hemodynamics. Structural devices modify cardiac structure and include valve prostheses, valve repair clips, devices for treating atrial septal abnormalities, left atrial appendage closure devices, and interatrial shunt devices. Circulatory assist devices support the failing heart or support cardiac function during high-risk cardiac procedures. Evidence for the use of these devices in individuals with kidney disease, effects of the devices on kidney health and function, specific considerations with devices in kidney disease, and important knowledge gaps are surveyed in this article. With the growing prevalence of combined cardiorenal disease and the increasing variety of cardiac devices, kidney disease considerations are an important aspect of device therapy.

Kidney Replacement Therapies and Ultrafiltration in Cardiorenal Syndrome.

BACKGROUND: Some patients with cardiorenal syndrome 1 and congestion exhibit resistance to diuretics. This scenario complicates management and is associated with a worse prognosis. In some cases, rescue treatment may be considered by starting kidney replacement therapies or ultrafiltration. This decision is complex and necessitates a profound understanding of these techniques and the pathophysiology of this syndrome. These modalities are classified into continuous, intermittent, and ultrafiltration therapies, each with its own advantages and disadvantages that are pertinent in selecting the optimal treatment. SUMMARY: In patients with diuretic-resistant cardiorenal syndrome, extracorporeal ultrafiltration and kidney replacement therapies have the potential to relieve congestion, restore the neurohormonal system, and improve quality of life. KEY MESSAGES: (i) In cardiorenal syndrome, the resistance to diuretics is common. (ii) Extracorporeal ultrafiltration and renal replacement therapies are rescue options that may improve the management of these patients. (iii) Better understanding of these modalities will help the development of new devices which are friendlier, safer, and more affordable for patients in these clinical settings.

Cardiorenal Syndrome: An Evolutionary Appraisal.

A recent American Heart Association Scientific Statement and Presidential Advisory recognized a new syndrome, the cardiovascular-kidney-metabolic syndrome. This expands our understanding of what has been called cardiorenal syndrome by incorporating the pathophysiological interrelatedness of metabolic risk factors into the previous concept of cardiorenal syndrome. Importantly, perturbation of cardiac or renal physiology combines to produce significant detrimental outcomes. The cardiorenal syndrome is a significant part of the cardiovascular-kidney-metabolic syndrome and contributes to health care cost, disability, and mortality. It is a vexing malady that has generated considerable interest. To understand the syndrome evaluation of its teleological origins is important. In life's beginning, eukaryotes acquired exocytosis for excretion, formed tubular secretory systems for clearance, and a mesenchymal nucleic acid vasoform for nutritional distribution. Those structures progressed to cardiovascular and renal systems of evolving organisms, whose migration to rivers and land imposed complex, coordinated, homeostatic roles to maintain intravascular stability. Tissue mineralization of vertebrate endoskeleton added renal calcium balance regulation, which in kidney failure results in cardiovascular calcification. Insight into cardiorenal disease can be traced to ancient Egyptian and Chinese medicine, through the Scientific Revolution, and into current insights regarding human physiology and pathophysiology. The post-World War II epidemic of cardiovascular mortality generated considerable information on cardiovascular disease, which being higher in patients with kidney disease, drew increasing health concerns. The cardiorenal syndrome was formally introduced in this setting with a focus on ultrafiltration to manage volume overload. An evolutionary review of insight into cardiorenal syndrome will help us better understand the new cardiovascular-kidney-metabolic syndrome.

Publication Trends and Research Hotspots of the Cardiorenal Syndrome: A Bibliometrics and Visual Analysis from 2003 to 2023.

INTRODUCTION: Cardiorenal syndrome encompasses a range of disorders involving both the heart and kidneys, wherein dysfunction in one organ may induce dysfunction in the other, either acutely or chronically. METHODS: This study conducted a literature search on cardiorenal syndrome from January 1, 2003, to September 8, 2023. Meanwhile, a quantitative analysis of the developmental trajectory, research hotspots and evolutionary trends in the field of cardiorenal syndrome through bibliometric analysis and knowledge mapping was carried out. RESULTS: The annual publication trend analysis revealed a consistent annual increase in cardiorenal syndrome literature over the last 20 years. The IL6, REN, and INS genes were identified as the current research hotspots. CONCLUSION: The field of cardiorenal syndrome exhibits promising potential to grow and is emerging as a prominent research area. Future endeavours should prioritise a comprehensive understanding of the field and foster multi-centre co-operation among different countries and regions.

Cardiorenal Syndromes and Their Role in Water and Sodium Homeostasis.

Sodium is the main osmotically active ion in the extracellular fluid and its concentration goes hand in hand with fluid volume. Under physiological conditions, homeostasis of sodium and thus amount of fluid is regulated by neural and humoral interconnection of body tissues and organs. Both heart and kidneys are crucial in maintaining volume status. Proper kidney function is necessary to excrete regulated amount of water and solutes and adequate heart function is inevitable to sustain renal perfusion pressure, oxygen supply etc. As these organs are bidirectionally interconnected, injury of one leads to dysfunction of another. This condition is known as cardiorenal syndrome. It is divided into five subtypes regarding timeframe and pathophysiology of the onset. Hemodynamic effects include congestion, decreased cardiac output, but also production of natriuretic peptides. Renal congestion and hypoperfusion leads to kidney injury and maladaptive activation of renin-angiotensin-aldosterone system and sympathetic nervous system. In cardiorenal syndromes sodium and water excretion is impaired leading to volume overload and far-reaching negative consequences, including higher morbidity and mortality of these patients. Keywords: Cardiorenal syndrome, Renocardiac syndrome, Volume overload, Sodium retention.

Serial direct sodium removal in patients with heart failure and diuretic resistance.

AIMS: Loop diuretics may exacerbate cardiorenal syndrome (CRS) in heart failure (HF). Direct sodium removal (DSR) using the peritoneal membrane, in conjunction with complete diuretic withdrawal, may improve CRS and diuretic resistance. METHODS AND RESULTS: Patients with HF requiring high-dose loop diuretics were enrolled in two prospective, single-arm studies: RED DESERT (n = 8 euvolaemic patients), and SAHARA (n = 10 hypervolaemic patients). Loop diuretics were withdrawn, and serial DSR was utilized to achieve and maintain euvolaemia. At baseline, participants required a median 240 mg (interquartile range [IQR] 200-400) oral furosemide equivalents/day, which was withdrawn in all participants during DSR (median time of DSR 4 weeks [IQR 4-6]). Diuretic response (queried by formal 40 mg intravenous furosemide challenge and 6 h urine sodium quantification) increased substantially from baseline (81 ± 37 mmol) to end of DSR (223 ± 71 mmol, p < 0.001). Median time to re-initiate diuretics was 87 days, and the median re-initiation dose was 8% (IQR 6-10%) of baseline. At 1 year, diuretic dose remained substantially below baseline (30 [IQR 7.5-40] mg furosemide equivalents/day). Multiple dimensions of kidney function such as filtration, uraemic toxin excretion, kidney injury, and electrolyte handling improved (p < 0.05 for all). HF-related biomarkers including N-terminal pro-B-type natriuretic peptide, carbohydrate antigen-125, soluble ST2, interleukin-6, and growth differentiation factor-15 (p < 0.003 for all) also improved. CONCLUSIONS: In patients with HF and diuretic resistance, serial DSR therapy with loop diuretic withdrawal was feasible and associated with substantial and persistent improvement in diuretic resistance and several cardiorenal parameters. If replicated in randomized controlled studies, DSR may represent a novel therapy for diuretic resistance and CRS. CLINICAL TRIAL REGISTRATION: RED DESERT (NCT04116034), SAHARA (NCT04882358).

Hepato-Cardio-Renal Syndrome.

Hepatorenal syndrome has conventionally been regarded as a multisystem syndrome in which pathophysiologic pathways that link cirrhosis with impairment in kidney function are followed by dysfunction of several organs such as the heart. The advances in cardiac studies have helped diagnose more subtle cardiac abnormalities that would have otherwise remained unnoticed in a significant subset of patients with advanced liver disease and cirrhosis. Accumulating data suggests that in many instances, the cardiac dysfunction precedes and predicts development of kidney disease in such patients. These observations point to the heart as a key player in hepatorenal syndrome and challenge the notion that the cardiac abnormalities are either the consequence of aberrancies in hepatorenal interactions or have only minor effects. As such, the disturbances traditionally bundled within hepatorenal syndrome may indeed represent a hepatic form of cardiorenal syndrome whereby the liver affects the kidney in part through cardiorenal pathways (that is, hepato-cardio-renal syndrome).

Renal Sodium Avidity in Heart Failure.

BACKGROUND: Increased renal sodium avidity is a hallmark feature of the heart failure syndrome. SUMMARY: Increased renal sodium avidity refers to the inability of the kidneys to elicit potent natriuresis in response to sodium loading. This eventually causes congestion, which is a major contributor to hospital admissions and mortality in heart failure. KEY MESSAGES: Important novel concepts such as the renal tamponade hypothesis, accelerated nephron loss, and the role of hypochloremia, the sympathetic nervous system, inflammation, the lymphatic system, and interstitial sodium buffers are involved in the pathophysiology of renal sodium avidity. A good understanding of these concepts is crucially important with respect to treatment recommendations regarding dietary sodium restriction, fluid restriction, rapid up-titration of guideline-directed medical therapies, combination diuretic therapy, natriuresis-guided diuretic therapy, use of hypertonic saline, and ultrafiltration.

Rat Models of Cardiorenal Syndrome and Methods for Functional Assessment.

Cardiorenal syndrome (CRS) is a clinical disorder involving combined heart and kidney dysfunction, which leads to poor clinical outcomes. To understand the complex pathophysiology and mechanisms that lie behind this disease setting, and design/evaluate appropriate treatment strategies, suitable animal models are required. Described here are the protocols for establishing surgically induced animal models of CRS including important methods to determine clinically relevant measures of cardiac and renal function, commonly used to assess the degree of organ dysfunction in the model and treatment efficacy when evaluating novel therapeutic strategies.

Practical Approaches to the Management of Cardiorenal Disease beyond Congestion.

BACKGROUND: The coexistence of heart and kidney diseases, also called cardiorenal syndrome, is very common, leads to increased morbidity and mortality, and poses diagnostic and therapeutic difficulties. There is a risk-treatment paradox, such that patients with the highest risk are treated with lesser disease-modifying medical therapies. SUMMARY: In this document, different scientific societies propose a practical approach to address and optimize cardiorenal therapies and related comorbidities systematically in chronic cardiorenal disease beyond congestion. Cardiorenal programs have emerged as novel models that may assist in delivering coordinated and holistic management for these patients. KEY MESSAGES: (1) Cardiorenal disease is a ubiquitous entity in clinical practice and is associated with numerous barriers that limit medical treatment. (2) The present article focuses on the practical approaches to managing chronic cardiorenal disease beyond congestion to overcome some of these barriers and improve the treatment of this high-risk population.