Epidemiology of Cardiorenal Syndrome

Functional state of the kidneys in patients with acute coronary syndrome against the background of newly identified disorders of carbohydrate metabolism: a multidisciplinary problem

BACKGROUND

Determining the relationship between cardiovascular risks, carbohydrate metabolism disorders, and renal dysfunction can help in creating new tools for their management and for better interaction of specialists in a multidisciplinary team. The purpose of this study was to determine the functional state of the kidneys and carbohydrate metabolism in patients with acute coronary syndrome without a history of such disorders.

METHODS

200 patients of the cardiology department of the City Clinical Hospital No. 7 in Almaty were examined using laboratory diagnostics and subsequent statistical data processing.

RESULTS

Acute coronary syndrome develops in 63% of cases against the background of previous disorders of carbohydrate metabolism - prediabetes (45.5%) and type 2 diabetes mellitus (17.5%). In this group of patients, in the presence of disorders of carbohydrate metabolism, in all cases, it is accompanied by acute renal damage. It was noted that diabetes mellitus in newly diagnosed patients actually had a certain duration and occurred much earlier than cardiovascular complications - this was evidenced by an increased level of glycated hemoglobin.

CONCLUSIONS

Such results indicate the need for early diagnosis of cardio-reno-metabolic syndrome in patients with cardiovascular complications, as well as timely administration of drugs that simultaneously have antidiabetic, cardio- and nephroprotective effects.

Independent and joint associations of monocyte to high-density lipoprotein-cholesterol ratio and body mass index with cardiorenal syndrome: insights from NHANES 2003-2020

BACKGROUND

With the development of pathophysiology, cardiorenal syndrome (CRS), a complex and severe disease, has received increasing attention. Monocyte to high-density lipoprotein-cholesterol ratio (MHR) and body mass index (BMI) are independent risk factors for cardiovascular diseases, but their association with CRS remains unexplored. This study aims to explore the independent and joint effects of MHR and BMI on CRS.

METHODS

We included 42,178 NHANES participants. The determination of CRS referred to the simultaneous presence of cardiovascular disease (identified through self-report) and chronic kidney disease (eGFR < 60 mL/min per 1.73 m²). We employed multivariate weighted logistic regression to evaluate the odds ratio (OR) and 95% confidence interval (CI) for the independent and joint associations of MHR and BMI with CRS. We also conducted restricted cubic spines to explore nonlinear associations.

RESULTS

The prevalence of CRS was 3.45% among all participants. An increase in both MHR and BMI is associated with a higher risk of CRS (MHR: OR = 1.799, 95% CI = 1.520-2.129, P < 0.001, P-trend < 0.001; BMI: OR = 1.037, 95% CI = 1.023-1.051, P < 0.001). Individuals who simultaneously fall into the highest quartile of MHR and have a BMI of 30 or more face the highest risk of CRS compared to those in the lowest MHR quartile with a BMI of less than 25 (OR = 3.45, 95% CI = 2.40-4.98, P < 0.001). However, there is no interactive association between MHR and BMI with CRS.

CONCLUSIONS

Higher MHR and BMI are associated with higher odds of CRS. MHR and BMI can serve as tools for early prevention and intervention of CRS, respectively.

Association between echocardiographic indexes and urinary Neutrophil Gelatinase-Associated Lipocalin (uNGAL) in dogs with myxomatous mitral valve disease

Neutrophil gelatinase-associated lipocalin (NGAL) is a biomarker of tubular damage, and its elevation has been described in human and canine cardiorenal syndrome. The aim was to evaluate the association between echocardiographic indexes and urine NGAL (uNGAL) and uNGAL normalized to urine creatinine (uNGALC) in dogs with MMVD. This is a multicentric prospective cross-sectional study. A total of 77 dogs with MMVD at different ACVIM stages were included. All dogs underwent echocardiography, serum chemistry, and urinalysis. Echocardiographic data analyzed were shortening fraction (SF), left ventricular diastolic (LVIDDn) and systolic (LVIDSn) diameters normalized for body weight, left atrium to aortic root ratio (LA/Ao), maximal (LAVMax) and minimal (LAVMin) left atrial volumes, LA stroke volume (LASV), early diastolic mitral peak velocity (EVmax), EVmax to tissue Doppler E' wave (E/E'), aortic (VTIAo) and mitralic (VTIMit) velocity time integrals and their ratio (VTIMit/VTIAo), and tricuspid regurgitation velocity (TRVmax). In the univariate analysis LASV, TRVmax, LAVMax, LVIDDn, and VTIMit/VTIAo were independent predictors of increased uNGAL and uNGALC; however, only LASV [(OR: 1.96, 95% CI: 1.16 to 3.31) P = 0.01 for NGAL, and (OR: 2.79, 95% CI: 1.50 to 5.17) P < 0.001 for NGALC] and TRVmax [(OR: 1.73, 95% CI: 1.20-2.51) P = 0.002 for NGAL, and (OR: 1.50, 95% CI: 10.07-2.10) P = 0.015 for NGALC] remained statistically significant in the multivariable analysis. Based on our results, LASV and TRVmax are associated with increased uNGAL and uNGALC. These parameters might detect dogs with MMVD at higher risk of developing kidney damage.

Unraveling Chronic Cardiovascular and Kidney Disorder through the Butterfly Effect

Chronic Cardiovascular and Kidney Disorder (CCKD) represents a growing challenge in healthcare, characterized by the complex interplay between heart and kidney diseases. This manuscript delves into the "butterfly effect" in CCKD, a phenomenon in which acute injuries in one organ lead to progressive dysfunction in the other. Through extensive review, we explore the pathophysiology underlying this effect, emphasizing the roles of acute kidney injury (AKI) and heart failure (HF) in exacerbating each other. We highlight emerging therapies, such as renin-angiotensin-aldosterone system (RAAS) inhibitors, SGLT2 inhibitors, and GLP1 agonists, that show promise in mitigating the progression of CCKD. Additionally, we discuss novel therapeutic targets, including Galectin-3 inhibition and IL33/ST2 pathway modulation, and their potential in altering the course of CCKD. Our comprehensive analysis underscores the importance of recognizing and treating the intertwined nature of cardiac and renal dysfunctions, paving the way for more effective management strategies for this multifaceted syndrome.

Venous Doppler flow patterns, venous congestion, heart disease and renal dysfunction: A complex liaison

The World Journal of Cardiology published an article written by Kuwahara et al that we take the pleasure to comment on. We focused our attention on venous congestion. In intensive care settings, it is now widely accepted that venous congestion is an important clinical feature worthy of investigation. Evaluating venous Doppler profile abnormalities at multiple sites could suggest adequate treatment and monitor its efficacy. Renal dysfunction could trigger or worsen fluid overload in heart disease, and cardio-renal syndrome is a well-characterized spectrum of disorders describing the complex interactions between heart and kidney diseases. Fluid overload and venous congestion, including renal venous hypertension, are major determinants of acute and chronic renal dysfunction arising in heart disease. Organ congestion from venous hypertension could be involved in the development of organ injury in several clinical situations, such as critical diseases, congestive heart failure, and chronic kidney disease. Ultrasonography and abnormal Doppler flow patterns diagnose clinically significant systemic venous congestion. Cardiologists and nephrologists might use this valuable, non-invasive, bedside diagnostic tool to establish fluid status and guide clinical choices.

Impact of recombinant human brain natriuretic peptide on emergency dialysis and prognosis in end-stage renal disease patients with type 4 cardiorenal syndrome

Recombinant human brain natriuretic peptide (rhBNP) effects on type 4 cardiorenal syndrome (CRS) and adverse events such as heart failure rehospitalization and all-cause mortality have not been assessed in large-scale research. This study evaluated the impact of rhBNP on emergency dialysis and prognosis in end-stage renal disease (ESRD) patients with type 4 CRS, and the risk factors of emergency dialysis. This retrospective cohort study included patients with type 4 CRS and ESRD admitted for decompensated heart failure between January 2016 and December 2021. Patients were divided into the rhBNP and non-rhBNP cohorts, according to whether they were prescribed rhBNP. The primary outcomes were emergency dialysis at first admission and cardiovascular events within a month after discharge. A total of 77 patients were included in the rhBNP cohort (49 males and 28 females, median age 67) and 79 in the non-rhBNP cohort (47 males and 32 females, median age 68). After adjusting for age, residual renal function, and primary diseases, Cox regression analysis showed that rhBNP was associated with emergency dialysis (HR = 0.633, 95% CI 0.420-0.953) and cardiovascular events (HR = 0.410, 95% CI 0.159-0.958). In addition, multivariate logistic regression analysis showed that estimated glomerular filtration rate (eGFR) (OR = 0.782, 95% CI 0.667-0.917, P = 0.002) and procalcitonin (PCT) levels (OR = 1.788, 95% CI 1.193-2.680, P = 0.005) at the first visit were independent risk factors for emergency dialysis while using rhBNP was a protective factor for emergency dialysis (OR = 0.195, 95% CI 0.084-0.451, P < 0.001). This study suggests that RhBNP can improve cardiac function and reduce the occurrence of emergency dialysis and cardiovascular events in ESRD patients with type 4 CRS.

Dapagliflozin protects heart function against type-4 cardiorenal syndrome through activation of PKM2/PP1/FUNDC1-dependent mitophagy

Dapagliflozin (DAPA) confers significant protection against heart and kidney diseases. However, whether DAPA can alleviate type 4 cardiorenal syndrome (CRS-4)-related cardiomyopathy remains unclear. We tested the hypothesis that DAPA attenuates CRS-4-related myocardial damage through pyruvate kinase isozyme M2 (PKM2) induction and FUN14 domain containing 1 (FUNDC1)-related mitophagy. Cardiomyocyte-specific PKM2 knockout (PKM2CKO) and FUNDC1 knockout (FUNDC1CKO) mice were subjected to subtotal (5/6) nephrectomy to establish a CRS-4 model in vivo. DAPA enhanced PKM2 expression and improved myocardial function and structure in vivo, and this effect was abrogated by PKM2 knockdown. A significant improvement in mitochondrial function was observed in HL-1 cells exposed to sera from DAPA-treated mice, as featured by increased ATP production, decreased mtROS production, improved mitochondrial membrane potential, preserved mitochondrial complex activity, and reduced mitochondrial apoptosis. DAPA restored FUNDC1-dependent mitophagy through post-transcriptional dephosphorylation in a manner dependent on PKM2 whereas ablation of FUNDC1 abolished the defensive actions of DAPA on myocardium and mitochondria under CRS-4. Co-IP and molecular docking assays indicated that PKM2 directly interacted with protein phosphatase 1 (PP1) and FUNDC1, leading to PP1-mediated FUNDC1 dephosphorylation. These results suggest that DAPA attenuates CRS-4-related cardiomyopathy through activating the PKM2/PP1/FUNDC1-mitophagy pathway.

Impact of erythropoietin therapy on cardiorenal syndrome: A systematic review with meta-analysis

BACKGROUND

Heart and kidney dysfunction frequently coexist in patients with acute heart failure due to the overlap between these two organ systems. Cardiorenal syndrome (CRS) results from pathology occurring in the heart and kidneys along with the consequences of dysfunction in one organ contributing to dysfunction in the other and vice versa.

AIM

To evaluate the use of erythropoietin (EPO) in patients with CRS and its effects on hemoglobin (Hb), major cardiovascular (CV) events, and hospitalization rates.

METHODS

On February 24, 2022, searches were conducted using PubMed, MEDLINE, and EMBASE, and 148 articles were identified. A total of nine studies were considered in this systematic review. We assessed the included articles based on the National Heart, Lung, and Blood Institute quality assessment tools for controlled intervention and observational cohort or cross-sectional studies. An assessment of bias risk was conducted on the chosen studies, and data relevant to our review was extracted.

RESULTS

The systematic review of these studies concluded that most existing literature indicates that EPO improves baseline Hb levels and decreases myocardial remodeling and left ventricular dysfunction without reducing CV mortality. In addition, the effect of EPO on the hospitalization rate of patients with CRS needs to be further studied since this relationship is unknown. Future studies, such as randomized controlled clinical trials and prospective cohort studies, should be conducted to enhance the literature on the potential of EPO therapy in patients with CRS.

CONCLUSION

Our systematic review suggests that EPO therapy may have a significant role in managing CRS. The review highlights the potential benefits of EPO in improving baseline Hb levels, reducing the risk of major CV events, improving cardiac remodeling, myocardial function, New York Heart Association class, and B-type natriuretic peptide levels. However, the effect of EPO treatment on hospitalization remains unclear and needs further exploration.

A comprehensive review of acute cardio-renal syndrome: need for novel biomarkers

Cardiorenal syndrome represents a wide-spectrum disorder involving the heart and kidneys as the primary affected organs. India has an increasingly high burden of acute CRS, coinciding with the rise in global statistics. Up to 2022, approximately 46.1% of all cardiorenal patients have been diagnosed with acute CRS in India. Acute CRS involves a sudden deterioration of kidney functionalities, referred to as acute kidney injury (AKI) in acute heart failure patients. The pathophysiology of CRS involves hyperactivation of the sympathetic nervous system (SNS) and the renin-angiotensin-aldosterone system (RAAS) following acute myocardial stress. The pathological phenotype of acute CRS is associated with perturbed inflammatory, cellular, and neurohormonal markers in circulation. These complications increase the risk of mortality in clinically diagnosed acute CRS patients, making it a worldwide healthcare burden. Hence, effective diagnosis and early prevention are crucial to prevent the progression of CRS in AHF patients. Present biomarkers, such as serum creatinine (sCr), cystatin C (CysC), glomerular filtration rate (GFR), blood urea nitrogen (BUN), serum and/or urine neutrophil gelatinase-associated lipocalin (NGAL), B-type natriuretic peptide (BNP), and NT-proBNP, are clinically used to diagnose AKI stages in CRS patients but are limitedly sensitive to the early detection of the pathology. Therefore, the need for protein biomarkers is emerging for early intervention in CRS progression. Here, we summarized the cardio-renal nexus in acute CRS, with an emphasis on the present clinicopathological biomarkers and their limitations. The objective of this review is to highlight the need for novel proteomic biomarkers that will curb the burgeoning concern and direct future research trials.

NT-proBNP/urine hepcidin-25 ratio and cardiorenal syndrome type 1 in patients with severe symptomatic aortic stenosis

Background: This study aimed to determine whether novel and conventional cardiorenal biomarkers in patients before transcatheter aortic valve implantation may be associated with cardiorenal syndrome (CRS) type 1. Methods: Serum NT-proBNP and urine biomarkers (hepcidin-25, NGAL, IL-6) were measured before and 24 h after transcatheter aortic valve implantation. Results: 16/95 patients had CRS type 1. Those patients had longer length of stay in hospital (12.5 [9.0-16.0] vs 9.0 [8-12] days; p = 0.025) and were more frequently readmitted to hospital within 6 months after discharge (46.7 vs 15.6%; odds ratio: 4.7; 95% CI: 1.5-15.5; p = 0.007). The NT-proBNP/urine hepcidin-25 ratio (odds ratio: 2.89; 95% CI: 1.30-6.41; p = 0.009) was an independent modifier of CRS type 1. Conclusion: The NT-proBNP/urine hepcidin-25 ratio appears to be a modifier of risk of CRS type 1.

Type 2 diabetes and cardiorenal syndromes. A nationwide French hospital cohort study

AIM

Type 2 diabetes mellitus (T2DM) is a risk factor for cardiac and renal complications; its effect on cardiorenal syndromes is unknown.

METHODS

In a French nationwide cohort of 5,123,193 patients hospitalized in 2012 with ≥5 years of follow-up, we assessed the effect of T2DM on cardiorenal syndrome (CRS) (using cardiorenal, renocardiac, and simultaneous subtypes) incidence and outcomes using 1:1 propensity matching.

RESULTS

Among 4,605,236 adults without cardiorenal syndrome, 380,581 (8.5%) with T2DM were matched to 380,581 adults without T2DM. During follow-up, CRS occurred in 104,788 patients: simultaneous n = 25,225 (24.0%); cardiorenal n = 51,745 (49.4%); renocardiac n = 27,818 (26.5%). T2DM doubled the risk of incident CRS (1.30% versus 0.65%/year; adjusted hazard ratio (HR) for any cardiorenal syndrome: 2.14 [95% confidence interval 2.10;2.19]; renocardiac: 2.43 [2.34;2.53]; cardiorenal: 2.09 [2.03;2.15]; simultaneous: 1.94 [1.86;2.03]. Among the 26,396 adults with CRS in 2012, 11,355 (43.0%) had T2DM and were younger than non-diabetic adults (77.4 ± 9.5 versus 82.3 ± 10.0); 8,314 patients with T2DM were matched to 8,314 patients without. T2DM increased risk of: end-stage kidney disease, adjusted HR 1.50 [1.39;1.62]; myocardial infarction 1.35 [1.19;1.53]; cardiovascular death 1.20 [1.13;1.27]; heart failure 1.17 [1.12;1.21]; and all-cause death 1.09 [1.06;1.13], but not ischemic stroke.

CONCLUSION

Patients with T2DM represent almost half of patients with CRS and are younger than their non-diabetic counterparts. T2DM doubles the risk of CRS and increases the risk of death, cardiovascular outcome, and end-stage kidney disease but not ischemic stroke after CRS.

Acute Cardiorenal Syndrome: An Update

The complex dynamic pathophysiological interplay between the heart and kidney causes a vicious cycle of worsening renal and/or cardiovascular function. Acute decompensated heart failure causing worsening renal function defines Type 1 cardiorenal syndrome (CRS). Altered hemodynamics coupled with a multitude of nonhemodynamic factors namely pathological activation of the renin angiotensin aldosterone system and systemic inflammatory pathways mechanistically incite CRS type 1. A multipronged diagnostic approach utilizing laboratory markers, noninvasive and/or invasive modalities must be implemented to enable timely initiation of effective treatment strategies. In this review, we discuss the pathophysiology, diagnosis, and emerging treatment options for CRS type 1.

Caractéristiques et mortalité des patients avec et sans syndrome cardio-rénal traités par dialyse péritonéale en France

IntroductionGlobalement, la dialyse péritonéale (DP) est de plus en plus indiquée dans l’insuffisance cardiaque réfractaire. Cette étude a pour but d’analyser les caractéristiques et la survie des patients traités par DP, en les divisant en deux groupes, avec et sans syndrome cardio-rénal (CRS). MéthodesIl s’agit d’une étude rétrospective incluant tous les patients inscrits dans le Registre de Dialyse Péritonéale de Langue Française (RDPLF) entre le 01/01/2010 et le 01/12/2021. La cohorte a été divisée en deux groupes afin de comparer les patients avec et sans CRS. La survie a été analysée par la méthode de Kaplan Meier et une régression de Cox a identifié les facteurs associés avec la mortalité dans les deux groupes. Résultats11730 patients en DP ont été inclus. L’âge moyen était de 66.78±16.72 ans. 766 patient (6,53 %) ont été pris en charge en DP pour CRS et 10 964 pour une autre néphropathie. Les malades avec CRS étaient plus âgés et comorbides. La survie est significativement meilleure dans le groupe sans CRS (Log Rank test < 0.001). La médiane de survie est de 17.7±1.2 mois et 49.6±0.7 mois chez les patients avec et sans CRS respectivement. En analyse multivariée, l’âge, le sexe masculin, le diabète, les pathologies cardio-vasculaires et le manque d’autonomie sont liés à une mortalité accrue dans le groupe sans CRS. Par contre, chez les patients avec CRS, seules les variables âge et antécédent d’hépatopathie sont significativement associées à un sur risque de décès. Le nombre de péritonites présentées par le patient est significativement associé à un moindre risque de décès dans les deux groupes. ConclusionCette étude nationale portant sur un grand nombre de patients traités par DP a révélé les grandes différences dans les caractéristiques et la survie entre ceux qui ont un CRS contre ceux qui n’en ont pas. En particulier, les deux facteurs les plus liés à la mortalité dans le groupe avec CRS sont l’âge et la pathologie hépatique.

A molecular phenotypic screen reveals that lobetyolin alleviates cardiac dysfunction in 5/6 nephrectomized mice by inhibiting osteopontin

BACKGROUND

Cardiovascular diseases are the major cause of mortality in patients with advanced chronic kidney diseases. The predominant abnormality observed among this population is cardiac dysfunction secondary to myocardial remodelings, such as hypertrophy and fibrosis, emphasizing the need to develop potent therapies that maintain cardiac function in patients with end-stage renal disease.

AIMS

To identify potential compounds and their targets as treatments for cardiorenal syndrome type 4 (CRS) using molecular phenotyping and in vivo/in vitro experiments.

METHODS

Gene expression was assessed using bioinformatics and verified in animal experiments using 5/6 nephrectomized mice (NPM). Based on this information, a molecular phenotyping strategy was pursued to screen potential compounds. Picrosirius red staining, wheat germ agglutinin staining, Echocardiography, immunofluorescence staining, and real-time quantitative PCR (qPCR) were utilized to evaluate the effects of compounds on CRS in vivo. Furthermore, qPCR, immunofluorescence staining and flow cytometry were applied to assess the effects of these compounds on macrophages/cardiac fibroblasts/cardiomyocytes. RNA-Seq analysis was performed to locate the targets of the selected compounds. Western blotting was performed to validate the targets and mechanisms. The reversibility of these effects was tested by overexpressing Osteopontin (OPN).

RESULTS

OPN expression increased more remarkably in individuals with uremia-induced cardiac dysfunction than in other cardiomyopathies. Lobetyolin (LBT) was identified in the compound screen, and it improved cardiac dysfunction and suppressed remodeling in NPM mice. Additionally, OPN modulated the effect of LBT on cardiac dysfunction in vivo and in vitro. Further experiments revealed that LBT suppressed OPN expression via the phosphorylation of c-Jun N-terminal protein kinase (JNK) signaling pathway.

CONCLUSIONS

LBT improved CRS by inhibiting OPN expression through the JNK pathway. This study is the first to describe a cardioprotective effect of LBT and provides new insights into CRS drug discovery.

Heart Failure and Cardiorenal Syndrome: A Narrative Review on Pathophysiology, Diagnostic and Therapeutic Regimens-From a Cardiologist's View

In cardiorenal syndrome (CRS), heart failure and renal failure are pathophysiologically closely intertwined by the reciprocal relationship between cardiac and renal injury. Type 1 CRS is most common and associated with acute heart failure. A preexistent chronic kidney disease (CKD) is common and contributes to acute kidney injury (AKI) in CRS type 1 patients (acute cardiorenal syndrome). The remaining CRS types are found in patients with chronic heart failure (type 2), acute and chronic kidney diseases (types 3 and 4), and systemic diseases that affect both the heart and the kidney (type 5). Establishing the diagnosis of CRS requires various tools based on the type of CRS, including non-invasive imaging modalities such as TTE, CT, and MRI, adjuvant volume measurement techniques, invasive hemodynamic monitoring, and biomarkers. Albuminuria and Cystatin C (CysC) are biomarkers of glomerular filtration and integrity in CRS and have a prognostic impact. Comprehensive "all-in-one" magnetic resonance imaging (MRI) approaches, including cardiac magnetic resonance imaging (CMR) combined with functional MRI of the kidneys and with brain MRI are proposed for CRS. Hospitalizations due to CRS and mortality are high. Timely diagnosis and initiation of effective adequate therapy, as well as multidisciplinary care, are pertinent for the improvement of quality of life and survival. In addition to the standard pharmacological heart failure medication, including SGLT2 inhibitors (SGLT2i), renal aspects must be strongly considered in the context of CRS, including control of the volume overload (diuretics) with special caution on diuretic resistance. Devices involved in the improvement of myocardial function (e.g., cardiac resynchronization treatment in left bundle branch block, mechanical circulatory support in advanced heart failure) have also shown beneficial effects on renal function.

Uremic toxins in chronic kidney disease highlight a fundamental gap in understanding their detrimental effects on cardiac electrophysiology and arrhythmogenesis

Chronic kidney disease (CKD) and cardiovascular disease (CVD) have an estimated 700-800 and 523 million cases worldwide, respectively, with CVD being the leading cause of death in CKD patients. The pathophysiological interplay between the heart and kidneys is defined as the cardiorenal syndrome (CRS), in which worsening of kidney function is represented by increased plasma concentrations of uremic toxins (UTs), culminating in dialysis patients. As there is a high incidence of CVD in CKD patients, accompanied by arrhythmias and sudden cardiac death, knowledge on electrophysiological remodeling would be instrumental for understanding the CRS. While the interplay between both organs is clearly of importance in CRS, the involvement of UTs in pro-arrhythmic remodeling is only poorly investigated, especially regarding the mechanistic background. Currently, the clinical approach against potential arrhythmic events is mainly restricted to symptom treatment, stressing the need for fundamental research on UT in relation to electrophysiology. This review addresses the existing knowledge of UTs and cardiac electrophysiology, and the experimental research gap between fundamental research and clinical research of the CRS. Clinically, mainly absorbents like ibuprofen and AST-120 are studied, which show limited safe and efficient usability. Experimental research shows disturbances in cardiac electrical activation and conduction after inducing CKD or exposure to UTs, but are scarcely present or focus solely on already well-investigated UTs. Based on UTs data derived from CKD patient cohort studies, a clinically relevant overview of physiological and pathological UTs concentrations is created. Using this, future experimental research is stimulated to involve electrophysiologically translatable animals, such as rabbits, or in vitro engineered heart tissues.

Current considerations for heart-kidney transplantation

Cardiorenal syndrome is a complex syndrome characterized by dysfunction of the heart and kidneys in an interdependent fashion and is further divided into different subtypes based on primary organ dysfunction. Simultaneous Heart-Kidney transplantation is the treatment of choice for end-stage irreversible dysfunction of both organs, however it may be avoided with determination of cardiorenal subtype and management of primary organ dysfunction. This article discusses types of cardiorenal syndrome, indications and concerns regarding the use of simultaneous heart-kidney transplantation, and outlines algorithms for determination of need for dual vs. single organ transplantation.

Cardiorenal syndrome: Pathophysiology as a key to the therapeutic approach in an under-diagnosed disease

Cardiorenal syndrome is a clinical condition that impacts both the heart and the kidneys. One organ's chronic or acute impairment can lead to the other's chronic or acute dysregulation. The cardiorenal syndrome has been grouped into five subcategories that describe the etiology, pathophysiology, duration, and pattern of cardiac and renal dysfunction. This classification reflects the large spectrum of interrelated dysfunctions and underlines the bidirectional nature of heart-kidney interactions. However, more evidence is needed to apply these early findings in medical practice. Understanding the relationship between these two organs during each organ's impairment has significant clinical implications that are relevant for therapy in both chronic and acute conditions. The epidemiology, definition, classification, pathophysiology, therapy, and outcome of each form of cardiorenal syndrome are all examined in this review.

Eplerenone Prevents Cardiac Fibrosis by Inhibiting Angiogenesis in Unilateral Urinary Obstruction Rats

Introduction

Cardiovascular disease constitutes the leading cause of mortality in patients with chronic kidney disease (CKD), which is termed cardiorenal syndrome type 4 (CRS-4). Here, we report the development of pathological cardiac remodeling and fibrosis in unilateral urinary obstruction (UUO) rats.

Methods

Hematoxylin and eosin (H&E) staining was performed to observe the pathology of myocardial tissue. The degree of myocardial tissue fibrosis was observed by Masson and Sirius red staining. Immunohistochemical staining was applied to detect the expression of CD34 and CD105 in myocardial tissue, and immunofluorescent staining was performed to examine the expression of CD34, collagen I/collagen III, and alpha smooth muscle actin (α-SMA). The expression of the signal pathway-related proteins vascular endothelial growth factor A (VEGFA), vascular endothelial growth factor receptor 2 (VEGFR2), nuclear factor κB (NF-κB), and interleukin (IL)-1β was tested by western blotting. Reverse transcription-polymerase chain reaction (RT-PCR) was used to detect the mRNA levels of serum and glucocorticoid-inducible kinase (SGK)-1, NF-κB, and interleukin-1β (IL-1β).

Results

The results showed the development of pathological cardiac remodeling and cardiac dysfunction in UUO rats. Moreover, there was more angiogenesis and endothelial-mesenchymal transition (End-MT) in the UUO group, and these effects were inhibited by eplerenone.

Conclusions

The results indicated that this cardiac fibrosis was associated with angiogenesis and that End-MT was related to aldosterone and mineralocorticoid receptor (MR) activation. Moreover, in association with the MR/IL-1β/VEGFA signaling pathway, early treatment with the MR antagonist eplerenone in rats with UUO-induced CKD may significantly attenuate MR activation and cardiac fibrosis.

Lung function impairment and risk of incident heart failure: the NHLBI Pooled Cohorts Study

AIMS

The aim is to evaluate associations of lung function impairment with risk of incident heart failure (HF).

METHODS AND RESULTS

Data were pooled across eight US population-based cohorts that enrolled participants from 1987 to 2004. Participants with self-reported baseline cardiovascular disease were excluded. Spirometry was used to define obstructive [forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC) <0.70] or restrictive (FEV1/FVC ≥0.70, FVC <80%) lung physiology. The incident HF was defined as hospitalization or death caused by HF. In a sub-set, HF events were sub-classified as HF with reduced ejection fraction (HFrEF; EF <50%) or preserved EF (HFpEF; EF ≥50%). The Fine-Gray proportional sub-distribution hazards models were adjusted for sociodemographic factors, smoking, and cardiovascular risk factors. In models of incident HF sub-types, HFrEF, HFpEF, and non-HF mortality were treated as competing risks. Among 31 677 adults, there were 3344 incident HF events over a median follow-up of 21.0 years. Of 2066 classifiable HF events, 1030 were classified as HFrEF and 1036 as HFpEF. Obstructive [adjusted hazard ratio (HR) 1.17, 95% confidence interval (CI) 1.07-1.27] and restrictive physiology (adjusted HR 1.43, 95% CI 1.27-1.62) were associated with incident HF. Obstructive and restrictive ventilatory defects were associated with HFpEF but not HFrEF. The magnitude of the association between restrictive physiology and HFpEF was similar to associations with hypertension, diabetes, and smoking.

CONCLUSION

Lung function impairment was associated with increased risk of incident HF, and particularly incident HFpEF, independent of and to a similar extent as major known cardiovascular risk factors.

Experimental models of acute kidney injury for translational research

Preclinical models of human disease provide powerful tools for therapeutic discovery but have limitations. This problem is especially apparent in the field of acute kidney injury (AKI), in which clinical trial failures have been attributed to inaccurate modelling performed largely in rodents. Multidisciplinary efforts such as the Kidney Precision Medicine Project are now starting to identify molecular subtypes of human AKI. In addition, over the past decade, there have been developments in human pluripotent stem cell-derived kidney organoids as well as zebrafish, rodent and large animal models of AKI. These organoid and AKI models are being deployed at different stages of preclinical therapeutic development. However, the traditionally siloed, preclinical investigator-driven approaches that have been used to evaluate AKI therapeutics to date rarely account for the limitations of the model systems used and have given rise to false expectations of clinical efficacy in patients with different AKI pathophysiologies. To address this problem, there is a need to develop more flexible and integrated approaches, involving teams of investigators with expertise in a range of different model systems, working closely with clinical investigators, to develop robust preclinical evidence to support more focused interventions in patients with AKI.

Risk Factors and Outcome Variables of Cardiorenal Syndrome Type 1 in Acute Myocardial Infarction Patients

Purpose

This study’s goal was to explore risk factors affecting short-term prognosis of cardiorenal syndrome type 1 (CRS1) in acute myocardial infarction (AMI) patients.

Methods

In this retrospective analysis of CRS1 in AMI patients hospitalized from January 2011 to December 2014, the patients were classified into deceased or survivor groups. Clinical data, including demographics, laboratory results, and 28-day outcomes, were collected.

Results

The incidence rate of CRS1 in AMI patients was 15.2% (274 in 1801). Ultimately, 88 patients were enrolled and 25 (28.4%) were classified into the deceased group, while 63 were classified into the survivor group. There were statistically significant differences between the groups for hypertension, mechanical ventilation, KIDGO stage, NT-proBNP, Hb, ALB, PCI, decreased LVEF, 7th-day SCr value, and the highest SCr value recorded within 7 days (all P < 0.05). Multivariate logistic regression showed that the following factors were significantly related to whether a patient died: requiring mechanical ventilation, increased NT-proBNP levels and 7th-day SCr values, and decreased LVEFs. The APACHE II, SOFA, and SASP II scores on the 7th day were significantly higher in the deceased group (all P < 0.05). The accuracy of APACHE II, SOFA, and SASP II scores on the 7th day for predicting death were 84.1%, 78.4% and 79.5%, respectively. The AUC of 7th-day APACHE II, SOFA, and SASP II scores was 0.844, 0.803, and 0.827, respectively, with no statistically significant differences between the three scores (P > 0.05).

Conclusion

The mortality rate of CRS1 in AMI patients was 28.4% (25 in 88) within 28 days. Mechanical ventilation, increased NT-proBNP levels, the 7th-day SCr value, and decreased LVEF were related to death in AMI patients with CRS1. APACHE II, SOFA, and SAPS II scores on the 7th day were satisfactorily accurate in predicting death within 28 days.

Siddha fasting in obese acute decompensated heart failure may improve hospital outcomes through empowerment and natural ketosis

BACKGROUND

Morbid obesity (BMI > 35 kg/m2 with comorbid conditions) is present in 25 - 35% of acute decompensated heart failure (AHF) patients. Prevalence of HF increases with duration of morbid obesity from 30% at 15 years to over 90% at 30 years. There is a need to develop pragmatic therapies that address the unique physical and mental challenges faced by obese AHF patients. Siddha is 5,000 year old Tamil Medicine using yoga and mind-body methods towards higher consciousness. Hunger gratitude Experience (HUGE) is intuitive Siddha fasting method which may improve in-hospital AHF outcomes independent of weight reduction.

CASE SUMMARY

We present 5 cases of morbidly obese patients with cardiorenal syndrome (CRS) that began intermittent fasting either during their AHF hospitalization or in the outpatient setting for refractory symptoms despite hospitalization. Initiation of fasting correlated with reduction of respiratory distress and edema as well as improvements in psychological wellbeing and functional capacity.

DISCUSSION

Siddha fasting mediates hemodynamic and anti-inflammatory effects through natural ketosis and psychological benefits through empowerment in AHF. Potential role of fasting in reducing myocardial workload, coronary steal, angina, volume overload, and CRS needs further study in cardiac patients.

Attenuation of Circulating Trimethylamine N-Oxide Prevents the Progression of Cardiac and Renal Dysfunction in a Rat Model of Chronic Cardiorenal Syndrome

Chronic heart failure (HF) frequently causes progressive decline in kidney function, known as cardiorenal syndrome-2 (CRS2). Current treatment options for CRS2 remain unacceptably limited. Trimethylamine-N-oxide (TMAO), a metabolite of gut microbiota, has recently been implicated in the pathogenesis of both HF and chronic kidney disease. Here we examined whether circulating TMAO is elevated in CRS2 and if so, whether attenuation of circulating TMAO would ameliorate the progression of CRS2. Sprague-Dawley rats underwent surgery for myocardial infarction (MI) or sham (week 0) followed by subtotal (5/6) nephrectomy (STNx) or sham at week 4 to induce CRS2 or control. At week 6, MI + STNx rats and control rats received vehicle or 1.0% 3,3-Dimethyl-1-butanol (DMB, a TMAO inhibitor) treatment for 8 weeks. Compared with control rats, MI + STNx rats exhibited elevated serum TMAO at week 6, which was increased further at week 14 but was attenuated by DMB treatment. MI + STNx rats showed cardiac dysfunction as assessed by echocardiography and renal dysfunction as evidenced by increased serum creatinine and urinary kidney injury molecule-1 and decreased creatinine clearance at week 6. The cardiac and renal dysfunction in MI + STNx rats was exacerbated at week 14 but was prevented by DMB treatment. Molecular and histological studies revealed myocyte hypertrophy and increases in interstitial myocardial fibrosis and gene expression of pro-hypertrophic and pro-fibrotic markers in both heart and kidney at week 14, which were accompanied by elevated gene expression of proinflammatory cytokines. The changes in molecular and histological parameters observed in MI + STNx rats were significantly reduced by DMB treatment. These findings suggest that rats with CRS2 have elevated circulating TMAO, which is associated with the exacerbation of cardiac and renal dysfunction. Attenuation of circulating TMAO can ameliorate cardiac and renal injury and prevents the progression of CRS2.

Using Deep-Learning Algorithms to Simultaneously Identify Right and Left Ventricular Dysfunction From the Electrocardiogram

OBJECTIVES

This study sought to develop DL models capable of comprehensively quantifying left and right ventricular dysfunction from ECG data in a large, diverse population.

BACKGROUND

Rapid evaluation of left and right ventricular function using deep learning (DL) on electrocardiograms (ECGs) can assist diagnostic workflow. However, DL tools to estimate right- ventricular (RV) function do not exist, whereas those to estimate left ventricular (LV) function are restricted to quantification of very low LV function only.

METHODS

A multicenter study was conducted with data from 5 New York City hospitals: 4 for internal testing and 1 serving as external validation. We created novel DL models to classify left ventricular ejection fraction (LVEF) into categories derived from the latest universal definition of heart failure, estimate LVEF through regression, and predict a composite outcome of either RV systolic dysfunction or RV dilation.

RESULTS

We obtained echocardiogram LVEF estimates for 147,636 patients paired to 715,890 ECGs. We used natural language processing (NLP) to extract RV size and systolic function information from 404,502 echocardiogram reports paired to 761,510 ECGs for 148,227 patients. For LVEF classification in internal testing, area under curve (AUC) at detection of LVEF ≤40%, 40% < LVEF ≤50%, and LVEF >50% was 0.94 (95% CI: 0.94-0.94), 0.82 (95% CI: 0.81-0.83), and 0.89 (95% CI: 0.89-0.89), respectively. For external validation, these results were 0.94 (95% CI: 0.94-0.95), 0.73 (95% CI: 0.72-0.74), and 0.87 (95% CI: 0.87-0.88). For regression, the mean absolute error was 5.84% (95% CI: 5.82%-5.85%) for internal testing and 6.14% (95% CI: 6.13%-6.16%) in external validation. For prediction of the composite RV outcome, AUC was 0.84 (95% CI: 0.84-0.84) in both internal testing and external validation.

CONCLUSIONS

DL on ECG data can be used to create inexpensive screening, diagnostic, and predictive tools for both LV and RV dysfunction. Such tools may bridge the applicability of ECGs and echocardiography and enable prioritization of patients for further interventions for either sided failure progressing to biventricular disease.

Fibrosis, the Bad Actor in Cardiorenal Syndromes: Mechanisms Involved

Cardiorenal syndrome is a term that defines the complex bidirectional nature of the interaction between cardiac and renal disease. It is well established that patients with kidney disease have higher incidence of cardiovascular comorbidities and that renal dysfunction is a significant threat to the prognosis of patients with cardiac disease. Fibrosis is a common characteristic of organ injury progression that has been proposed not only as a marker but also as an important driver of the pathophysiology of cardiorenal syndromes. Due to the relevance of fibrosis, its study might give insight into the mechanisms and targets that could potentially be modulated to prevent fibrosis development. The aim of this review was to summarize some of the pathophysiological pathways involved in the fibrotic damage seen in cardiorenal syndromes, such as inflammation, oxidative stress and endoplasmic reticulum stress, which are known to be triggers and mediators of fibrosis.

Fighting Oxidative Stress with Sulfur: Hydrogen Sulfide in the Renal and Cardiovascular Systems

Hydrogen sulfide (H2S) is an essential gaseous signaling molecule. Research on its role in physiological and pathophysiological processes has greatly expanded. Endogenous enzymatic production through the transsulfuration and cysteine catabolism pathways can occur in the kidneys and blood vessels. Furthermore, non-enzymatic pathways are present throughout the body. In the renal and cardiovascular system, H2S plays an important role in maintaining the redox status at safe levels by promoting scavenging of reactive oxygen species (ROS). H2S also modifies cysteine residues on key signaling molecules such as keap1/Nrf2, NFκB, and HIF-1α, thereby promoting anti-oxidant mechanisms. Depletion of H2S is implicated in many age-related and cardiorenal diseases, all having oxidative stress as a major contributor. Current research suggests potential for H2S-based therapies, however, therapeutic interventions have been limited to studies in animal models. Beyond H2S use as direct treatment, it could improve procedures such as transplantation, stem cell therapy, and the safety and efficacy of drugs including NSAIDs and ACE inhibitors. All in all, H2S is a prime subject for further research with potential for clinical use.

Association between left ventricular diastolic dysfunction and septic acute kidney injury in severe sepsis and septic shock: A multicenter retrospective study

INTRODUCTION

Left ventricular diastolic dysfunction (LVDD) adversely impacts renal function, and E/e' is a significant predictor of adverse kidney events under different clinical conditions. However, no studies have evaluated the association between LVDD and septic acute kidney injury (AKI) among patients with severe sepsis and septic shock.

METHODS

This multicenter retrospective study evaluated adult patients with severe sepsis or septic shock between January 1, 2013, and December 31, 2019, who underwent echocardiography within 24 hours after admission to an intensive care unit.

RESULTS

A total of 495 adult patients were enrolled in the study. LVDD grades II and III were associated with severe (stage 3) AKI (p < 0.001, p for trend < 0.001). E/e' and e' were risk factors for septic AKI (OR, 1.155; 95% CI, 1.088-1.226, p < 0.001; and OR, 7.218; 95% CI, 2.942-17.712, p < 0.001, respectively) in the multivariate logistic regression analysis. The area under the receiver operating characteristic curve of E/e' and e' was 0.728 (95% CI, 0.680-0.777, p < 0.001) and 0.715 (95% CI, 0.665-0.764, p < 0.001), respectively.

CONCLUSIONS

LVDD was associated with septic AKI, and E/e' and e' are useful predictors of septic AKI among patients with severe sepsis or septic shock.

TRIAL REGISTRATION

The study was registered at the Chinese Clinical Trial Registry (Protocol No. ChiCTR2000033083).

RNA interactions in right ventricular dysfunction induced type II cardiorenal syndrome

Right ventricular (RV) dysfunction induced type II cardiorenal syndrome (CRS) has a high mortality rate, but little attention has been paid to this disease, and its unique molecular characteristics remain unclear. This study aims to investigate the transcriptomic expression profile in this disease and identify key RNA pairs that regulate related molecular signaling networks. We established an RV dysfunction-induced type II CRS mouse model by pulmonary artery constriction (PAC). PAC mice developed severe RV hypertrophy and fibrosis; renal atrophy and dysfunction with elevated creatinine were subsequently observed. Expression profiles in RV and kidney tissues were obtained by whole transcriptome sequencing, revealing a total of 741 and 86 differentially expressed (DE) mRNAs, 159 and 29 DEmiRNAs and 233 and 104 DEcircRNAs between RV and kidney tissue, respectively. Competing endogenous RNA (ceRNA) networks were established. A significant alteration in proliferative, fibrotic and metabolic pathways was found based on GO and KEGG analyses, and the network revealed key ceRNA pairs, such as novel_circ_002631/miR-181a-5p/Creb1 and novel_circ_002631/miR-33-y/Kpan6. These findings indicate that significantly dysregulated pathways in RV dysfunction induced type II CRS include Ras, PI3K/Akt, cGMP-PKG pathways, and thyroid metabolic pathways. These ceRNA pairs can be considered potential targets for the treatment of type II CRS.

MicroRNAs in Chronic Kidney Disease: Four Candidates for Clinical Application

There are still major challenges regarding the early diagnosis and treatment of chronic kidney disease (CKD), which is in part due to the fact that its pathophysiology is very complex and not clarified in detail. The diagnosis of CKD commonly is made after kidney damage has occurred. This highlights the need for better mechanistic insight into CKD as well as improved clinical tools for both diagnosis and treatment. In the last decade, many studies have focused on microRNAs (miRs) as novel diagnostic tools or clinical targets. MiRs are small non-coding RNA molecules that are involved in post-transcriptional gene regulation and many have been studied in CKD. A wide array of pre-clinical and clinical studies have highlighted the potential role for miRs in the pathogenesis of hypertensive nephropathy, diabetic nephropathy, glomerulonephritis, kidney tubulointerstitial fibrosis, and some of the associated cardiovascular complications. In this review, we will provide an overview of the miRs studied in CKD, especially highlighting miR-103a-3p, miR-192-5p, the miR-29 family and miR-21-5p as these have the greatest potential to result in novel therapeutic and diagnostic strategies.

An Update on the Pathophysiology and Treatment of Cardiorenal Syndrome

Cardiorenal syndrome (CRS) encompasses various disorders of the heart and kidneys; dysfunction of one organ leads to acute or chronic dysfunction of the other. It incorporates the intersection of heart-kidney interactions across several mediums, hemodynamically, through the alterations in neurohormonal markers, and increased venous and renal pressure, all of which are hallmarks of its clinical phenotypes. This article explores the epidemiology, pathology, classification and treatment of each type of CRS.