Cardiorenal Syndrome in the Hospital

Gut microbiota-derived metabolites: Potential targets for cardiorenal syndrome

The characteristic of cardiorenal syndrome (CRS) is simultaneous damage to both the heart and kidneys. CRS has caused a heavy burden of mortality and incidence rates worldwide. The regulation of host microbiota metabolism that triggers heart and kidney damage is an emerging research field that promotes a new perspective on cardiovascular risk. We summarize current studies from bench to bedside of gut microbiota-derived metabolites to better understand CRS in the context of gut microbiota-derived metabolites. We focused on the involvement of gut microbiota-derived metabolites in the pathophysiology of CRS, including lipid and cholesterol metabolism disorders, coagulation abnormalities and platelet aggregation, oxidative stress, endothelial dysfunction, inflammation, mitochondrial damage and energy metabolism disorders, vascular calcification and renal fibrosis, as well as emerging therapeutic approaches targeting CRS metabolism in gut microbiota-derived metabolites which provides an innovative treatment approach for CRS to improve patient prognosis and overall quality of life.

Lack of ALCAT1 enhances the protective effects of aerobic exercise on kidney in HFpEF mice

AIMS

Heart failure with preserved ejection fraction (HFpEF) is an increasingly prevalent cardiovascular disease, which is often accompanied by kidney dysfunction. Exercise has been recognized as a feasible strategy to improve renal function. The aim of this study was to investigate whether aerobic exercise (AE) could ameliorate HFpEF-induced renal injury by regulating the expression of acyl-coenzyme A: lysocardiolipin acyltransferase-1 (ALCAT1).

MATERIALS AND METHODS

Eight-week-old C57BL/6 and Alcat1 knockout mice were used to establish a HFpEF induced kidney injury model. Mice in the exercise-intervention group were performed a six-week of AE training. Cardiac function and blood pressure were assessed using echocardiography and a non-invasive intelligent blood pressure monitor. Renal morphology and function were detected by HE, Masson, and PAS staining, as well as biochemical assays using commercial kits. Oxidative stress, inflammation, apoptosis, and renal fibrosis-related proteins were detected by Western Blotting.

KEY FINDINGS

In the HFpEF induced kidney injury model, ALCAT1 protein expression was upregulated, accompanied by cardiac and renal dysfunction. These pathological changes were reversed by AE. In addition, Alcat1 knockout significantly alleviated HFpEF-induced oxidative stress, inflammation, apoptosis, and fibrosis in the kidneys. Furthermore, Alcat1 knockout further enhanced the protective effects of exercise, ameliorating renal injury and improving renal function in HFpEF mice.

SIGNIFICANCE

AE significantly improved renal function by alleviating oxidative stress, inflammation, apoptosis, and fibrosis in HFpEF mice. These beneficial effects were further enhanced in the lack of ALCAT1. Thus, ALCAT1 might represent a potential therapeutic target for the treatment of HFpEF-induced kidney injury.

Prognostic Markers of Adverse Outcomes in Acute Heart Failure: Use of Machine Learning and Network Analysis with Real Clinical Data

Background: Acute heart failure (AHF) is one of the leading causes of admissions to the emergency department (ED). There is a need to develop an easy-to-use score that can be used in the ED to risk-stratify patients with AHF and in hospitalization decisions regarding cardiac wards or intensive care units (ICUs). Methods: A retrospective observational study was conducted at a city hospital. The data from the presentation of AHF patients at the ED were collected. The combined primary endpoint included death from any cause during hospitalization or transfer to an intensive care unit (ICU) for using inotropes/vasopressors. Feature selection was performed using artificial intelligence. Results: From August 2020 to August 2021, 908 patients were enrolled (mean age: 71.6 ± 13 years; 500 (55.1%) men). We found significant predictors of in-hospital mortality and ICU transfers for inotrope/vasopressor use and built two models to assess the need for ICU admission of patients from the ED. The first model included SpO2 < 90%, QTc duration, prior diabetes mellitus and HF diagnosis, serum chloride concentration, respiratory rate and atrial fibrillation on admission, blood urea nitrogen (BUN) levels, and any implanted devices. The second model included left ventricular end-diastolic size, systolic blood pressure, pulse blood pressure, BUN levels, right atrium size, serum chloride, sodium and uric acid concentrations, prior loop diuretic use, and pulmonary artery systolic blood pressure. Conclusions: We developed two models that demonstrated a high negative predictive value, which allowed us to distinguish patients with low risk and determine patients who can be hospitalized and sent from the ED to the floor. These easy-to-use models can be used at the ED.

Inverse associations of the lifestyle critical 9 with cardiorenal syndrome: the mediating role of the dietary inflammatory index

Background

Cardiorenal syndrome (CRS) represents a burgeoning global health concern characterized by its increasing prevalence. Life's Crucial 9 (LC9), an innovative tool for cardiovascular health assessment, and the Dietary Inflammatory Index (DII), which quantifies diet's impact on body inflammation, have not been previously studied in conjunction regarding their association with CRS.

Objective

This study aims to explore the relationship between LC9 and CRS, using data from the National Health and Nutrition Examination Survey (NHANES), and to examine whether DII serves as a mediator in this association.

Methods

This research included data from 25,792 NHANES participants spanning from 2005 to 2018. The study leverages the dataset's comprehensive representativeness and robust statistical power to ensure generalizable and reliable findings. We employed weighted logistic regression to evaluate the association between LC9 scores and CRS presence, conducted subgroup analyses, and performed mediation analysis to investigate the role of DII.

Results

Our analysis demonstrated a significant inverse relationship between LC9 and CRS. Upon controlling for confounders, each 10-point rise in LC9 correlates with a 26% reduction in CRS prevalence (p < 0.001). Additionally, stratifying LC9 into tertiles with T1 as the reference group revealed that T2 (OR = 0.59, 95% CI = 0.48-0.72, p < 0.001) and T3 (OR = 0.57, 95% CI = 0.38-0.88, p < 0.001) exhibited a strong negative correlation trend. The dose-response curve illustrates a linear relationship between LC9 and CRS; as LC9 increases, the occurrence of CRS decreases. DII shows a significant positive connection with CRS (p < 0.001), but DII indicates a decreasing trend when LC9 rises (β = -0.65, p < 0.001). Mediation analysis reveals that DII mediates the association between LC9 and CRS, with a mediation proportion of 12.5% (p < 0.001).

Conclusion

The findings indicate a robust inverse correlation between LC9 scores and CRS incidence, with DII is associated with this relationship. This suggests potential preventive strategies against CRS through lifestyle modifications guided by LC9.

Clinical outcomes in patients with cardiorenal multimorbidity: the role of serum uric acid/serum creatinine ratio

INTRODUCTION

Serum uric acid (SUA), the final product of purine metabolism, is an independent risk factor for cardiovascular (CV) disease. Since SUA levels depend on renal function, SUA to serum creatinine ratio (SUA/sCr) is emerging as a more specific biomarker of CV risk.

AIM

To evaluate in hospitalized patients with cardiorenal multimorbidity (CRM) if the SUA/sCr ≥ 5.35 is associated with clinical outcomes. The primary outcome was in-hospital mortality. The secondary outcome was the composite of all-cause of mortality and adverse clinical events.

METHODS

We conducted a retrospective review of medical records from consecutive CRM inpatients admitted to the medical ward. The composite endpoint was calculated as all-cause mortality and adverse clinical events such as acute coronary syndrome, stroke, infections, and renal replacement therapy.

RESULTS

In our cohort, 141 patients (mean age of 75.6 ± 10.2 years) were identified with CRM. In-hospital mortality occurred in 17 patients (16%), and 64 patients (60.4%) experienced adverse clinical outcomes. Among the 106 patients, 20 (18.9%) had an SUA/sCr ≥ 5.35, while 86 (81.1%) had an SUA/sCr < 5.35. Male gender was significantly associated with SUA/sCr ≥ 5.35 (p = 0.007). In-hospital mortality was significantly higher in patients with SUA/sCr ≥ 5.35 (p = 0.010), and a positive correlation with adverse clinical outcomes was documented in this subgroup (p = 0.012).

CONCLUSION

in patients with CRM, SUA/sCr ≥ 5.35 is associated with increased in-hospital mortality and worse clinical outcomes. The ratio and related cut-off value of SUA/sCr could represent a useful biomarker to assess in-hospital complications in CRM patients.

Cardiorenal syndrome: evolving concepts and pediatric knowledge gaps

Cardiorenal syndrome (CRS) refers to concomitant dysfunction of both the heart and kidneys. The pathology in CRS is bidirectional. Many individuals with kidney disease will develop cardiovascular complications. Conversely, rates of acute kidney injury and chronic kidney disease are high in cardiac patients. While our understanding of CRS has greatly increased over the past 15 years, most research has occurred in adult populations. Improving cardiorenal outcomes in children and adolescents requires increased collaboration and research that spans organ systems. The purpose of this review is to discuss key features of CRS and help bring to light future opportunities for pediatric-specific research.

Impact of natriuresis on worsening renal function during episodes of acute heart failure

INTRODUCTION AND OBJECTIVES

Worsening renal function (WRF) is a frequent complication in acute heart failure (AHF) with a controversial prognostic value. We aimed to study the usefulness of natriuresis to evaluate WRF.

METHODS

We conducted an observational, prospective, multicenter study of patients with AHF who underwent a furosemide stress test. The patients were classified according to whether WRF was present or absent and according to the median natriuretic response. The main endpoint was the combination of mortality, rehospitalization due to HF, and heart transplant at 6 months of follow-up.

RESULTS

One hundred and fifty-six patients were enrolled, and WRF occurred in 60 (38.5%). The patients were divided into 4 groups: a) 47 (30.1%) no WRF/low UNa (UNa ≤ 109 mEq/L); b) 49 (31.4%) no WRF/high UNa (UNa >109 mEq/L); c) 31 (19.9%) WRF/low UNa and d) 29 (18.6%) WRF/high UNa. The parameters of the WRF/low UNa group showed higher clinical severity and worse diuretic and decongestive response. The development of WRF was associated with a higher risk of the combined event (HR, 1.88; 95%CI, 1.01-3.50; P=.046). When stratified by natriuretic response, WRF was associated with an increased risk of adverse events in patients with low natriuresis (HR, 2.28; 95%CI, 1.15-4.53; P=.019), but not in those with high natriuresis (HR, 1.18; 95%CI, 0.26-5.29; P=.826).

CONCLUSIONS

Natriuresis could be a useful biomarker for interpreting and prognosticating WRF in AHF. WRF is associated with a higher risk of adverse events only in the context of low natriuresis.

Assessing the risk of acute kidney injury associated with a four-drug regimen for heart failure: a ten-year real-world pharmacovigilance analysis based on FAERS events

BACKGROUND

The four-drug regimen for heart failure with reduced ejection fraction (HFrEF) significantly reduces the risks of hospitalization and mortality. To identify key adverse drug events (ADEs) warranting attention with this regimen, we conducted a real-world pharmacovigilance analysis based on the FDA Adverse Event Reporting System (FAERS) events.

RESEARCH DESIGN AND METHODS

We collected ADE reports of the four-drug regimen from FAERS that matched this regimen over a 10-year period. Disproportionality analysis and subgroup analysis were performed using four algorithms. Time-to-onset (TTO) analysis was used to assess the temporal risk patterns of ADE occurrence. Lastly, logistic regression was applied to investigate the relationship-value between patient characteristics and ADEs.

RESULTS

A total of 1,237 cases with 6,580 ADE reports were collected. Disproportionality analysis identified the most frequent ADEs as hypotension, acute kidney injury (AKI), and hyperkalemia. TTO analysis revealed a median TTO of 39 days for all important medical events, and the median TTO for AKI was 28 days, both fitting an early failure curve.

CONCLUSION

In the comprehensive management of HFrEF with the four-drug regimen, in addition to routine monitoring of ADEs such as hypotension and hyperalemia, early-onset AKI should be a particular focus.

Cardiorenal syndrome: clinical diagnosis, molecular mechanisms and therapeutic strategies

As the heart and kidneys are closely connected by the circulatory system, primary dysfunction of either organ usually leads to secondary dysfunction or damage to the other organ. These interactions play a major role in the pathogenesis of a clinical entity named cardiorenal syndrome (CRS). The pathophysiology of CRS is complicated and involves multiple body systems. In early studies, CRS was classified into five subtypes according to the organs associated with the vicious cycle and the acuteness and chronicity of CRS. Increasing evidence shows that CRS is associated with a variety of pathological mechanisms, such as haemodynamics, neurohormonal changes, hypervolemia, hypertension, hyperuraemia and hyperuricaemia. In this review, we summarize the classification and currently available diagnostic biomarkers of CRS. We highlight the recently revealed molecular pathogenesis of CRS, such as oxidative stress and inflammation, hyperactive renin‒angiotensin‒aldosterone system, maladaptive Wnt/β-catenin signalling pathway and profibrotic TGF‒β1/Smad signalling pathway, as well as other pathogeneses, such as dysbiosis of the gut microbiota and dysregulation of noncoding RNAs. Targeting these CRS-associated signalling pathways has new therapeutic potential for treating CRS. In addition, various chemical drugs, natural products, complementary therapies, blockers, and agonists that protect against CRS are summarized. Since the molecular mechanisms of CRS remain to be elucidated, no single intervention has been shown to be effective in treating CRS. Pharmacologic therapies designed to block CRS are urgently needed. This review presents a critical therapeutic avenue for targeting CRS and concurrently illuminates challenges and opportunities for discovering novel treatment strategies for CRS.

Association between triglyceride-glucose index and its composite obesity indexes and cardio-renal disease: analysis of the NHANES 2013-2018 cycle

Background

The association between triglyceride-glucose (TYG) and its composite obesity indexes and cardio-renal disease in the American population remains insufficiently researched.

Methods

This study examined a cohort of 11,491 American adults aged 20 years and older from the 2003-2018 National Health and Nutrition Examination Survey (NHANES). To explore the associations between TYG, TyG-Waist-to-Height Ratio (TyG-WHtR), TyG-Body Mass Index (TyG-BMI), TyG-Waist Circumference (TyG-WC), and chronic kidney disease (CKD), cardiovascular disease (CVD), and cardiorenal syndrome (CRS), we utilized weighted multivariate logistic regression, restricted cubic spline (RCS), Receiver operating characteristic (ROC), and subgroup analyses.

Results

Adjusted for confounding factors, there are positive associations between the likelihood of CKD, CVD, and CRS, as well as TYG and its composite obesity indexes. The TYG index was correlated most strongly with CKD (OR 1.42, 95% CI 1.11, 1.82; P = 0.007), while TyG-WHtR had the strongest correlations with CVD (OR 1.63, 95% CI 1.19, 2.22; P = 0.003) and CRS (OR 1.44, 95% CI 1.00, 2.08; P = 0.055). A nonlinear connection was found by RCS analysis between TYG and its composite obesity indexes with CKD (P for overall < 0.001, P for nonlinear < 0.05), while the association with CVD and CRS was predominantly linear (P for overall < 0.001, P for nonlinear > 0.05). Based on ROC curves, TyG-WHtR and TyG-WC emerged as more reliable diagnostic tools than TYG for cardiac and renal diseases. According to subgroup analyses, TyG and its composite obesity measurements were more strongly associated with CKD in younger individuals (≤ 50), males, and those with diabetes mellitus (P for interaction 0.05).

Conclusions

The TyG-WHtR and TyG-WC are associated with an increased risk of cardiac and renal disease, indicating enhanced diagnostic accuracy. These metrics provide an effective tool for identifying early cardiorenal disease and improving risk stratification.

Landscape of cardiorenal syndrome research: A bibliometric analysis

To comprehensively review cardiorenal syndrome (CRS)-related research, this study analyzes its whole landscape and future trends from a bibliometric perspective. Using "cardiorenal syndrome" as the key word, a representative dataset of CRS was constructed in the Web of Science Core Collection (Science Citation Index Expanded) database up to November 2023. VOSviewer (version 1.6.18) and R-Studio (version 1.4) were used to visualize CRS-related author and national collaboration networks, hotspot distribution clustering and historical citation networks. The annual number of publications shows an upward trend, especially since 2009. The United States is the most active country and closely cooperates with European countries. Cardiorenal Medicine is the journal that publishes the most CRS-related research. Urology & Nephrology and Cardiovascular System & Cardiology are the most prominent areas of CRS literature output. The leaders in CRS-related research are Ronco C from Italy and Mccullough PA, from the United States. Combined with keyword co-occurrence, theme evolution, and strategic distribution analysis, it was found that centering on the mechanism of CRS (cardiovascular lesions, venous congestion, and fibrosis), prognosis (transplantation, dialysis, hospitalization, mortality) and cardiac function management (b-type natriuretic peptide, diastolic dysfunction, left ventricular hypertrophy) is a possible research direction for a long time to come. Although CRS has a relatively short history, it has received a lot of attention and is currently enjoying a high level of overall acceptance. In conclusion, this study explores the major research areas, frontiers and trends in CRS, which are important for future research.

Mitral Valve Transcatheter Edge-to-Edge Repair (MV-TEER) in Patients with Secondary Mitral Regurgitation Improves Hemodynamics, Enhances Renal Function, and Optimizes Quality of Life in Patients with Advanced Renal Insufficiency

BACKGROUND/OBJECTIVES

Secondary mitral regurgitation (MR) is a common valvular heart disease burdening the prognosis of patients with co-existing chronic heart failure. Transcatheter edge-to-edge mitral valve repair (MV-TEER) is a minimally invasive treatment option for high-risk patients. However, the effects of MV-TEER on expanded hemodynamics, tissue perfusion, and quality of life, particularly in patients with advanced renal failure, remain underexplored.

METHODS

This prospective, single-center study evaluated the impact of MV-TEER on hemodynamics, renal function, and quality of life in 45 patients with severe MR. Non-invasive bioimpedance monitoring with NICaS® was used to assess hemodynamics pre- and 3-5 days post-procedure. Quality of life was assessed using the EQ-5D-3L questionnaire before and 3 months post-procedure. For further analysis, patients were divided into subgroups based on the estimated baseline glomerular filtration rate (eGFR < 35 mL/min vs. eGFR ≥ 35 mL/min).

RESULTS

A significant reduction in systemic vascular resistance (SVR; p = 0.003) and an increase in eGFR (p = 0.03) were observed in the entire cohort after MV-TEER, indicating improved tissue perfusion. Notably, particularly patients with eGFR < 35 mL/min showed a significant increase in cardiac output (CO; p = 0.035), cardiac index (CI; p = 0.031), and eGFR (p = 0.018), as well as a reduction in SVR (p = 0.007). Consistent with these findings, quality of life significantly improved, with the EQ-5D-3L index and EQ-VAS score increasing from 0.44 to 0.66 (p < 0.001) and from 51.7% to 62.9% (p < 0.001).

A comparative study of femoral artery and combined femoral and axillary artery cannulation in veno-arterial extracorporeal membrane oxygenation patients

Objective

Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is a critical support technique for cardiac surgery patients. This study compares the outcomes of femoral artery cannulation vs. combined femoral and axillary artery cannulation in post-cardiotomy VA-ECMO patients. This study aimed to compare the clinical outcomes of critically ill patients post-cardiac surgery under VA-ECMO support using different cannulation strategies. Specifically, the focus was on the impact of femoral artery (FA) cannulation vs. combined femoral artery and axillary artery (FA+AA) cannulation on patient outcomes.

Methods

Through a retrospective analysis, we compared 51 adult patients who underwent cardiac surgery and received VA-ECMO support based on the cannulation strategy employed-FA cannulation in 27 cases vs. FA+AA cannulation in 24 cases.

Results

The FA+AA group showed significant advantages over the FA group in terms of the incidence of chronic renal failure (CRF) (37.50% vs. 14.81%, p = 0.045), preoperative blood filtration requirement (37.50% vs. 11.11%, p = 0.016), decreased platelet count (82.67 ± 44.95 vs. 147.33 ± 108.79, p = 0.014), and elevated creatinine (Cr) levels (151.80 ± 60.73 vs. 110.26 ± 57.99, p = 0.041), although the two groups had similar 30-day mortality rates (FA group 40.74%, FA+AA group 33.33%). These findings underscore that a combined approach may offer more effective hemodynamic support and better clinical outcomes when selecting an ECMO cannulation strategy.

Conclusion

Despite the FA+AA group patients presenting with more preoperative risk factors, this group has exhibited lower rates of complications and faster recovery during ECMO treatment. While there has been no significant difference in 30-day mortality rates between the two cannulation strategies, the FA+AA approach may be more effective in reducing complications and improving limb ischemia. These findings highlight the importance of individualized treatment strategies and meticulous monitoring in managing post-cardiac surgery ECMO patients.

Early risk predictors of acute kidney injury and short-term survival during Impella support in cardiogenic shock

Acute kidney injury (AKI) is one of the most frequent and prognostic-relevant complications of cardiogenic shock (CS) complicating myocardial infarction (MI). Mechanical circulatory assist devices (MCS) like left ventricular Impella microaxial pump have increasingly been used in the last decade for stabilization of hemodynamics in those patients. Moreover, a protective effect of Impella on renal organ perfusion could recently be demonstrated. However, data identifying early risk predictors for developing AKI during Impella support in CS are rare. Data of hemodynamics and renal function from 50 Impella patients (January 2020 and February 2022) with MI-related CS (SCAI stage C), were retrospectively analyzed using e.g. multivariate logistic regression analysis as well as Kaplan-Meier curves and Cox regression analysis. 30 patients (60%) developed AKI. Central venous pressure as an indicator for venous congestion (OR 1.216, p = 0.02), GFR at admission indicating existing renal damage (OR 0.928, p = 0.002), and reduced central venous oxygen saturation (SvO2) as a marker for decreased tissue perfusion (OR 0.930, p = 0.029) were independently associated with developing an AKI. The 30-day mortality rate was significantly higher in patients with AKI stage 3 (Stage 1: 0%, Stage 2: 0%, Stage 3; 41.6%, p = 0.014) while AKI stage 3 (HR 0.095, p = 0.026) and norepinephrine dosage (HR 1.027, p = 0.008) were independent predictors for 30-day mortality. AKI as a complication of MI-related CS occurs frequently with a major impact on prognosis. Venous congestion, reduced tissue perfusion, and an already impaired renal function are independent predictors of AKI. Thus, timely diagnostics and a focused treatment of the identified factors could improve prognosis and outcome.

MAPK/NF-κB signaling mediates atrazine-induced cardiorenal syndrome and antagonism of lycopene

Atrazine (ATZ) is the most prevalent herbicide that has been widely used in agriculture to control broadleaf weeds and improve crop yield and quality. The heavy use of ATZ has caused serious environmental pollution and toxicity to human health. Lycopene (LYC), is a carotenoid that exhibits numerous health benefits, such as prevention of cardiovascular diseases and nephropathy. However, it remains unclear that whether ATZ causes cardiorenal injury or even cardiorenal syndrome (CRS) and the beneficial role of LYC on it. To test this hypothesis, mice were treated with LYC and/or ATZ for 21 days by oral gavage. This study demonstrated that ATZ exposure caused cardiorenal morphological alterations, and several inflammatory cell infiltrations mediated by activating NF-κB signaling pathways. Interestingly, dysregulation of MAPK signaling pathways and MAPK phosphorylation caused by ATZ have been implicated in cardiorenal diseases. ATZ exposure up-regulated cardiac and renal injury associated biomarkers levels that suggested the occurrence of CRS. However, these all changes were reverted, and the phenomenon of CAR was disappeared by LYC co-treatment. Based on our findings, we postulated a novel mechanism to elucidate pesticide-induced CRS and indicated that LYC can be a preventive and therapeutic agent for treating CRS by targeting MAPK/NF-κB signaling pathways.

An Updated Review of the Management of Chronic Heart Failure in Patients with Chronic Kidney Disease

Chronic kidney disease (CKD) is common in patients with heart failure (HF) and is associated with high morbidity and mortality. There has been remarkable progress in the treatment of HF over recent years with the establishment of guideline-directed medical therapies including: (1) Beta-blockers, (2) renal angiotensin aldosterone system (RAAS) inhibition (i.e., angiotensin-converting enzyme inhibitor [ACEi], aldosterone receptor blocker [ARB] or angiotensin receptor-neprilysin inhibitor [ARNI]); (3) mineralocorticoid receptor antagonists (MRA), and (4) sodium-glucose cotransporter-2 inhibitors (SGLT2i). However, there are challenges to the implementation of these medications in patients with concomitant CKD due to increased vulnerability to common side-effects (including worsening renal function, hyperkalaemia, hypotension), and most of the pivotal trials which provide evidence of the efficacy of these medications excluded patients with severe CKD. Patients with CKD and HF often have regular healthcare encounters with multiple professionals and can receive conflicting guidance regarding their medication. Thus, despite being at higher risk of adverse cardiovascular events, patients who have both HF and CKD are more likely to be under-optimised on evidence-based therapies. This review is an updated summary of the evidence available for the management of HF (including reduced, mildly reduced and preserved left ventricular ejection fraction) in patients with various stages of CKD. The review covers the evidence for recommended medications, devices such as implantable cardioverter-defibrillator (ICD), cardiac resynchronization therapy (CRT), intravenous (IV) iron, and discusses how frailty affects the management of these patients. It also considers emerging evidence for the prevention of HF in the cohort of patients with CKD. It synthesises the available evidence regarding when to temporarily stop, continue or rechallenge medications in this cohort. Chronic HF in context of CKD remains a challenging scenario for clinicians to manage, which is usually complicated by frailty, multimorbidity and polypharmacy. Treatment should be tailored to a patients individual needs and management in specialised cardio-renal clinics with a multi-disciplinary team approach has been recommended. This review offers a concise summary on this expansive topic.

From heart failure and kidney dysfunction to cardiorenal syndrome: TMAO may be a bridge

The study of trimethylamine oxide (TMAO), a metabolite of gut microbiota, and heart failure and chronic kidney disease has made preliminary achievements and been summarized by many researchers, but its research in the field of cardiorenal syndrome is just beginning. TMAO is derived from the trimethylamine (TMA) that is produced by the gut microbiota after consumption of carnitine and choline and is then transformed by flavin-containing monooxygenase (FMO) in the liver. Numerous research results have shown that TMAO not only participates in the pathophysiological progression of heart and renal diseases but also significantly affects outcomes in chronic heart failure (CHF) and chronic kidney disease (CKD), besides influencing the general health of populations. Elevated circulating TMAO levels are associated with adverse cardiovascular events such as HF, myocardial infarction, and stroke, patients with CKD have a poor prognosis as well. However, no study has confirmed an association between TMAO and cardiorenal syndrome (CRS). As a syndrome in which heart and kidney diseases intersect, CRS is often overlooked by clinicians. Here, we summarize the research on TMAO in HF and kidney disease and review the existing biomarkers of CRS. At the same time, we introduced the relationship between exercise and gut microbiota, and appropriately explored the possible mechanisms by which exercise affects gut microbiota. Finally, we discuss whether TMAO can serve as a biomarker of CRS, with the aim of providing new strategies for the detection, prognostic, and treatment evaluation of CRS.

Resistant Hypertension and Related Outcomes in a Cohort of Patients with Cardiorenal Multimorbidity Hospitalized in an Internal Medicine Ward

INTRODUCTION

Resistant hypertension (RH) is characterized by the failure to reach a goal blood pressure despite the administration of three medications at maximally tolerated doses, one of which being a diuretic. RH can be observed in a variety of clinical conditions, such as heart failure and reduced renal function and may confer high cardiovascular risk.

AIM

To evaluate the prevalence of RH and its association with clinical outcomes; the primary outcome was in-hospital mortality and the composite outcome was all-cause of mortality and morbidity in a cohort of patients with cardiorenal multimorbidity hospitalized in an internal medicine ward.

METHODS

We conducted a retrospective analysis of consecutive hypertensive patients with cardiorenal multimorbidity. The composite outcome incorporated all-cause of in-hospital mortality and occurrence of sepsis, pulmonary embolism, acute coronary syndrome, stroke and renal replacement therapy.

RESULTS

We collected data in 141 inpatients with a mean age of 77 years ± 10 (males 65.9 %), estimated glomerular filtration rate of 34 ± 18.6 ml/min with length of stay of 17 ± 12 days. The prevalence of RH was 52.4%. In-hospital mortality was observed in 24 patients (17%) and the composite outcome occurred in 87 patients (61.7%) and among these 74 (85.1%) were patients with RH. Free survival for composite outcome was significantly higher in patients without RH than patients with RH (log rank 7.52, p = 0.006). Resistant hypertension was a risk factor for composite outcome [HR 1.857(C.I. 1.170-2.946, p = 0.009)].

CONCLUSION

In patients with cardiorenal multimorbidity there is a high proportion of RH that represents a risk factor for composite outcome but not for in-hospital mortality.