Cardio-renal syndrome type 4: epidemiology, pathophysiology and treatment

Chronic Kidney Disease Increases Risk of Incident HFrEF Following Percutaneous Coronary Intervention

Background

Chronic kidney disease (CKD) is very common in patients who are at a high risk of developing incident heart failure with reduced ejection fraction (HFrEF). However, the harmful effect of CKD on incident HFrEF has not yet been examined among patients with coronary artery disease (CAD) undergoing percutaneous coronary intervention (PCI).

Methods

Patients undergoing PCI with baseline left ventricular ejection fraction (LVEF) ≥ 40% were included from January 2007 to December 2018 (ClinicalTrials.gov NCT04407936). We defined incident HFrEF as a follow-up LVEF of <40% within 3–12 months after discharge. Multivariable logistical regression was performed to examine the association of CKD with incident HFrEF.

Results

Overall, of 2,356 patients (mean age 62.4 ± 10.7 years, 22.2% women), 435 (18.5%) had CKD, and 83 (3.5%) developed incident HFrEF following PCI. The rate of incident HFrEF in the CKD group was higher than that in the non-CKD group (6.9 vs. 2.8%; p < 0.001). Multivariate logistic regression analysis indicated that CKD was an independent risk factor of incident HFrEF [adjusted odds ratio (aOR) = 1.75; 95% CI, 1.03–2.92; p = 0.035] after adjustment for confounders including age, gender, diabetes, hypertension, atrial fibrillation, congestive heart failure (CHF), baseline LVEF, ACEI/ARB, and statins. Furthermore, patients with incident HFrEF have a higher ratio of all-cause mortality compared to those without HFrEF (26.5 vs. 8.1%; p < 0.001).

Conclusions

Our results suggested that CKD was associated with increased risk of incident HFrEF, which was related to higher all-cause mortality in patients with CAD undergoing PCI. On this basis, more aggressive measures should be taken to prevent patients with CKD undergoing PCI from developing HFrEF.

Activated Platelets, the Booster of Chronic Kidney Disease and Cardiovascular Complications

<b><i>Background:</i></b> Chronic kidney disease (CKD) has become a global public health problem nowadays. As cardiovascular diseases (CVDs) are the primary cause of death in advanced CKD patients, much attention has been paid to resolving their cardiovascular complications. However, managing CKD and cardiovascular complications is still a big challenge for nephrologists, as satisfactory treatments are still lacking. Platelets, the second most abundant cells in the blood, are the major participants of hemostasis, thrombosis, and wound healing. In recent years, platelets have been reported in various physiological and pathological processes, including CKD and CKD-related CVDs.

Cardiorenal Syndrome: Emerging Role of Medical Imaging for Clinical Diagnosis and Management

Cardiorenal syndrome (CRS) concerns the interconnection between heart and kidneys in which the dysfunction of one organ leads to abnormalities of the other. The main clinical challenges associated with cardiorenal syndrome are the lack of tools for early diagnosis, prognosis, and evaluation of therapeutic effects. Ultrasound, computed tomography, nuclear medicine, and magnetic resonance imaging are increasingly used for clinical management of cardiovascular and renal diseases. In the last decade, rapid development of imaging techniques provides a number of promising biomarkers for functional evaluation and tissue characterization. This review summarizes the applicability as well as the future technological potential of each imaging modality in the assessment of CRS. Furthermore, opportunities for a comprehensive imaging approach for the evaluation of CRS are defined.

Developing the subspecialty of cardio-nephrology: The time has come. A position paper from the coordinating committee from the Working Group for Cardiorenal Medicine of the Spanish Society of Nephrology

Patients with the dual burden of chronic kidney disease (CKD) and cardiovascular disease (CVD) experience unacceptably high rates of morbidity and mortality, which also entail unfavorable effects on healthcare systems. Currently, concerted efforts to identify, prevent and treat CVD in CKD patients are lacking at the institutional level, with emphasis still being placed on individual specialty views on this topic. The authors of this position paper endorse the need for a dedicated interdisciplinary team of subspecialists in cardio-nephrology that manages appropriate clinical interventions across the inpatient and outpatient settings. There is a critical need for training programs, guidelines and best clinical practice models, and research funding from nephrology, cardiology and other professional societies, to support the development of the subspecialty of cardio-nephrology. This position paper from the coordinating committee from the Working Group for Cardiorenal Medicine of the Spanish Society of Nephrology (S.E.N.) is intended to be the starting point to develop the subspecialty of cardio-nephrology within the S.E.N.. The implementation of the subspecialty in day-to-day nephrological practice will help to diagnose, treat, and prevent CVD in CKD patients in a precise, clinically effective, and health cost-favorable manner.

Developing the subspecialty of cardio-nephrology: The time has come. A position paper from the coordinating committee from the Working Group for Cardiorenal Medicine of the Spanish Society of Nephrology

Patients with the dual burden of chronic kidney disease (CKD) and cardiovascular disease (CVD) experience unacceptably high rates of morbidity and mortality, which also entail unfavorable effects on healthcare systems. Currently, concerted efforts to identify, prevent and treat CVD in CKD patients are lacking at the institutional level, with emphasis still being placed on individual specialty views on this topic. The authors of this position paper endorse the need for a dedicated interdisciplinary team of subspecialists in cardio-nephrology that manages appropriate clinical interventions across the inpatient and outpatient settings. There is a critical need for training programs, guidelines and best clinical practice models, and research funding from nephrology, cardiology and other professional societies, to support the development of the subspecialty of cardio-nephrology. This position paper from the coordinating committee from the Working Group for Cardiorenal Medicine of the Spanish Society of Nephrology (S.E.N.) is intended to be the starting point to develop the subspecialty of cardio-nephrology within the S.E.N.. The implementation of the subspecialty in day-to-day nephrological practice will help to diagnose, treat, and prevent CVD in CKD patients in a precise, clinically effective, and health cost-favorable manner.

The safety and efficacy of low-dose mineralocorticoid receptor antagonists in dialysis patients: A meta-analysis

INTRODUCTION

Our aim was to evaluate the safety and efficacy of low-dose mineralocorticoid receptor antagonists (MRAs) in dialysis patients.

METHODS

We systematically searched PubMed, EMBASE, and Cochrane libraries for clinical trials on the use of MRAs in dialysis patients. Review Manager 5.3 software was used to analyze relevant data and evaluate the quality of evidence.

RESULTS

We identified nine randomized controlled trials including 1128 chronic dialysis patients. In terms of safety, when hyperkalemia was defined as serum potassium level ≥5.5 mmol/L, low-dose MRAs were significantly associated with hyperkalemia (relative risk [RR] 1.76, 95% confidence intervals [CI] 1.07-2.89, P = .02); however, when hyperkalemia was defined as serum potassium level ≥6.0 mmol/L or serum potassium level ≥6.5 mmol/L, no significant association was observed between low-dose MRAs and hyperkalemia (RR 1.40, 95% CI 0.83-2.37, P = .20; RR 1.98, 95% CI 0.91-4.30, P = .09, respectively). Use of low-dose MRAs can reduce cardiovascular mortality by 54% compared with the control group (0.46, 95% CI 0.28-0.76, P = .003). Similarly, the RR of all-cause mortality for the low-dose MRAs group was 0.48 (95% CI 0.33-0.72, P = .0003).

CONCLUSION

Low-dose MRAs may benefit dialysis patients without significantly increasing moderate to severe hyperkalemia.

Antihypertensive Effects of Gynura divaricata (L.) DC in Rats with Renovascular Hypertension

Gynura divaricata (L.) DC (Compositae) (GD) could be found in various parts of Asia. It has been used as a traditional medicine to treat diabetes, high blood pressure, and other diseases, but its effects have not yet been scientifically confirmed. Therefore, we aimed at determining whether GD could affect renal function regulation, blood pressure, and the renin-angiotensin-aldosterone system (RAAS). Cardio-renal syndrome (CRS) is a disease caused by the interaction between the kidney and the cardiovascular system, where the acute or chronic dysfunction in one organ might induce acute or chronic dysfunction of the other. This study investigated whether GD could improve cardio-renal mutual in CRS type 4 model animals, two-kidney one-clip (2K1C) renal hypertensive rats. The experiments were performed on the following six experimental groups: control rats (CONT); 2K1C rats (negative control); OMT (Olmetec, 10 mg/kg/day)-treated 2K1C rats (positive control); and 2K1C rats treated with GD extracts in three different doses (50, 100, and 200 mg/kg/day) for three weeks by oral intake. Each group consisted of 10 rats. We measured the systolic blood pressure weekly using the tail-cuff method. Urine was also individually collected from the metabolic cage to investigate the effect of GD on the kidney function, monitoring urine volume, electrolyte, osmotic pressure, and creatinine levels from the collected urine. We observed that kidney weight and urine volume, which would both display typically increased values in non-treated 2K1C animals, significantly decreased following the GD treatment (###p < 0.001 vs. 2K1C). Osmolality and electrolytes were measured in the urine to determine how renal excretory function, which is reduced in 2K1C rats, could be affected. We found that the GD treatment improved renal excretory function. Moreover, using periodic acid-Schiff staining, we confirmed that the GD treatment significantly reduced fibrosis, which is typically increased in 2K1C rats. Thus, we confirmed that the GD treatment improved kidney function in 2K1C rats. Meanwhile, we conducted blood pressure and vascular relaxation studies to determine if the GD treatment could improve cardiovascular function in 2K1C rats. The heart weight percentages of the left atrium and ventricle were significantly lower in GD-treated 2K1C rats than in non-treated 2K1C rats. These results showed that GD treatment reduced cardiac hypertrophy in 2K1C rats. Furthermore, the acetylcholine-, sodium nitroprusside-, and atrial natriuretic peptide-mediated reduction of vasodilation in 2K1C rat aortic rings was also ameliorated by GD treatment (GD 200 mg/kg/day; p < 0.01, p < 0.05, and p < 0.05 vs. 2K1C for vasodilation percentage in case of each compound). The mRNA expression in the 2K1C rat heart tissue showed that the GD treatment reduced brain-type natriuretic peptide and troponin T levels (p < 0.001 and p < 0.001 vs. 2K1C). In conclusion, this study showed that GD improved the cardiovascular and renal dysfunction observed in an innovative hypertension model, highlighting the potential of GD as a therapeutic agent for hypertension. These findings indicate that GD shows beneficial effects against high blood pressure by modulating the RAAS in the cardio-renal syndrome. Thus, it should be considered an effective traditional medicine in hypertension treatment.

Effect of dialysis dependence and duration on post-coronary artery bypass grafting outcomes in patients with chronic kidney disease: A nationwide cohort study in Asia

BACKGROUND

Chronic kidney disease (CKD) is associated with adverse outcomes in patients who undergo coronary artery bypass grafting (CABG). However, the impact of preoperative dialysis dependence and duration in CKD patients on outcomes after CABG has limited research.

OBJECTIVES

To evaluate the effect of preoperative dialysis dependence and duration on CABG outcomes in patients with CKD.

METHODS

A total of 33,920 patients without CKD and 2573 patients with CKD, all of whom underwent isolated CABG between 1998 and 2009, were identified using the Taiwan National Health Insurance Research Database. The patients with CKD were divided into non-dialysis (N=1167), dialysis<3years (N=749), and dialysis≥3years (N=657) groups. The primary outcomes were cumulative incidence of all-cause mortality, cardiovascular (CV) death, and myocardial infarction (MI) or repeat revascularization.

RESULTS

After adjustment of all covariates, a higher all-cause mortality was associated with dialysis≥3years than with dialysis<3years (hazard ratio [HR], 1.56; 95% confidence interval [CI], 1.35-1.80; P<0.001) and with non-dialysis (HR, 1.41; 95% CI, 1.20-1.66; P<0.001) after 2years of follow-up. Similar results were observed for CV death. In addition, both the dialysis groups had a higher risk of MI or revascularization than the non-dialysis group. Furthermore, subgroup analysis revealed that longer duration was associated with a higher risk of 30-day mortality (P for linear trend <0.001).

CONCLUSIONS

Among the CABG recipients, dialysis dependence is associated with a higher incidence of MI or repeat revascularization, and longer dialysis duration is associated with a higher risk of mortality.

Evidence for extensive pleiotropy among pharmacogenes

AIM

We sought to identify potential pleiotropy involving pharmacogenes.

METHODS

We tested 184 functional variants in 34 pharmacogenes for associations using a custom grouping of International Classification and Disease, Ninth Revision billing codes extracted from deidentified electronic health records of 6892 patients.

RESULTS

We replicated several associations including ABCG2 (rs2231142) and gout (p = 1.73 × 10(-7); odds ratio [OR]: 1.73; 95% CI: 1.40-2.12); and SLCO1B1 (rs4149056) and jaundice (p = 2.50 × 10(-4); OR: 1.67; 95% CI: 1.27-2.20).

CONCLUSION

In this systematic screen for phenotypic associations with functional variants, several novel genotype-phenotype combinations also achieved phenome-wide significance, including SLC15A2 rs1143672 and renal osteodystrophy (p = 2.67 × 10(-) (6); OR: 0.61; 95% CI: 0.49-0.75).

Clinical and Echocardiographic Factors Associated with Right Ventricular Systolic Dysfunction in Hemodialysis Patients

BACKGROUND

Chronic kidney disease is a disorder of epidemic proportions that impairs cardiac function. Cardiovascular diseases are the leading cause of death in hemodialysis patients, and the understanding of new nontraditional predictors of mortality could improve their outcomes. Right ventricular systolic dysfunction (RVSD) has recently been recognized as a predictor of cardiovascular death in heart failure and hemodialysis patients. However, the factors contributing to RVSD in hemodialysis patients remain unknown. The aim of this study was to evaluate the clinical and echocardiographic factors associated with RVSD in hemodialysis patients.

METHODS

A cross-sectional study was conducted in which 100 outpatients with end-stage renal disease on chronic hemodialysis were evaluated. A transthoracic echocardiographic examination was performed at optimal dry weight. Right ventricular systolic function was evaluated using tricuspid annular plane systolic excursion (TAPSE). Clinical and echocardiographic data were recorded for each patient. A multivariate linear logistic regression was created using RVSD (TAPSE <14 mm) as the dependent variable.

RESULTS

Fifteen patients with RVSD and 85 patients without RVSD were analyzed. TAPSE had a positive correlation with left ventricular ejection fraction (LVEF) and myocardial relaxation velocity. Independent contributors to RVSD were LVEF (OR 1.14, 95% CI 1.05-1.26), left ventricular mass index (OR 1.02, 95% CI 1.00-1.04), and myocardial relaxation velocity (OR 1.81, 95% CI 1.18-3.19).

CONCLUSIONS

Echocardiographic factors were significant contributors to RVSD. These measurements could be included as part of the routine workup in all end-stage renal disease patients on hemodialysis.

Renocardiac syndromes: physiopathology and treatment stratagems

Purpose of review

Bidirectional inter-organ interactions are essential for normal functioning of the human body; however, they may also promote adverse conditions in remote organs. This review provides a narrative summary of the epidemiology, physiopathological mechanisms and clinical management of patients with combined renal and cardiac disease (recently classified as type 3 and 4 cardiorenal syndrome). Findings are also discussed within the context of basic research in animal models with similar comorbidities.

Sources of information

Pertinent published articles were identified by literature search of PubMed, MEDLINE and Google Scholar. Additional data from studies in the author’s laboratory were also consulted.

Findings

The prevalence of renocardiac syndrome throughout the world is increasing in part due to an aging population and to other risk factors including hypertension, diabetes and dyslipidemia. Pathogenesis of this disorder involves multiple bidirectional interactions between the kidneys and heart; however, participation of other organs cannot be excluded. Our own work supports the hypothesis that the uremic milieu, caused by kidney dysfunction, produces major alterations in vasoregulatory control particularly at the level of the microvasculature that results in impaired oxygen delivery and blood perfusion.

Limitations

Recent clinical literature is replete with articles discussing the necessity to clearly define or characterize what constitutes cardiorenal syndrome in order to improve clinical management of affected patients. Patients are treated after onset of symptoms with limited available information regarding etiology. While understanding of mechanisms involved in pathogenesis of inter-organ crosstalk remains a challenging objective, basic research data remains limited partly because of the lack of animal models.

Implications

Preservation of microvascular integrity may be the most critical factor to limit progression of multi-organ disorders including renocardiac syndrome. More fundamental studies are needed to help elucidate physiopathological mechanisms and for development of treatments to improve clinical outcomes.

Cardiorenal syndrome: understanding the connections between cardiac and renal disease

Renal and cardiac diseases are nearly ubiquitous in hospitalized patients and common causes of morbidity in outpatients. Although the connection between the heart and kidneys is relatively well known in the medical community, a more formal classification for the clinical interplay of the two systems has been developed only recently. Cardiorenal syndrome was described by Italian nephrologist Claudio Ronco in 2008. This classification allows for justification of management strategies in these complex patients and will guide further research studies.

Estimated pulmonary artery systolic pressure and self-reported physical function in patients on hemodialysis

BACKGROUND/AIMS

Patients on chronic hemodialysis have a high prevalence of heart disease and poor self-reported physical function. The association between structural heart disease and self-reported physical function in patients on hemodialysis is unknown.

METHODS

We studied the association between elevated pulmonary artery systolic pressure (PASP) and self-reported physical function in ESRD in 253 patients in the USRDS ACTIVE/ADIPOSE study between 2009 and 2011. We used multivariate linear regression with PASP obtained from clinical echocardiogram reports as the primary predictor and the Physical Function (PF) subscale of the SF-36 as the primary outcome. To determine whether associations between PASP and PF were driven by fluid overload or left ventricular hypertrophy, we assessed whether PASP was associated with bioimpedance spectroscopy (BIS)-derived extracellular water (ECW) and with left ventricular posterior wall thickness.

RESULTS

In a multivariable model, each 10 mm Hg higher PASP was associated with a 3.32-point lower PF score (95% CI -5.95, -0.68). In a multivariable model that included BIS estimates, both left ventricular posterior wall thickness (LVPW, per 5 mm) and ECW were associated with a higher PASP (LVPW 4.21 mm Hg, 95% 0.38-8.04; ECW 1.12 mm Hg per liter, 95% CI 0.07-2.18). Higher LVPW and ECW were independently associated with a lower PF score.

CONCLUSION

Left ventricular hypertrophy and elevated pulmonary pressure are associated with worse self-reported physical function in patients on hemodialysis. The role of chronic volume overload on PASP and PF score should be evaluated in a prospective manner.

Prognostic value of worsening renal function in outpatients with chronic heart failure

INTRODUCTION AND OBJECTIVES

Renal function impairment predicts poor survival in heart failure. Attention has recently shifted to worsening renal function, based mostly on serum creatinine and estimated glomerular filtration rate. We assessed the prognostic effect of worsening renal function in ambulatory heart failure patients.

METHODS

Data from 306 ambulatory patients were abstracted from medical files. Worsening renal function was based on the change in estimated glomerular filtration rate, serum creatinine and urea within 6 months of referral. Prognosis was assessed by the composite endpoint all-cause death or heart failure hospitalization, censored at 2 years. Hazard ratios were estimated for worsening renal function, adjusted for sex, age, diabetes, New York Heart Association class, left ventricular systolic dysfunction, medications and baseline renal function.

RESULTS

The agreement among definitions was fair, with kappa coefficients generally not surpassing 0.5. Worsening renal function was associated with poor outcome with adjusted hazard ratios (95% confidence interval) of 3.2 (1.8-5.9) for an increase of serum creatinine >0.3mg/dl; 2.2 (1.3-3.7) for an increase in serum urea >20mg/dl and 1.9 (1.1-3.3) for a decrease in estimated glomerular filtration rate >20%, independent of baseline renal function. The 2-year risk of death/heart failure hospitalization was approximately 50% in patients with an increase in serum creatinine or in serum urea; this positive predictive value was higher than for decreasing estimated glomerular filtration rate.

CONCLUSIONS

In conclusion, worsening renal function was significantly associated with a worse outcome. Different definitions identified different patients at risk and increasing creatinine/urea performed better than decreasing estimated glomerular filtration rate.

The association between glomerular filtration rate and left ventricular function in two independent community-based cohorts of elderly

Background

The cardiorenal syndrome, the detrimental bi-directional interplay between symptomatic heart failure and chronic kidney disease, is a major clinical challenge. Nonetheless, it is unknown if this interplay begins already at an asymptomatic stage. Therefore we investigated whether the glomerular filtration rate (GFR) is associated with left ventricular function in participants free from clinical heart failure and with a left ventricular ejection fraction (LVEF) >40% and with pre-specified sub-group analyses in individuals with a GFR >60 mL/min/m².

Methods

Two independent community-based cohorts were used; the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS; n = 911; 50% women; mean age: 70 years) and the Uppsala Longitudinal Study of Adult Men (ULSAM; n = 538; mean age: 71 years). We investigated cross-sectional association between cystatin C-based GFR (estimated glomerular function [eGFR]) and systolic (LVEF), diastolic- (isovolumic relaxation time [IVRT]) and global left ventricular function (myocardial performance index [MPI]) determined by echocardiography.

Results

In both PIVUS and ULSAM, higher eGFR was significantly associated with higher LVEF (P = 0.004 [PIVUS] and P = 0.005 [ULSAM]). In PIVUS, higher eGFR was significantly associated with lower IVRT (P = 0.001) and MPI (P = 0.006), in age- and sex-adjusted models. After further adjustment for cardiovascular risk factors, the association between higher eGFR and higher LVEF was still statistically significant (P = 0.008 [PIVUS] and P = 0.02 [ULSAM]). In PIVUS, the age- and sex-adjusted association between eGFR and left ventricular function was similar in participants with eGFR >60 mL/min/m².

Conclusions

Our data suggest that the interplay between kidney and heart function begins prior to the development of symptomatic heart failure and kidney disease.

Raising awareness of acute kidney injury: a global perspective of a silent killer

Worldwide, acute kidney injury (AKI) is associated with poor patient outcomes. Over the last few years, collaborative efforts, enabled by a common definition of AKI, have provided a description of the epidemiology, natural history, and outcomes of this disease and improved our understanding of the pathophysiology. There is increased recognition that AKI is encountered in multiple settings and in all age groups, and that its course and outcomes are influenced by the severity and duration of the event. The effect of AKI on an individual patient and the resulting societal burden that ensues from the long-term effects of the disease, including development of chronic kidney disease (CKD) and end-stage renal disease (ESRD), is attracting increasing scrutiny. There is evidence of marked variation in the management of AKI, which is, to a large extent, due to a lack of awareness and an absence of standards for prevention, early recognition, and intervention. These emerging data point to an urgent need for a global effort to highlight that AKI is preventable, its course is modifiable, and its treatment can improve outcomes. In this article, we provide a framework of reference and propose specific strategies to raise awareness of AKI globally, with the goal to ultimately improve outcomes from this devastating disease.