The cardiorenal syndrome: lessons from the ADHERE database and treatment options

Effect of rehabilitation on renal outcomes after acute kidney injury associated with cardiovascular disease: a retrospective analysis

BACKGROUND

Acute kidney injury (AKI) incidence is extremely high worldwide, and patients who develop AKI are at increased risk of developing chronic kidney disease (CKD), CKD progression, and end-stage kidney disease (ESKD). However, there is no established treatment strategy for AKI. Based on the idea that exercise has a stabilizing effect on hemodynamics, we hypothesized that rehabilitation would have beneficial renal outcomes in patients with AKI associated with cardiovascular disease. Therefore, the purpose of this study was to determine whether rehabilitation can stabilize hemodynamics and positively impact renal outcomes in patients with AKI associated with cardiovascular disease.

METHODS

In total, 107 patients with AKI associated with cardiovascular disease were enrolled in this single-center retrospective study and were either assigned to the exposure group (n = 36), which received rehabilitation at least once a week for at least 8 consecutive weeks, or to the control group (n = 71). Estimated glomerular filtration rate was assessed at baseline before admission, at the lowest value during hospitalization, and at 3, 12, and 24 months after enrolment. Trends over time (group × time) between the two groups were compared using generalized estimating equations. Moreover, congestive status was assessed by amino-terminal pro-B-type natriuretic peptide (NT-proBNP), and the effect of rehabilitation on congestion improvement was investigated using logistical regression analysis.

RESULTS

The time course of renal function after AKI, from baseline to each of the three timepoints suggested significant differences between the two groups (p < 0.01). However, there was no significant difference between the two groups at any time point in terms of percentage of patients who experienced a 40% estimated glomerular filtration rate reduction from that at baseline. The proportion of patients with improved congestion was significantly higher in the exposure group compared with that in the control group (p = 0.018). Logistic regression analysis showed that rehabilitation was significantly associated with improved congestion (p = 0.021, OR: 0.260, 95%CI: 0.083-0.815).

CONCLUSION

Our results suggest that rehabilitation in patients with AKI associated with cardiovascular disease correlates with an improvement in congestion and may have a positive effect on the course of renal function.

Demographic trends of cardiorenal and heart failure deaths in the United States, 2011-2020

BACKGROUND

Heart failure (HF) and kidney disease frequently co-occur, increasing mortality risk. The cardiorenal syndrome results from damage to either the heart or kidney impacting the other organ. The epidemiology of cardiorenal syndrome among the general population is incompletely characterized and despite shared risk factors with HF, differences in mortality risk across key demographics have not been well described. Thus, the primary goal of this study was to analyze annual trends in cardiorenal-related mortality, evaluate if these trends differed by age, sex, and race or ethnicity, and describe these trends against a backdrop of HF mortality.

METHODS AND FINDINGS

The Centers for Disease Control and Prevention Wide-ranging ONline Data for Epidemiologic Research database was used to examine cardiorenal- and HF-related mortality in the US between 2011and 2020. International Classification of Diseases, 10 Revision codes were used to classify cardiorenal-related deaths (I13.x) and HF-related deaths (I11.0, I13.0, I13.2, and I50.x), among decedents aged 15 years or older. Decedents were further stratified by age group, sex, race, or ethnicity. Crude and age-adjusted mortality rates (AAMR) per 100,000 persons were calculated. A total of 97,135 cardiorenal-related deaths and 3,453,655 HF-related deaths occurred. Cardiorenal-related mortality (AAMR, 3.26; 95% CI: 3.23-3.28) was significantly lower than HF-related mortality (AAMR, 115.7; 95% CI: 115.6-115.8). The annual percent change (APC) was greater and increased over time for cardiorenal-related mortality (2011-2015: APC, 7.1%; 95% CI: 0.7-13.9%; 2015-2020: APC, 19.7%, 95% CI: 16.3-23.2%), whereas HF-related mortality also increased over that time period, but at a consistently lower rate (2011-2020: APC, 2.4%; 95% CI: 1.7-3.1%). Mortality was highest among older and male decedents for both causes. Cardiorenal-related deaths were more common in non-Hispanic or Latino Blacks compared to Whites, but similar rates were observed for HF-related mortality. A larger proportion of cardiorenal-related deaths, compared to HF-related deaths, listed cardiorenal syndrome as the underlying cause of death (67.0% vs. 1.2%).

CONCLUSIONS

HF-related deaths substantially outnumber cardiorenal-related deaths; however, cardiorenal-related deaths are increasing at an alarming rate with the highest burden among non-Hispanic or Latino Blacks. Continued surveillance of cardiorenal-related mortality trends is critical and future studies that contain detailed biomarker and social determinants of health information are needed to identify mechanisms underlying differences in mortality trends.

Possible organ-protective effects of renal denervation: insights from basic studies

Inappropriate sympathetic nervous activation is the body's response to biological stress and is thought to be involved in the development of various lifestyle-related diseases through an elevation in blood pressure. Experimental studies have shown that surgical renal denervation decreases blood pressure in hypertensive animals. Recently, minimally invasive catheter-based renal denervation has been clinically developed, which results in a reduction in blood pressure in patients with resistant hypertension. Accumulating evidence in basic studies has shown that renal denervation exerts beneficial effects on cardiovascular disease and chronic kidney disease. Interestingly, recent studies have also indicated that renal denervation improves glucose tolerance and inflammatory changes. In this review article, we summarize the evidence from animal studies to provide comprehensive insight into the organ-protective effects of renal denervation beyond changes in blood pressure.

Significance of Kidney Disease in Cardiovascular Disease Patients

Cardiorenal syndrome is a condition where is a bidirectional and mutually detrimental relationship between the heart and kidneys. The mechanisms underlying cardiorenal syndrome are multifactorial and complex. Patients with kidney disease exhibit increased cardiovascular risk, presenting as coronary and peripheral artery disease, structural heart disease, arrhythmias, heart failure, and sudden cardiac death, largely occurring because of a systemic proinflammatory state, causing myocardial and vascular remodeling, manifesting as atherosclerotic lesions, vascular and valvular calcification, and myocardial fibrosis, particularly among those with advanced disease. This review summarizes the current understanding and clinical implications of kidney disease in patients with cardiovascular disease.

Cardiorenal Syndrome: A Literature Review

Cardiorenal syndrome (CRS) is a condition characterized by the intricate two-way relationship between the heart and kidneys, which can lead to acute or chronic dysfunction in these organs. The interplay between cardiorenal connectors and both hemodynamic and non-hemodynamic factors is crucial to understanding this syndrome. The clinical importance of these interactions is evident in the changes observed in hemodynamic factors, neurohormonal markers, and inflammatory processes. Identifying and understanding biomarkers associated with CRS is valuable for early detection and enabling intervention before significant organ dysfunction occurs. This comprehensive review focuses on the clinical significance of biomarkers in the diagnosis, prognosis, and management of CRS. Finally, it highlights the necessity for further advancements in managing this condition.

Is Sacubitril/Valsartan a Safe and Effective Option in Real World Patients with Mild to Severe Chronic Kidney Disease?

Aims: Sacubitril/valsartan has shifted the landscape of heart failure (HF) treatment. As renal function (RF) is often compromised in HF patients, this study aimed to assess the evolution of RF in patients with HF with a reduced ejection fraction (HFrEF) and initiating treatment with sacubitril/valsartan. Methods and results: We present a secondary data analysis of a prospective cohort of HFrEF patients. Inclusion criteria: patients who started sacubitril/valsartan between November 2017 and August 2019, after previous optimal medical therapy, had a New York Heart Association classification of II or III, at least 6 months of follow-up, and an estimated glomerular filtration rate (eGFR) below 90 mL/min/1.73 m2. Main endpoint: annualized change in eGFR. A total of 52 patients met the inclusion criteria. The average eGFR reduced from 54.2 to 52.5 mL/min/1.73 m2, at baseline and last follow-up, respectively. The average eGFR annualized change from baseline decreased 3.1 mL/min/1.73 m2/year without statistical significance (95% confidence interval: −8.7 to 2.5). No subgroup analysis presented a statistically significant annualized change in eGFR. Mean left ventricular ejection fraction increased from 30.4% to 37.9% at last follow-up. Conclusion: This real-world study demonstrated sacubitril/valsartan promoted no major harm in renal function, while maintaining effectiveness in a population of HFrEF patients with mild to severe renal disease.

Cardiorenal Syndrome: The Role of Neural Connections Between the Heart and the Kidneys

The maintenance of cardiovascular homeostasis is highly dependent on tightly controlled interactions between the heart and the kidneys. Therefore, it is not surprising that a dysfunction in one organ affects the other. This interlinking relationship is aptly demonstrated in the cardiorenal syndrome. The characteristics of the cardiorenal syndrome state include alterations in neurohumoral drive, autonomic reflexes, and fluid balance. The evidence suggests that several factors contribute to these alterations. These may include peripheral and central nervous system abnormalities. However, accumulating evidence from animals with experimental models of congestive heart failure and renal dysfunction as well as humans with the cardiorenal syndrome suggests that alterations in neural pathways, from and to the kidneys and the heart, including the central nervous system are involved in regulating sympathetic outflow and may be critically important in the alterations in neurohumoral drive, autonomic reflexes, and fluid balance commonly observed in the cardiorenal syndrome. This review focuses on studies implicating neural pathways, particularly the afferent and efferent signals from the heart and the kidneys integrating at the level of the paraventricular nucleus in the hypothalamus to alter neurohumoral drive, autonomic pathways, and fluid balance. Further, it explores the potential mechanisms of action for the known beneficial use of various medications or potential novel therapeutic manipulations for the treatment of the cardiorenal syndrome. A comprehensive understanding of these mechanisms will enhance our ability to treat cardiorenal conditions and their cardiovascular complications more efficaciously and thoroughly.

Value of Renal Vascular Doppler Sonography in Cardiorenal Syndrome Type 1

OBJECTIVES

Worsening of renal function in a patient with acute decompensated heart failure is called cardiorenal syndrome (CRS) type 1. Recent studies have shown an association of persistent systemic venous congestion with renal dysfunction. This trial was set up to investigate the changes of renal Doppler parameters with diuretic therapy in patients with CRS type 1.

METHODS

Cases of CRS type 1 were identified among patients hospitalized for decompensated heart failure. Serial measurements of the renal venous impedance index (VII) and arterial resistive index (ARI) were calculated by pulsed wave Doppler sonography.

RESULTS

A total of 30 patients who had creatinine improvement with diuresis (group 1) and 34 patients without any improvement (group 2) were analyzed. Patients in group 1 had higher median VII and ARI (VII, 0.86 versus 0.66; P < .001; ARI, 0.78 versus 0.65; P < .001) on admission. A high ARI on admission (odds ratio, 6.25; 95% confidence interval, 1.84-14.3; P = .003) predicted the improvement of serum creatinine levels with diuretic therapy independent of confounding factors in patients with CRS type 1.

CONCLUSIONS

Renal vascular Doppler parameters might offer guidance on the diagnostic and therapeutic strategies in prescribing decongestive therapy for decompensated heart failure.

Cardio-nephrology MDT meetings play an important role in the management of cardiorenal syndrome

Cardiorenal syndrome is a complex condition associated with significant morbidity in the form of symptoms secondary to fluid overload, leading to hospitalisations, and portends increased mortality. Both the diagnosis and management of the conditions are complicated by the fact that there is dysfunction of the heart as well as the kidney, usually with uncertainty with regards to the timing of the first insult. Management in primary care, or in the emergency setting, tends to be predominantly focused on short-term improvement in function of one organ, leading to deleterious effects on the other. A consensus multi-disciplinary approach involving both cardiologists and nephrologists has been advocated in order to devise a unified management plan. Our report presents findings of monthly cardio-nephrology multi-disciplinary team meetings and illustrates that this can be an efficacious approach both in terms of avoiding unnecessary outpatient clinic visits, as well as consensus decision-making.

New renal haemodynamic indices can predict worsening of renal function in acute decompensated heart failure

AIMS

Worsening of renal function (WRF) is a common complication in patients with acute decompensated heart failure (ADHF). We aimed to evaluate the role of intrarenal Doppler ultrasound (IRD) in the early prediction of WRF in this patient group.

METHODS AND RESULTS

Among 90 patients (age: 57.5 ± 11.1 years; 62% male) hospitalized with ADHF, resistivity index (RI), acceleration time (AT), and pulsatility index (PI) were measured on admission and at 24 and 72 h. WRF was defined as increased serum creatinine ≥0.3 mg/dL from baseline. Adverse clinical outcomes were defined as the composite of death, use of vasopressors, and need for ultrafiltration for refractory oedema. WRF developed in 40% of patients. Mean values of renal AT, RI, and PI on admission were 59.7 ± 15, 0.717 ± 0.08, and 1.5 ± 0.48 ms, respectively. At 24 h, there was significant decrease in AT (to 56.7 ± 10 ms, P = 0.02) and renal RI (to 0.732 ± 0.07; P < 0.001); these changes were maintained up to 72 h. Renal PI showed no significant changes. Independent predictors of WRF were renal AT at 24 h and admission values of renal RI, left ventricular ejection fraction, and plasma cystatin C. Renal AT at 24 h ≥ 57.8 ms had 89% sensitivity and 70% specificity for the prediction of WRF. Independent predictors for adverse clinical outcomes were left ventricular end systolic dimension and WRF.

CONCLUSIONS

Among ADHF patients receiving diuretic therapy, measurement of renal AT and RI by IRD can help identify patients at increased risk for WRF.

Neutrophil gelatinase-associated lipocalin does not predict acute kidney injury in heart failure

BACKGROUND

Acute cardiorenal syndrome type 1 (CRS-1) is defined by a rapid cardiac dysfunction leading to acute kidney injury (AKI). Neutrophil gelatinase-associated lipocalin (NGAL) is expressed on the surface of human neutrophils and epithelial cells, such as renal tubule cells, and its serum (sNGAL) and urinary have been used to predict AKI in different clinical settings.

AIM

To characterize CRS-1 in a cohort of patients with acute heart diseases, evaluating the potentiality of sNGAL as an early marker of CRS-1.

METHODS

We performed a retrospective cohort, multi-centre study. From January 2010 to December 2011, we recruited 202 adult patients admitted to the coronary intensive care unit (CICU) with a diagnosis of acute heart failure or acute coronary syndrome. We monitored the renal function to evaluate CRS-1 development and measured sNGAL levels within 24 h and after 72 h of CICU admission.

RESULTS

Overall, enrolled patients were hemodynamically stable with a mean arterial pressure of 92 (82-107) mmHg, 55/202 (27.2%) of the patients developed CRS-1, but none of them required dialysis. Neither the NGAL delta value (AUC 0.40, 95%CI: 0.25-0.55) nor the NGAL peak (AUC 0.45, 95%CI: 0.36-0.54) or NGAL cut-off (≥ 140 ng/mL) values were statistically significant between the two groups (CRS-1 vs no-CRS1 patients). The area under the ROC curve for the prediction of CRS-1 was 0.40 (95%CI: 0.25-0.55) for the delta NGAL value and 0.45 (95%CI: 0.36-0.54) for the NGAL peak value. Finally, in multivariate analysis, the risk of developing CRS-1 was correlated with age > 60 years, urea nitrogen at admission and 24 h-urine output (AUC 0.83, SE = 60.5% SP = 93%), while sNGAL was not significantly correlated.

CONCLUSION

In our population, sNGAL does not predict CRS-1, probably as a consequence of the mild renal injury and the low severity of heart disease. So, these data might suggest that patient selection should be taken into account when considering the utility of NGAL measurement as a biomarker of kidney damage.

MALAT1: a therapeutic candidate for a broad spectrum of vascular and cardiorenal complications

Cardiovascular and renal complications cover a wide array of diseases. The most commonly known overlapping complications include cardiac and renal fibrosis, cardiomyopathy, cardiac hypertrophy, hypertension, and cardiorenal failure. The known or reported causes for the abovementioned complications include injury, ischemia, infection, and metabolic stress. To date, various targets have been reported and investigated in detail that are considered to be the cause of these complications. In the past 5 years, the role of noncoding RNAs has emerged in the area of cardiovascular and renal research, especially in relation to metabolic stress. The long noncoding RNA MALAT1 (metastasis-associated lung adenocarcinoma transcript 1) has shown immense promise among the long noncoding RNA targets for treating cardiorenal complications. In this review, we shed light on the role of MALAT1 as a primary and novel target in treating cardiovascular and renal diseases as a whole.

Renal denervation improves sodium excretion in rats with chronic heart failure: effects on expression of renal ENaC and AQP2

Previously we have shown that increased expression of renal epithelial sodium channels (ENaC) may contribute to the renal sodium and water retention observed during chronic heart failure (CHF). The goal of this study was to examine whether renal denervation (RDN) changed the expressions of renal sodium transporters ENaC, sodium-hydrogen exchanger-3 proteins (NHE3), and water channel aquaporin 2 (AQP2) in rats with CHF. CHF was produced by left coronary artery ligation in rats. Four weeks after ligation surgery, surgical bilateral RDN was performed. The expression of ENaC, NHE3, and AQP2 in both renal cortex and medulla were measured. As a functional test for ENaC activation, diuretic and natriuretic responses to ENaC inhibitor benzamil were monitored in four groups of rats (Sham, Sham+RDN, CHF, CHF+RDN). Western blot analysis indicated that RDN (1 wk later) significantly reduced protein levels of α-ENaC, β-ENaC, γ-ENaC, and AQP2 in the renal cortex of CHF rats. RDN had no significant effects on the protein expression of kidney NHE3 in both Sham and CHF rats. Immunofluorescence studies of kidney sections confirmed the reduced signaling of ENaC and AQP2 in the CHF+RDN rats compared with the CHF rats. There were increases in diuretic and natriuretic responses to ENaC inhibitor benzamil in rats with CHF. RDN reduced the diuretic and natriuretic responses to benzamil in CHF rats. These findings suggest a critical role for renal nerves in the enhanced expression of ENaC and AQP2 and subsequent pathophysiology of renal sodium and water retention associated with CHF.NEW & NOTEWORTHY This is the first study to show in a comprehensive way that renal denervation initiated after a period of chronic heart failure reduces the expression of epithelial sodium channels and aquaporin 2 leading to reduced epithelial sodium channel function and sodium retention.

Interactive and potentially independent roles of renin-angiotensin-aldosterone system blockade and the development of cardiorenal syndrome type 1 on in-hospital mortality among elderly patients admitted with acute decompensated congestive heart failure

Purpose

Cardiorenal syndrome type 1 (CRS1), defined as worsening renal function from acute decompensated congestive heart failure (ADCHF), is complicated by the fact that CRS1 limits the use of common therapeutic strategies, such as angiotensin converting-enzyme inhibitors (ACEIs) or angiotensin II-receptor blockers (A2RB). The present study examines retrospectively the role of ACEI/A2RB usage on in-hospital mortality among elderly ADCHF patients, in particular those who developed CRS1.

Methods

We retrospectively examined the effects of ACEI/A2RB usage and CRS1 development (in-hospital change in serum creatinine ≥0.3 mg/dL or ≥0.5 mg/dL), as well as their potential interaction, on in-hospital mortality among elderly ADCHF patients (aged ≥65 years). Employing univariate and multivariate analyses, we performed risk-factor analysis on a cohort of 419 patients (51 nonsurvivors [12.2%]) for whom we had complete clinical and laboratory data (median follow-up 5 days) from 2,361 consecutive elderly ADCHF patients (106 nonsurvivors [4.6%]).

Results

By multivariate analysis, the two strongest independent predictors of in-hospital mortality were CRS1 development (OR 7.8, 95% CI 3.9–15.5; P=0.00001) and lack of ACEI/A2RB usage (OR 0.49, CI 0.25–0.93; P=0.043). The effect of CRS1 was graded, with increasing CRS1 severity associated with increased mortality. On multivariate subgroup analysis, the association between lack of ACEI/A2RB usage and increased mortality remained a significant independent predictor among patients not developing CRS1 (OR 0.24, CI 0.083–0.721; P=0.011).

Conclusion

Our data suggest that development of CRS1 and lack of ACEI/A2RB usage are statistically independent predictors of in-hospital mortality for elderly ADCHF patients, with CRS1 being the stronger of the two risk factors. While it remains unclear whether lack of ACEI/ A2RB usage is causally related to increased mortality or reflects another risk factor inducing physicians to forego ACEIs/A2RBs, our findings nevertheless indicate the need to address this issue in future prospective studies.

Moving From Heart Failure Guidelines to Clinical Practice: Gaps Contributing to Readmissions in Patients With Multiple Comorbidities and Older Age

This feature article for the thematic series on congestive heart failure (CHF) readmissions aims to outline important gaps in guidelines for patients with multiple comorbidities and the elderly. Congestive heart failure diagnosis manifests as a 3-phase journey between the hospital and community, during acute, chronic stable, and end-of-life (palliative) phases. This journey requires in variable intensities a combination of multidisciplinary care within tertiary hospital or ambulatory care from hospital outpatients or primary health services, within the general community. Management goals are uniform, ie, to achieve the lowest New York Heart Association class possible, with improvement in ejection fraction, by delivering gold standard therapies within a CHF program. Comorbidities are an important common denominator that influences outcomes. Comorbidities include diabetes mellitus, chronic obstructive airways disease, chronic renal impairment, hypertension, obesity, sleep apnea, and advancing age. Geriatric care includes the latter as well as syndromes such as frailty, falls, incontinence, and confusion. Many systems still fail to comprehensively achieve all aspects of such programs. This review explores these factors.

Histopathological Changes in the Kidney following Congestive Heart Failure by Volume Overload in Rats

BACKGROUND

This study investigated histopathological changes and apoptotic factors that may be involved in the renal damage caused by congestive heart failure in a rat model of infrarenal aortocaval fistula (ACF).

METHODS

Heart failure was induced using a modified approach of ACF in male Wistar rats. Sham-operated controls and ACF rats were characterized by their morphometric and hemodynamic parameters and investigated for their histopathological, ultrastructural, and apoptotic factor changes in the kidney.

RESULTS

ACF-induced heart failure is associated with histopathological signs of congestion and glomerular and tubular atrophy, as well as nuclear and cellular degeneration in the kidney. In parallel, overexpression of proapoptotic Bax protein, release of cytochrome C from the outer mitochondrial membrane into cell cytoplasm, and nuclear transfer of activated caspase 3 indicate apoptotic events. This was confirmed by electron microscopic findings of apoptotic signs in the kidney such as swollen mitochondria and degenerated nuclei in renal tubular cells.

CONCLUSIONS

This study provides morphological evidence of renal injury during heart failure which may be due to caspase-mediated apoptosis via overexpression of proapoptotic Bax protein, subsequent mitochondrial cytochrome C release, and final nuclear transfer of activated caspase 3, supporting the notion of a cardiorenal syndrome.

The Kidney in Critical Cardiac Disease: Proceedings From the 10th International Conference of the Pediatric Cardiac Intensive Care Society

The field of cardiac intensive care continues to advance in tandem with congenital heart surgery. The focus of intensive care unit care has now shifted to that of morbidity reduction and eventual elimination. Acute kidney injury (AKI) after cardiac surgery is associated with adverse outcomes, including prolonged intensive care and hospital stays, diminished quality of life, and increased long-term mortality. Acute kidney injury occurs frequently, complicating the care of both postoperative patients and those with heart failure. Patients who become fluid overloaded and/or require dialysis are at high risk of mortality, but even minor degrees of AKI portend a significant increase in mortality and morbidity. Clinicians continue to seek methods of early diagnosis and risk stratification of AKI to prevent its adverse sequelae. Previous conventional wisdom that survivors of AKI fully recover renal function without subsequent consequences may be flawed.

Acute Kidney Injury and Cardiorenal Syndromes in Pediatric Cardiac Intensive Care

OBJECTIVES

The objectives of this review are to discuss the definition, diagnosis, and pathophysiology of acute kidney injury and its impact on immediate, short-, and long-term outcomes. In addition, the spectrum of cardiorenal syndromes will be reviewed including the pathophysiology on this interaction and its impact on outcomes.

DATA SOURCE

MEDLINE and PubMed.

CONCLUSION

The field of cardiac intensive care continues to advance in tandem with congenital heart surgery. As mortality has become a rare occurrence, the focus of cardiac intensive care has shifted to that of morbidity reduction. Acute kidney injury adversely impact outcomes of patients following surgery for congenital heart disease as well as in those with heart failure (cardiorenal syndrome). Patients who become fluid overloaded and/or require dialysis are at a higher risk of mortality, but even minor degrees of acute kidney injury portend a significant increase in mortality and morbidity. Clinicians continue to seek methods of early diagnosis and risk stratification of acute kidney injury to prevent its adverse sequelae.

Urinary Proteolytic Activation of Renal Epithelial Na+ Channels in Chronic Heart Failure

One of the key mechanisms involved in renal Na(+) retention in chronic heart failure (CHF) is activation of epithelial Na(+) channels (ENaC) in collecting tubules. Proteolytic cleavage has an important role in activating ENaC. We hypothesized that enhanced levels of proteases in renal tubular fluid activate ENaC, resulting in renal Na(+) retention in rats with CHF. CHF was produced by left coronary artery ligation in rats. By immunoblotting, we found that several urinary serine proteases were significantly increased in CHF rats compared with sham rats (fold increases: furin 6.7, prostasin 23.6, plasminogen 2.06, and plasmin 3.57 versus sham). Similar increases were observed in urinary samples from patients with CHF. Whole-cell patch clamp was conducted in cultured renal collecting duct M-1 cells to record Na(+) currents. Protease-rich urine (from rats and patients with CHF) significantly increased the Na(+) inward current in M-1 cells. Two weeks of protease inhibitor treatment significantly abrogated the enhanced diuretic and natriuretic responses to ENaC inhibitor benzamil in rats with CHF. Increased podocyte lesions were observed in the kidneys of rats with CHF by transmission electron microscopy. Consistent with these results, podocyte damage markers desmin and podocin expressions were also increased in rats with CHF (increased ≈2-folds). These findings suggest that podocyte damage may lead to increased proteases in the tubular fluid, which in turn contributes to the enhanced renal ENaC activity, providing a novel mechanistic insight for Na(+) retention commonly observed in CHF.

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.

Serum alkaline phosphatase as a predictor of worsening renal function in patients with acute decompensated heart failure

BACKGROUND

Venous congestion has come into focus as an important hemodynamic factor for worsening renal function (WRF) in patients with acute decompensated heart failure (ADHF). Serum alkaline phosphatase (ALP) was reported as a biological marker of liver congestion in ADHF. The purpose of this study was to determine whether ALP is a predictor of WRF in patients with ADHF.

METHODS

We enrolled consecutive patients admitted to a single cardiovascular center with ADHF, and defined WRF as an increase in creatinine of >0.3 mg/dl during hospitalization and chronic kidney disease (CKD) as an estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m(2). The patients were classified into tertiles by ALP level (<203, 203-278, and >278 IU/L).

RESULTS

A total of 972 patients (mean age, 76±13 years; 54% male) were retrospectively analyzed. WRF was identified in 132 patients (13.6%). In multivariate logistic regression analysis, baseline CKD [odds ratio (OR) 2.46, 95% confidence interval (CI) 1.48-4.08, p<0.001], serum albumin (OR 0.52, 95% CI 0.35-0.77, p=0.001), and diabetes (OR 2.07, 95% CI 1.37-3.12, p<0.001) were associated with WRF. Compared with the lowest tertile (ALP <203 IU/L), an adjusted OR of WRF was 1.69 (95% CI 1.02-2.79, p=0.04) in the middle tertile (ALP, 203-278 IU/L) and 1.95 (95% CI 1.20-3.21, p=0.008) in the highest tertile (ALP >278 IU/L).

CONCLUSION

Serum ALP is an independent predictor of WRF in the clinical course of ADHF.

Biomarkers and physiopathology in the cardiorenal syndrome

Acute cardiorenal syndrome (CRS) corresponds to an association of acute heart failure and a worsening of renal function. The detection of acute kidney injury (AKI) unfortunately occurs at a late stage of CRS, leading to an increased mortality of the patients. In this review, we described the pathophysiology of CRS and discussed the potential interest of biochemical biomarkers (namely creatinine, cystatin C, NGAL, KIM-1, fatty acid binding protein, Nacetyl-β-D-glucosaminidase and IL-18) that could potentially help to detect AKI earlier and thus reduce the morbi-mortality of the patients suffering from CRS.

Recombinant human relaxin-2: (how) can a pregnancy hormone save lives in acute heart failure?

Acute heart failure (AHF) syndrome, characterized by pulmonary and/or venous congestion owing to increased cardiac filling pressures with or without diminished cardiac output, is still associated with high post-discharge mortality and hospitalization rates. Many novel and promising therapeutic approaches, among them endothelin-1, vasopressin and adenosine antagonists, calcium sensitization, and recombinant B-type natriuretic hormone, have failed in large studies. Likewise, the classic drugs, vasodilators, diuretics, and inotropes, have never been shown to lower mortality.The phase III trial RELAX-AHF tested recombinant human relaxin-2 (rhRlx) and found it to improve clinical symptoms moderately, to be neutral regarding the combination of death and hospitalization at day 60, to be safe, and to lower mortality at day 180. This review focuses on basic research and pre-clinical findings that may account for the benefit of rhRlx in AHF. The drug combines short-term hemodynamic advantages, such as moderate blood pressure decline and functional endothelin-1 antagonism, with a wealth of protective effects harboring long-term benefits, such as anti-inflammatory, anti-fibrotic, and anti-oxidative actions. These pleiotropic effects are exerted through a complex and intricate signaling cascade involving the relaxin-family peptide receptor-1, the glucocorticoid receptor, nitric oxide, and a cell type-dependent variety of kinases and transcription factors.

Prevalence and clinical features of patients with the cardiorenal syndrome admitted to an internal medicine ward

BACKGROUND

Many patients admitted to a Department of Internal Medicine have different degrees of heart and kidney dysfunction. Mortality, morbidity and cost of care greatly increase when cardiac and renal diseases coexist.

METHODS

A retrospective cohort study was conducted on 1,087 patients admitted from December 2009 to December 2012 to evaluate the prevalence of the cardiorenal syndrome (CRS) and clinical features.

RESULTS

Out of 1,087 patients discharged from our unit during the study period, 190 (17.5%) were diagnosed as having CRS and classified into five types. CRS was more common in males (68.9%). CRS type 1 was associated with higher age (79.9 ± 8.9 years) and accounted for 61.5% of all deaths (p < 0.001), representing a risk factor for mortality (OR 4.23, 95% CI 1.8-10). Congestive heart failure was significantly different among the five CRS types (p < 0.0001) with a greater frequency in type 1 patients. Infectious diseases were more frequent in CRS types 1, 3 and 5 (p < 0.05). Pneumonia presented a statistically higher frequency in CRS types 1 and 5 compared to other classes (p < 0.01), and community-acquired infections were statistically more frequent in CRS types 1 and 5 (p < 0.05). The distribution of community-acquired pneumonia was different among the classes (p < 0.01) with a higher frequency in CRS types 1, 3 and 5.

CONCLUSION

CRS is a condition that is more frequently observed in the clinical practice. The identification of predisposing trigger factors, such as infectious diseases, particularly in the elderly, plays a key role in reducing morbidity and mortality. An early recognition can be useful to optimize therapy, encourage a multidisciplinary approach and prevent complications.

Cardiorenal syndrome--current understanding and future perspectives

Combined cardiac and renal dysfunction has gained considerable attention. Hypotheses about its pathogenesis have been formulated, albeit based on a relatively small body of experimental studies, and a clinical classification system has been proposed. Cardiorenal syndrome, as presently defined, comprises a heterogeneous group of acute and chronic clinical conditions, in which the failure of one organ (heart or kidney) initiates or aggravates failure of the other. This conceptual framework, however, has two major drawbacks: the first is that, despite worldwide interest, universally accepted definitions of cardiorenal syndrome are lacking and characterization of heart and kidney failure is not uniform. This lack of consistency hampers experimental studies on mechanisms of the disease. The second is that, although progress has been made in developing hypotheses for the pathogenesis of cardiorenal syndrome, these initiatives are at an impasse. No hierarchy has been identified in the myriad of haemodynamic and non-haemodynamic factors mediating cardiorenal syndrome. This Review discusses current understanding of cardiorenal syndrome and provides a roadmap for further studies in this field. Ultimately, discussion of the definition and characterization issues and of the lack of organization among pathogenetic factors is hoped to contribute to further advancement of this complex field.

Cardiorenal syndrome: pathophysiology and treatment

CRS is a common problem in patients with advanced heart failure. Arterial underfilling with consequent neurohormonal activation, systemic and intrarenal vasoconstriction, and salt and water retention cause the main clinical features of CRS which include a progressive decline in renal function, worsening renal function during treatment of heart failure (HF) decompensation and resistance to loop diuretics. Impaired renal function in HF patients often reflects more advanced stages of cardiac failure, and thus is associated with a worse prognosis. However, a transient fall in glomerular filtration rate may be a result of successful treatment of congestion, and thereby might not be associated with decreased survival in HF patients. This review covers basic pathophysiological mechanisms underlying the CRS and current trends in practical approaches to treat these patients.

Heart failure: clinical problem and management issues

Heart failure (HF) often presents as dyspnea either with exertion and/or recumbency. Patients also experience dependent swelling and fatigue. Measurement of the left ventricular ejection fraction (LVEF) identifies HF patients who may respond to pharmacologic therapy and/or electrophysiologic device implantation. Angiotension converting enzyme inhibitors, beta blockers, and aldosterone inhibitors can significantly lower the mortality and morbidity of HF in patients with an LVEF less than 35%. Cardiac defibrillators and biventricular pacemakers can also improve outcomes in selected patients with a decreased LVEF. The authors provide a guide for therapeutic decisions based on the inclusion criteria of the major clinical trials.

The cardiorenal syndrome in heart failure: cardiac? renal? syndrome?

There has been increasing interest on the so-called cardiorenal syndrome (CRS), defined as a complex pathophysiological disorder of the heart and kidneys whereby acute or chronic dysfunction in one organ may induce acute or chronic dysfunction in the other. In this review, we contend that there is lack of evidence warranting the adoption of a specific clinical construct such as the CRS within the heart failure (HF) syndrome by demonstrating that: (a) the approaches and tools regarding the definition of kidney involvement in HF are suboptimal; (b) development of renal failure in HF is often confounded by age, hypertension, and diabetes; (c) worsening of renal function (WRF) in HF may be largely independent of alterations in cardiac function; (d) the bidirectional association between HF and renal failure is not unique and represents one of the several such associations encountered in HF; and (e) inflammation is a common denominator for HF and associated noncardiac morbidities. Based on these arguments, we believe that dissecting one of the multiple bidirectional associations in HF and constructing the so-called cardiorenal syndrome is not justified pathophysiologically. Fully understanding of all morbid associations and not only the cardiorenal is of great significance for the clinician who is caring for the patient with HF.

Comorbid Heart Failure and Renal Impairment: Epidemiology and Management

Heart failure mortality is significantly increased in patients with baseline renal impairment and those with underlying heart failure who subsequently develop renal dysfunction. This accelerated progression occurs independent of the cause or grade of renal dysfunction and baseline risk factors. Recent large prospective databases have highlighted the depth of the current problem, while longitudinal population studies support an increasing disease burden. We have extensively reviewed the epidemiological and therapeutic data among these patients. The evidence points to a progression of heart failure early in renal impairment, even in the albuminuric stage. The data also support poor prescription of prognostic therapies. As renal function is the most important prognostic factor in heart failure, it is important to establish the current understanding of the disease burden and the therapeutic implications.

Renal function in patients with hypertension associated congestive cardiac failure seen in a tertiary hospital

Background. Chronic kidney disease is frequently seen in patients with congestive cardiac failure and is an independent risk factor for morbidity and mortality. The aim of this study was to determine the prevalence of chronic kidney disease in patients with hypertension associated congestive cardiac failure. Method. One hundred and fifty patients with hypertension associated congestive cardiac failure were recruited consecutively from the medical outpatient department and the medical wards of the Nnamdi Azikiwe University Teaching Hospital Nnewi over a one year period, January to December 2010. Patients' biodata and medical history were obtained, detailed physical examination done and each patient had a chest X-ray, 12 lead ECG, urinalysis, serum urea and creatinine assay done. Ethical clearance was obtained from the Ethical Review Board of our institution and data analysed using SPSS-version 16. Results. There were 86 males and 64 females with mean age 62.7 ± 12.5 years. The mean blood pressures were systolic 152.8 ± 28.5 mmHg and diastolic 94.3 ± 18 mmHg. 84.7% had blood pressure ≥140/90 mmHg on presentation. The mean GFR was 70.1 ± 31.3 mls/min. 76% of subjects had GFR <90 mls/min and no statistical significant difference between males and females, P = 0.344. The mean serum urea was 7.2 ± 51 mmol/L while the mean serum creatinine was 194 ± 416.2 mmol/L. Conclusions. This study has demonstrated that majority of patients presenting with hypertension associated congestive cardiac failure have some degree of chronic kidney disease.

Treating volume overload in acutely decompensated heart failure: established and novel therapeutic approaches

BACKGROUND

Most patients hospitalized for acutely decompensated heart failure (ADHF) present with symptoms and signs of volume overload, which is also associated with substantially high rates of death and rehospitalization in ADHF.

OBJECTIVE

To review the recent experimental and clinical evidence on existing therapeutic algorithms and investigational drugs used for the treatment of volume overload in ADHF patients.

METHODS

A systematic search of peer-reviewed publications was performed on Medline and EMBASE from January 1990 to March 2012. The results of unpublished trials were obtained from presentations at national and international meetings.

RESULTS

Apart from intrinsic renal insufficiency and neurohormonal activation, volume overload through venous congestion may be the primary haemodynamic factor triggering the worsening of renal function in ADHF patients. It is well known that heart and kidneys are closely interrelated and an acute or chronic disorder in one organ may induce acute or chronic dysfunction in the other organ. Established therapeutic strategies, (e.g. loop diuretics, vasodilators, and inotropes), are sometimes associated with limited clinical success due to tolerance and the need for frequent up titration of the doses in order to achieve the desired effect. That leads to an increasing interest in novel options, such as the use of adenosine A1 receptor antagonists, vasopressin antagonists, and renal-protective dopamine. Initial clinical trials have shown quite encouraging results in some heart failure subpopulations but have failed to demonstrate a clear beneficial role of these agents. On the other hand, ultrafiltration appears to be a more promising therapeutic procedure that will improve volume regulation, while preserving renal and cardiac function.

CONCLUSION

Further clinical studies are required in order to determine their net effect on renal function and potential cardiovascular outcomes. Until then, management of volume overload in ADHF patients remains a challenge for the clinicians.

The risk for chronic kidney disease in patients with heart diseases: a 7-year follow-up in a cohort study in Taiwan

Background

The worldwide increasing trend of chronic kidney disease (CKD) is of great concern and the role of heart disease deserves longitudinal studies. This study investigated the risk of developing CKD among patients with heart diseases.

Methods

From universal insurance claims data in Taiwan, we retrospectively identified a cohort of 26005 patients with newly diagnosed heart diseases and 52010 people without such disease from the 2000–2001 claims. We observed prospectively both cohorts until the end of 2007 to measure CKD incidence rates in both cohorts and hazard ratios (HR) of CKD.

Results

The incidence of CKD in the cohort with heart disease was 4.1 times greater than that in the comparison cohort (39.5 vs. 9.65 per 10,000 person-years). However, the HR changed into 2.37 (95% confidence interval (CI) = 2.05 – 2.74) in the multivariate Cox proportional hazard model after controlling for sociodemographic characteristics and comorbidity. Compared with individuals aged < 40 years, the HRs for CKD ranged from 2.70 to 4.99 in older age groups. Significant estimated relative risks of CKD observed in our patients were also independently associated with hypertension (HR = 2.26, 95% CI = 1.94 - 2.63) and diabetes mellitus (HR = 2.44, 95% CI = 2.13 - 2.80), but not with hyperlipidemia (HR =1.13, 95% CI = 0.99-1.30).

Conclusions

This population study provides evidence that patients with heart disease are at an elevated risk of developing CKD. Hypertension and diabetes mellitus are also comorbidity associated with increasing the CKD risk independently.

Cardiorenal syndrome type 1: pathophysiological crosstalk leading to combined heart and kidney dysfunction in the setting of acutely decompensated heart failure

Cardiorenal syndrome (CRS) type 1 is characterized as the development of acute kidney injury (AKI) and dysfunction in the patient with acute cardiac illness, most commonly acute decompensated heart failure (ADHF). There is evidence in the literature supporting multiple pathophysiological mechanisms operating simultaneously and sequentially to result in the clinical syndrome characterized by a rise in serum creatinine, oliguria, diuretic resistance, and in many cases, worsening of ADHF symptoms. The milieu of chronic kidney disease has associated factors including obesity, cachexia, hypertension, diabetes, proteinuria, uremic solute retention, anemia, and repeated subclinical AKI events all work to escalate individual risk of CRS in the setting of ADHF. All of these conditions have been linked to cardiac and renal fibrosis. In the hospitalized patient, hemodynamic changes leading to venous renal congestion, neurohormonal activation, hypothalamic-pituitary stress reaction, inflammation and immune cell signaling, systemic endotoxemic exposure from the gut, superimposed infection, and iatrogenesis all contribute to CRS type 1. The final common pathway of bidirectional organ injury appears to be cellular, tissue, and systemic oxidative stress that exacerbate organ function. This review explores in detail the pathophysiological pathways that put a patient at risk and then effectuate the vicious cycle now recognized as CRS type 1.

Cardiorenal Syndrome in Hypertensive Rats: Microalbuminuria, Inflammation and Ventricular Hypertrophy

The aim of our study was to evaluate a possible association between microalbuminuria (MA), several low-grade inflammation factors and left ventricular hypertrophy (LVH) by using a pharmacological approach. This may provide new insights into the pathophysiologic mechanisms of the cardiorenal syndrome (CRS) linking early renal impairment with elevated cardiovascular risk. Two kidney-one clip (2K-1C) renovascular hypertension was induced in 24 male Wistar rats (220-250 g). After the development of hypertension, rats were divided into four groups: 2K-1C (untreated), calcium channel blocker (amlodipine-treated), angiotensin receptor blocker (losartan-treated) and peripheral vasodilator (hydralazine-treated), which were treated for 10 weeks. Rats in the 2K-1C group had all developed hypertension, a significant increase in plasma levels of tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), brain natriuretic peptide (BNP) and C-reactive protein (CRP). Moreover MA and creatininaemia underwent a significant increase. Under treatment decreases were observed in systolic blood pressure (SBP), TNF-α, CRP, IL-6, BNP concentrations and creatininaemia. These results were related to the absence of MA which was significantly associated with reductions in cardiac mass and hypertrophy markers (BNP and β-MHC gene expression) as well as renal interstitial inflammation. In conclusion, our results suggest that the reduction of MA is correlated with the decrease of the inflammatory components and seems to play an important role in protecting against cardiac hypertrophy and renal injury.

Renal sympathetic denervation suppresses de novo podocyte injury and albuminuria in rats with aortic regurgitation

BACKGROUND

The presence of chronic kidney disease is a significant independent risk factor for poor prognosis in patients with chronic heart failure. However, the mechanisms and mediators underlying this interaction are poorly understood. In this study, we tested our hypothesis that chronic cardiac volume overload leads to de novo renal dysfunction by coactivating the sympathetic nervous system and renin-angiotensin system in the kidney. We also examined the therapeutic potential of renal denervation and renin-angiotensin system inhibition to suppress renal injury in chronic heart failure.

METHODS AND RESULTS

Sprague-Dawley rats underwent aortic regurgitation and were treated for 6 months with vehicle, olmesartan (an angiotensin II receptor blocker), or hydralazine. At 6 months, albuminuria and glomerular podocyte injury were significantly increased in aortic regurgitation rats. These changes were associated with increased urinary angiotensinogen excretion, kidney angiotensin II and norepinephrine (NE) levels, and enhanced angiotensinogen and angiotensin type 1a receptor gene expression and oxidative stress in renal cortical tissues. Aortic regurgitation rats with renal denervation had decreased albuminuria and glomerular podocyte injury, which were associated with reduced kidney NE, angiotensinogen, angiotensin II, and oxidative stress. Renal denervation combined with olmesartan prevented podocyte injury and albuminuria induced by aortic regurgitation.

CONCLUSIONS

In this chronic cardiac volume-overload animal model, activation of the sympathetic nervous system augments kidney renin-angiotensin system and oxidative stress, which act as crucial cardiorenal mediators. Renal denervation and olmesartan prevent the onset and progression of renal injury, providing new insight into the treatment of cardiorenal syndrome.

Changes in renal function after implantation of continuous-flow left ventricular assist devices

OBJECTIVES

The aim of this study was to determine renal outcomes after left ventricular assist device (LVAD) implantation.

BACKGROUND

Renal dysfunction before LVAD placement is frequent, and it is unclear whether it is due to primary renal disease or to poor perfusion.

METHODS

A retrospective single-center analysis was conducted in 83 consecutive patients implanted with HeartMate II continuous-flow LVADs (Thoratec Corp., Pleasanton, California). Calculated glomerular filtration rate (GFR) was assessed on admission and 1, 3, and 6 months after implantation. To define predictors for improvement in GFR, clinical variables were examined in patients with decreased renal function (GFR <60 ml/min/1.73 m(2)) before LVAD, surviving and dialysis-free at 1 month (n = 44).

RESULTS

GFR significantly increased from admission (53.2 ± 21.4 ml/min/1.73 m(2)) to 1 month after LVAD implantation (87.4 ± 27.9 ml/min/1.73 m(2)) (p < 0.0001). Subsequently, at 3 and 6 months, GFR remained significantly (p < 0.0001) above pre-LVAD values. Of the 51 patients with GFRs <60 ml/min/1.73 m(2) before LVAD surviving at 1 month, 34 (67%) improved to GFRs >60 ml/min/1.73 m(2). Univariate pre-operative predictors for improvement in renal function at 1 month included younger age (p = 0.049), GFR improvement with optimal medical therapy (p < 0.001), intra-aortic balloon pump use (p = 0.004), kidney length above 10 cm (p = 0.023), no treatment with angiotensin-converting enzyme inhibitors or angiotensin receptor blockers (p = 0.029), higher bilirubin (p = 0.002), higher Lietz-Miller score (p = 0.019), and atrial fibrillation (p = 0.007). Multivariate analysis indicated pre-operative improved GFR (slope = 0.5 U per unit improved; 95% confidence interval: 0.2 to 0.8; p = 0.003), atrial fibrillation (slope = 27; 95% confidence interval: 8 to 46; p = 0.006), and intra-aortic balloon pump use (slope = 14; 95% confidence interval: 2 to 26; p = 0.02) as independent predictors.

CONCLUSIONS

In most patients with end-stage heart failure considered for LVAD implantation, renal dysfunction is reversible and likely related to poor renal perfusion.

Prognostic utility of plasma neutrophil gelatinase-associated lipocalin in patients with acute heart failure: the NGAL EvaLuation Along with B-type NaTriuretic Peptide in acutely decompensated heart failure (GALLANT) trial

Aims

Neutrophil gelatinase-associated lipocalin (NGAL) is a measure of acute kidney injury. Renal dysfunction portends significant risk after discharge from acute heart failure (AHF). Thus, a sensitive marker of renal injury might also help to risk stratify HF patients.

Methods and results

GALLANT [NGAL EvaLuation Along with B-type NaTriuretic Peptide (BNP) in acutely Decompensated Heart Failure] was a multicentre, prospective study to assess the utility of plasma NGAL, alone and in combination with BNP, as an early risk marker of adverse outcomes. We studied 186 patients (61% male). There were 29 events (AHF readmissions and all-cause mortality) at 30 days (16%). Patients with events had higher levels of NGAL than those without (134 vs. 84 ng/mL, P < 0.001). The area under the receiver operating characteristic curve was higher for NGAL (0.72) than BNP (0.65), serum creatinine (0.57), or estimated glomerular filtration rate (eGFR; 0.55). In multivariable analyses, NGAL predicted events (P= 0.001), BNP approached significance (P= 0.052 and 0.070 without creatinine and GFR, respectively) while neither serum creatinine nor eGFR were significant. The addition of discharge NGAL over BNP alone improved classification by a net 10.3% in those with events and 19.5% in those without events, for a net reclassification improvement of 29.8% (P= 0.010). Subjects with both BNP and NGAL elevated were at significant risk [hazard ratio (HR) = 16.85, P= 0.006], as were subjects with low BNP and high NGAL (HR = 9.95, P= 0.036).

Conclusions

Plasma NGAL is a measure of kidney injury that at the time of discharge is a strong prognostic indicator of 30 days outcomes in patients admitted for AHF.

Clinical trial registration number: NCT 00693745

Optimizing fluid management in patients with acute decompensated heart failure (ADHF): the emerging role of combined measurement of body hydration status and brain natriuretic peptide (BNP) levels

The study tests the hypothesis that in patients admitted with acutely decompensated heart failure (ADHF), achievement of adequate body hydration status with intensive medical therapy, modulated by combined bioelectrical vectorial impedance analysis (BIVA) and B-type natriuretic peptide (BNP) measurement, may contribute to optimize the timing of patient’s discharge and to improve clinical outcomes. Three hundred patients admitted for ADHF underwent serial BIVA and BNP measurement. Therapy was titrated to reach a BNP value of <250 pg/ml, whenever possible. Patients were categorized as early responders (rapid BNP fall below 250 pg/ml); late responders (slow BNP fall below 250 pg/ml, after aggressive therapy); and non-responders (BNP persistently >250 pg/ml). Worsening of renal function (WRF) was evaluated during hospitalization. Death and rehospitalization were monitored with a 6-month follow-up. BNP value on discharge of ≤250 pg/ml led to a 25% event rate within 6 months (Group A: 17.4%; Group B: 21%, Chi2; n.s.), whereas a value >250 pg/ml (Group C) was associated with a far higher percentage (37%). At discharge, body hydration was 73.8 ± 3.2% in the total population and 73.2 ± 2.1, 73.5 ± 2.8, 74.1 ± 3.6% in the three groups, respectively. WRF was observed in 22.3% of the total. WRF occurred in 22% in Group A, 32% in Group B, and 20% in Group C (P = n.s.). Our study confirms the hypothesis that combined BNP/BIVA sequential measurements help to achieve adequate fluid balance status in patients with ADHF and can be used to drive a “tailored therapy,” allowing clinicians to identify high-risk patients and possibly to reduce the incidence of complications secondary to fluid management strategies.

Cardiac resynchronization therapy in the cardiorenal syndrome

The cardiorenal syndrome (CRS) is a complex clinical syndrome in which dysfunction of either the heart or the kidneys affects the functioning of the other organ system. Many therapies used in heart failure have further detrimental effects on renal function. Cardiac resynchronization therapy (CRT) is a relatively new form of device therapy that reduces morbidity and mortality in patients with heart failure. This review will discuss the effects of CRT on renal function in patients with CRS, the impact of baseline renal function on response to CRT, and potential risks associated with CRT in this unique population.

Pharmacological management of cardiorenal syndromes

Cardiorenal syndromes are disorders of the heart and kidneys whereby acute or chronic dysfunction in one organ may induce acute or chronic dysfunction of the other. The pharmacological management of Cardiorenal syndromes may be complicated by unanticipated or unintended effects of agents targeting one organ on the other. Hence, a thorough understanding of the pathophysiology of these disorders is paramount. The treatment of cardiovascular diseases and risk factors may affect renal function and modify the progression of renal injury. Likewise, management of renal disease and associated complications can influence heart function or influence cardiovascular risk. In this paper, an overview of pharmacological management of acute and chronic Cardiorenal Syndromes is presented, and the need for high-quality future studies in this field is highlighted.