Cardiac and renal dysfunction in chronic heart failure: relation to neurohumoral activation and prognosis

Fluid balance in heart failure

Fluid retention is a major determinant of symptoms in patients with heart failure (HF), and it is closely associated with prognosis. Hence, congestion represents a critical therapeutic target in this clinical setting. The first therapeutic strategy in HF patients with fluid overload is optimization of diuretic intervention to maximize water and sodium excretion. When diuretic therapy fails to relieve congestion, renal replacement therapy represents the only alternative option for fluid removal, as well as a way to restore diuretic responsiveness. On this background, the pathophysiology of fluid balance in HF is complex, with heart, kidney, and lung being deeply involved in volume regulation and management. Therefore, the interplay between these organs should be appreciated and considered when fluid overload in HF patients is targeted.

Physical Exercise Affects Quality of Life and Cardiac Autonomic Modulation in Patients With Chronic Kidney Failure Submitted to Hemodialysis: A Randomized Clinical Trial

Performing physical exercise during hemodialysis has been debated regarding safety and efficacy for improving life quality for patients with chronic kidney disease (CKD). Thus, we explored the influence of physical exercise during hemodialysis on both autonomic modulation of heart rate and quality of life for patients with CKF in a randomized clinical trial. We randomly allocated participants requiring hemodialysis to an experimental exercise group (EG) and a control no-exercise group (CG) and assessed their quality of life with the Kidney Disease Quality of Life Short Form—KDQOL-SF™ 1.3 and with Polar RS800CX to monitor their heart rate variability (HRV) before and three months after the end of the exercise intervention. EG participants reported a significant increase in their quality of life ( p = .05, physical function, physical aspects, pain, emotional well-being, emotional function; p = .03, energy and fatigue) and showed HRV improvement ( p = .05, RMSSD, SDNN, and SD2; p = .004, SD1) after three months of exercise. Thus, we recommend supervised physical exercise during hemodialysis for carefully selected patients.

Simple Clinical Criteria to Determine the Prognosis of Heart Failure

Objective: To determine whether easily obtained clinical parameters serve as predictors of survival in patients with congestive heart failure. Several scoring systems to predict heart failure survival have been developed; however, many of these deal principally with transplant recipients or do not account for a patient’s response to therapy.

Methods: A total of 680 patients with an ejection fraction of less than 40% were included in the analysis. Baseline assessments were performed and treatment regimens were identified; patients were then followed for up to 5 years. Univariate and multivariate Cox regression models were used to determine clinically important predictors of survival. Kaplan-Meier survival functions for patients with and without the prognostic variable were constructed and mortality was calculated at 1 year and 5 years.

Results: Ejection fraction improvement at 6 months, diabetes mellitus, age, serum creatinine, and blood urea nitrogen (BUN) were significant predictors for survival in the univariate model. Ejection fraction improvement, age, and BUN were significant predictors in the multivariate model. These findings were used to construct a model for predicting patient mortality. Improved ejection fraction (>15 ejection fraction units) gave a 1-year mortality of 2% and a 5-year mortality of 11%. Mortality rates according to patient age and BUN levels were also calculated.

Conclusion: Ejection fraction improvement was the most important predictor for survival in patients with systolic dysfunction; monitoring ejection fraction changes through repeat echocardiograms has important prognostic value. In patients without ejection fraction improvement, age and renal function are important survival determinants.

Variability in inpatient serum creatinine: its impact upon short- and long-term mortality

BACKGROUND

Long-staying medical inpatients carry a significant burden of acute and chronic illness. Prediction of their in-hospital and longer-term mortality risk is important.

AIM

The aim of this study was to determine to what extent creatinine variability predicts in-hospital and 1-year mortality in inpatients.

DESIGN

Retrospective cohort analysis.

METHODS

Patients were included if aged 18 years or older and if admitted for 7 days or longer. The main outcome variables were mortality in hospital and after discharge.

RESULTS

Increasing age, the presence of heart failure and a reduced estimated glomerular filtration rate (eGFR) on admission (<60 ml/min/1.73 m(2)) all associated with death risk (both in hospital and within a year of discharge). The creatinine change was related to mortality risk for the patient whilst in hospital and within 1 year after discharge independently of these other factors. The threshold of creatinine change, above which the in-hospital mortality rose significantly was 25 µmol/l (P < 0.001). A creatinine change of >10 µmol/l predicted significantly higher mortality within a year of discharge (P < 0.001). Every 5 µmol/l change in creatinine was associated with an in-hospital mortality increase of 3% (P < 0.001) and a 1-year mortality increase of 1% (P < 0.007).

CONCLUSIONS

Patients with a creatinine rise or fall of >10 µmol/l during admission are at higher risk of death after discharge than those with more stable creatinine. These patients therefore merit further attention that might include more focused nutritional assessment, cardiovascular risk factor management or advance care planning.

Continuous ultrafiltration in acute decompensated heart failure: current issues and future directions

Most patients hospitalized for acutely decompensated heart failure (ADHF) present with symptoms and signs of volume overload, which are also associated with high rates of death and re-hospitalization. Several studies have investigated the possible use of extracorporeal ultrafiltration in the management of ADHF, evaluating potential clinical benefits in terms of hospitalization and survival rates versus those of conventional diuretic therapy. Though ultrafiltration remains an extremely appealing therapeutic option for patients with AHDF, some of the most recent studies have reported conflicting results. Differences in the selection of study population, heterogeneity of the indications for the use of ultrafiltration, disparity in the ultrafiltration protocols, and high variability in the pharmacologic therapies used for the control group could explain some of these contradictory findings. The purpose of the present review is to provide an overview and an update on the mechanisms and clinical effects of ultrafiltration and on currently available evidence supporting its use in ADHF.

Ultrafiltration for congestive heart failure: the past and the present

PURPOSE OF REVIEW

To provide an overview on the most recent evidence for the use of extracorporeal and peritoneal ultrafiltration in heart failure, focusing on the major publications from the last few years.

RECENT FINDINGS

There have been several studies investigating the possible use of extracorporeal and peritoneal ultrafiltration in the management of acute and chronic heart failure. These trials have investigated the potential benefits and advantages of ultrafiltration over conventional medical therapy, in terms of clinical outcomes.

SUMMARY

Although ultrafiltration remains an extremely appealing therapeutic option for patients with heart failure and congestion, with several theoretical beneficial effects, some of the most recent studies have reported inconsistent findings. Differences in the selection of the study population, heterogeneity of the indications for use of ultrafiltration, variation in the ultrafiltration protocols, and high variability in the pharmacologic therapy used for the control group could explain some of these conflicting findings.

Extracorporeal ultrafiltration for heart failure: focus on organ cross talk and clinical trials

Despite major advances in pharmacological therapy and cardiac devices, heart failure patients continue to be frequently (re-)hospitalized with signs and symptoms of fluid overload. Diuretics improve the symptoms of fluid overload, but their effectiveness is reduced by a number of factors including excess salt intake, underlying chronic kidney disease, renal adaptation to their actions and neurohormonal activation. Ultrafiltration (UF) is a mechanical method of fluid removal with several potential advantages over diuretic-based conventional therapies: several recent studies have demonstrated favorable clinical response to UF therapy. Such studies have shown that removal of large amounts of isotonic fluid, in addition to relieving symptoms of congestion, can improve exercise capacity, reduce cardiac filling pressures, restore diuretic responsiveness, and portend a favorable effect on cardio-pulmonary, cardiorenal interactions, and neurohormonal hyperactivation. However, despite these proposed benefits, so far, no clinical study has yet been carried out to explore the impact of UF therapy on hard clinical endpoints such as long-term mortality. In this article, we review a number of mechanistic aspects of UF therapy, with particular emphasis on cardio-pulmonary and cardiorenal interactions, and revisit the results of more recent clinical trials in order to highlight the characteristics that can help identify patients who are more likely to benefit from this therapeutic modality.

Renal impairment, worsening renal function, and outcome in patients with heart failure: an updated meta-analysis

AIMS

Chronic kidney disease (CKD) and worsening renal function (WRF) have been associated with poor outcome in heart failure (HF).

METHODS AND RESULTS

Articles were identified by literature search of MEDLINE (from inception to 1 July 2012) and Cochrane. We included studies on HF patients and mortality risk with CKD and/or WRF. In a secondary analysis, we selected studies investigating predictors of WRF. We retrieved 57 studies (1,076,104 patients) that investigated CKD and 28 studies (49,890 patients) that investigated WRF. The prevalence of CKD was 32% and associated with all-cause mortality: odds ratio (OR) 2.34, 95% confidence interval (CI) 2.20-2.50, P < 0.001). Worsening renal function was present in 23% and associated with unfavourable outcome (OR 1.81, 95% CI 1.55-2.12, P < 0.001). In multivariate analysis, moderate renal impairment: hazard ratio (HR) 1.59, 95% CI 1.49-1.69, P < 0.001, severe renal impairment, HR 2.17, 95% CI 1.95-2.40, P < 0.001, and WRF, HR 1.95, 95% CI 1.45-2.62, P < 0.001 were all independent predictors of mortality. Across studies, baseline CKD, history of hypertension and diabetes, age, and diuretic use were significant predictors for the occurrence of WRF.

CONCLUSION

Across all subgroups of patients with HF, CKD, and WRF are prevalent and associated with a strongly increased mortality risk, especially CKD. Specific conditions may predict the occurrence of WRF and thereby poor prognosis.

Gene transfer of neuronal nitric oxide synthase to the paraventricular nucleus reduces the enhanced glutamatergic tone in rats with chronic heart failure

Our previous studies have shown that the decreased NO and increased glutamatergic mechanisms on sympathetic regulation within the paraventricular nucleus (PVN) may contribute to the elevated sympathoexcitation during chronic heart failure (CHF). In the present study, we investigated the effects of neuronal NO synthase (nNOS) gene transfer on N-methyl-D-aspartic acid receptor subunit NR(1) in the rats with a coronary ligation model of CHF. Adenovirus vectors encoding nNOS (AdnNOS) or adenovirus vectors encoding β-galactosidase were transfected into the PVN in vivo. Five days after application of AdnNOS, the increased expression of nNOS within the PVN was confirmed by NADPH-diaphorase staining, real-time PCR, and Western blot. In anesthetized rats, AdnNOS treatment significantly enhanced the blunted renal sympathetic nerve activity, blood pressure, and heart rate responses to NO synthase inhibitor N(G)-monomethyl-L-arginine in the rats with CHF compared with CHF-adenovirus vectors encoding β-galactosidase group. AdnNOS significantly decreased the enhanced renal sympathetic nerve activity, blood pressure, and heart rate responses to N-methyl-D-aspartic acid in the rats with CHF (renal sympathetic nerve activity: 44±2% versus 79±6%; P<0.05) compared with CHF-adenovirus vectors encoding the β-galactosidase group. AdnNOS transfection significantly reduced the increased NR(1) receptor mRNA expression (Δ35±5%) and protein levels (Δ24±4%) within the PVN in CHF rats. Furthermore, in neuronal NG-108 cells, NR(1) receptor protein expression decreased in a dose-dependent manner after AdnNOS transfection. According to our results, nNOS downregulation enhances glutamate transmission in the PVN by increasing NR(1) subunit expression. This mechanism may enhance renal sympathetic nerve activity in CHF rats.

Congestive heart failure: where homeostasis begets dyshomeostasis

Despite today's standard of care, aimed at preventing homeostatic neurohormonal activation, one in every five patients recently hospitalized with congestive heart failure (CHF) will be readmitted within 30 days of discharge because of a recurrence of their symptoms and signs. In light of recent pathophysiological insights, it is now propitious to revisit CHF with a view toward complementary and evolving management strategies. CHF is a progressive systemic illness. Its features include: oxidative stress in diverse tissues; an immunostimulatory state with circulating proinflammatory cytokines; a wasting of soft tissues; and a resorption of bone. Its origins are rooted in homeostatic mechanisms gone awry to beget dyshomeostasis. For example, marked excretory losses of Ca2+ and Mg2+ accompany renin-angiotensin-aldosterone system activation, causing ionized hypocalcemia and hypomagnesemia that lead to secondary hyperparathyroidism with consequent bone resorption and a propensity to atraumatic fractures. Parathyroid hormone accounts for paradoxical intracellular Ca2+ overloading in diverse tissues and consequent systemic induction of oxidative stress. In cardiac myocytes and mitochondria, these events orchestrate opening of the mitochondrial permeability transition pore with an ensuing osmotic-based destruction of these organelles and resultant cardiomyocyte necrosis with myocardial scarring. Contemporaneous with Ca2+ and Mg2+ dyshomeostasis is hypozincemia and hyposelenemia, which compromise metalloenzyme-based antioxidant defenses, whereas hypovitaminosis D threatens Ca2+ stores needed to prevent secondary hyperparathyroidism. An intrinsically coupled dyshomeostasis of intracellular Ca2+ and Zn2+, representing pro-oxidant and antioxidant, respectively, is integral to regulating the mitochondrial redox state; it can be uncoupled by a Zn2+ supplement in favor of antioxidant defenses. Hence, the complementary use of nutriceuticals to nullify dyshomeostatic responses involving macro- and micronutrients should be considered. Evolving strategies with mitochondria-targeted interventions interfering with their uptake of Ca2+ or serving as selective antioxidant or mitochondrial permeability transition pore inhibitor may also prove efficacious in the overall management of CHF.

Risk Factors and Clinical Outcomes for Contrast-induced Nephropathy After Percutaneous Coronary Intervention in Patients with Normal Serum Creatinine

Introduction: We aim to examine the risk predictors of contrast-induced nephropathy (CIN) in patients with normal baseline serum creatinine (Cr). CIN is an important complication post percutaneous coronary intervention (PCI). Previous studies examined CIN predictors in patients with chronic renal impairment. No large studies investigated patients with normal renal function which constitute the majority undergoing PCI. We aim to identify risk predictors in this cohort and examine the clinical outcomes. Materials and Methods: A total of 3036 patients with normal baseline Cr (<1.5 mg/dL) who did not receive prophylaxis while undergoing PCI were enrolled. We examined the occurrence of CIN and the mortality outcome at 1 and 6 months. Results: CIN occurred in 7.3% of patients. The median age was 59.5 years (range, 26 to 86), 78.7% men, 34.6% diabetics. Risk predictors for CIN include age [odds ratio (OR), 6.4; 95% CI, 1.01-13.3; P = 0.042], female gender (OR, 2.0; 95% CI, 1.5-2.7; P = 0.001), abnormal left ventricular ejection fraction (LVEF) <50%(OR,1.02; 95% CI, 1.01-1.04; P = 0.01), anaemia with haemoglobin <11 mg/dL (OR, 1.5; 95% CI, 1.01-2.4; P = 0.044) and systolic hypotension with blood pressure <100 mmHg (OR, 1.5; 95% CI, 1.01-2.2; P = 0.004). Diabetics on insulin therapy were at the highest risk compared with diabetics on oral hypoglycaemics and diet control (18.9% vs 6.8% vs 3.6%; P = 0.001). Patients who developed CIN had higher mortality at 1 month (14.5% vs 1.1%; P <0.001) and 6 months (17.8% vs 2.2%; P <0.001). Conclusions: Subgroups of patients with normal baseline Cr undergoing PCI are at risk of developing CIN with resultant higher mortality. Age, female gender, insulin dependent diabetes mellitus, presence of hypotension, anaemia and low LVEF are predictors of CIN. Prophylaxis may be considered in these patients. Key words: Anaemia, Female gender, Haemoglobin, Left ventricular ejection fraction

Enhanced angiotensin-mediated excitation of renal sympathetic nerve activity within the paraventricular nucleus of anesthetized rats with heart failure

Chronic heart failure (HF) is characterized by increased sympathetic drive. Enhanced angiotensin II (ANG II) activity may contribute to the increased sympathoexcitation under HF condition. The present study examined sympathoexcitation by 1) the effects of ANG II in the paraventricular nucleus (PVN) on renal sympathetic nerve activity (RSNA), and 2) the altered ANG II type 1 (AT(1)) receptor expression during HF. Left coronary artery ligation was used to induce HF. In the anesthetized Sprague-Dawley rats, microinjection of ANG II (0.05-1 nmol) into the PVN increased RSNA, mean arterial pressure (MAP), and heart rate (HR) in both sham-operated and HF rats. The responses of RSNA and HR were significantly enhanced in rats with HF compared with sham rats (RSNA: 64 +/- 8% vs. 33 +/- 4%, P < 0.05). Microinjection of AT(1) receptor antagonist losartan into the PVN produced a decrease of RSNA, MAP, and HR in both sham and HF rats. The RSNA and HR responses to losartan in HF rats were significantly greater (RSNA: -25 +/- 4% vs. -13 +/- 1%, P < 0.05). Using RT-PCR and Western blot analysis, we found that there were significant increases in the AT(1) receptor mRNA (Delta186 +/- 39%) and protein levels (Delta88 +/- 20%) in the PVN of rats with HF (P < 0.05). The immunofluorescence of AT(1) receptors was significantly higher in the PVN of rats with HF. These data support the conclusion that an increased angiotensinergic activity on sympathetic regulation, due to the upregulation of ANG II AT(1) receptors within the PVN, may contribute to the elevated sympathoexcitation that is observed during HF.

The effect of amlodipine and the combination of amlodipine and enalapril on the renin-angiotensin-aldosterone system in the dog

Excessive aldosterone secretion is detrimental to the heart, vessels and kidneys, contributing to hypertension and the signs and progression of heart failure. Aldosterone secretion, abnormally elevated in heart failure and hypertension, can be blunted with angiotensin-converting enzyme inhibitors. Amlodipine, used to treat hypertension and heart failure, was hypothesized to activate the renin-angiotensin-aldosterone system (RAAS). A study was conducted with six normal adult male beagle dogs. Each dog received amlodipine (0.57 mg/kg b.i.d.) for 6 days, followed by amlodipine (0.57 mg/kg b.i.d.) and enalapril (0.57 mg/kg b.i.d.) for 4 days. Blood pressure, heart rate, serum chemistries and urinary aldosterone excretion, as a measure of RAAS activation, were compared with baseline values. Blood pressure fell by approximately 7% with amlodipine (P = 0.05) and a further 7% with the combination of amlodipine and enalapril (P < 0.01). Blood urea nitrogen increased with the combination (P < 0.05) but only one dog became mildly azotemic. Renin-angiotensin-aldosterone system activation, based on 24 h urinary aldosterone excretion and by aldosterone:creatinine ratio was increased by approximately threefold (P < 0.05) with amlodipine administration. This effect was blunted by enalapril, such that aldosterone excretion was no longer different from that observed under control conditions, although values for 24-h aldosterone excretion did not return to pretreament levels.

Renal impairment and outcomes in heart failure: systematic review and meta-analysis

OBJECTIVES

We estimated the prevalence of renal impairment in heart failure (HF) patients and the magnitude of associated mortality risk using a systematic review of published studies.

BACKGROUND

Renal impairment in HF patients is associated with excess mortality, although precise risk estimates are unclear.

METHODS

A systematic search of MEDLINE (through May 2005) identified 16 studies characterizing the association between renal impairment and mortality in 80,098 hospitalized and non-hospitalized HF patients. All-cause mortality risks associated with any renal impairment (creatinine >1.0 mg/dl, creatinine clearance [CrCl] or estimated glomerular filtration rate [eGFR] <90 ml/min, or cystatin-C >1.03 mg/dl) and moderate to severe impairment (creatinine > or =1.5, CrCl or eGFR <53, or cystatin-C > or =1.56) were estimated using fixed-effects meta-analysis.

RESULTS

A total of 63% of patients had any renal impairment, and 29% had moderate to severe impairment. After follow-up > or =1 year, 38% of patients with any renal impairment and 51% with moderate to severe impairment died versus 24% without impairment. Adjusted all-cause mortality was increased for patients with any impairment (hazard ratio [HR] = 1.56; 95% confidence interval [CI] 1.53 to 1.60, p < 0.001) and moderate to severe impairment (HR = 2.31; 95% CI 2.18 to 2.44, p < 0.001). Mortality worsened incrementally across the range of renal function, with 15% (95% CI 14% to 17%) increased risk for every 0.5 mg/dl increase in creatinine and 7% (95% CI 4% to 10%) increased risk for every 10 ml/min decrease in eGFR.

CONCLUSIONS

Renal impairment is common among HF patients and confers excess mortality. Renal function should be considered in risk stratification and evaluation of therapeutic strategies for HF patients.

Kidney function and mortality among patients with left ventricular systolic dysfunction

Kidney disease has emerged as a risk factor for mortality in heart failure populations. The objective of this study was to determine the impact of different stages of kidney dysfunction (defined using the Kidney Disease Outcomes Quality Initiative [K/DOQI] classification system) and changes in kidney function on mortality in a cohort of patients with heart failure. A retrospective analysis was conducted of data from the randomized controlled trials Studies of Left Ventricular Dysfunction. A total of 6640 participants with asymptomatic and symptomatic heart failure were studied. Estimated GFR (eGFR) were calculated and then categorized according to the K/DOQI classification system into the following categories: > or =90, 60 to 89, 30 to 59, and 15 to 29 ml/min per 1.73 m2. Reduction in eGFR from baseline was calculated and subsequently categorized according to rate of decline (<5, 5 to 10, 11 to 15, and >15 ml/min per 1.73 m2 per year). Independent of baseline differences, lower levels of eGFR were associated with a higher total mortality compared with those with eGFR > or =90 ml/min (30 to 59 ml/min per 1.73 m2: hazard ratio [HR] 1.32, 95% confidence interval [CI] 1.10 to 1.59, P = 0.004; 15 to 29 ml/min per 1.73 m2: HR 2.54, 95% CI 1.54 to 4.19, P < 0.001). eGFR deteriorated rapidly (>15 ml/min per 1.73 m2 per year) in 12% of participants. This decline was associated with a significant increase in mortality compared with slower decline (<5 ml/min per 1.73 m2 per year), despite adjustments for baseline kidney function, baseline heart failure, or change in heart failure (HR 5.63; 95% CI 4.90 to 6.46; P < 0.0001). The levels of eGFR from the K/DOQI classification system are associated with mortality in a well-characterized heart failure population. Rate of decline in kidney function is a strong predictor of increased mortality in this population, independent of worsening heart failure and baseline kidney function.

Contrast-induced nephropathy in patients undergoing primary angioplasty for acute myocardial infarction

OBJECTIVES

The aim of this research was to assess the incidence, clinical predictors, and outcome of contrast-induced nephropathy (CIN) after primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI).

BACKGROUND

Contrast-induced nephropathy is associated with significant morbidity and mortality after PCI. Patients undergoing primary PCI may be at higher risk of CIN because of hemodynamic instability and unfeasibility of adequate prophylaxis.

METHODS

In 208 consecutive AMI patients undergoing primary PCI, we measured serum creatinine concentration (Cr) at baseline and each day for the following three days. Contrast-induced nephropathy was defined as a rise in Cr >0.5 mg/dl.

RESULTS

Overall, CIN occurred in 40 (19%) patients. Of the 160 patients with baseline Cr clearance >/=60 ml/min, only 21 (13%) developed CIN, whereas it occurred in 19 (40%) of those with Cr clearance <60 ml/min (p < 0.0001). In multivariate analysis, age >75 years (odds ratio [OR] 5.28, 95% confidence interval [CI] 1.98 to 14.05; p = 0.0009), anterior infarction (OR 2.17, 95% CI 0.88 to 5.34; p = 0.09), time-to-reperfusion >6 h (OR 2.51, 95% CI 1.01 to 6.16; p = 0.04), contrast agent volume >300 ml (OR 2.80, 95% CI 1.17 to 6.68; p = 0.02) and use of intraaortic balloon (OR 15.51, 95% CI 4.65 to 51.64; p < 0.0001) were independent correlates of CIN. Patients developing CIN had longer hospital stay (13 +/- 7 days vs. 8 +/- 3 days; p < 0.001), more complicated clinical course, and significantly higher mortality rate (31% vs. 0.6%; p < 0.001).

CONCLUSIONS

Contrast-induced nephropathy frequently complicates primary PCI, even in patients with normal renal function. It is associated with higher in-hospital complication rate and mortality. Thus, preventive strategies are needed, particularly in high-risk patients.