Targeting hyponatremia and hemodynamics in acute decompensated heart failure: is there a role for vasopressin antagonists?

Improvement of hyponatremia is associated with lower mortality risk in patients with acute decompensated heart failure: a meta-analysis of cohort studies

Hyponatremia at admission is predictive of poor prognosis in patients with acute decompensated heart failure (ADHF). We performed a meta-analysis of cohort studies to evaluate whether improvement of hyponatremia is associated with improved survival in patients with ADHF and hyponatremia. Relevant studies were identified through systematic search of PubMed and Embase. A random-effect model was used to pool the results. Predefined subgroup analyses were performed to explore the source of heterogeneity. Five thousand seven hundred fourteen patients with ADHF and hyponatremia from eight cohort studies were included. Results showed that improvement of hyponatremia during hospitalization was associated with lower risk of all-cause mortality (RR = 0.65, 95% CI 0.53 to 0.80, p < 0.001) as compared with those without improvement of hyponatremia. Results of subgroup analyses indicated that improvement of hyponatremia was associated with more remarkable changes of short-term (within 3 months after discharge) mortality (RR = 0.54) as compared with long-term mortality (RR = 0.74). Other factors such as study design, sample size, and heart failure subtypes did not affect the association. This was further confirmed by the meta-analysis of studies with multivariate analysis, which also suggested an association between improved hyponatremia and lower risk of all-cause mortality in ADHF patients (adjusted RR = 0.63, 95% CI 0.43 to 0.92, p = 0.02; I² = 63%). These results suggested that improvement of hyponatremia in ADHF patients is associated with lower mortality risk during follow-up, particularly for the short-term mortality.

Hormone treatments in congestive heart failure

The common ultimate pathological feature for all cardiovascular diseases, congestive heart failure (CHF), is now considered as one of the main public health burdens that is associated with grave implications. Neurohormonal systems play a critical role in cardiovascular homeostasis, pathophysiology, and cardiovascular diseases. Hormone treatments such as the newly invented dual-acting drug valsartan/sacubitril are promising candidates for CHF, in addition to the conventional medications encompassing beta receptor blockers, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and mineralocorticoid receptor antagonists. Clinical trials also indicate that in CHF patients with low insulin-like growth factor-1 or low thyroid hormone levels, supplemental treatment with growth hormone or thyroid hormone seems to be cardioprotective; and in CHF patients with volume overload the vasopressin antagonists can relieve the symptoms superior to loop diuretics. Furthermore, a combination of selective glucocorticoid receptor agonist and mineralocorticoid receptor antagonist may be used in patients with diuretic resistance. Finally, the potential cardiovascular efficacy and safety of incretin-based therapies, testosterone or estrogen supplementation needs to be prudently evaluated in large-scale clinical studies. In this review, we briefly discuss the therapeutic effects of several key hormones in CHF.

Effects of tolvaptan in patients with chronic kidney disease and chronic heart failure

BACKGROUND

Tolvaptan, a vasopressin V₂ receptor blocker, has a diuretic effect for patients with heart failure. However, there were a few data concerning the effects of tolvaptan in patients with chronic kidney disease (CKD).

METHODS

We retrospectively analyzed 21 patients with chronic heart failure and CKD. Tolvaptan was co-administered with other diuretics in-use, every day. We compared clinical parameters before and after the treatments with tolvaptan. Furthermore, we examined the correlations between baseline data and the change of body weight.

RESULTS

Tolvaptan decreased the body weight and increased the urine volume (p = 0.001). The urine osmolality significantly decreased throughout the study period. Urinary Na/Cr ratio and FENa changed significantly after 4 h, and more remarkable after 8 h (p = 0.003, both). Serum creatinine increased slightly after 1 week of treatment (p = 0.012). The alteration of body weight within the study period correlated negatively with the baseline urine osmolality (r = -0.479, p = 0.038), the baseline urine volume (r = -0.48, p = 0.028), and the baseline inferior vena cava diameter (IVCD) (r = -0.622, p = 0.017). Hyponatremia was improved to the normal value, and the augmentations of the sodium concentration were negatively associated with the basal sodium levels (p = 0.01, r = -0.546).

CONCLUSIONS

Tolvaptan is effective in increasing diuresis and improved hyponatremia, even in patients with CKD. The baseline urine osmolality, urine volume, and IVCD may be useful predictors for diuretic effects of tolvaptan.

Vasopressin Receptor Antagonists for the Correction of Hyponatremia in Chronic Heart Failure: An Underutilized Therapeutic Option in Current Clinical Practice?

In the congestive heart failure (CHF) setting, chronic hyponatremia is very common. The present review aims at addressing topics relevant to the pathophysiology of hyponatremia in the course of CHF as well as its optimal treatment, including the main advantages and the limitations resulting from the use of the available dietary and pharmacological measures approved for the treatment of this electrolytic trouble. A narrative review is carried out in order to represent the main modalities of therapy for chronic hyponatremia that frequently complicates CHF. The limits of usual therapies implemented for CHF-related chronic hyponatremia are outlined, while an original analysis of the main advancements achieved with the use of vasopressin receptor antagonists (VRAs) is also executed. The European regulatory restrictions that currently limit the use of VRAs in the management of CHF are substantially caused by financial concerns, i.e., the high costs of VRA therapy. A thoughtful reworking of current restrictions would be warranted in order to enable VRAs to be usefully associated to loop diuretics for decongestive treatment of CHF patients with hyponatremia.

Vasopressin receptor antagonists in patients with chronic heart failure

In this brief review, the pathophysiology of hyponatremia and its clinical significance in the course of chronic heart failure (CHF) are illustrated. Moreover, issues concerning the optimal treatment for hyponatremia during CHF are addressed and discussed. In addition, advantages and limitations resulting from the use of vasopressin receptor antagonists, drugs that have recently emerged as the best available resource against hyponatremia, are highlighted.

Drug Treatment of Heart Failure in Children: Focus on Recent Recommendations from the ISHLT Guidelines for the Management of Pediatric Heart Failure

The International Society of Heart and Lung Transplantation (ISHLT) recently updated consensus pediatric heart failure guidelines from those published in 2004 with an aim to provide a practical evidence-based resource whilst recognizing the influence of adult heart failure practice. The new guidelines were formed from published evidence for heart failure management and used parallels with adult literature where pediatric evidence was lacking. This is a summary of the pharmacological therapies discussed in the new 2014 guidelines, emphasizing changes from the previous recommendations with regards to treatment of chronic heart failure with reduced ejection fraction, chronic heart failure with preserved ejection fraction, and acute decompensated heart failure. Each recommendation is classified according to strength and level of evidence. We also discuss future perspectives in the pharmacological treatment of heart failure. The 2014 ISHLT guidelines have evolved considerably from those published in 2004 with extensive information surrounding the underlying pathophysiology, investigations and recommended treatment. The new guidelines contain a modest amount of new pediatric data on pharmacological therapies and extrapolate adult data when appropriate. It is likely that most new recommendations for pediatric heart failure will continue to be based on therapies of proven benefit in adult heart failure studies.

Effects of limiting fluid intake on clinical and laboratory outcomes in patients with heart failure. Results of a meta-analysis of randomized controlled trials

BACKGROUND

The guidelines of the Scientific Societies of Cardiology recommend limiting fluid intake as a nonpharmacological measure for the management of chronic heart failure (HF). However, many patients with HF may suffer from severe thirst. A meta-analysis was performed to evaluate the effect of limiting fluid consumption based on various clinical and laboratory outcomes in patients with chronic HF.

METHODS

Only randomized controlled trials comparing liberal and restricted fluid oral intake in patients with HF were included. Primary outcomes were HF hospitalizations and all-cause mortality. Secondary outcomes were the sensation of thirst, the duration of therapy with intravenous diuretics, and the serum levels of creatinine, sodium, and B-type natriuretic peptide (BNP).

RESULTS

Six studies met the inclusion criteria. Significant heterogeneity was detected for the majority of outcomes. In 5 studies, patients with restricted fluid intake compared to patients with free consumption of beverages had similar rehospitalization and mortality rates. There were no differences regarding patients' sense of thirst (4 studies), duration of intravenous diuretic treatment (2 studies), serum creatinine levels (5 studies), and serum sodium levels (5 studies). Serum BNP levels were significantly higher in the group with free fluid intake (4 studies).

CONCLUSION

In patients with HF, liberal fluid consumption does not seem to exert an unfavorable impact on HF rehospitalizations or all-cause mortality. Further randomized controlled trials are warranted to definitively confirm the present findings.

Blood Urea Nitrogen/Creatinine Ratio and Response to Tolvaptan in Patients with Decompensated Heart Failure: A Retrospective Analysis

INTRODUCTION

Arginine vasopressin-stimulated reabsorption of urea occurs in the collecting duct via increased expression of the urea transporter.

OBJECTIVE

The aim of this study was to evaluate whether the blood urea nitrogen/creatinine (BUN/Cr) ratio is useful for predicting tolvaptan response in patients with decompensated heart failure (HF).

METHODS

Among 71 consecutive patients with HF who received oral tolvaptan between 2010 and 2014, we retrospectively studied 33 patients with decompensated HF without any mechanical circulatory assistance or inotropic support who had already been treated with loop diuretics. A responder to tolvaptan was defined as an individual who experienced a ≥30 % increase in their respective 24-h urine volume.

RESULTS

Among the 33 patients, 21 met the criteria of a responder. The area under the receiver operating characteristic curves of BUN/Cr and BUN were 0.790 and 0.714, respectively, and the respective cut-off values for responders to tolvaptan were 23.8 and 49.0. BUN/Cr and BUN retained their significant relationships with the responder status (odds ratio for BUN/Cr >23.8: 20.9; 95 % confidence interval [CI] 2.7-531.1; p = 0.002; odds ratio for BUN ≥49: 7.7; 95 % CI 1.4-65.8; p = 0.02).

CONCLUSION

Our results suggest that high BUN/Cr may be a predictor of response to tolvaptan in decompensated HF patients. A prospective study with a large sample size is required to confirm this preliminary finding.

Therapeutic potential of vasopressin-receptor antagonists in heart failure

Arginine vasopressin (AVP) is a 9-amino acid peptide that is secreted from the posterior pituitary in response to high plasma osmolality and hypotension. AVP has important roles in circulatory and water homoeostasis, which are mediated by oxytocin receptors and by AVP receptor subtypes: V(1a) (mainly vascular), V(1b) (pituitary), and V(2) (renal). Vaptans are orally and intravenously active nonpeptide vasopressin-receptor antagonists. Recently, subtype-selective nonpeptide vasopressin-receptor agonists have been developed. A selective V(1a)-receptor antagonist, relcovaptan, has shown initial positive results in the treatment of Raynaud's disease, dysmenorrhea, and tocolysis. A selective V(1b)-receptor antagonist, nelivaptan, has beneficial effects in the treatment of psychiatric disorders. Selective V2-receptor antagonists including mozavaptan, lixivaptan, satavaptan, and tolvaptan induce highly hypotonic diuresis without substantially affecting the excretion of electrolytes. A nonselective V(1a)/V(2)-receptor antagonist, conivaptan, is used in the treatment for euvolaemic or hypervolemic hyponatremia. Recent basic and clinical studies have shown that AVP-receptor antagonists, especially V2-receptor antagonists, may have therapeutic potential for heart failure. This review presents current information about AVP and its antagonists.

Global gene expression analysis of amniotic fluid cell-free RNA from recipient twins with twin-twin transfusion syndrome

OBJECTIVE

The objective of this study was to understand the biological pathways involved in twin-twin transfusion syndrome (TTTS) by performing global gene expression analysis of amniotic fluid (AF) cell-free RNA.

METHODS

A prospective whole transcriptome microarray study analyzing cell-free RNA in AF from TTTS recipient twins and singleton controls was carried out. Significantly differentially regulated genes in TTTS cases (N = 8) versus matched controls (N = 8) were identified and pathways analyses performed. Significant gene expression differences between stage II TTTS recipients (N = 5) and stage III TTTS recipients with abnormal Doppler measurements (N = 5) were also analyzed.

RESULTS

Analysis of paired data from TTTS cases and controls revealed differential expression of 801 genes, which were significantly enriched for neurological disease and cardiovascular system pathways. We also identified cardiovascular genes and pathways associated with the presence of critically abnormal Doppler measurements in stage III TTTS recipients.

CONCLUSIONS

This study provides the first transcriptome-wide data on the impact of TTTS on fetal development. Our results show that gene expression involving neurological and cardiovascular pathways are altered in recipient fetuses prior to surgical treatment. This has relevance for the origins of long-term complications seen in survivors and for the development of future fetal biomarkers.