A Multicenter, Randomized, Double-blind, Placebo-controlled Study of Tolvaptan Monotherapy Compared to Furosemide and the Combination of Tolvaptan and Furosemide in Patients With Heart Failure and Systolic Dysfunction

The role of tolvaptan add-on therapy in patients with acute heart failure: a systematic review and network meta-analysis

Background

Several conflicting reviews have concluded that the use of loop diuretics is associated with poorer clinical and safety outcomes. Therefore, this study aimed to investigate the efficacy and safety of tolvaptan as an adjunct to conventional diuretic therapy in patients with acute heart failure (AHF).

Methods

A comprehensive search was conducted on PubMed, Embase, ProQuest, EBSCO, and Cochrane Library until 24 May 2023 to identify randomized controlled trials that compared the effects of tolvaptan with conventional therapy and placebo in patients with AHF. The quality assessment of the included trials was conducted using the Cochrane risk of bias. A network meta-analysis (NMA) was conducted to examine the dosage effect of tolvaptan.

Result

A total of 17 studies with 18 reports, involving 10,039 patients, were selected. The tolvaptan add-on therapy significantly alleviated dyspnea [24 h: RR 1.16 (1.04, 1.29), 48 h: RR 1.18 (1.04, 1.33)], reduced body weight within 48 h [Asian group, MD -0.93 (-1.48, -0.38); non-Asian group, MD -2.76 (-2.88, -2.65)], reduced edema [RR 1.08 (1.02, 1.15)], increased serum sodium [non-Asian group, MD 3.40 (3.02, 3.78)], and resulted in a change in serum creatinine [MD -0.10 (-0.18, -0.01)]. No significant differences were observed in mortality and rehospitalization. The NMA suggested that an intermediate dosage (15 mg/day) might offer the best efficacy in reducing dyspnea within 24 h, reducing edema, increasing serum sodium, and lowering the incidence of worsening renal function (WRF).

Conclusion

In conclusion, the meta-analysis showed that tolvaptan contributed to the short-term alleviation of congestive symptoms, elevated sodium levels, and a lower incidence of WRF. However, no significant benefits were observed in long-term symptoms, rehospitalization rates, and mortality. An intermediate dosage of tolvaptan might be considered the optimal choice for various clinical outcomes.

Systematic Review Registration

https://www.crd.york.ac.uk/, PROSPERO (CRD42023420288).

Hyponatremia in Stable Patients with Advanced Heart Failure: Association to Hemodynamics and Outcome

INTRODUCTION

Hyponatremia is associated with worse outcomes in patients with chronic heart failure (HF) and reduced ejection fraction (HFrEF). However, it is unclear whether the worse prognosis is driven by hemodynamic derangement and how this potentially could be associated with hyponatremia.

METHODS

The study included 502 patients with HFrEF evaluated for advanced HF therapies, who underwent a right heart catheterization (RHC). Hyponatremia was defined as p-Na ≤136 mmol/L. The risk of all-cause mortality and a composite endpoint including mortality, left ventricular assist device (LVAD) implantation, implantation of total artificial heart (TAH), or heart transplantation (HTx) was evaluated using Cox regression analyses and Kaplan-Meier models.

RESULTS

Included patients were predominantly men 79% and had a median age of 54 years (IQR: 43-62). A third (165) of the patients had hyponatremia. In both univariate and multivariate regression analyses, p-Na was associated with increased central venous pressure (CVP), pulmonary capillary wedge pressure (PCWP), and mean pulmonary artery pressure (mPAP) but not with cardiac index. Hyponatremia was significantly associated with the combined endpoint (HR: 1.36 [95% CI, 1.07-1.74]; p = 0.01), but not all-cause mortality in adjusted Cox models.

CONCLUSION

In stable HFrEF patients evaluated for advanced HF therapies, lower p-Na was associated with more deranged invasive hemodynamic measurements. Hyponatremia remained significantly associated with the combined endpoint but not all-cause mortality in adjusted Cox models. The study suggests that the increased mortality associated with hyponatremia in HFrEF patients could partly be driven by hemodynamic derangement.

Management of Hyponatremia in Heart Failure: Practical Considerations

Hyponatremia is commonly encountered in the setting of heart failure, especially in decompensated, fluid-overloaded patients. The pathophysiology of hyponatremia in patients with heart failure is complex, including numerous mechanisms: increased activity of the sympathetic nervous system and the renin-angiotensin-aldosterone system, high levels of arginine vasopressin and diuretic use. Symptoms are usually mild but hyponatremic encephalopathy can occur if there is an acute decrease in serum sodium levels. It is crucial to differentiate between dilutional hyponatremia, where free water excretion should be promoted, and depletional hyponatremia, where administration of saline is needed. An inappropriate correction of hyponatremia may lead to osmotic demyelination syndrome which can cause severe neurological symptoms. Treatment options for hyponatremia in heart failure, such as water restriction or the use of hypertonic saline with loop diuretics, have limited efficacy. The aim of this review is to summarize the principal mechanisms involved in the occurrence of hyponatremia, to present the main guidelines for the treatment of hyponatremia, and to collect and analyze data from studies which target new treatment options, such as vaptans.

Postoperative tolvaptan use in left ventricular assist device patients: The TOLVAD randomized pilot study

PURPOSE

Tolvaptan, a selective vasopressin type-2 antagonist, has been shown to increase serum sodium (Na) and urine output in hyponatremic left ventricular assist device (LVAD) patients in retrospective studies. In this prospective randomized pilot study, we aimed to assess the efficacy of tolvaptan in this population.

METHODS

We conducted a prospective, randomized, non-blinded pilot study of LVAD recipients with post-operative hyponatremia (Na < 135 mEq/L) (NCT05408104). Eligible participants were randomized to receive tolvaptan 15 mg daily in addition to usual care versus usual care alone. The primary outcome was a change in Na level and estimated glomerular filtration rate (eGFR), from the first post-operative day of hyponatremia (the day of randomization) to discharge.

RESULTS

A total of 33 participants were enrolled, and 28 underwent randomization (median age 55 [IQR 50-62]), 21% women, 54% Black, 32% ischemic cardiomyopathy, median baseline Na 135 (IQR 134-138). Fifteen participants were randomized to tolvaptan (TLV) and 13 were randomized to usual care alone (No-TLV). Mean change in Na from randomization to discharge in the TLV group was 2.7 mEq/L (95%CI 0.7-4.7, p = 0.013) and 1.8 (95%CI 0.5-4.0, p = 0.11) in the No-TLV group, though baseline and final Na levels were similar between groups. The mean change in eGFR was 2.6 ml/min/1.73 m2 (95%CI 10.1-15.3, p = 0.59) in TLV versus 7.5 ml/min/1.73 m2 (95%CI 5.2-20.2, p = 0.15) in No-TLV. TLV participants had significantly more urine output than No-TLV patients during their first 24 h after randomization (3294 vs 2155 ml, p = 0.043).

CONCLUSION

TLV significantly increases urine output, with nominal improvement in Na level, in hyponatremic post-operative LVAD patients without adversely impacting renal function.

Vasopressin: a possible link between hypoxia and hypertension

Cardiovascular and respiratory diseases are frequently associated with transient and prolonged hypoxia, whereas hypoxia exerts pro-hypertensive effects, through stimulation of the sympathetic system and release of pressor endocrine factors. This review is focused on the role of arginine vasopressin (AVP) in dysregulation of the cardiovascular system during hypoxia associated with cardiovascular disorders. AVP is synthesized mainly in the neuroendocrine neurons of the hypothalamic paraventricular nucleus (PVN) and supraoptic nucleus (SON), which send axons to the posterior pituitary and various regions of the central nervous system (CNS). Vasopressinergic neurons are innervated by multiple neuronal projections releasing several neurotransmitters and other regulatory molecules. AVP interacts with V1a, V1b and V2 receptors that are present in the brain and peripheral organs, including the heart, vessels, lungs, and kidneys. Release of vasopressin is intensified during hypernatremia, hypovolemia, inflammation, stress, pain, and hypoxia which frequently occur in cardiovascular patients, and blood AVP concentration is markedly elevated in cardiovascular diseases associated with hypoxemia. There is evidence that hypoxia stimulates AVP release through stimulation of chemoreceptors. It is suggested that acting in the carotid bodies, AVP may fine-tune respiratory and hemodynamic responses to hypoxia and that this effect is intensified in hypertension. There is also evidence that during hypoxia, augmentation of pro-hypertensive effects of vasopressin may result from inappropriate interaction of this hormone with other compounds regulating the cardiovascular system (catecholamines, angiotensins, natriuretic peptides, steroids, nitric oxide). In conclusion, current literature indicates that abnormal mutual interactions between hypoxia and vasopressin may significantly contribute to pathogenesis of hypertension.

Efficacy and Safety of Combination Therapy with Tolvaptan and Furosemide in Children with Nephrotic Syndrome and Refractory Edema: A Prospective Interventional Study

OBJECTIVE

Severe edema in children with nephrotic syndrome is often refractory to conventional diuretics. Tolvaptan has been used satisfactorily for managing edema in patients with heart failure and cirrhosis. The safety and efficacy of combination therapy with oral tolvaptan and intravenous (IV) furosemide was assessed in patients with furosemide refractory edema.

METHODS

Patients, aged 5-18 y with nephrotic syndrome and severe edema, were screened for eligibility. After excluding hypovolemia, patients received IV furosemide (3-4 mg/kg/d) for 48 h. Those refractory to IV furosemide (weight loss < 3%) received tolvaptan (0.5-1 mg/kg once daily) and IV furosemide for the next 48 h. Parameters were compared between 48 h of furosemide alone and combination therapy.

RESULTS

A total of 24 patients (18 boys) with mean age of 8.0 ± 3.0 y were enrolled. Urine volume significantly increased with combination therapy as compared to furosemide therapy (mean difference: 1.2 mL/kg/h; 95% CI: 0.8-1.65 mL/kg/h) (p < 0.001). Compared to therapy with furosemide alone, combination therapy resulted in significant reduction in body weight from 26.9 ± 10.3 kg to 24.8 ± 9.7 kg (p < 0.001). Estimated glomerular filtration rate did not change (p = 0.81) but serum sodium increased from 135.7 ± 3.3 mEq/L to 140.4 ± 4.8 mEq/L (p < 0.001) with combination therapy; 2 patients showed asymptomatic hypernatremia.

CONCLUSION

The combination of oral tolvaptan and IV furosemide is effective in augmenting diuresis and reducing weight in patients with furosemide refractory edema but requires monitoring of electrolytes and volume status.

Tolerability of the Intravenously Administered Tolvaptan Prodrug, OPC-61815, in Patients With Congestive Heart Failure Who Have Difficulty With, or Are Incapable of, Oral Intake (TRITON-HF) - A Phase III, Multicenter, Open-Label Trial

BACKGROUND

OPC-61815, a prodrug of tolvaptan, is an injectable aquaretic drug. This study evaluated the tolerability of OPC-61815 in patients with congestive heart failure (CHF) who had difficulty with, or were incapable of, oral intake in a multicenter, uncontrolled, open-label Phase III study.

METHODS AND RESULTS

Forty-five patients were enrolled at 30 Japanese sites. OPC-61815 infusion was administered once daily; the 8 mg initial dose could be increased to 16 mg if the dose escalation criteria were met. Patients were treated for up to 5 days. Thirty-eight patients maintained the 8-mg dose and 7 had a dose increase to 16 mg; 41 completed the trial (34 completed early). One patient had mild hypernatremia. No significant safety concerns were observed with OPC-61815 administration at a starting dose of 8 mg and with dose escalation in accordance with the protocol-specified criteria. Treatment resulted in weight decrease (-3.01 kg); improvement or disappearance rates for other CHF symptoms (including edema, dyspnea, orthopnea, pulmonary congestion, and rales) indicated that treatment was effective. Urine excretion was increased 0-1 h after OPC-61815 administration and reached a maximum level at 1-2 h.

CONCLUSIONS

The tolerability of once daily (up to 5 days) intravenous OPC-61815 (8 mg or 16 mg) was confirmed in patients with CHF who had difficulty with, or were incapable of, oral intake.

Diuretic therapy in congestive heart failure

In heart failure, fluid overload is a major pathological mechanism leading to vascular congestion, pulmonary congestion and elevated jugular venous pressures. Diuretics play a significant role in the management of patients with congestive heart failure. It is used to relieve the congestive symptoms of heart failure. However, the appropriate use of diuretics remains challenging due to various complications like electrolyte abnormalities, worsening renal function and diuretic resistance. This has prompted towards the search of safer and effective alternatives. This review evaluates the use of diuretics in congestive heart failure and discusses the complications of different types of diuretics, which is essential for successful management of congestion in patients with heart failure and hence to optimise the outcome for the patients.

Pharmacokinetics, Pharmacodynamics, Efficacy, and Safety of OPC-61815, a Prodrug of Tolvaptan for Intravenous Administration, in Patients With Congestive Heart Failure - A Phase II, Multicenter, Double-Blind, Randomized, Active-Controlled Trial

BACKGROUND

Tolvaptan is an orally administered aquaretic drug indicated for patients with congestive heart failure (CHF) to remove excess fluid. OPC-61815, a prodrug of tolvaptan with improved water solubility, is considered suitable for intravenous (IV) administration. This Phase II study investigated the OPC-61815 dose that would result in an exposure equivalent to tolvaptan 15 mg.

METHODS AND RESULTS

We conducted a multicenter, randomized study in Japanese patients aged 20-85 years with CHF and volume overload despite treatment with diuretics other than vasopressin antagonists. Patients received IV OPC-61815 2 mg (n=13), 4 mg (n=12), 8 mg (n=12), 16 mg (n=11), or oral tolvaptan 15 mg (n=12). The primary endpoint was tolvaptan exposure on treatment Day 1; efficacy and safety were also assessed. Tolvaptan exposure increased in a dose-dependent manner following a single IV administration of OPC-61815; the exposure following an IV dose of OPC-61815 16 mg was similar to that of a tolvaptan 15-mg tablet, with no marked differences in safety or tolerability. OPC-61815 increased urine volume from baseline, resulting in decreased body weight and improved lower limb edema. No notable safety concerns were observed.

CONCLUSIONS

In this first study of OPC-61815 in patients with CHF, exposure following a single IV administration of OPC-61815 16 mg was comparable with a single oral administration of tolvaptan 15 mg, with no safety concerns.

Renoprotection by long-term low-dose tolvaptan in patients with heart failure and hyponatremia

AIMS

In previous randomized controlled trials, the use of tolvaptan (TLV) at a fixed dose of 30 mg/day for 1 year did not provide renal benefits in patients with heart failure (HF). This retrospective, cohort study examined the renoprotective effects of long-term, flexible-dose, and lower-dose TLV use.

METHODS AND RESULTS

Tolvaptan users were defined as patients receiving TLV for at least 180 consecutive days or those who continued it until death, any cardiac events, or renal replacement therapy even if it was taken for <180 days. Of a total of 584 HF patients, 78 TLV users were identified. The median age, baseline B-type natriuretic peptide, and estimated glomerular filtration rate (eGFR) were 71 years, 243 pg/mL, and 54 mL/min/1.73 m² , respectively. During follow-up (median, 461 days), TLV use (median average dose, 7.5 mg/day) was associated with frequent dose reductions of loop diuretics (incidence rate ratio [IRR], 1.5; 95% confidence interval [CI], 1.1-2.2), particularly in patients with serum sodium ≤135 mEq/L (IRR, 2.9; 95% CI, 1.5-5.7) (P_interaction  = 0.04). In a mixed effects model, propensity score (PS)-matched TLV users had higher eGFRs over time than PS-matched never-users (P < 0.01). The entire cohort analyses (N = 584) yielded similar results. The renal benefit of TLV in terms of annualized eGFR slope was more pronounced in patients with lower sodium levels (P_interaction  = 0.03). This effect modification was extinguished when patients who underwent a loop diuretic dose reduction during the follow-up period were excluded from the analysis.

CONCLUSIONS

Long-term, flexible-dose, and low-dose TLV use was associated with better renal function, particularly in hyponatremic HF, possibly due to its loop diuretic dose-sparing effect in the long term.

Vasopressin antagonism in heart failure: a review of the hemodynamic studies and major clinical trials

For decades, plasma arginine vasopressin (AVP) levels have been known to be elevated in patients with congestive heart failure (HF). Excessive AVP signaling at either or both the V1a and V2 receptors could contribute to the pathophysiology of HF by several mechanisms. V1a activation could cause vasoconstriction and/or direct myocardial hypertrophy as intracellular signaling pathways are closely related to those for angiotensin II. V2 activation could cause fluid retention and hyponatremia. A hemodynamic study with the pure V2 antagonist tolvaptan (TV) showed minimal hemodynamic effects. Compared with furosemide in another study, the renal and neurohormonal effects of TV were favorable. Several clinical trials with TV as adjunctive therapy in acute HF have shown beneficial effects on fluid balance and dyspnea, with no worsening of renal function or neurohormonal stimulation. Two smaller studies, one in acute and one in chronic HF, have shown comparable clinical and more favorable renal and neurohormonal effects of TV compared with loop diuretics. However, long-term treatment with TV did not alter outcomes in acute HF. No data are available other than single-dose studies of an intravenous pure V1a antagonist, which showed a vasodilating effect if plasma AVP levels were elevated. One hemodynamic study and one short-duration clinical trial with the balanced intravenous V1a/V2 antagonist conivaptan (CV) showed hemodynamic and clinical effects largely similar to those with TV in similar studies. A new orally effective balanced V1/V2 antagonist (pecavaptan) is currently undergoing phase II study as both adjunctive and alternative therapy during and after hospitalization for acute HF. The purpose of this review is to summarize what we have learned from the clinical experience with TV and CV, and to suggest implications of these findings for future work with newer agents.

A metabolically stable apelin-17 analog decreases AVP-induced antidiuresis and improves hyponatremia

Apelin and arginine-vasopressin (AVP) are conversely regulated by osmotic stimuli. We therefore hypothesized that activating the apelin receptor (apelin-R) with LIT01-196, a metabolically stable apelin-17 analog, may be beneficial for treating the Syndrome of Inappropriate Antidiuresis, in which AVP hypersecretion leads to hyponatremia. We show that LIT01-196, which behaves as a potent full agonist for the apelin-R, has an in vivo half-life of 156 minutes in the bloodstream after subcutaneous administration in control rats. In collecting ducts, LIT01-196 decreases dDAVP-induced cAMP production and apical cell surface expression of phosphorylated aquaporin 2 via AVP type 2 receptors, leading to an increase in aqueous diuresis. In a rat experimental model of AVP-induced hyponatremia, LIT01-196 subcutaneously administered blocks the antidiuretic effect of AVP and the AVP-induced increase in urinary osmolality and induces a progressive improvement of hyponatremia. Our data suggest that apelin-R activation constitutes an original approach for hyponatremia treatment.

Dual Vasopressin Receptor Antagonism to Improve Congestion in Patients With Acute Heart Failure: Design of the AVANTI Trial

BACKGROUND

Loop diuretics are the main treatment for patients with acute heart failure, but are associated with neurohormonal stimulation and worsening renal function and do not improve long-term outcomes. Antagonists to arginine vasopressin may provide an alternative strategy to avoid these effects. The AVANTI study will investigate the efficacy and safety of pecavaptan, a novel, balanced dual-acting V1a/V2 vasopressin antagonist, both as adjunctive therapy to loop diuretics after admission for acute heart failure, and later as monotherapy.

METHODS AND RESULTS

AVANTI is a double-blind, randomized phase II study in 571 patients hospitalized with acute heart failure and signs of persistent congestion before discharge. In part A, patients will receive either pecavaptan 30 mg/d or placebo with standard of care for 30 days. In part B, eligible patients will continue treatment or receive pecavaptan or diuretics as monotherapy for another 30 days. The primary end points for part A are changes in body weight and serum creatinine; for part B, changes in body weight and blood urea nitrogen/creatinine ratio.

CONCLUSIONS

This study will provide the first evidence that a balanced V1a/V2 antagonist may safely enhance decongestion, both as an adjunct to loop diuretics and as an alternative strategy.

TRIAL REGISTRATION NUMBER

NCT03901729.

Tolvaptan vs. furosemide-based diuretic regimens in patients hospitalized for heart failure with hyponatremia (AQUA-AHF)

AIMS

Hyponatremia is associated with poorer outcomes and diuretic response in patients hospitalized for heart failure. This study compared a tolvaptan-based vs. furosemide-based diuretic regimen on short-term clinical responses in hyponatremic acute heart failure.

METHODS AND RESULTS

Prospective, randomized, open-label, parallel-group, single-centre study comparing oral tolvaptan vs. continuous infusion furosemide. Thirty-three subjects requiring hospitalization for acute congestive heart failure, and a serum sodium < 135 mmol/L, were randomized to tolvaptan 30 mg orally daily or furosemide 5 mg/h intravenously for initial 24 h, after which treatments could be escalated. Median daily dose throughout was tolvaptan 30 mg and furosemide 120 mg, with four subjects in each group requiring dose escalation. Urine output and net fluid balance were not different between groups at 24 h or subsequent time points up to 96 h. Changes in estimated glomerular filtration rate were comparable. Cystatin C improved at 24 h with tolvaptan compared with furosemide (-6.4 ± 11.8 vs. 4.1 ± 17.2% change, P = 0.036), but the effect was transient. No significant between group differences were seen for NT-proBNP, plasma renin activity, or urinary neutrophil gelatinase-associated lipocalin:Cr. Serum sodium, as well as copeptin levels, increased with tolvaptan compared with furosemide.

CONCLUSIONS

Oral tolvaptan was associated with similar, but not superior, diuresis compared with intravenous furosemide for acute heart failure with concomitant hyponatremia.

Tolvaptan add-on therapy in patients with acute heart failure: A systematic review and meta-analysis

This study aimed to investigate the short-term efficacy and safety of tolvaptan as an add-on to traditional diuretics in patients with acute heart failure (AHF). The PubMed, EMBASE, Cochrane Library, and Web of Science databases were comprehensively searched for all randomized controlled trials (RCTs) that examined AHF patients treated with tolvaptan as a combination therapy with traditional diuretics published on or before December 2, 2019. Efficacy indicators such as improved dyspnea, reduced edema, and changes in urine output and body weight were evaluated. In-hospital mortality and worsening renal function (WRF) were measured as safety indicators. Data from the published literature included in this study were independently extracted by two reviewers. The Cochrane risk of bias tool was used to evaluate the quality of the included RCTs. Twelve RCTs involving 5577 patients admitted for AHF were included. Compared with traditional diuretics alone, add-on tolvaptan significantly relieved dyspnea, reduced weight, increased total urine volume and changes in urine volume from baseline, reduced edema, and increased serum sodium concentration in the short term without increasing the mortality. Most importantly, a low dose of tolvaptan (7.5-15 mg/d) significantly reduced the incidence of WRF, while a high dose (30 mg/d) had the opposite effect. Short-term add-on tolvaptan in hospitalized AHF patients could significantly relieve shortness of breath, reduce body weight, improve edema, and increase urine output and serum sodium concentrations without increasing mortality. The protective effects of add-on tolvaptan against WRF, however, were observed at low doses, but not at high doses.

Tolvaptan for Volume Management in Heart Failure

Volume management in acute decompensated and chronic heart failure (HF) remains a significant challenge. Although progress has been made in the development of mortality-reducing neurohormonal regimens in the reduced ejection fraction population, no clinical trial has yet demonstrated anything more than symptomatic relief or biomarker reduction with pharmacotherapeutic volume-based interventions made in the acutely decompensated individual or those with evolving outpatient congestion. As the number of patients with HF continues to grow, in addition to HF-related hospitalizations, identifying therapies that have the potential to aid in diuresis more safely and efficaciously is paramount to decreasing inpatient length of stay and preventing unnecessary admissions. More recently, a significant amount of research has been dedicated to the use of vasopressin antagonists, specifically tolvaptan, as adjunctive therapy to loop and thiazide diuretics. Although these agents do not seem to have a pervasive role in fluid management in the acute decompensated and chronic HF populations, they are effective tools to have available for specific clinical situations. This review summarizes the literature surrounding the use of tolvaptan for volume management in congestive HF, as well as offering practical guidance for use of this agent.

Short-Term Effects of Tolvaptan in Tricuspid Insufficiency Combined with Left Heart Valve Replacement-Caused Volume-Overload Patients: Results of a Prospective Pilot Study

OBJECTIVES

Our objective was to explore the effects of tolvaptan as a new therapeutic approach in patients with right heart failure with tricuspid insufficiency (TI).

METHODS

This prospective, multicenter, non-randomized controlled pilot study enrolled patients (N = 40) with TI from the Shanghai Chest Hospital and Shanghai Tongren Hospital who fulfilled inclusion criteria between March 2015 and June 2016. Participants were assigned to receive either tolvaptan combined with torasemide (n = 20) or torasemide monotherapy (n = 20; control group). The primary endpoints were changes in patient weight and in tricuspid annular plane systolic excursion (TAPSE) after 10 days of treatment. The secondary endpoints included net fluid balance and cardiac functions before and after medication from the first to the tenth day of treatment. Safety was evaluated by monitoring adverse and serious adverse events.

RESULTS

TAPSE significantly increased in the tolvaptan group compared with the control group after 10 days of medication (P = 0.029). Daily weight losses in the tolvaptan group significantly increased as the time of treatment increased (time × group, P = 0.022). Recovery to New York Heart Association (NYHA) grade I occurred 4 days earlier in the tolvaptan group. In addition, the net fluid balance and median net fluid balance were significantly higher in the tolvaptan group. Eight adverse events and one serious adverse event were recorded in the tolvaptan group and 15 adverse events were recorded in the control group.

CONCLUSIONS

Our results indicate that tolvaptan might be a useful and safe drug to improve heart function in patients with right heart failure with TI after left heart valve replacement.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov identifier no. NCT02644616.

Arginine vasopressin antagonism in heart failure: Current status and possible new directions

Modulating neurohormonal imbalance is the cornerstone of successful therapy in patients with chronic heart failure with reduced ejection fraction (HFrEF). Plasma arginine vasopressin (AVP) levels are elevated in HFrEF and may contribute to disease progression by excess signaling at either the V1a or V2 receptors. The effects of V1a receptor antagonism are almost completely unexplored, but V1a signaling is closely related to that for angiotensin II and blocking that receptor deserves further study. Interfering with V2 signaling causes free water diuresis and improves congestion without worsening renal function when added to loop diuretics but alone did not improve outcomes when carried into the post-acute phase in one large study. Outcomes in chronic HFrEF are quite good while outcomes in acute HF remain poor. Therefore, further study of V2 or combined V1/V2 blockade of the effects of AVP would most likely yield positive results in patients with acute HF, perhaps especially as alternative, not adjunctive therapy to loop diuretics.

Efficacy of tolvaptan for chronic heart failure: Study protocol for a systematic review of randomized controlled trial

BACKGROUND

The protocol of this study will be proposed for systematic evaluation of the efficacy and safety of tolvaptan in the treatment of chronic heart failure (CHF).

METHODS

We will retrieve the following electronic databases for randomized controlled trials assessing the efficacy of tolvaptan in patients with CHF: PubMed, Embase, Cochrane Central Register of Controlled Trials, Web of Science, Scopus, Chinese Biomedical Literature Database, China National Knowledge Infrastructure, VIP Information, and Wanfang Data. Each database will be retrieved from inception to February 1, 2019 without any limitations. The entire process of study selection, data extraction, and methodological quality evaluation will be conducted by 2 independent authors.

RESULTS

The protocol of this proposed study will compare the efficacy and safety of tolvaptan in the treatment of patients with CHF. The outcomes will include all-cause mortality, change in body weight, urine output, change in serum sodium; and incidence of all adverse events.

CONCLUSION

The findings of this proposed study will summarize the current evidence of tolvaptan for CHF.

ETHICS AND DISSEMINATION

All data used in this systematic review will be collected from the previous published trials. Thus, no research ethics approval is needed for this study. The findings of this study will be published at a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

PROSPERO CRD42019120818.

The Role of Tolvaptan Administration After Cardiac Surgery: A Meta-Analysis

OBJECTIVE

To evaluate the efficacy and safety of tolvaptan in fluid management after cardiac surgery compared with conventional diuretic treatment.

DESIGN

Systematic review of the literature with meta-analyses.

SETTING

The Medline, Scopus, Cochrane Central Register of Controlled Trials, Clinicaltrials.gov, and Google Scholar databases were searched from inception to July 30, 2018.

PARTICIPANTS

The study comprised 759 patients undergoing cardiac surgery.

INTERVENTIONS

Tolvaptan administration (n = 397) or standard diuretic therapy (n = 398).

MEASUREMENTS AND MAIN RESULTS

Ten studies were included in the present meta-analysis. Tolvaptan administration was associated with a significantly faster return to preoperative body weight (mean difference [MD)] -1.48 d, 95% confidence interval [CI] -1.92 to 1.03), shorter duration of hospital stay (MD -2.58 d, 95% CI -5.09 to -0.07), lower incidence of acute kidney injury (odds ratio 0.34, 95% CI 0.16-0.69), and greater urine output (MD 0.47 L/d, 95% CI 0.25-0.69) and sodium levels (MD 2.85 mEq/L, 95% CI 1.90-3.80). No significant differences were present regarding duration of intensive care unit stay (MD -0.09 d, 95% CI -0.33 to 0.15), arrhythmia incidence (odds ratio 0.58, 95% CI 0.33-1.02), and serum creatinine values (MD -0.08 mg/dL, 95% CI -0.20 to 0.04).

CONCLUSIONS

The outcomes of the present meta-analysis suggest the promising role of tolvaptan administration in the management of fluid retention in patients after cardiac surgery. Future large-scale clinical trials should be conducted to fully elucidate its efficacy and to assess the optimal treatment protocol to be applied in the clinical setting.

Safety and Effectiveness of Tolvaptan Administration after Total Arch Replacement

BACKGROUND

Postoperative fluid overload in cardiovascular surgery is associated with increased mortality and morbidity. Recently, tolvaptan (TLV), a selective vasopressin V2 antagonist, has been used for perioperative fluid management. This study aimed to validate the safety and effectiveness of TLV administration after total arch replacement (TAR) using selective cerebral perfusion.

METHODS

From August 2016 to December 2016, 11 patients who had undergone TAR for thoracic aortic aneurysm were included in this study. In addition to the conventional diuretics furosemide (20 mg) and spironolactone (25 mg), TLV (7.5 mg) was administered orally.

RESULTS

TLV increased urine output 1-3 days after administration. Body weight was gradually and steadily reduced until discharge. Neither renal nor liver dysfunction was recognized during the TLV administration.

CONCLUSION

The concomitant use of TLV and conventional diuretics is safe and effective for fluid management after TAR using cardiopulmonary bypass, selective cerebral perfusion, and hypothermic circulatory arrest.

Comparison of the effects of tolvaptan and furosemide on renal water and sodium excretion in patients with heart failure and advanced chronic kidney disease: a subanalysis of the K-STAR study

BACKGROUND

Tolvaptan (TLV) is known to increase electrolyte-free water clearance. However, TLV actions on renal electrolytes including urine sodium (uNa) excretion and its consequences are less well understood. This subanalysis investigated the effect of add-on TLV compared to increased furosemide (FUR) on both electrolyte-free water and electrolyte clearance in patients with congestive heart failure (CHF) complicated by advanced chronic kidney disease (CKD).

METHODS

The Kanagawa Aquaresis Investigators Trial of TLV on HF Patients with Renal Impairment (K-STAR) was a multicenter, open-labeled, randomized, and controlled prospective clinical study. Eighty-one Japanese patients with CHF and residual signs of congestion despite oral FUR treatment (≥ 40 mg/day) were recruited and randomly assigned to a 7-day add-on treatment with either ≤ 40 mg/day FUR or ≤ 15 mg/day TLV. Electrolyte-free water clearance, electrolyte osmolar clearance and electrolyte excretion were compared between the two groups before and after therapy.

RESULTS

The change (Δ) in electrolyte-free water clearance was significantly higher in the add-on TLV group than in the add-on FUR group. However, Δelectrolyte osmolar clearance was also higher in the add-on TLV group than in the increased FUR group. This was primarily because ΔuNa excretion was significantly higher in the add-on TLV group than in the increased FUR group, since Δurine potassium excretion was significantly lower in the add-on TLV group than in the increased FUR group.

CONCLUSIONS

Add-on TLV may increase both renal water and Na excretion in CHF patients with advanced CKD to a greater degree than increased FUR.

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.

Upregulation of hypothalamic arginine vasopressin by peripherally administered furosemide in transgenic rats expressing arginine vasopressin-enhanced green fluorescent protein

Furosemide, which is used worldwide as a diuretic agent, inhibits sodium reabsorption in the Henle's loop, resulting in diuresis and natriuresis. Arginine vasopressin (AVP) is synthesized in the supraoptic nucleus (SON), paraventricular nucleus (PVN), and suprachiasmatic nucleus (SCN) of the hypothalamus. The synthesis AVP in the magnocellular neurons of SON and PVN physiologically regulated by plasma osmolality and blood volume and contributed water homeostasis by increasing water reabsorption in the collecting duct. Central AVP dynamics after peripheral administration of furosemide remain unclear. Here, we studied the effects of intraperitoneal (i.p.) administration of furosemide (20 mg/kg) on hypothalamic AVP by using transgenic rats expressing AVP-enhanced green fluorescent protein (eGFP) under the AVP promoter. The i.p. administration of furosemide did not affect plasma osmolality in the present study; however, eGFP in the SON and magnocellular divisions of the PVN (mPVN) were significantly increased after furosemide administration compared to the control. Immunohistochemical analysis revealed Fos-like immunoreactivity (IR) in eGFP-positive neurons in the SON and mPVN 90 min after i.p. administration of furosemide, and AVP heteronuclear (hn) RNA and eGFP mRNA levels were significantly increased. These furosemide-induced changes were not observed in the suprachiasmatic AVP neurons. Furthermore, furosemide induced a remarkable increase in Fos-IR in the organum vasculosum laminae terminals (OVLT), median preoptic nucleus (MnPO), subfornical organ (SFO), locus coeruleus (LC), nucleus of the solitary tract (NTS), and rostral ventrolateral medulla (RVLM) after i.p. administration of furosemide. In conclusion, we were able to visualize and quantitatively evaluate AVP-eGFP synthesis and neuronal activations after peripheral administration of furosemide, using the AVP-eGFP transgenic rats. The results of this study may provide new insights into the elucidation of physiological mechanisms underlying body fluid homeostasis induced by furosemide. This article is protected by copyright. All rights reserved.

Dual Vasopressin V1a/V2 Antagonism: The Next Step in Neurohormonal Modulation in Patients With Heart Failure?

Stimulation of the V1a receptor for arginine vasopressin produces myocardial and vascular effects similar to those of angiotensin II while stimulation of the V2 receptor causes fluid retention. There are no data with sustained blockade of the V1a receptor while single-dose experiments suggest benefit. Acute and chronic administration of selective V2 receptor antagonists reliably relieves dyspnea and produces diuresis without adverse effects on renal function or neurohormonal stimulation, either as adjunctive or alternative therapy to loop diuretics, but has not been shown to improve outcomes as adjunctive therapy. Combined antagonism has been tried only in single-dose studies in stable patients or over the short-term in acute heart failure, with encouraging results. Based on the both the pathophysiologic rationale for additional neurohormonal blockade and these results, chronically blocking both receptors, particularly in more congested patients, may offer significant benefit either as adjunctive or alternative therapy to standard diuretics.

Pharmacologic Approaches to Electrolyte Abnormalities in Heart Failure

Electrolyte abnormalities are common in heart failure and can arise from a variety of etiologies. Neurohormonal activation from ventricular dysfunction, renal dysfunction, and heart failure medications can perturb electrolyte homeostasis which impact both heart failure-related morbidity and mortality. These include disturbances in serum sodium, chloride, acid-base, and potassium homeostasis. Pharmacological treatments differ for each electrolyte abnormality and vary from older, established treatments like the vaptans or acetazolamide, to experimental or theoretical treatments like hypertonic saline or urea, or to newer, novel agents like the potassium binders: patiromer and zirconium cyclosilicate. Pharmacologic approaches range from limiting electrolyte intake or directly repleting the electrolyte, to blocking or promoting their resorption, and to neurohormonal antagonism. Because of the prevalence and clinical impact of electrolyte abnormalities, understanding both the older and newer therapeutic options is and will continue to be necessity for the management of heart failure.

Tolvaptan for Heart Failure, Systematic Review and Meta-Analysis of Trials

The vasopressin type 2 receptor antagonist tolvaptan (TLV) is available to treat congestion in patients with heart failure. However, there is paucity of evidence guiding its use, and lack of evidence of its long-term efficacy. Our objectives are to perform a systematic review of studies examining the effects of TLV in patients with heart failure; and a quantitative meta-analysis comparing primary and secondary outcomes between TLV and placebo. Only double-blinded randomized controlled trials, with no restriction on the language or the time of publication, were included. Our main outcome measures were all-cause mortality, change in body weight, change in urine volume, and change in serum sodium. Extracted summary estimates included mean difference and SD for change in body weight, change in urine volume and change in serum sodium levels, and hazard ratio with 95% confidence interval for all-cause mortality. We found 8 double-blinded randomized controlled trials, seven of which were included in this meta-analysis. Assessment of risk of bias was conducted by investigating random sequence generation, allocation concealment, blinding, completeness of outcome data, and potential for selective reporting. We found no evidence of significant bias. TLV showed benefits in reducing body weight, increasing urine volume, and increasing serum sodium. No reduction in mortality was detected. However, the subgroup of patients with hyponatremia might have better mortality outcome with TLV. TLV seemed to be safe, as it did not cause worsening of the renal function or hypotension. In conclusion, a meta-analysis of the published literature suggests short-term benefits of TLV. However, the impact on mortality is inconclusive.

Effects and safety of oral tolvaptan in patients with congestive heart failure: A systematic review and network meta-analysis

AIMS

Several studies reported treatment benefits of tolvaptan in patients with congestive heart failure (CHF). However, the optimal dosage remains unclear. We aimed to compare different dosage of tolvaptan to determine the optimal dosage in terms of the efficacy and safety.

METHODS

We searched MEDLINE, PubMed, EMBASE, Cochrane CENTRAL and ClinicalTrials.gov through Aug 31, 2016. Randomized controlled trials (RCTs) comparing tolvaptan of different dosages or to placebo in patients with CHF were included. We used network meta-analysis to look for the optimal dosage in terms of effectiveness and safety. Urine output, body weight change and change in serum sodium were the main outcomes of efficacy. Adverse effects were the secondary outcomes. Quality was assessed by Cochrane risk-of-bias tool.

RESULTS

Twelve RCTs reporting 14 articles with 5793 patients (mean age, 65.7 ± 11.9 years; 73.7% man) were included. Compared with placebo, the tolvaptan 30 mg had similar effects to tolvaptan 45-90 mg in terms of urine output (mean difference [MD] 2.03 liter; 95% confidence interval [CI] 1.3 to 2.71), body weight change (MD -1.12 kg; 95% CI -1.37 to -0.88) and change in serum sodium (MD 3.06 meq/L; 95% CI 2.43 to 3.68). Compared with placebo, tolvaptan of different dosage showed a non-significant higher risk of adverse effects.

CONCLUSIONS

These findings suggest that tolvaptan 30 mg and 45 mg may be the optimum dosage for CHF patients, because of its ability to provide favourable clinical results without greater adverse effects. However, tolvaptan is not beneficial for reducing all-cause mortality in CHF patients.

Experience with long-term administration of tolvaptan to patients with acute decompensated heart failure

Tolvaptan (TLV) is an oral selective vasopressin type 2 receptor antagonist. Long-term use of TLV is not recommended in patients with heart failure (HF) if fluid retention disappears and/or body weight is within the target range. However, some patients require long-term use of TLV. The current study investigated the efficacy and safety of long-term use of TLV. Subjects were 258 consecutive patients with HF who received TLV during hospitalization from January 2011 to March 2015. The rate of continuing administration of TLV was evaluated. Moreover, the one-year mortality rate and rate of re-hospitalization either with or without TLV were investigated. Results at discharge and one year later were compared for patients who continued to receive TLV one year after discharge. Oral concomitant medications, blood pressures, heart rate, blood tests, chest X-ray and transthoracic echocardiography were investigated. In-hospital and one-year mortality rates were 15.9% and 27.8%, respectively. Moreover, the mortality rate and/or rate of re-hospitalization within one year was 54.4%. The rate of re-hospitalization for HF was significantly higher in patients who continued to receive TLV after discharge compared to patients who ceased receiving TLV after discharge (p < 0.001). However, the subjects who continued to receive TLV for up to one year after discharge tended to have a longer duration until re-hospitalization for HF and significantly decreased brain natriuretic peptide levels (577.6 ± 528.5 pg/mL to 397.3 ± 365.8 pg/mL, p = 0.015). Long-term use of TLV might delay re-hospitalization for HF in patients with severe HF. Large-scale clinical studies are necessary to verify these results.

Combined aquaretic and diuretic therapy in acute heart failure

Introduction

Acute heart failure (AHF) is a leading cause of hospitalization and readmission in the US. The present study evaluated maximum diuresis while minimizing electrolyte imbalances, hemodynamic instability, and kidney dysfunction, to achieve a euvolemic state safely in a shorter period of time.

Methods and results

A protocol of combined therapy with furosemide, metolazone, and spironolactone, with or without tolvaptan and acetazolamide, was used in 17 hospitalized patients with AHF. The mean number of days on combination diuretic protocol was 3.8 days. The mean daily fluid balance was 3.0±2.1 L negative. The mean daily urine output (UOP) was 4.1±2.0 L (range 1.8–10.5 L). There were minimal fluctuations in serum electrolyte levels and serum creatinine over the duration of diuretic therapy. There was no statistically significant change in patients’ creatinine from immediately prior to therapy to the last day of therapy, with a mean increase in creatinine of 0.14 mg/dL (95% CI −0.03, +0.30, p=0.10).

Conclusion

Our strategy of treating AHF by achieving high UOP, while maintaining stable electrolytes and creatinine in a short period to euvolemic state, is safe.

Dilemmas in the Dosing of Heart Failure Drugs: Titrating Diuretics in Chronic Heart Failure

Despite advances in medical therapy over the past few decades, the incidence of heart failure hospitalisation continues to rise. Diuretics are the most common therapy used to treat heart failure as they relieve congestion. However, there is a lack of guidance on how to best use these medications. Guidelines support the use of diuretics at the lowest clinically effective dose but do not specify a diuretic strategy beyond that. Here we review the diuretics available for treatment, potential mechanisms of diuretic resistance and ways to address this in the ambulatory setting, and review tools that have been developed to help guide diuretic use in the treatment of chronic heart failure.

Vasopressin and Vasopressin Antagonists in Heart Failure

Despite the introduction of multiple new pharmacological agents over the past three decades in the field of heart failure (HF), overall prognosis remains poor. Hyponatremia is prevalent in HF patients and has been suggested as a contributor to poor response to standard therapy. Elevated levels of arginine vasopressin (AVP), a peptide hormone produced in the hypothalamus, play a role in development of hyponatremia, and AVP and its surrogate, copeptin, are related to changes in osmolality, hemodynamics, neuro-hormones as well as in overall outcome in HF patients. Of current pharmacological interest are the selective and non-selective vasopressin receptor antagonists (VRAs), which inhibit vasoconstriction and cardiac remodeling mediated by the V_1a receptors in smooth blood vessels, and water retention (increased urine osmolality and decreased water excretion) by increasing aquaporin-2 water channels mediated by the V₂ receptors in the renal collecting tubules. The optimal use of VRAs is yet to be determined, especially in patients with congestive HF. Although long-term effects on improvement in mortality have not been shown in the Efficacy of Vasopressin Antagonism in Heart Failure Outcome Study with Tolvaptan (EVEREST) trial, the only long-term outcome trial to date, many short-term studies indicate beneficial aquaretic- and hemodynamic-effects of the VRAs. In contrast to loop diuretics, these new agents tend to increase urine flow and the excretion of electrolyte-free water (so-called aquaresis) in patients with HF, without substantial changes in sodium or potassium excretion. This chapter reviews the role of AVP and copeptin in HF, and the treatment potential of VRAs in HF.

The short-term and long-term effects of tolvaptan in patients with heart failure: a meta-analysis of randomized controlled trials

A comprehensive evaluation of the benefits of tolvaptan for the management of heart failure (HF) is lacking. The objective of this meta-analysis was to assess the short-term and long-term effects of tolvaptan in patients with HF. Articles were searched from PubMed, MEDLINE and Cochrane Library before March 31, 2015. Randomized controlled trials enrolling adult HF patients and reporting the all-cause mortality, cardiac events, body weight change or changes of serum electrolytes including sodium, potassium and creatinine were included in our meta-analysis. Ten studies covering 5574 patients met the inclusion criteria. Based on the data of meta-analysis, tolvaptan had no impact on the all-cause mortality [relative risk (RR) 0.96; 95 % confidence interval (CI) 0.87-1.06; P = 0.40] and incidence of cardiac events (RR 1.03; 95 % CI 0.96-1.11; P = 0.40) of HF patients. Furthermore, in comparison with control treatments, tolvaptan significantly decreased the body weight [weight mean difference (WMD), -0.87; 95 % CI -1.03 to -0.71; P < 0.001] and statistically increased serum sodium (WMD, 2.58; 95 % CI -1.83 to 3.33; P < 0.001) without any change in serum potassium (WMD, 0.01; 95 % CI -0.03 to 0.05; P = 0.577). However, serum creatinine may be increased slightly by tolvaptan (WMD, 0.05; 95 % CI 0.03-0.07; P < 0.001). This meta-analysis suggests that in HF patients, tolvaptan may not bring long-term benefits, but it effectively improves the volume overload and hyponatremia without obvious increases in serum potassium and creatinine. Hence, tolvaptan is likely to be a promising diuretic for the treatment of HF.

Randomized pilot trial comparing tolvaptan with furosemide on renal and neurohumoral effects in acute heart failure

AIMS

Loop diuretics are first-line medications for congestive heart failure (CHF); however, they are associated with serious adverse effects, including decreased renal function, and sympathetic nervous and renin-angiotensin system activation. We tested whether tolvaptan, a vasopressin V2-receptor antagonist, could reduce unfavourable furosemide-induced effects during CHF treatment.

METHODS AND RESULTS

Sixty patients emergently hospitalized owing to CHF-induced dyspnea were randomly assigned to receive either 40 mg intravenous furosemide daily or 7.5 mg oral tolvaptan for 5 days after admission. Both groups also received intravenous carperitide and canrenoate potassium. As results, baseline patient characteristics were similar between the furosemide (n = 30) and the tolvaptan (n = 30) groups, with no significant difference in 5 day urine volume or fluid balance. Brain natriuretic peptide and body weight improvements were similar between groups. However, serum creatinine (Cr) level did not increase, and the incidence of worsening renal function was significantly lower in the tolvaptan group. Consequently, the Cr increase to gain 1000 mL urine was 2.5-fold lower in the tolvaptan group. Furthermore, the blood urea nitrogen (BUN)/Cr ratio significantly decreased in the tolvaptan group, suggesting that renal perfusion was preserved, and urea reuptake and passive water reabsorption were suppressed following tolvaptan treatment. Although catecholamine improvements after treatment were not significantly different, plasma renin activity was enhanced in the furosemide group.

CONCLUSIONS

As compared with furosemide, tolvaptan in patients with acute heart failure is associated with comparable decongestion, better preservation of renal function and less activation of renin-angiotensin system. (UMIN 000014134).

A new approach to treatment of acute heart failure

Conventional therapies for acute decongestion have yielded uniformly poor results in patients with acute heart failure (AHF). The failure of current strategies may be due to advanced disease in hospitalized patients, incomplete therapy, inherent limitations to existing therapy, or some combination of all three factors. Loop diuretics are the mainstay of current therapy and are in theory not ideal since while producing immediate intravascular volume reduction and relief of symptoms they activate neurohormonal forces that are deleterious to both the heart and the kidney. Ultrafiltration is an alternative to loop diuretics but has not proved advantageous in the setting of renal dysfunction, and if not carefully applied may also aggravate neurohormonal imbalance. In theory decongestive therapy for AHF should remove large volumes of fluid quickly and safely and improve symptoms, particularly dyspnea, without aggravating renal dysfunction or causing neurohormonal activation. Several studies have now suggested that the use of aquaretics such as antagonists to the V2 receptor for arginine vasopressin may be useful as adjunctive therapy in AHF, particularly when renal dysfunction and/or hyponatremia are present. These agents leverage osmotic forces to produce tissue decongestion while causing a water diuresis. They do not adversely affect renal function or neurohormonal balance. Building on the current base of knowledge about outcomes in AHF together with the only study of vasopressin antagonists as short-term monotherapy in chronic heart failure, it would be reasonable to design a trial in AHF in which the use of loop diuretics was minimized in favor of these agents.

Clinical Effectiveness of Tolvaptan in Patients With Acute Heart Failure and Renal Dysfunction

BACKGROUND

More efficacious and/or safer decongestive therapy is clearly needed in acute heart failure (AHF) patients complicated by renal dysfunction. We tested the hypothesis that adding tolvaptan, an oral vasopressin-2 receptor antagonist, to conventional therapy with loop diuretics would be more effective treatment in this population.

METHODS AND RESULTS

A multicenter, open-label, randomized control trial was performed, and 217 AHF patients with renal dysfunction (estimated glomerular filtration rate 15-60 mL • min(-1) • 1.73 m(-2)) were randomized 1:1 to treatment with tolvaptan (n=108) or conventional treatment (n=109). The primary end point was 48-hour urine volume. The tolvaptan group showed more diuresis than the conventional treatment group (6464.4 vs 4999.2 mL; P <.001) despite significantly lower amounts of loop diuretic use (80 mg vs 120 mg; P <.001). Dyspnea relief was achieved significantly more frequently in the tolvaptan group at all time points within 48 hours except 6 hours after enrollment. The rate of worsening of renal function (≥0.3 mg/dL increase from baseline) was similar between the tolvaptan and conventional treatment groups (24.1% vs 27.8%, respectively; P =.642).

CONCLUSIONS

Adding tolvaptan to conventional treatment achieved more diuresis and relieved dyspnea symptoms in AHF patients with renal dysfunction.

CLINICAL TRIAL REGISTRATION

URL: http://www.umin.ac.jp/ctr/index/htm/ Unique identifier: UMIN000007109.

Clinical Issues and Controversies in Heart Failure and Transplantation

Heart failure is a common problem among children admitted in the intensive care unit and is associated with significant morbidity and mortality. As such, the 2014 meeting of the Pediatric Cardiac Intensive Care Society included a session on Clinical Controversies in Heart Failure and Transplantation. This review contains the summaries of the podium presentations of this session and will cover some of the challenging aspects of caring for these patients including medical and mechanical support, fluid overload states, high-risk populations including those after heart transplantation, and end-of-life considerations.

Effect of tolvaptan on acute heart failure with hyponatremia--a randomized, double blind, controlled clinical trial

Objectives

To assess the efficacy of tolvaptan in acute heart failure with hyponatremia using a randomized double-blinded placebo-controlled study design.

Background

Tolvaptan is a selective vasopressin receptor 2 antagonist. There are no published clinical trials on the utility of tolvaptan in acute heart failure with hyponatremia in the Indian population.

Methods

After screening and informed consent, 51 HF patients with hyponatremia were randomized using computer-generated randomization sequence to receive placebo or 15 mg of tolvaptan for 5 days along with conventional medical therapy. The patient's perception of dyspnea using Likert score and the plasma sodium was measured at baseline and for the next 4 days.

Results

There was a mean improvement in sodium concentration by 5 mEq/L (p = 0.001) in patients receiving tolvaptan, whereas no significant improvement was seen in the placebo group (p = 0.33). Significant improvement in Likert score was observed in both the groups (p = 0.001), even though there was no difference between both the groups. Dry mouth and thirst were the most commonly occurring adverse effects observed in both the groups. There were no significant hemodynamic changes with tolvaptan therapy.

Conclusion

Tolvaptan at a dose of 15 mg is effective in reversing hyponatremia in acute heart failure and may be a suitable option in these patients.

Fluid Management in Patients with Chronic Heart Failure

Congestion, or fluid overload, is a classic clinical feature of patients presenting with heart failure patients, and its presence is associated with adverse outcome. However, congestion is not always clinically evident, and more objective measures of congestion than simple clinical examination may be helpful. Although diuretics are the mainstay of treatment for congestion, no randomised trials have shown the effects of diuretics on mortality in chronic heart failure patients. Furthermore, appropriate titration of diuretics in this population is unclear. Research is required to determine whether a robust method of detecting - and then treating - subclinical congestion improves outcomes.

Autonomic Dysregulation as a Therapeutic Target for Acute HF

OPINION STATEMENT

Despite major advances that have led to effective therapeutic modalities for the treatment of heart failure (HF), this syndrome has continued to be a staggering health problem associated with significant mortality and morbidity. The increasing number of hospital admissions and readmissions related to acute HF continues to pose a fiscal challenge leading to constant interest in development of novel approaches. These point to multiple areas of unmet needs especially in acute HF, thus, necessitating further efforts to develop novel strategies for prevention and treatment of acute HF. One area of continuing focus is targeting the role of autonomic imbalance associated with the development of HF. Autonomic dysregulation, manifested by increased sympathetic drive and reduced parasympathetic activity, has been recognized as a mediator of increased mortality and morbidity in HF and myocardial infarction. Furthermore, vagal withdrawal has been shown to precede acute decompensation, though whether this represents cause or effect is unknown. This review discusses the potential role of autonomic dysregulation as a therapeutic modality for patients with acute decompensated HF.

Blood pressure-lowering efficacy of loop diuretics for primary hypertension

BACKGROUND

Antihypertensive drugs from the thiazide diuretic drug class have been shown to reduce mortality and cardiovascular morbidity. Loop diuretics are indicated and used to treat hypertension, but a systematic review of their blood pressure-lowering efficacy or effectiveness in terms of reducing cardiovascular mortality or morbidity from randomized controlled trial (RCT) evidence has not been conducted.

OBJECTIVES

To determine the dose-related decrease in systolic or diastolic blood pressure, or both, as well as adverse events leading to participant withdrawal and adverse biochemical effects (serum potassium, uric acid, creatinine, glucose and lipids profile) due to loop diuretics versus placebo control in the treatment of people with primary hypertension.

SEARCH METHODS

We searched the Cochrane Hypertension Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL, 2014, Issue 9), MEDLINE, MEDLINE In-Process, EMBASE, and ClinicalTrials.gov to 27 October 2014.

SELECTION CRITERIA

We included double-blind randomized placebo-controlled trials of at least three weeks duration comparing loop diuretic with a placebo in people with primary hypertension defined as blood pressure greater than 140/90 mmHg at baseline.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the risk of bias and extracted data. We used weighted mean difference and a fixed effects model to combine continuous outcome data. We analysed the drop outs due to adverse effects using relative risk ratio.

MAIN RESULTS

Nine trials evaluated the dose-related blood pressure-lowering efficacy of five drugs within the loop diuretics class (furosemide 40 mg to 60 mg, cicletanine 100 mg to 150 mg, piretanide 3 mg to 6 mg, indacrinone enantiomer -2.5 mg to -10.0/+80 mg, and etozolin 200 mg) in 460 people with baseline blood pressure of 162/103 mmHg for a mean duration of 8.8 weeks. The best estimate of systolic/diastolic blood pressure-lowering efficacy of loop diuretics was -7.9 (-10.4 to -5.4) mmHg/ -4.4 (-5.9 to -2.8) mmHg. Withdrawals due to adverse effects and serum biochemical changes did not show a significant difference.We performed additional searches in 2012 and 2014, which found no additional trials meeting the minimum inclusion criteria.

AUTHORS' CONCLUSIONS

Based on the limited number of published RCTs, the systolic/diastolic blood pressure-lowering effect of loop diuretics is -8/-4 mmHg, which is likely an overestimate. We graded the quality of evidence for both systolic and diastolic blood pressure estimates as "low" due to the high risk of bias of included studies and the high likelihood of publication bias. We found no clinically meaningful blood pressure-lowering differences between different drugs within the loop diuretic class. The dose-ranging effects of loop diuretics could not be evaluated. The review did not provide a good estimate of the incidence of harms associated with loop diuretics because of the short duration of the trials and the lack of reporting of adverse effects in many of the trials.