Effects of Tolvaptan on Systemic and Renal Hemodynamic Function in Dogs with Congestive Heart Failure

Effectiveness and safety of Tolvaptan in infants with congenital heart disease

BACKGROUND

Tolvaptan (TLV) is a selective vasopressin receptor 2 antagonist administered for congestive heart failure (CHF) after inadequate response to other diuretics. The effectiveness and safety of TLV have been evaluated well in adult patients. However, reports on its use in pediatric patients, especially infants, are scarce.

METHODS

We retrospectively evaluated 41 children younger than 1 year of age who received TLV for CHF for congenital heart disease (CHD) between January 2010 and August 2021. We monitored the occurrence of adverse events, including acute kidney injury and hypernatremia, as well as laboratory data trends.

RESULTS

Of the 41 infants included, 51.2% were male. The median age when TLV was initiated was 2 months, interquartile range (IQR) 1-4 months, and all infants had been administered other diuretics previously. The median dose of TLV was 0.1 mg/kg/day (IQR, 0.1-0.1). Urine output increased significantly after 48 h of treatment: baseline, 315 mL/day (IQR, 243-394); 48 h, 381 mL/day (IQR, 262-518) , p = 0.0004; 72 h, 385 mL/day (IQR, 301-569), p = 0.0013; 96 h, 425 mL/day (IQR, 272-524), p = 0.0006; and 144 h, 396 mL/day (IQR, 305-477), p = 0.0036. No adverse events were observed.

CONCLUSIONS

Tolvaptan can be used safely and efficiently in infants with CHD. From the perspective of adverse effects, initiating administration at a lower dosage is preferable because this was found to be sufficiently effective.

Protective Effect on Pancreatic Acinar Cell by Maintaining Cardiac Output in Canine Heart Failure Model With Decreased Pancreatic Blood Flow

Heart failure cause hypoperfusion-induced damage to abdominal organs due to decreased cardiac output (CO). Using a model dog with heart failure caused by rapid ventricular pacing (RVP), we have previously demonstrated that a decrease in CO reduces pancreatic blood flow (PBF). Furthermore, we have revealed that pancreatic acinar cell atrophy, which is a change in the pre-stage of pancreatitis was caused. However, the mechanism by which pancreatic acinar cell atrophy was caused in RVP dogs remains unknown. This study aimed to clarify the association between cardiac function, PBF, and histopathological changes in pancreatic acinar cells by administrating pimobendan, which increase CO, to RVP dogs. RVP dogs were divided into the control group (no medication, n = 5) and the pimobendan group (pimobendan at 0.25 mg/kg BID, n = 5). Non-invasive blood pressure measurement, echocardiography, and contrast-enhanced ultrasonography for PBF measurement were performed before initiating RVP and at 4 weeks after initiating RVP (4 weeks). At 4 weeks, the decreases in CO, mean blood pressure and PBF due to RVP were suppressed in pimobendan group. Furthermore, histopathological examination showed no changes in pancreatic acinar cells in the pimobendan group. Overall, it was clarified that the decrease in PBF due to cardiac dysfunction was a direct cause of pancreatic acinar cell atrophy. This suggests that maintaining PBF is clinically important for treating dogs with heart failure. In addition, these findings offer a reliable basis for developing new therapeutic strategies for heart failure in dogs, that is, pancreatic protection.

Management of Chronic Congestive Heart Failure Caused by Myxomatous Mitral Valve Disease in Dogs: A Narrative Review from 1970 to 2020

Simple Summary

Myxomatous mitral valve disease (MMVD) is the most common acquired cardiovascular disease in dogs. The progression of the disease and the increasing severity of valvular regurgitation cause a volume overload of the left heart, leading to left atrial and ventricular remodeling and congestive heart failure (CHF). The treatment of chronic CHF secondary to MMVD in dogs has not always been the same over time. In the last fifty years, the drugs utilized have considerably changed, as well as the therapeutic protocols. Some drugs have also changed their intended use. An analysis of the literature concerning the therapy of chronic heart failure in dogs affected by this widespread degenerative disease is not available; a synthesis of the published literature on this topic and a description of its current state of art are needed. To the authors’ knowledge, a review of this topic has never been published in veterinary medicine; therefore, the aim of this study is to overview the treatments of chronic CHF secondary to MMVD in dogs from 1970 to 2020 using the general framework of narrative reviews.

Abstract

The treatment of chronic congestive heart failure (CHF), secondary to myxomatous mitral valve disease (MMVD) in dogs, has considerably changed in the last fifty years. An analysis of the literature concerning the therapy of chronic CHF in dogs affected by MMVD is not available, and it is needed. Narrative reviews (NRs) are aimed at identifying and summarizing what has been previously published, avoiding duplications, and seeking new study areas that have not yet been addressed. The most accessible open-access databases, PubMed, Embase, and Google Scholar, were chosen, and the searching time frame was set in five decades, from 1970 to 2020. The 384 selected studies were classified into categories depending on the aim of the study, the population target, the pathogenesis of MMVD (natural/induced), and the resulting CHF. Over the years, the types of studies have increased considerably in veterinary medicine. In particular, there have been 43 (24.29%) clinical trials, 41 (23.16%) randomized controlled trials, 10 (5.65%) cross-over trials, 40 (22.60%) reviews, 5 (2.82%) comparative studies, 17 (9.60%) case-control studies, 2 (1.13%) cohort studies, 2 (1.13%) experimental studies, 2 (1.13%) questionnaires, 6 (3.40%) case-reports, 7 (3.95%) retrospective studies, and 2 (1.13%) guidelines. The experimental studies on dogs with an induced form of the disease were less numerous (49–27.68%) than the studies on dogs affected by spontaneous MMVD (128–72.32%). The therapy of chronic CHF in dogs has considerably changed in the last fifty years: in the last century, some of the currently prescribed drugs did not exist yet, while others had different indications.

Changes in renin-angiotensin-aldosterone system during cardiac remodeling after mitral valvuloplasty in dogs

BACKGROUND

Information regarding changes in renin-angiotensin-aldosterone system (RAAS) during cardiac remodeling after mitral valvuloplasty (MVP) in dogs remains lacking.

HYPOTHESIS/OBJECTIVES

To assess the longitudinal effects of MVP on circulating RAAS activity.

ANIMALS

Eight client-owned dogs receiving MVP for myxomatous mitral valve disease (MMVD).

METHODS

This is a cohort study. Plasma renin activity (PRA), angiotensin II (AT2), aldosterone (PAC), blood urea nitrogen (BUN), and creatinine concentrations, were measured in these dogs before (baseline) and at 3 consecutive monthly follow-ups (Post-1M, Post-2M, Post-3M). Echocardiography was concomitantly used to assess the process of cardiac recovery after MVP.

RESULTS

The echocardiography revealed a significant decrease in LVIDDN, LA/Ao, FS, E velocity, E/A, E' sep, S' lat, E' lat, and A' lat after MVP compared with baseline (P < .05). There was a significant reduction in the PRA (2.45, 3.05, 2.74 vs 8.8 ng/mL/h; P = .002), AT2 (466, 315, 235 vs 1200 pg/mL; P = .009), and PAC (39.88, 47, 54.62 vs 179.5 pg/mL; P = .01), respectively at Post-1M, Post-2M, Post-3M compared to the baseline. Additionally, BUN and creatinine concentrations decreased from Post-1M. The RAAS variables showed significant, weak to moderate, relationship with selected echocardiographic variables.

CONCLUSIONS AND CLINICAL IMPORTANCE

Mitral valvuloplasty contributes to decreased RAAS activity in MMVD dogs, which paralleled the process of cardiac reverse remodeling up to Post-3M. This information facilitates formulating strategies to optimize clinical outcomes for dogs after MVP.

Effect of oral tolvaptan for 1 year in patients with functional mitral regurgitation

The effect of the oral selective vasopressin V2-receptor antagonist tolvaptan for chronic phase therapy on patients with FMR remains unclear. We aimed to determine the efficacy of oral tolvaptan in patients with significant functional mitral regurgitation (FMR) to reduce the mortality and rehospitalization due to worsening heart failure (HF). We enrolled 219 patients (mean age 76 ± 9 years, 59.4% men) who were admitted at our hospital due to congestive HF during different two 1-year periods. The patients were divided into 2 groups: those who had significant FMR (MR ≥ grade 2 [n = 76]) and those who did not (MR < grade 2 [n = 143]) at discharge. The patients were further divided into a study group that received tolvaptan during follow-up and a control group that did not receive tolvaptan. We used an inverse probability of treatment weighting method with the primary end point defined as overall all-cause mortality and rehospitalization due to worsening HF within 1 year. Of the 76 patients with significant FMR at discharge, 2 of 20 (10%) who were administered tolvaptan died and 8 (40%) were readmitted to a hospital. Of the 56 patients who did not receive tolvaptan, 2 (3.5%) died and 18 (27.5%) required rehospitalization. After multiple adjustments, there were no significant differences for overall survival and rehospitalization between the groups (log-rank p = 0.700 and 0.510, respectively). Our results suggest that oral tolvaptan administration in addition to conventional diuretics had less impact on outcomes in patients with significant FMR.

The Efficacy and Renal Protective Effect of Tolvaptan in Chronic Kidney Disease Patients after Open-Heart Surgery

Purpose: Unlike loop diuretics, tolvaptan is reported to have a renal protective effect. The purpose of this study was to retrospectively assess the efficacy of tolvaptan administration in chronic kidney disease (CKD) patients following open-heart surgery.

Methods: From February 2017 to August 2020, 75 patients with preoperative CKD stages IIIb–V were enrolled in this study and were divided into two groups: the control group (n = 30) and the tolvaptan group (n = 45). All patients routinely received conventional diuretics starting from postoperative day (POD) 1. Tolvaptan at 7.5–15 mg/day was administered if the patients had persistent fluid retention or poor response to conventional diuretics.

Results: Tolvaptan administration was initiated at a mean of POD 2.9 ± 2.2, and the mean dosing period was 4.1 ± 3.0 days. The mean time to return to the preoperative body weight in the control and tolvaptan groups was similar. However, estimated glomerular filtration rate (eGFR) was significantly increased at the time when body weight reached the preoperative level and at discharge in the tolvaptan group than in the control group.

Conclusion: This study demonstrated the renal protective effect of tolvaptan even in advanced CKD patients after open-heart surgery.

Long-term administration of tolvaptan ameliorates annual decline in estimated glomerular filtration rate in outpatients with chronic heart failure

Protective effects of tolvaptan against worsening renal function in acute heart failure have been shown. However, long-term effects of its agent on renal function remain to be elucidated. The present study investigated retrospectively whether long-term treatment with tolvaptan exerts renoprotective effects in patients with chronic heart failure, by comparing serial changes in estimated glomerular filtration rate (eGFR) for years before and after tolvaptan administration. From 63 outpatients with chronic heart failure taking diuretics including tolvaptan, 34 patients whose eGFR levels were continuously measured for more than 6 months both before and after administration of tolvaptan (average dose, 7.8 mg/day at the end of the follow-up period) were selected as eligible for the present analyses. All eGFR values were separately plotted before and after the initiation of treatment with tolvaptan (except hospitalization periods) along the time course axis and the slope of the linear regression curve was calculated as an annual change in eGFR. The mean follow-up periods before and after tolvaptan administration were 1197 and 784 days (3.3 and 2.1 years), respectively. Changing rates of eGFR per year were significantly ameliorated after treatment with tolvaptan (mean ± SD, - 8.02 ± 9.35 to - 1.62 ± 5.09 mL/min/1.73m² /year, P = 0.001). In echocardiographic parameters, inferior vena cava (IVC) diameter significantly decreased after tolvaptan administration, and the decrease in IVC diameter was correlated with the improvement of eGFR decline slope after administration of tolvaptan (P = 0.0075). This longitudinal observational study indicated that long-term treatment with tolvaptan ameliorated annual decline in eGFR in outpatients with chronic heart failure. Our findings suggest that tolvaptan has a protective effect against chronically worsening renal function in heart failure patients.

Correction of serum chloride concentration in dogs with congestive heart failure

Background

Hypochloremia associated with congestive heart failure (CHF) in dogs is likely multifactorial. Loop diuretics cause 1:2 sodium [Na⁺]:chloride [Cl⁻] loss, whereas water retention causes a 1:1 [Na⁺]:[Cl⁻] dilution. Mathematical [Cl⁻] correction separates these effects on [Cl⁻].

Hypothesis

We hypothesized that corrected [Cl⁻] (c[Cl⁻]) would not differ from measured [Cl⁻] (m[Cl⁻]) in dogs with controlled CHF because of loop diuretics, and dogs with refractory CHF would have higher c[Cl⁻] than m[Cl⁻], indicating relative water excess.

Animals

Seventy‐one client‐owned dogs with acquired heart disease, without CHF (NO‐CHF), 76 with Stage C CHF and 24 with Stage D CHF.

Methods

Clinicopathological data from a previous study were retrospectively analyzed. Corrected [Cl⁻], m[Cl⁻], and differences were compared among NO‐CHF, Stage C CHF, and Stage D CHF, using the formula: c[Cl⁻] = (mid‐reference range [Na⁺]/measured [Na⁺]) × m[Cl⁻].

Results

Corrected [Cl⁻] and m[Cl⁻] were lower in Stage D vs Stage C and NO‐CHF (all P < .0001). The c[Cl⁻] was higher than m[Cl⁻] in Stage D (P < .0001) but not Stage C or NO‐CHF. Median difference between c[Cl⁻] and m[Cl⁻] was higher for Stage D vs Stage C (P = .0003). No hypochloremic Stage D dogs had normal c[Cl⁻], but 11/24 had [Cl⁻] that was increased by >2 mmol/L.

Conclusions and Clinical Importance

Serum [Cl⁻] increased after mathematical correction in Stage D CHF dogs but not in Stage C and NO‐CHF dogs. Although c[Cl⁻] was higher than m[Cl⁻] in Stage D dogs supportive of relative water excess, hypochloremia persisted, consistent with concurrent loop diuretic effects on electrolytes. Future study correlating c[Cl⁻] to antidiuretic hormone concentrations is warranted.

Arginine vasopressin receptor 2 activation promotes microvascular permeability in sepsis

Methicillin-resistant Staphylococcus aureus (MRSA) sepsis is a severe condition associated with vascular leakage and poor prognosis. The hemodynamic management of sepsis targets hypotension, but there is no specific treatment available for vascular leakage. Arginine vasopressin (AVP) has been used in sepsis to promote vasoconstriction by activating AVP receptor 1 (V₁R). However, recent evidence suggests that increased fluid retention may be associated with the AVP receptor 2 (V₂R) activation worsening the outcome of sepsis. Hence, we hypothesized that the inhibition of V₂R activation ameliorates the severity of microvascular hyperpermeability during sepsis. The hypothesis was tested using a well-characterized and clinically relevant ovine model of MRSA pneumonia/sepsis and in vitro assays of human lung microvascular endothelial cells (HMVECs). in vivo experiments demonstrated that the treatment of septic sheep with tolvaptan (TLVP), an FDA-approved V₂R antagonist, significantly attenuated the sepsis-induced fluid retention and markedly reduced the lung water content. These pathological changes were not affected by the treatment with V₂R agonist, desmopressin (DDAVP). Additionally, the incubation of cultured HMVECs with DDAVP, and DDAVP along with MRSA significantly increased the paracellular permeability. Finally, both the DDAVP and MRSA-induced hyperpermeability was significantly attenuated by TLVP. Subsequent protein and gene expression assays determined that the V₂R-induced increase in permeability is mediated by phospholipase C beta (PLCβ) and the potent permeability factor angiopoietin-2. In conclusion, our results indicate that the activation of the AVP-V₂R axis is critical in the pathophysiology of severe microvascular hyperpermeability during Gram-positive sepsis. The use of the antagonist TLVP should be considered as adjuvant treatment for septic patients. The results from this clinically relevant animal study are highly translational to clinical practice.

COVID-19 concomitant with infective endocarditis: A case report and review of management

Coronavirus disease 2019 (COVID-19) has emerged as a pandemic and public health crisis across the world. With its high infectivity and rapid spread, the severity of the disease is escalating in certain populations, especially in patients with pre-existing cardiovascular disease. In developing countries, infective endocarditis remains a problem in patients with rheumatic heart disease. We report the case of a patient with a diagnosis of infective endocarditis concomitant with COVID-19, including the diagnosis, management, and main outcomes.

Comparison of pancreatic and renal blood flow in a canine tachycardia-induced cardiomyopathy model

The pancreas is believed to be vulnerable to hypoperfusion. In dogs with acute pancreatitis, pancreatic ischemia due to heart failure can worsen the condition. However, changes in pancreatic blood flow associated with decreased cardiac function have not been previously studied in dogs. Therefore, we aimed to identify and compare changes in pancreatic versus renal blood flow as a result of cardiac dysfunction. Seven dogs were subjected to rapid ventricular pacing to create heart failure models. Noninvasive blood pressure measurement, ultrasonic cardiography, contrast-enhanced ultrasonography for pancreatic blood flow measurement, and para-aminohippuric acid clearance for renal blood flow measurement were performed before starting and at 2 and 4 weeks after starting the pacing. Left ventricular cardiac output and mean blood pressure decreased at 2 and 4 weeks after starting the pacing, and pancreatic blood flow decreased at 2 and 4 weeks after starting the pacing. However, renal blood flow did not change at 2 weeks but decreased 4 weeks after starting the pacing. Overall, this study demonstrated that reduced pancreatic blood flow due to cardiac dysfunction occurs, similar to renal blood flow. This suggests that decreased pancreatic blood flow is not unusual and may frequently occur in dogs with heart failure. The results of this study support the speculation that heart failure can exacerbate acute pancreatitis. Additionally, this study provides useful basic information for designing further studies to study this association.

A novel soluble guanylate cyclase activator with reduced risk of hypotension by short-acting vasodilation

Cinaciguat, a soluble guanylate cyclase (sGC) activator, was under clinical development for use in acute decompensated heart failure (ADHF), but was discontinued due to occurrence of hypotension. We hypothesized that short-term activation of sGC in ADHF patients would exert a vasodilative effect without hypotension irrespective of disease state, using a novel short-acting sGC activator, TY-55002. The objective of this study was to investigate the vasodilation and hemodynamic effects of TY-55002 in comparison with those of cinaciguat. TY-55002 and cinaciguat activated both normal and heme-oxidized sGC in a dose-dependent manner and caused rapid relaxation of phenylephrine-contracted rat aorta. However, TY-55002 had a milder effect than cinaciguat in enhancing the dose-activity response between normal and oxidized sGC. Therefore, we suggest that the pharmacological effect of TY-55002 is less subject than cinaciguat to oxidative stress associated with complications such as cardiovascular disease or diabetes. In normal dogs, the effects of intravenous TY-55002 or cinaciguat on blood pressure were evaluated in conjunction with the plasma concentrations of the compounds, and pharmacokinetic (PK)-pharmacodynamic (PD) analyses were carried out. The plasma-to-effect-site transfer rate constant (Ke0) for TY-55002 was three times greater than for cinaciguat. On the other hand, there was a small difference in blood half-life (T1/2) between the compounds. It is possible that the rapid fall in blood pressure after the initial administration of TY-55002 and the quick recovery after cessation were due to the pharmacodynamic property of the compound. In heart failure-model dogs, TY-55002 and cinaciguat improved the condition to the same degree, and the short-term action of TY-55002 was replicated. In conclusion, TY-55002 is a novel short-acting sGC activator, which offers the possibility of easy dose management without excessive hypotension. It therefore holds potential to serve as an innovative drug in the pharmacotherapy of ADHF.

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.

Tolvaptan for Fluid Management in Living Donor Liver Transplant Recipients

BACKGROUND Tolvaptan, an antagonist of the vasopressin V2 receptor is a novel oral diuretic that promotes water excretion selectively. We have used furosemide as a primary diuretic and added human atrial natriuretic peptide (hANP) if necessary for fluid management postoperatively in living-donor liver transplantation (LDLT) recipients. Recently we introduced tolvaptan and used both tolvaptan and furosemide as primary diuretics. MATERIAL AND METHODS Clinical outcomes were compared between LDLT recipients whose postoperative fluid management was performed before (control group, n=10) and after (tolvaptan group, n=16) introduction of tolvaptan. RESULTS Preoperative and intraoperative demographic data did not differ significantly between the groups except for the period of post-surgical follow-up and total ischemic time. Urine volume was 1,242±692, 2,240±1307, and 2,268±1262 mL on postoperative day 1, 3, and 7, respectively, in the tolvaptan group. These volumes did not significantly differ from those in control group (1,027±462, 1,788±909, and 2,057±1216 mL on day 1, 3, and 7 postoperatively, respectively). Body weight gain and fluid volume from abdominal drainage tubes postoperatively did not differ significantly between groups. The time from hANP initiation to discontinuation and the time to removal of central vein catheters were significantly reduced in tolvaptan-treated patients. No severe side effects directly related to tolvaptan were observed. The survival rate at month 6 was 90.0% in control patients versus 93.8% in tolvaptan-treated patients. CONCLUSIONS The outcomes of this investigation indicate that tolvaptan in combination with furosemide provides an adequate diuretic for fluid management subsequent to LDLT without causing adverse effects.

Effects of Tolvaptan Addition to Furosemide in Normo- and Hyponatremia Patients with Heart Failure and Chronic Kidney Disease Stages G3b-5: A Subanalysis of the K-STAR Study

BACKGROUND

Tolvaptan increases free water clearance (aquaresis) and thereby improves hyponatremia. Although hyponatremia on admission is common in patients with congestive heart failure (CHF), little is known regarding the response to tolvaptan in those who also have chronic kidney disease (CKD) with or without hyponatremia. The aim of this subanalysis was to investigate the differences in treatment response between normo- and hyponatremia patients with CHF and CKD stages G3b-5.

METHODS

The Kanagawa Aquaresis Investigators Trial of Tolvaptan on HF Patients with Renal Impairment (K-STAR) was a multicenter, open-label, randomized, controlled prospective clinical trial that included 81 Japanese patients with CHF and residual signs of congestion despite oral furosemide treatment (≥40 mg/day). All patients were randomly assigned to 7-day treatment with either ≤15 mg/day of new add-on tolvaptan or ≤40 mg/day of increased furosemide. A subanalysis was conducted for 73 patients, who were classified into 2 groups according to their assigned treatment, then further stratified into 2 subgroups according to their serum sodium concentration [Na+]. The differences between the urine and serum parameters from day 1 to 3 were compared between the groups and between the subgroups in each group.

RESULTS

The change (Δ) in urine volume (ΔUV) and Δurine osmolality were greater in the tolvaptan group than in the furosemide group; however, ΔUV and Δurine osmolality did not show significant differences between the normonatremia subgroup and the hyponatremia subgroup in each group. In addition, Δserum [Na+] was greater in the tolvaptan group, although the change was not clinically significant. In contrast, Δserum [Na+] did not show significant differences between the normo- and hyponatremia subgroups in each group.

CONCLUSION

Tolvaptan added to furosemide resulted in a greater diuretic effect than increased furosemide, even in normonatremia patients with CHF complicated by CKD stages G3b-5 in the very early treatment phase.

Favorable effects of early tolvaptan administration in very elderly patients after repeat hospitalizations for acute decompensated heart failure

Tolvaptan (TLV) is an oral selective vasopressin 2 receptor antagonist that acts on the distal nephrons, causing a loss of electrolyte-free water. To date, its early administration in very elderly patients after repeat hospitalizations for acute decompensated heart failure (ADHF) despite receiving optimal medical therapy has not been evaluated. Fifty-six ADHF patients who were >80 years old and had been repeatedly hospitalized were retrospectively enrolled in this study. Twenty-five patients (14 men; mean age 86.7 ± 5.3 years; control group) received standard therapy and 31 patients (15 men; mean age 85.5 ± 4.5 years; TLV group) received oral TLV within 24 h of admission. The rate of worsening renal function was significantly lower in the TLV group than in the control group (13 vs. 40%, P < 0.05). The duration of the return to body weight at a steady state was significantly shorter in the TLV group (5.3 ± 2.8 days) than in the control group (13.9 ± 9.2 days, P < 0.01). Consequently, the hospitalization period in the TLV group (13.5 ± 5.9 days) was significantly shorter than that in the control group (24.7 ± 12.3 days, P < 0.01). In conclusion, the early administration of TLV to very elderly patients who underwent repeat hospitalizations for ADHF resulted in immediate decongestion and thus reduced the hospitalization period with a lower incidence of worsening renal function.

Predictive factors for responders to tolvaptan in fluid management after cardiovascular surgery

Objective

To identify the predictive factors for responders to tolvaptan, a novel vasopressin type 2 receptor antagonist for fluid management after cardiovascular surgery.

Methods

Between January 2013 and May 2014, 113 patients were treated with tolvaptan for fluid management after cardiovascular surgery. As indicators for the effects of tolvaptan, change in bodyweight during the tolvaptan administration period and correlations with perioperative factors were assessed. Thirty-one patients were administered tolvaptan at the first day after surgery (early tolvaptan group). In this group, urine volume during the 6 h before the initial tolvaptan administration was compared with that at 6 h after administration.

Results

For all the patients, the change in bodyweight during the tolvaptan administration period significantly correlated with pre-operative serum creatinine (r = 0.19, p = 0.04) and albumin levels before tolvaptan administration (r = −0.29, p = 0.002). In the early tolvaptan group, the ratio of urine volume at 6 h before and 6 h after the initial tolvaptan administration significantly correlated with the pre-operative serum creatinine level (r = 0.43, p = 0.02), the serum albumin level before tolvaptan administration (r = −0.50, p = 0.004), and change in bodyweight (r = 0.38, p = 0.03).

Conclusions

In patients undergoing cardiovascular surgery, deteriorating renal function, increased bodyweight, and hypoalbuminemia were found to be predictive factors for responders to tolvaptan for postoperative fluid management.

Administration of tolvaptan with reduction of loop diuretics ameliorates congestion with improving renal dysfunction in patients with congestive heart failure and renal dysfunction

In patients with congestive heart failure and renal dysfunction, high dose of diuretics are necessary to improve congestion, which may progress to renal dysfunction. We examined the efficacy of tolvaptan with reduction of loop diuretics to improve renal function in patients with congestive heart failure and renal dysfunction. We conducted a multicenter, prospective, randomized study in 44 patients with congestive heart failure and renal dysfunction (serum creatinine concentration ≥1.1 mg/dl) treated with conventional diuretics. Patients were randomly divided into two groups: tolvaptan (15 mg) with a fixed dose of diuretics or with reducing to a half-dose of diuretics for 7-14 consecutive days. We examined the change of urine volume, body weight, serum creatinine and electrolyte concentrations in each group. Both groups demonstrated significant urine volume increase (724 ± 176 ml/day in the fixed-dose group and 736 ± 114 ml/day in the half-dose group) and body weight reduction (1.6 ± 1.5 kg and 1.6 ± 1.9 kg, respectively) from baseline, with no differences between the two groups. Serum creatinine concentration was significantly increased in the fixed-dose group (from 1.60 ± 0.47 to 1.74 ± 0.66 mg/dl, p = 0.03) and decreased in the half-dose group (from 1.98 ± 0.91 to 1.91 ± 0.97 mg/dl, p = 0.10). So the mean changes in serum creatinine concentration from baseline significantly differed between the two groups (0.14 ± 0.08 mg/dl in the fixed-dose group and -0.07 ± 0.19 mg/dl in the half-dose group, p = 0.006). The administration of tolvaptan with reduction of loop diuretics was clinically effective to ameliorate congestion with improving renal function in patients with congestive heart failure and renal dysfunction.

Combination of Urinary Sodium/Creatinine Ratio and Plasma Brain Natriuretic Peptide Level Predicts Successful Tolvaptan Therapy in Patients With Heart Failure and Volume Overload

To evaluate the short-term clinical and hemodynamic effects of tolvaptan therapy and to identify predictors of the therapeutic outcomes, we retrospectively recruited 60 consecutive hospitalized heart failure (HF) patients (70 ± 11 years) with volume overload. The subjects were divided into two groups on the basis of the changes in HF symptom scores and hemodynamic status assessed by right heart catheterization after tolvaptan therapy (median: 7 days). The majority of patients were successfully treated (group 1). However, 22% of patients (group 2) were unsuccessfully treated, in whom 1) the HF symptom score worsened or 2) there was a stationary HF symptom score ≥ 6 points, and mean PCWP > 18 mmHg and mean RAP > 10 mmHg, after tolvaptan therapy. HF symptom scores, hemodynamic parameters, and plasma brain natriuretic peptide (BNP) level improved in group 1, but all of these parameters remained unchanged in group 2. Lower urine sodium/creatinine ratio (UNa/UCr) and higher BNP level at baseline were independently associated with unsuccessful tolvaptan therapy, and UNa/UCr best predicts unsuccessful tolvaptan therapy with a cut-off value of 46.5 mEq/g·Cr (AUC 0.847, 95% CI: 0.718-0.976, sensitivity 77%, specificity 81%, P < 0.01). Double-positive results of UNa/UCr < 46.5 mEq/g·Cr and plasma BNP level > 778 pg/mL predicted unsuccessful tolvaptan therapy with high diagnostic accuracy (sensitivity 54%, specificity 100%, positive predictive value 100%, negative predictive value 89%, and accuracy 90%). In summary, short-term tolvaptan therapy ameliorated HF symptoms and provided hemodynamic improvement in the majority of patients, and UNa/UCr and BNP level strongly predicted the therapeutic outcomes.

Clinical benefit of tolvaptan in patients with acute decompensated heart failure and chronic kidney disease

Tolvaptan, a vasopressin type 2 receptor antagonist, has an aquaretic effect without affecting renal function. The effects of long-term tolvaptan administration in heart failure patients with renal dysfunction have not been clarified. Here, we assessed the clinical benefit of tolvaptan during a 6-month follow-up in acute decompensated heart failure (ADHF) patients with severe chronic kidney disease (CKD; estimated glomerular filtration rate (eGFR) <45 mL/min/1.73 m(2)). We compared 33 patients with ADHF and severe CKD who were administered tolvaptan in addition to loop diuretics (TLV group), with 36 patients with ADHF and severe CKD who were administered high-dose loop diuretics (≥40 mg) alone (LD group). Alterations in serum creatinine and eGFR levels from the time of hospital discharge to 6-month follow-up were significantly different between the groups, with those in the TLV group being more favorable. Furthermore, Kaplan-Meier analysis revealed that rehospitalization for heart failure (HF) was significantly lower in the TLV group compared with the LD group. In ADHF patients with severe CKD, tolvaptan use for 6 months reduced worsening of renal function and rehospitalization rates for HF when compared with conventional diuretic therapy. In conclusion, tolvaptan could be a safe and effective agent for long-term management of HF and CKD.

Effects of tolvaptan in the early postoperative stage after heart valve surgery: results of the STAR (Study of Tolvaptan for fluid retention AfteR valve surgery) trial

PURPOSE

The purpose of this study was to assess the efficacy of tolvaptan, a vasopressin V2 receptor antagonist, for the management of postoperative surgical fluid retention after heart valve surgery.

METHODS

This was a prospective observational study of 64 patients with heart valve disease who underwent valve surgery between 2013 and 2014. Those in the tolvaptan group received tolvaptan in addition to conventional diuretic therapy. The results were compared to the results of 55 patients who underwent heart valve surgery between 2007 and 2010 and received conventional postoperative diuretics alone.

RESULTS

The time to return to the preoperative BW was significantly shorter in the patients who received tolvaptan (6.1 ± 3.8 vs. 8.7 ± 6.7 days, p < 0.05), while the level of sodium was significantly decreased in the patients who received conventional diuretics. The degree of increase in the creatinine level tended to be smaller in the tolvaptan group. The response to tolvaptan was related to the postoperative degree of BW increase and the preoperative creatinine level.

CONCLUSIONS

Tolvaptan was effective in treating fluid retention during the early postoperative stage in cardiac surgery patients, without increased renal failure or abnormal electrolyte levels. This new type of diuretic therapy may be a suitable option for postoperative fluid management in patients undergoing cardiac surgery.

Echocardiographic characteristics of patients with acute heart failure requiring tolvaptan: a retrospective study

BACKGROUND

No study has investigated the admission echocardiographic characteristics of acute heart failure (AHF) patients who are resistant to conventional diuretics and require tolvaptan.

METHODS

We retrospectively analyzed the echocardiographic characteristics of AHF patients who were resistant to conventional diuretics and took tolvaptan (tolvaptan group: 26 patients), and compared them to those who were sensitive to conventional diuretics (conventional group: 180 patients).

RESULTS

The tolvaptan group had a higher left atrial volume index (96.0 ± 85.0 mL/m2 vs. 45.8 ± 25.9 mL/m2, p < 0.0001), maximum inferior vena cava diameter (20.7 ± 6.9 mm vs. 18.1 ± 4.2 mm, p < 0.01), and higher tricuspid regurgitation grade (1.1 ± 0.8 vs. 0.8 ± 0.6, p < 0.05) than the conventional group. However, the left ventricular ejection fraction and end diastolic diameter were similar between the groups. Responders of tolvaptan had no significant echocardiographic differences compared to the non-responders.

CONCLUSIONS

The admission echocardiographic characteristics of AHF patients requiring tolvaptan included a larger left atrium, inferior vena cava, and more severe tricuspid regurgitation. Echocardiography may provide useful information for the early and appropriate initiation of tolvaptan.

Low Na, high K diet and the role of aldosterone in BK-mediated K excretion

A low Na, high K diet (LNaHK) is associated with a low rate of cardiovascular (CV) disease in many societies. Part of the benefit of LNaHK relies on its diuretic effects; however, the role of aldosterone (aldo) in the diuresis is not understood. LNaHK mice exhibit an increase in renal K secretion that is dependent on the large, Ca-activated K channel, (BK-α with accessory BK-β4; BK-α/β4). We hypothesized that aldo causes an osmotic diuresis by increasing BK-α/β4-mediated K secretion in LNaHK mice. We found that the plasma aldo concentration (P[aldo]) was elevated by 10-fold in LNaHK mice compared with control diet (Con) mice. We subjected LNaHK mice to either sham surgery (sham), adrenalectomy (ADX) with low aldo replacement (ADX-LA), or ADX with high aldo replacement (ADX-HA). Compared to sham, the urinary flow, K excretion rate, transtubular K gradient (TTKG), and BK-α and BK-β4 expressions, were decreased in ADX-LA, but not different in ADX-HA. BK-β4 knockout (β4KO) and WT mice exhibited similar K clearance and TTKG in the ADX-LA groups; however, in sham and ADX-HA, the K clearance and TTKG of β4KO were less than WT. In response to amiloride treatment, the osmolar clearance was increased in WT Con, decreased in WT LNaHK, and unchanged in β4KO LNaHK. These data show that the high P[aldo] of LNaHK mice is necessary to generate a high rate of BK-α/β4-mediated K secretion, which creates an osmotic diuresis that may contribute to a reduction in CV disease.

Vasopressin receptor antagonists, heart failure, and polycystic kidney disease

The synthesis of nonpeptide orally bioavailable vasopressin antagonists devoid of agonistic activity (vaptans) has made possible the selective blockade of vasopressin receptor subtypes for therapeutic purposes. Vaptans acting on the vasopressin V2 receptors (aquaretics) have attracted attention as a possible therapy for heart failure and polycystic kidney disease. Despite a solid rationale and encouraging preclinical testing, aquaretics have not improved clinical outcomes in randomized clinical trials for heart failure. Additional clinical trials with select population targets, more flexible dosing schedules, and possibly a different drug type or combination (balanced V1a/V2 receptor antagonism) may be warranted. Aquaretics are promising for the treatment of autosomal dominant polycystic kidney disease and have been approved in Japan for this indication. More studies are needed to better define their long-term safety and efficacy and optimize their utilization.

Efficacy of tolvaptan in a patient with right-sided heart failure and renal dysfunction refractory to diuretic therapy

The use of loop diuretics has been shown to deteriorate renal dysfunction and is associated with a poor prognosis in patients with heart failure (HF). Tolvaptan, a vasopressin V2-receptor antagonist, has been reported to be effective in treating HF due to its potent effects of water diuresis and is expected to improve fluid retention without adversely affecting renal function. The present case is a 77-year-old man with pulmonary hypertension associated with chronic pulmonary artery thrombosis and old pulmonary tuberculosis who developed worsening right-sided HF with marked fluid retention and renal dysfunction. In this case, tolvaptan was effective in improving HF without deteriorating the patient's renal dysfunction. <Learning objective: Tolvaptan is effective in treating patients with right-sided heart failure associated with marked fluid retention and renal dysfunction who are refractory to loop diuretics and can improve and control heart failure symptoms without worsening renal dysfunction.>.

Immediate administration of tolvaptan prevents the exacerbation of acute kidney injury and improves the mid-term prognosis of patients with severely decompensated acute heart failure

BACKGROUND

 Tolvaptan, an oral selective vasopressin 2 receptor antagonist that acts on the distal nephrons to cause a loss of electrolyte-free water, is rarely used during the acute phase of acute heart failure (AHF).

METHODS AND RESULTS

 We investigated 183 AHF patients admitted to the intensive care unit and administered tolvaptan (7.5mg) with continuous intravenous furosemide, and then additionally at 12-h intervals until HF was compensated. When intravenous furosemide was changed to peroral use, the administration of tolvaptan was stopped. The patients were assigned to tolvaptan (n=52) or conventional treatment (n=131) groups. The amount of intravenous furosemide was significantly lower (35.4 [16.3-56.0] mg vs. 80.0 [30.4-220.0] mg), the urine volume was significantly higher on days 1 and 2 (3,691 [3,109-4,198] ml and 2,953 [2,128-3,592] ml vs. 2,270 [1,535-3,258] ml and 2,129 [1,407-2,906] ml) and the numbers of patients with worsening-AKI (step-up RIFLE Class to I or F) and Class F were significantly fewer (5.8% and 1.9% vs. 19.1% and 16.0%) in the tolvaptan group than in the conventional group, respectively. One of the specific medications indicated worsening-AKI and in-hospital mortality was tolvaptan (odds ratio [OR] 0.155, 95% confidence interval [CI] 0.037-0.657 and OR 0.191, 95% CI 0.037-0.985). The Kaplan-Meier curves showed that the death rate within 6 months was significantly lower in the tolvaptan group. The same result was found after propensity matching of the data.

CONCLUSIONS

 Early administration of tolvaptan could prevent exacerbation of AKI and improve the prognosis for AHF patients. 

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.

Tolvaptan attenuates left ventricular fibrosis after acute myocardial infarction in rats

Tolvaptan, a non-peptide V2-receptor antagonist, is a newly developed diuretic agent. Recently, we reported that tolvaptan has diuretic as well as anti-inflammatory and anti-fibrotic actions in chronic heart failure. In this study, we investigated whether tolvaptan has a cardioprotective effect in acute heart failure after myocardial infarction (MI). After MI induction, rats were randomized into 6 groups as follows: vehicle group, group treated with 15 mg∙kg⁻¹∙day⁻¹ furosemide, 2 groups treated with 3 or 10 mg∙kg⁻¹∙day⁻¹ tolvaptan, and 2 groups treated with 15 mg∙kg⁻¹∙day⁻¹ furosemide combined with 3 or 10 mg∙kg⁻¹∙day⁻¹ tolvaptan. Each agent was administered for 2 weeks, and blood pressure levels and infarct sizes were similar in all MI groups. Lower left ventricular end-systolic volumes and greater improvement of left ventricular ejection fraction were observed in the tolvaptan-treated groups compared with the vehicle group. In contrast, furosemide alone did not improve them. Sirius red staining revealed that tolvaptan significantly repressed MI-induced interstitial fibrosis in the left ventricle. MI-induced mRNA expressions related to cardiac load, inflammation, and fibrosis were significantly attenuated in the combination group. The combination treatment also repressed MI-induced mineralocorticoid receptor expression. Tolvaptan, or combination of furosemide and tolvaptan, may improve cardiac function in acute MI.

Tolvaptan for the treatment of hyponatremia and hypervolemia in patients with congestive heart failure

Patients with heart failure often show increased arginine vasopressin secretion and enhanced sympathetic and renin-angiotensin-aldosterone activation, which accelerate renal water reabsorption, causing water retention and volume overload. Tolvaptan is an orally active antagonist of arginine vasopressin type 2 receptors in the collecting duct of the kidney that inhibits water reabsorption without substantially affecting the electrolyte balance. Tolvaptan in combination with conventional diuretics improves fluid retention and congestive symptoms in patients with heart failure and volume overload, with minimal effects on hemodynamics and serum potassium. Tolvaptan slightly increases serum sodium concentrations, generally within the normal range. Although it does not seem to affect long-term mortality, tolvaptan does improve short-term water retention and congestive symptoms in heart failure patients with volume overload despite the use of conventional diuretics, and is approved for this indication in Japan.

The effects of tolvaptan on patients with severe chronic kidney disease complicated by congestive heart failure

Background

Tolvaptan, a diuretic with a new mechanism of action, selectively binds to the vasopressin V2 receptor and inhibits reabsorption of water. Its effect on heart failure is proven, but its benefit for patients with chronic kidney disease (CKD) has not been not confirmed. In this study, we examined the effect of tolvaptan on patients with severe CKD.

Methods

We analyzed patients with stage 4 or higher CKD who had congestive heart failure that was resistant to existing diuretics. The patients were administered an initial tolvaptan dose of 7.5 mg/day. We assumed urine volume and urine osmolality to be the main effective endpoint and recorded free water clearance, serum osmolality, serum creatinine (Cr) level, and adverse events.

Results

There was no instance of clinically significant hypernatremia. The urine volume increased significantly (P < 0.0001), as did the urine osmolality (P = 0.0053). Free water clearance showed a tendency to increase, although the difference was not statistically significant. The serum creatinine level did not change significantly, and there was no clear effect on renal function. However, in patients with stage 5 CKD, the serum creatinine level decreased significantly (n = 5, P = 0.0435). There were no adverse events.

Conclusion

We confirmed that tolvaptan has a diuretic effect in patients with both severe CKD and congestive heart failure without causing either clinically significant hypernatremia or an adverse effect on renal function. Tolvaptan is an effective diuretic for patients with CKD.

Tolvaptan Improves Left Ventricular Dysfunction after Myocardial Infarction in Rats

Background—

Arginine vasopressin, which promotes the reabsorption of renal water is increased in chronic heart failure. Here, we compared the effects of tolvaptan, a newly developed nonpeptide V 2 receptor antagonist, with those of furosemide, a loop diuretic, and a combination of these 2 agents in rats with left ventricular dysfunction after myocardial infarction (MI).

Methods and Results—

After 10 weeks of MI induction, the rats were separated them into the following 6 groups adjusted to the infarct size: a vehicle group, a group treated with 15 mg·kg -1 ·day -1 of furosemide, 2 groups treated with 3 or 10 mg·kg −1 ·day −1 of tolvaptan; and 2 groups treated with 15 mg·kg −1 ·day −1 of furosemide plus 3 or 10 mg·kg −1 ·day −1 tolvaptan. Each treatment agent was administered for 4 weeks, and all groups had similar blood pressure levels and infarct size. The tolvaptan-treated groups were found to have lower levels of left ventricular end-diastolic and systolic cardiac volumes than the vehicle group did. Furthermore, the improvement in the ejection fraction in the tolvaptan-treated groups was significantly greater than those in the vehicle group. ED-1 immunostaining and Sirius red staining revealed that tolvaptan significantly repressed MI-induced macrophage infiltration and interstitial fibrosis in the left ventricle, respectively. Tolvaptan attenuated the MI-induced mRNA expressions of atrial and brain natriuretic peptides, monocyte chemotactic protein-1, transforming growth factor-β1, arginine vasopressin V 1a receptor, and endothelin-1 in the marginal infarct region.

Conclusions—

Tolvaptan may improve cardiac dysfunction after MI, which is partially mediated by the suppression of V 1a receptor, neurohumoral activation and inflammation.

Short-term effects of low-dose tolvaptan on hemodynamic parameters in patients with chronic heart failure

BACKGROUND

We evaluated the short-term effects of low-dose tolvaptan treatment on hemodynamic parameters in patients with chronic heart failure (HF).

METHODS

We studied 22 patients (69 ± 10 years) with chronic HF and excess fluid retention despite receiving appropriate medical therapy, including loop and/or thiazide diuretics. The therapeutic effects of low-dose (7.5mg) once-daily tolvaptan on hemodynamics associated with changes in fluid balance and neurohumoral activations were investigated after a seven day treatment period.

RESULTS

After the treatment period, body weight decreased (-2.7 ± 2.3 kg) associated with increases in daily urine output. Whereas plasma arginine-vasopressin levels, serum aldosterone concentration, and plasma renin activity mildly increased, plasma levels of B-type natriuretic peptide and atrial natriuretic peptide significantly decreased after tolvaptan treatment. Serum electrolytes were not adversely affected by tolvaptan treatment. Although cardiac index and systemic vascular resistance index remained unchanged, mean pulmonary artery wedge pressure (22 ± 7 mmHg vs. 17 ± 7 mmHg, p<0.05), mean right atrial pressure (12 ± 5 mmHg vs. 9 ± 5 mmHg, p<0.05), mean pulmonary artery pressure (32 ± 9 mmHg vs. 25 ± 7 mmHg, p<0.05), and pulmonary vascular resistance index (332 ± 207 dynes/cm(-5)/m(2) vs. 245 ± 110 dynes/cm(-5)/m(2), p<0.05) significantly decreased after tolvaptan treatment. The extent of the reduction in pulmonary vascular resistance index after tolvaptan treatment strongly correlated with baseline values.

CONCLUSIONS

Short-term treatment with low-dose tolvaptan improved hemodynamic parameters and correlated with significant fluid removal in patients with chronic HF.