Increased urine aquaporin-2 relative to plasma arginine vasopressin is a novel marker of response to tolvaptan in patients with decompensated heart failure

Tolvaptan and the role of kidney aquaporin-2 abundance in managing volume overload in patients with CKD

Objective

This retrospective study evaluated tolvaptan's efficacy, safety, and predictive indicators in managing volume overload in chronic kidney disease (CKD) patients.

Methods

CKD patients with volume overload, treated with loop diuretics alone or with tolvaptan at Zhongda Hospital, Southeast University, from 1 March 2022 to 31 December 2023, were included. Patients were divided into loop diuretic (Group C) and loop diuretic combined with tolvaptan (Group T) cohorts. Primary outcomes included volume control, changes in weight, urine output, and laboratory parameters within 1 week post-medication. Adverse events such as hypernatremia and hyperkalemia, etc., were recorded. We further conducted immunohistochemical staining of renal biopsy tissues to investigate the roles of aquaporin-2 (AQP2) in the collecting duct and plasma albumin in predicting the efficacy of tolvaptan.

Results

Of 174 CKD patients with volume overload, 108 (67.07%) were male. Group C and Group T each comprised 87 patients. At baseline, no significant differences in urine output and weight were noted. By day 3, Group T exhibited a greater increase in urine output (P < .001) and weight reduction (P < .001). At day 7, Group T maintained more significant diuretic effects (P < .001). More Group C patients required ultrafiltration therapy (P = .040). Adverse event rates did not significantly differ. Notably, AQP2 expression in the collecting duct may predict tolvaptan responsiveness, while plasma albumin did not affect efficacy.

Conclusion

Tolvaptan showed efficacy and safety in managing volume overload in CKD patients. The expression of AQP2 in the collecting duct could predict tolvaptan's efficacy.This study protocol was approved by the Ethics Committee of Zhongda Hospital Affiliated to Southeast University (Approval No. 2023ZDSYLL180-P01, Clinical Trial Registration No. ChiCTR2300075274, Trial Registration Link: https://www.chictr.org.cn/guide.html).

Identifying the main predictors of urine output in autosomal-dominant polycystic kidney disease (ADPKD) patients taking tolvaptan

BACKGROUND

Few works have analyzed factors associated with urine output in ADPKD patients taking tolvaptan (TVP).

METHODS

We selected 24-h urine samples from ADPKD patients treated with TVP. Urine osmolality/creatinine ratio was used as estimator of urinary osmolar load.

RESULTS

We included 127 urine samples from 61 patients. After TVP, urine output doubled with a parallel reduction in urine solute concentration. However, when expressed as urine solute/creatinine ratios, no significant changes were observed. Daily osmolar load and osmolality/creatinine ratio did not change significantly. Before TVP, urine output was positively correlated with body weight and urine osmolality/creatinine ratio and negatively with eGFR, urine morning osmolality, and 24-h urine-calculated osmolality. After TVP, urine output was positively correlated with body weight, eGFR and negatively with age. There was a poor correlation with urine-calculated osmolality. We constructed a predictor model using mixed-effects modeling and we found that urine output was related to lower age, higher body weight, higher eGFR, and greater doses of TVP. When body weight was removed, urine output was also related to male sex and a higher daily osmolar excretion. Equation of prediction was: Urine output (mL/day) = 2771-52.9 × Age (years) + 58.4 × Weight (kg) + 18.7 × eGFR (mL/min) + 870 (if TVP = 90/30 mg) + 517 (if TVP = 60/30 mg).

CONCLUSION

Patients taking TVP will undergo an increase about twice in urine production from baseline. Greater doses of TVP cause a progressive increase in urine production. GFR, age, and body weight are the main predictors of future urine output in patients taking TVP.

Impact of urine cyclic AMP relative to plasma arginine vasopressin on response to tolvaptan in patients with chronic kidney disease and heart failure

BACKGROUND

The clinical utility of tolvaptan in chronic kidney disease (CKD) patients with heart failure remains uncertain. The level of urine cyclic adenosine monophosphate (AMP) relative to plasma arginine vasopressin (AVP) indicates the residual function of the collecting ducts in response to AVP stimulation and might be a key to predicting response of tolvaptan.

METHODS

CKD patients who were hospitalized to treat their congestive heart failure refractory to conventional loop diuretics were considered to receive tolvaptan and included in this prospective study. The impact of urine cyclic AMP/plasma AVP ratio for prediction of response to tolvaptan, which was defined as any increase in urine volume at day 7 from day 0, was investigated.

RESULTS

A total of 30 patients (median 75 years old, 24 men, and median estimated glomerular filtration rate 14.4 mL/min/1.73 m²) were included. As compared to baseline, urine volume increased at day 7 in 17 responders, whereas urine volume decreased at day 7 in 13 non-responders. Baseline urine cyclic AMP/plasma AVP ratio distributed between 0.25 and 4.01 with median 1.90. The urine cyclic AMP/plasma AVP ratio was a significant predictor of response to tolvaptan, which was adjusted for 6 potential confounders with a cutoff of 1.24.

CONCLUSIONS

Baseline urine cyclic AMP/plasma AVP ratio is an independent predictor of response to tolvaptan in advanced CKD patients with heart failure.

CLINICAL TRIAL REGISTRATION

UMIN000022422.

Impact of Goreisan upon aquaporin-2-incorporated aquaresis system in patients with congestive heart failure

We often encounter patients with congestive heart failure refractory to conventional diuretics therapy, and Kampo Goreisan is receiving great concern to mediate body water balance particularly for such a cohort. However, its detailed biological mechanism remains uncertain. We had two hospitalized patients with congestive heart failure receiving tolvaptan. Following the administration of Goreisan, both urine cyclic adenosine monophosphate concentration and urine aquaporin-2 concentration decreased, accompanied by incremental diluted urine volume. Although further studies are warranted to establish therapeutic strategy, Goreisan might be a promising therapeutic tool for those with congestive heart failure refractory to conventional diuretics including tolvaptan, via pleiotropic effects including suppression of aquaporin-incorporated water reabsorption system.

Impact of tolvaptan add-on treatment on patients with heart failure requiring long-term congestion management: A retrospective cohort study using a medical claim database in Japan

BACKGROUND

The impact of tolvaptan on the long-term outcomes of patients with heart failure (HF) remains inconclusive. We evaluated patients requiring long-term congestion management for the time to rehospitalization for HF (HF rehospitalization), the time to in-hospital death and explored the factors that may influence the outcomes.

METHODS

Using data (April 2008 to September 2019) from a medical claims database, patients with HF prescribed tolvaptan (tolvaptan cohort) and those prescribed loop diuretics before tolvaptan was introduced to the hospital (furosemide cohort) were compared. Patients with HF who experienced ≥2 HF hospitalizations and ≥ 1 tolvaptan or loop diuretic prescription during and after HF hospitalization were included. Data of patients with serum creatinine and estimated glomerular filtration rate were analyzed for time to HF rehospitalization and in-hospital death within 1 year after the second discharge and factors that may influence the outcomes.

RESULTS

Among the 1931 and 631 tolvaptan and furosemide cohort patients, respectively, time to HF rehospitalization was not significantly different (p = 0.0921); time to in-hospital death was significantly longer in the tolvaptan cohort than in the furosemide cohort (p = 0.0005). Age, serum sodium, angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers were identified as factors for both outcomes (p < 0.05).

CONCLUSIONS

Tolvaptan did not significantly affect time to HF rehospitalization. However, further worsening of the condition leading to death may be delayed, and time to in-hospital death may be prolonged in patients treated with tolvaptan, indicating its usefulness for long-term congestion management.

Prognostic impact of urine cyclic AMP levels in patients with chronic kidney disease

BACKGROUND

Urine cyclic adenosine monophosphate (cAMP) is a biomarker to assess the residual function of the collecting duct in the kidney. Prognostic implication of urine cAMP levels in patients with chronic kidney disease (CKD) remains unknown.

METHODS

Patients who were followed at our specific outpatient clinic to treat their CKD between December 2015 and December 2019 were included in this prospective study. The impact of urine cAMP levels on the composite of dialysis administration, cardiovascular death, and doubling of serum creatinine concentration was investigated.

RESULTS

A total of 106 patients (median 72 years old, 80 men, and median estimated glomerular filtration rate 28.4 mL/min/1.73 m²) were included. Urine cAMP levels ranged widely between 0.35 and 4.08 nmol/mg of creatinine with a median value of 1.99 nmol/mg of creatinine. A urine cAMP level was an independent predictor of the primary endpoint with a hazard ratio of 0.41 (95% confidence interval 0.18-0.91, p = 0.029) adjusted for 5 potential confounders with a cutoff of 1.55 nmol/mg of creatinine.

CONCLUSIONS

A lower urine cAMP is an independent predictor of renal deterioration and cardiovascular death in patients with CKD.

Altered arginine vasopressin-cyclic AMP-aquaporin 2 pathway in patients with chronic kidney disease

BACKGROUND

In the collecting ducts of the kidney, arginine vasopressin (AVP), cyclic adenosine monophosphate (cAMP), and aquaporin 2 (AQP2) play a pivotal role in maintaining fluid volume and serum osmolality in humans. However, their association among those with chronic kidney disease (CKD) remains uncertain.

METHODS

We prospectively included the out-patients with CKD and measured osmolality-related biomarkers including plasma AVP, urine cAMP, urine AQP2, and urine osmolality levels. Association among these parameters at each CKD stage was investigated.

RESULTS

A total of 121 patients were included (median age 71 years old [61-78], 89 men, estimated glomerular filtration ratio 28.6 [16.4-45.3] mL/min/1.73 m²). Serum osmolality increased as CKD progression, accompanying incremental plasma AVP levels, whereas urine cAMP, urine AQP2, and urine osmolality decreased as CKD progression. At advanced CKD stage, urine cAMP remained low irrespective of the AVP stimulation, whereas urine cAMP levels varied according to the levels of plasma AVP at less advanced CKD stage. The associations between urine cAMP and urine AQP2 and between urine AQP2 and urine osmolality remained preserved irrespective of the CKD stages.

CONCLUSIONS

Vasopressin type-2 receptor seems to be particularly impaired in patients with advanced CKD, whereas the signal cascade of the downstream of vasopressin type-2 receptor is relatively preserved. Urine cAMP might be a promising marker to estimate the residual function of the collecting duct.

Predictive Value of Urinary Aquaporin 2 for Acute Kidney Injury in Patients with Acute Decompensated Heart Failure

Acute kidney injury (AKI) is frequently encountered in people with acute decompensated heart failure (ADHF) and is associated with increased morbidity and mortality. Early detection of a urinary biomarker of kidney injury might allow a prompt diagnosis and improve outcomes. Levels of urinary aquaporin 2 (UAQP2), which is also associated with several renal diseases, are increased with ADHF. We aimed to determine whether UAQP2 predicted AKI in patients with ADHF. We conducted a prospective observation study in the coronary care unit (CCU) in a tertiary care university hospital in Taiwan. Individuals with ADHF admitted to the CCU between November 2009 and November 2014 were enrolled, and serum and urinary samples were collected. AKI was diagnosed in 69 (36.5%) of 189 adult patients (mean age: 68 years). Area under the receiver operating characteristic curve (AUROC) of biomarkers was evaluated to evaluate the diagnostic power for AKI. Both brain natriuretic peptide and UAQP2 demonstrated acceptable AUROCs (0.759 and 0.795, respectively). A combination of the markers had an AUROC of 0.802. UAQP2 is a potential biomarker of AKI in CCU patients with ADHF. Additional research on this novel biomarker is required.

Temporal Change in Renoprotective Effect of Tolvaptan on Patients with Heart Failure: AURORA Study

(1) Background: It has been reported that tolvaptan (TLV) has a renoprotective effect in acute decompensated heart failure (ADHF) patients, but whether this effect is continued for a long time is unclear. Thus, we evaluated the time course of the renoprotective effect of TLV, in addition to the prognosis, in ADHF patients. (2) Methods: We investigated 911 ADHF patients from the AURORA (Acute Heart Failure Registry in Osaka Rosai Hospital) registry. After propensity score matching, 58 patients who started to receive TLV at least two days after the hospitalization (TLV group) and 58 who did not (non-TLV group) were examined. We compared the changes in the creatinine (Cr) and estimated glomerular filtration rate (eGFR) between baseline and each time point (five days, discharge, and one year) as the index of the renoprotective effect, and rate of rehospitalizations and all-cause mortality for one year between the two groups. (3) Results: The change in Cr and eGFR levels was significantly higher in the TLV group than the non-TLV group five days after admission but the difference between the two groups gradually diminished. A Kaplan–Meier analysis showed that the survival and rehospitalization rates in the TLV and non-TLV groups were similar up to one year. (4) TLV revealed a temporal change in the renoprotective effect, which may be correlated with no long-term beneficial effect of TLV.

Updates and Perspectives on Aquaporin-2 and Water Balance Disorders

Ensuring the proper amount of water inside the body is essential for survival. One of the key factors in the maintenance of body water balance is water reabsorption in the collecting ducts of the kidney, a process that is regulated by aquaporin-2 (AQP2). AQP2 is a channel that is exclusively selective for water molecules and impermeable to ions or other small molecules. Impairments of AQP2 result in various water balance disorders, including nephrogenic diabetes insipidus (NDI), which is a disease characterized by a massive loss of water through the kidney and consequent severe dehydration. Dysregulation of AQP2 is also a cause of water retention with hyponatremia in heart failure, hepatic cirrhosis, and syndrome of inappropriate antidiuretic hormone secretion (SIADH). Antidiuretic hormone vasopressin is an upstream regulator of AQP2. Its binding to the vasopressin V2 receptor promotes AQP2 targeting to the apical membrane and thus enables water reabsorption. Tolvaptan, a vasopressin V2 receptor antagonist, is effective and widely used for water retention with hyponatremia. However, there are no studies showing improvement in hard outcomes or long-term prognosis. A possible reason is that vasopressin receptors have many downstream effects other than AQP2 function. It is expected that the development of drugs that directly target AQP2 may result in increased treatment specificity and effectiveness for water balance disorders. This review summarizes recent progress in studies of AQP2 and drug development challenges for water balance disorders.

Cost-Effectiveness of long-term tolvaptan administration for chronic heart failure treatment in Japan

BACKGROUND

Tolvaptan (TLV) is effective for acute heart failure (HF) with congestion, but its long-term administration in patients with chronic HF (CHF) remains controversial. Moreover, the cost-effectiveness of TLV for CHF treatment has not yet been investigated. Thus, we sought to validate the cost-effectiveness of TLV for CHF treatment in Japan.

METHODS

A Markov model was developed to compare total costs, quality-adjusted life years (QALYs), and incremental cost-effectiveness ratio (ICER) between long-term TLV strategy and the standard strategy using furosemide for CHF. The target population included 75-year-old patients with CHF. The effectiveness of the TLV strategy for CHF treatment was determined based on a systematic review and meta-analysis. We used a 10-year horizon, with sensitivity analyses for significant variables and a scenario analysis for patients with CHF receiving high-dose furosemide (≥60 mg per day).

RESULTS

In the base case analysis, the total cost of the long-term TLV strategy was higher than that of the standard strategy (\3,243,779 vs. \1,179,964). The total QALYs of the long-term TLV strategy were lower than those of the standard strategy (4.52 vs 4.59). Thus, a standard TLV prescription for CHF treatment has no clinical or economic benefit. In the scenario analysis (i.e. in patients with CHF receiving high-dose furosemide), the long-term TLV strategy was more effective (total QALYs, 5.10 vs. 4.41) but more expensive (total costs, \3,540,558 vs. \1,272,208) than the standard strategy. The ICER of the TLV strategy against the standard strategy (¥3,289,579/QALY) was below the willingness-to-pay of \5,000,000, which suggests that the long-term TLV strategy is cost-effective relative to the standard strategy in patients with CHF receiving high-dose furosemide.

CONCLUSIONS

Long-term TLV administration did not provide a clear benefit for all patients with CHF. However, this treatment strategy may be a cost-effective therapeutic option for patients who require high-dose furosemide.

Comparative quantitation of aquaporin-2 and arginine vasopressin receptor-2 localizations among chronic kidney disease and healthy kidney in dogs

BACKGROUND AND AIM

Aquaporin-2 (AQP2) and arginine vasopressin receptor-2 (AVPR2) are proteins that control water homeostasis in principal cells. Chronic kidney disease (CKD) is defined as the impairment and irreversible loss of kidney function and/or structure, which causes water imbalances and polyuria. The study aimed to know the expression of AQPs and AVPR2 in the kidneys of a canine with CKD.

MATERIALS AND METHODS

The kidneys were collected from two dog carcasses from Small Animal Teaching Hospital, Faculty of Veterinary Medicine, Chiang Mai University. The kidney tissue was prepared for immunohistochemistry and investigated the expression and localization of tissue's AQP2 and AVPR2. For statistical analysis, the Mann-Whitney U-test was applied to the data.

RESULTS

By immunohistochemistry, AQP2 was expressed strongly in the basolateral and apical membranes of the principal cells, whereas AVPR2 was localized in the principal cell's basolateral membrane in both renal cortex and renal medulla. In the normal kidney, the semi-quantitative immunohistochemistry for the percentage of protein expression of AQP2 and AVPR2 was 5.062±0.4587 and 4.306±0.7695, respectively. In contrast, protein expression of AQP2 and AVPR2 in CKD was found to be 1.218±0.1719 and 0.8536±0.1396, respectively. The data shows that the percentage of AQP2 and AVPR2 expression was decreased, corresponding to a 4-fold and 5-fold in CKD (p<0.001).

CONCLUSION

Our findings revealed that CKD was a marked decrease in AQP2 and AVPR2 expression. The central role of specific AQP2 and AVPR2 in regulating water homeostasis will provide correlations in case of CKD with polyuria.

Peak Lag Between Plasma Vasopressin and Urine Aquaporin-2 Following Cardiac Surgery

Tolvaptan, a vasopressin type-2 receptor antagonist, is utilized to ameliorate fluid retention following cardiac surgery. However, the optimal timing of tolvaptan administration considering novel biomarkers remains unknown. We prospectively included patients who underwent cardiac surgery between 2016 and 2020. We measured perioperative trends of free water reabsorption mediators including plasma arginine vasopressin and urine aquaporin-2. A total of 20 patients (68 [60, 75] years old, 18 men) were included. Urine volume decreased gradually after the initial 3 hours following cardiac surgery. The plasma arginine vasopressin level increased significantly with a peak at postoperative 6 hours, whereas the urine aquaporin-2 level increased later with a delayed peak at postoperative 12 hours. As a result, urine aquaporin-2 relative to the plasma arginine vasopressin level, which represents the activity of the collecting ducts and indicates predicted responses to tolvaptan, was a minimum at postoperative 6 hours. Tolvaptan administration immediately after cardiac surgery might not be recommended given the transient refractoriness to tolvaptan probably due to the stunning of kidney collecting ducts.

Urinary Aquaporin 2 as a Potential Indicator Predicting Tolvaptan Response in Patients With ADPKD

Introduction

Tolvaptan is used to treat autosomal dominant polycystic kidney disease (ADPKD) because it inhibits binding of the antidiuretic hormone vasopressin to the vasopressin V2 receptor (V2R), which suppresses the insertion of preformed water channel aquaporin 2 (AQP2) molecules in the luminal membrane of the collecting duct cells.

Methods

This single-center, prospective observational cohort study investigated whether decreased AQP2 elimination in urine affects the renal prognosis of patients who received tolvaptan. We selected 92 patients with ADPKD who were administered tolvaptan in our hospital. We evaluated correlations between changes in urinary AQP2 (U-AQP2) and clinical parameters and the annual change in total kidney volume (TKV) and estimated glomerular filtration rate (eGFR) as renal prognostic factors using univariable and multivariable multiple regression analyses.

Results

The observation period was 2.4 ± 1.5 years. U-AQP2 per milligram of urinary creatinine (U-AQP2/Cr) decreased from 67.8 ± 50.6 to 20.7 ± 15.1 fmol/mg urinary creatinine after 1 month of tolvaptan treatment. This initial change in U-AQP2/Cr was correlated with high baseline U-AQP2/Cr, low baseline eGFR, and a large initial change in eGFR (baseline to 1 month). The initial change in U-AQP2/Cr (baseline to 1 month) was strongly correlated with the annual change in TKV and eGFR in multivariable analysis.

Conclusion

Initial decrease in U-AQP2/Cr in the first month of treatment reflects the pharmacologic effect of tolvaptan and could be an indicator of renal prognosis during tolvaptan treatment.

Characterization of tolvaptan response and its impact on the outcome for patients with heart failure

BACKGROUND

Conventional diuretic therapy such as loop diuretics is a cornerstone of the treatment for heart failure (HF). Diuretic response is an important factor in determining resistance to HF therapy and has been shown to be associated with subsequent clinical outcome. Tolvaptan (TVP), a vasopressin V2 receptor antagonist, has a favorable profile in terms of rapid fluid removal and less aggravation of renal function. We hypothesized that the response to TVP might be associated with the subsequent clinical outcome.

METHOD

In this single-center retrospective study, 148 consecutive HF patients who were administered TVP from 2014 through 2018 [age 79 (69-86) years, male 89 (60%)] were included. Ninety-six patients were divided into TVP responder [N = 39 (41%)] and non-responder groups based on the cut-off value of gained urine output (+ 93 ml/mg TVP /day) on the day after TVP was introduced.

RESULTS

Early TVP introduction (p = 0.012) and lower dose of loop diuretics (p = 0.043) were predictors of TVP responder. For 2 years after discharge, TVP responders showed more favorable outcomes regarding the primary endpoint defined as the composite of all-cause death and HF readmission (p = 0.034, log-rank test) and HF readmission (p = 0.005). A multivariable Cox model analysis revealed that TVP responder was an independent predictor of the primary endpoint (hazard ratio 0.48, p = 0.041). TVP responders had a lower number of HF readmissions over a 1-year period (p = 0.002). TVP response was independently associated with the number of HF readmissions (p = 0.015). The proportion of patients with an extended period between discharge and HF readmission after TVP administration was higher in responders than non-responders (67% vs. 23%, p = 0.006). These associations of TVP response and post-discharge outcomes were more evident in patients who continued TVP after discharge.

CONCLUSION

TVP response can be indicative of subsequent clinical outcomes and may be informative when considering advanced care planning.

Aquaporins and diseases pathogenesis: From trivial to undeniable involvements, a disease-based point of view

Aquaporins (AQPs), as transmembrane proteins, were primarily identified as water channels with the ability of regulating the transmission of water, glycerol, urea, and other small-sized molecules. The classic view of AQPs involvement in therapeutic plan restricted them and their regulators into managing only a narrow spectrum of the diseases such as diabetes insipidus and the syndrome of inappropriate ADH secretion. However, further investigations performed, especially in the third millennium, has found that their cooperation in water transmission control can be manipulated to handle other burden-imposing diseases such as cirrhosis, heart failure, Meniere's disease, cancer, bullous pemphigoid, eczema, and Sjögren's syndrome.

[Retrospective Observational Study on Predictors of Body Weight and BNP Teduction in Cases of Tolvaptan Induction for Heart Failure]

Tolvaptan (TLV) carries the risk of serious side effects, and its introduction requires hospitalization. Therefore, it is important from the viewpoints of safety and medical economics to predict in advance, the patients for whom it will be effective and introduce it. The purpose of this study was to investigate the noninvasive and simple predictors for identifying TLV responders. We conducted a retrospective observational study of patients with heart failure who had TLV introduced at our hospital from January 1, 2017, to December 31, 2018. By using the body weight and BNP reduction as the effect indices, predictors of body weight and BNP reduction were extracted by logistic analysis. The sensitivity and specificity at the cutoff value obtained by ROC analysis were also examined. Among 85 subjects, urine sodium concentration >63 mEq/L [odds ratio (OR): 6.11, 95% confidence interval (CI): 1.36-27.4] was detected as a predictor of body weight reduction. The sensitivity at this cutoff value was 81%, and the specificity was 70%. Serum osmolarity>291 mOsm/L (OR: 3.76, 95% CI: 1.00-14.2), urine potassium concentration<21 mEq/L (OR: 4.45, 95% CI: 1.09-18.2), and urine sodium concentration>71 mEq/L (OR: 7.38, 95% CI: 2.05-26.6) were detected as predictors of BNP reduction. The sensitivities were 62%, 53%, and 73%, and the specificities were 58%, 68%, and 68%, respectively. Therefore, it was suggested that urine sodium concentration may be useful as a predictor of body weight and BNP decrease after TLV induction.

Impact of acute kidney injury on prognosis and the effect of tolvaptan in patients with hepatic ascites

BACKGROUND

In hepatic cirrhosis, ascites and acute kidney injury (AKI) portend poor prognosis. We examined the incidence and characteristics of AKI in patients with hepatic ascites and the impact of diuretics on AKI onset.

METHODS

This study included 337 patients with hepatic ascites treated with oral diuretics during September 2013-June 2019. Incidence of AKI, cumulative survival by AKI status, and prognostic factors were investigated. Patients were divided into those treated with tolvaptan (TLV) [TLV group (n = 244)] and those not treated with TLV [control group (n = 93)]. After propensity score matching, the incidence of AKI and changes in renal function and doses of diuretics were compared.

RESULTS

The incidence of AKI overall was 35% (n = 118). Patients with AKI had a significantly worse survival than those without AKI (P = 0.001), indicating that AKI is an independent prognostic factor for hepatic ascites (P = 0.025). After adjustment for background factors in the two groups (n = 77 each), the TLV group had a significantly lower incidence of AKI (27.6% vs. 44.7%, P = 0.028). While renal function worsened with higher natriuretic agent doses in the control group, no significant change was observed in the TLV group, suggesting that TLV is an independent prognostic factor for AKI onset.

CONCLUSIONS

Our study suggests that concomitant AKI significantly worsens survival in Japanese patients with hepatic ascites, and TLV and natriuretic agent combination therapy might lead to an excellent synergistic therapeutic effect of hepatic ascites and inhibition of AKI onset.

Expression of aquaporin-2 in the collecting duct and responses to tolvaptan

Tolvaptan, a vasopressin type-2 receptor antagonist, is indicated for fluid retention. It is considered that the response to tolvaptan reduces as renal function deteriorates, whereas we sometimes experience "non-responders" to tolvaptan despite well-preserved renal function. While the expression of aquaporin-2 might be a key to response to tolvaptan, detailed mechanism of refractoriness to tolvaptan remains unknown. We experienced two patients with congestive heart failure and diabetic nephropathy, in whom the responses to tolvaptan were uniquely opposite. In one case, immunohistochemical staining showed expression of aquaporin-2 in the collecting duct despite severely reduced renal function, followed by the good response to tolvaptan with increased urine output. In another case, immunohistochemical staining showed absence of aquaporin-2 with infiltration of inflammatory cells in the kidney medulla despite relatively preserved renal function, followed by refractoriness to tolvaptan without any increase in urine output. Inactivated aquaporin-2 expression in the collecting duct, which was for example caused by pre-clinical urinary infection as our latter case, might have an association with refractoriness to tolvaptan.

Micropeptide MIAC Inhibits HNSCC Progression by Interacting with Aquaporin 2

Several important micropeptides encoded by noncoding RNAs have been identified in recent years; however, there have never been any reports of micropeptides in head and neck squamous cell carcinoma (HNSCC). Here we report the discovery and characterization of a human endogenous peptide named micropeptide inhibiting actin cytoskeleton (MIAC). Comprehensive analysis of the TCGA (The Cancer Genome Atlas) database (n = 500), clinical fresh samples (n = 94), and tissue microarrays (n = 60) revealed that lower MIAC expression is correlated with poor overall survival of HNSCC patients. Meanwhile, RNA-sequencing analysis of 9657 human tissues across 32 cancer types from TCGA cohorts found that MIAC is significantly associated with the progression of 5 other different tumors. Mechanistically, MIAC directly interacts with AQP2 (Aquaporin 2) to inhibit the actin cytoskeleton by regulating SEPT2 (Septin 2)/ITGB4 (Integrin Beta 4) and ultimately suppressing the tumor growth and metastasis of HNSCC. Collectively, the mechanism investigation and evaluation of MIAC activity in vivo and in vitro highlights that MIAC plays an important role in HNSCC tumorigenesis.

Management of refractory ascites attenuates muscle mass reduction and improves survival in patients with decompensated cirrhosis

BACKGROUND

This study investigated time-course changes in skeletal muscle volume per year with tolvaptan in patients with refractory ascites that was unresponsive to loop diuretics and aldosterone antagonists.

METHODS

This retrospective study included 42 patients who received tolvaptan for refractory ascites and/or hepatic edema and underwent computed tomography (CT) before and ≥ 3 months after initiating tolvaptan. The time-course changes in skeletal muscle index per year [ΔSMI (%)] was calculated as follows: ΔSMI (%) = (SMI at final CT scan - SMI at initial CT scan)/SMI at initial CT scan × 100/years between CT scans.

RESULTS

Eligible patients were 23 men and 19 women of median age of 71 years (range 21-94 years). The median follow-up period was 22.7 (range 3.5-54.6) months. ΔSMI (%) was significantly higher in the responders group than in the nonresponder group. Multivariate analysis showed the response to tolvaptan was an independent and significant factor associated with an increase in muscle mass [odds ratio (OR) 20.364; 95% CI 2.327-178.97; P = 0.006]. Overall survival with tolvaptan was significantly higher in the responder group than in the nonresponder group. Multivariate analysis showed that the response to tolvaptan treatment was a significant contributor to good prognosis (OR 3.884; 95% CI 1.264-11.931; P = 0.018). A significant negative correlation was observed between the dosage of furosemide and ΔSMI (%) (P = 0.014).

CONCLUSIONS

Treatment of refractory ascites with tolvaptan may attenuate the progression of sarcopenia and improve the prognosis in patients with decompensated cirrhosis.

Old and New Drugs for Treatment of Advanced Heart Failure

BACKGROUND

Advanced heart failure (HF) is a progressive disease with high mortality and limited medical therapeutic options. Long-term mechanical circulatory support and heart transplantation remain goldstandard treatments for these patients; however, access to these therapies is limited by the advanced age and multiple comorbidities of affected patients, as well as by the limited number of organs available.

METHODS

Traditional and new drugs available for the treatment of advanced HF have been researched.

RESULTS

To date, the cornerstone for the treatment of patients with advanced HF remains water restriction, intravenous loop diuretic therapy and inotropic support. However, many patients with advanced HF experience loop diuretics resistance and alternative therapeutic strategies to overcome this problem have been developed, including sequential nephron blockade or use of the hypertonic saline solution in combination with high-doses of furosemide. As classic inotropes augment myocardial oxygen consumption, new promising drugs have been introduced, including levosimendan, istaroxime and omecamtiv mecarbil. However, pharmacological agents still remain mainly short-term or palliative options in patients with acute decompensation or excluded from mechanical therapy.

CONCLUSION

Traditional drugs, especially when administered in combination, and new medicaments represent important therapeutic options in advanced HF. However, their impact on prognosis remains unclear. Large trials are necessary to clarify their therapeutic potential and prognostic role in these fragile patients.

Long-Term Tolvaptan Treatment in Refractory Heart Failure

Background: The vasopressin type-2 receptor antagonist tolvaptan is an essential tool in the management of decompensated heart failure (HF) in the inpatient setting for short-term use with careful monitoring. There is conflicting evidence, however, for its long-term use.

Methods and Results: In this prospective, multi-center, open-labeled, randomized control trial, Assessment of QUAlity of life during long-term treatment of ToLVaptan in refractory HF (AQUA-TLV study), patients with congestive HF refractory to furosemide ≥60 mg/day were randomly assigned to a control group or tolvaptan add-on group and followed for 6 months, after confirmation of baseline urine osmolality ≥350 mOsm/L. Twenty-nine patients (median age, 60 years; 22 male) were enrolled and assigned to a control group (n=16) or a tolvaptan group (n=13). Minnesota Living with Heart Failure Questionnaire score improved significantly in the tolvaptan group (from 58 to 10, P=0.030). In the tolvaptan group, diuretics dose reduced (P=0.001), serum creatinine decreased (P=0.040), and hyponatremia tended to improve (P=0.12). The tolvaptan group had a lower HF readmission rate compared with the control group (0.213 vs. 1.242 events/year, P=0.13).

Conclusions: Six-month tolvaptan therapy improved quality of life and renal function and reduced HF readmissions, when given to the estimated responders (UMIN Clinical Trial Registry Number: UMIN 000009604).

Effect of tolvaptan on the prognosis of patients with hepatic ascites

AIM

Despite accumulating evidence concerning the efficacy of tolvaptan in the treatment of body fluid retention or hyponatremia, the effect of tolvaptan on the prognosis of patients with hepatic ascites has not been fully investigated.

METHODS

A total of 628 patients with hepatic ascites who were treated with diuretics (furosemide, spironolactone, or tolvaptan) between 2007 and 2017 were enrolled and divided into two groups: those who received tolvaptan (original tolvaptan group, n = 278) and those who did not (original control group, n = 350). The cumulative survival rates between the groups were compared and the factors associated with survival in patients with hepatic ascites were identified using a Cox regression analysis. In addition, propensity score matching was applied in patients who started conventional diuretics for new-onset hepatic ascites after September 2013 (pre-matching tolvaptan group, n = 177; pre-matching control group, n = 63), and the cumulative survival rates were compared between the post-matching tolvaptan and control groups.

RESULTS

The survival rate was significantly higher in the tolvaptan group than the control group (P = 0.005), and tolvaptan therapy was identified as an independent factor associated with survival (hazard ratio 0.721 for death relative to control, P < 0.001). The propensity score-matched comparison also showed a significantly higher survival rate in the tolvaptan group (n = 51) than in the control group (n = 51) (P = 0.009).

CONCLUSIONS

This study suggests that tolvaptan might improve the prognosis of patients with hepatic ascites.

Impact of serum albumin levels on the body fluid response to tolvaptan in chronic kidney disease patients

PURPOSE

Tolvaptan exerts an aquaretic effect by blocking vasopressin V2 receptor. Although tolvaptan ameliorates body fluid retention even in patients with chronic kidney disease (CKD), predictors of body fluid reduction induced by tolvaptan remain unclear. We, therefore, examined the clinical parameters associated with the effect of tolvaptan on fluid volume in CKD patients.

METHODS

Twelve CKD patients (stage 3-5) with fluid retention were treated with tolvaptan in addition to conventional diuretic treatment. Patients were divided into low and high responders by the median change in total body water (TBW) for 1 week measured by a bioimpedance analysis (BIA) device, and clinical parameters were compared between the groups.

RESULTS

The body weight significantly decreased by 2.0 ± 2.3 kg (p = 0.005), but the estimated glomerular filtration rate (eGFR) was not significantly changed (16.9 ± 11.9 vs. 17.4 ± 12.4 mL/min/1.73 m², p = 0.139) after 1 week. The BIA showed that the intracellular water (ICW) decreased by 6.0% ± 4.7% (p < 0.001), the extracellular water (ECW) decreased by 6.7% ± 5.4% (p = 0.001), and the TBW decreased by 6.3% ± 4.9% (median value - 6.02%, p < 0.001). The serum albumin level in the high responders was significantly lower than in the low responders (2.3 ± 0.5 vs. 3.3 ± 0.8 g/dL, p = 0.013). Significant partial correlations adjusted for the eGFR were observed between the baseline serum albumin level and changes in the ICW (r = 0.440, p = 0.048), ECW (r = 0.593, p = 0.009) and TBW (r = 0.520, p = 0.020).

CONCLUSIONS

Serum albumin levels predict the body fluid response to tolvaptan in CKD patients. Tolvaptan may be a promising therapeutic option for ameliorating body fluid retention, especially in patients with hypoalbuminemia.

Hemodynamic and Hormonal Effects of Tolvaptan for Heart Failure

Tolvaptan (TLV) is a diuretic agent administrated for heart failure (HF) only in Japan. Many clinical findings have been obtained from the accumulation of clinical experience, and the administration of TLV reportedly avoids causing a reduction in the renal function. In addition, TLV has been reported to exert effects other than diuresis. The early start of TLV after hospitalization shortens the length of the hospital stay, and continuous TLV after discharge extends the period until re-hospitalization of HF patients. TLV is thought to function via vasopressin V2 receptor antagonism. However, no significant differences in the long-term prognosis were noted between the group using TLV and not using TLV in the Endovascular Valve Edge-to-Edge Repair Study (EVEREST) trial, and effects other than diuresis are not useful for all HF patients. Therefore, it is necessary to identify patients who may experience effects other than diuresis with TLV administration. The accumulation of more patients and findings from further large-scale clinical trials will be necessary in order to clarify these points.

Right ventricular enlargement predicts responsiveness to tolvaptan in congestive heart failure patients with reduced ejection fraction

Background

Tolvaptan is a vasopressin type 2 receptor antagonist used in heart failure (HF) with refractory diuretic resistance. However, since tolvaptan is also ineffective in some HF patients with reduced ejection fraction (HFrEF), the identification of responders is important.

Methods

The study population consisted of 51 HFrEF patients who were administered tolvaptan (EF, 28 ± 7%). We defined responders as patients with a ≥50% increase in urine volume during the 24-hours after administration of tolvaptan. All patients underwent comprehensive transthoracic echocardiography before administration of tolvaptan. Patients were followed for 120 days to ascertain secondary events (cardiac death and rehospitalization for HF).

Results

Multiple regression analysis indicated that right ventricular (RV) enlargement (defined as basal RV diameter > 41 mm and midlevel RV diameter > 35 mm, according to guidelines) remained a predictor of response after adjustment for age, sex, starting dosage of tolvaptan, and estimated glomerular filtration rate (odds ratio, 4.88; 95%-confidence interval, 1.26–18.9; P < 0.05), whereas left ventricular parameters and RV dysfunction were not. Kaplan-Meier curves indicated responsiveness to tolvaptan was associated with better prognosis among the overall population (P < 0.05); similar trends were observed among patients with RV dilatation (P = 0.056).

Conclusions

These findings suggest that RV enlargement, which represents right-sided volume overload, elevated filling pressure, and diastolic dysfunction similar to that seen in constrictive pericarditis, predicts responsiveness to tolvaptan in patients with HFrEF. Moreover, administration of tolvaptan may have the potential to improve the reportedly poor prognosis for HFrEF patients with RV dilatation.

Prognostic factors for long-term outcomes in acute decompensated heart failure patients under tolvaptan treatment

Inconsistent results have been reported concerning the effect of tolvaptan treatment on long-term prognostic outcomes in patients with acute decompensated heart failure (ADHF) and data are limited on prognostic factors affecting this patient population. We investigated prognostic factors influencing long-term clinical outcomes in patients with ADHF treated with tolvaptan in a real-world setting. A total of 263 consecutive patients hospitalized for ADHF and treated with tolvaptan were retrospectively enrolled. The patients were stratified into those who developed the combined event of cardiac death or rehospitalization for worsening heart failure within 1 year (n = 108) and those who were free of this combined event within 1 year (n = 155). Adjusted multivariate Cox proportional hazards model revealed that change in serum sodium level between pre-treatment and 24 h after tolvaptan administration [hazard ratio (HR) 0.913, 95% confidence interval (CI) 0.841-0.989, p = 0.025] and the time taken for tolvaptan initiation from admission (HR 1.043, 95% CI 1.009-1.074, p = 0.015) were independent predictors of combined event occurrence within 1 year. Moreover, change in serum sodium level > 1 mEq/L between pre-treatment and 24 h after administration and initiation of tolvaptan < 5 days after admission correlated significantly with the incidence of the combined event (log-rank test p = 0.003 and p = 0.002, respectively). In conclusion, increased serum sodium level early after administration and early initiation of tolvaptan are possibly useful for assessing the long-term prognosis after tolvaptan treatment in patients with ADHF.

Low aquaporin-2 excretion in the nephrotic syndrome: an escape from the vasopressin regulating effect

Purpose

Experimental studies suggest that the nephrotic syndrome is associated with “vasopressin escape”, characterized by low aquaporin-2 (AQP2) expression in the collecting duct despite high vasopressin secretion. We investigated this phenomenon in patients with the nephrotic syndrome.

Patients and methods

We recruited 47 patients with proteinuric kidney disease who were distributed into the following four groups: 1) nephrotic syndrome with kidney dysfunction (n=10); 2) nephrotic syndrome with normal kidney function (n=16); 3) partial remission of nephrotic syndrome (n=10); and 4) minimal proteinuria (n=11). Nine healthy volunteers comprised a control group. Serum copeptin level (as a marker of vasopressin secretion) and urinary AQP2 were measured using ELISA.

Results

Nephrotic syndrome was associated with a significant increase in serum copeptin levels compared with those in the other groups (all P<0.05). In patients with nephrotic syndrome and a partial remission of nephrotic syndrome combined, there was more than a ten-fold decrease in the median urinary AQP2 excretion (0.03 ng/mL) compared with healthy volunteers (0.41 ng/mL; P<0.001) and more than a five-fold decrease compared with patients with minimal proteinuria (0.21 ng/mL; P<0.05). Unlike copeptin levels, the median urinary AQP2 excretion in patients with minimal proteinuria also decreased but less significantly than in those with nephrotic syndrome. There was a negative correlation between the urinary AQP2 excretion and daily proteinuria (R=−0.41; P=0.005).

Conclusion

Our clinical study was the first to demonstrate low AQP2 excretion in nephrotic syndrome that may indicate an escape from the vasopressin regulating effect.

The effects of tolvaptan dose on cardiac mortality in patients with acute decompensated heart failure after hospital discharge

Tolvaptan (TLV) is a newly developed oral vasopressin-2 receptor antagonist that is mostly used for patients with acute decompensated heart failure (ADHF) refractory to conventional diuretic therapy. The aim of this study was to investigate the effects of outpatient TLV dose on cardiac mortality in patients discharged after hospitalization for ADHF. One hundred and five patients with ADHF who had been treated with TLV for the first time during hospitalization were retrospectively divided into three groups based on outpatient TLV use and dose. The non-TLV group comprised patients who were not treated with TLV after discharge (n = 36). Patients who continued TLV after discharge were further classified into two groups: low-dose (LD)-TLV (3.75 mg/day, n = 27) and high-dose (HD)-TLV (7.5 or 15 mg/day, n = 42). The primary endpoint was cardiac mortality. Secondary endpoint included the composite of all-cause mortality or re-hospitalization due to worsening of ADHF. There were no significant differences in demographic variables other than body mass index (p = 0.0026), echocardiographic data, laboratory data other than serum chloride before TLV administration (p = 0.041), serum sodium (p = 0.040) and potassium (p = 0.027) at discharge, and concomitant medications among the three groups. The Kaplan-Meier curve showed that the survival rate was lower in HD-TLV than in non-TLV, whereas LD-TLV showed the highest survival rate among the three groups (p = 0.0001). Multivariable Cox regression analysis of the clinical characteristics used for predicting cardiac mortality revealed that LD-TLV (hazard ratio [HR] 0.16, 95% confidence interval [CI] 0.01-0.93, p = 0.040) and HD-TLV (HR 2.43, 95% CI 1.06-6.26, p = 0.035) were significant predictors after adjustment for predictive covariates. In conclusion, the judgement of the continuation of LD-TLV according to patient hemodynamics and severity of congestion may not cause worsened prognosis.

Response criteria of tolvaptan for the treatment of hepatic edema

BACKGROUND

Although tolvaptan is an effective treatment for hepatic edema, there are no established criteria for assessment of the therapeutic effect. The present study evaluates the association between body weight change and clinical symptoms to identify an effective indicator of tolvaptan response.

METHODS

The study comprised 460 patients. The first data set contained 147 patients with hepatic edema who received tolvaptan in Kagoshima Kouseiren Hospital, a representative institution of this study. From these data, an optimal cutoff value of body weight change, which accurately indicated symptom reduction, was identified. The response rates obtained based on the cutoff value were evaluated by receiver-operating characteristic (ROC) analysis and kappa coefficients. The kappa coefficient was then validated internally using the bootstrap method and externally using the validation data set of 313 patients from four other hospitals.

RESULTS

A cutoff value for body weight loss of 1.5 kg/week produced the largest area under the ROC curve (0.961; sensitivity, 89.8%; specificity, 92.0%) and a high kappa coefficient (0.831). The correlation between symptom reduction and body weight loss of 1.5 kg/week was evaluated internally and externally, and the cutoff value was validated.

CONCLUSIONS

The cutoff value of body weight change that most accurately reflected symptom reduction was 1.5 kg/week; this value is expected to be an effective indicator of response to tolvaptan in clinical practice.

Increased serum C-reactive protein and decreased urinary aquaporin 2 levels are predictive of the efficacy of tolvaptan in patients with liver cirrhosis

AIM

Water retention, hepatic ascites, and peripheral edema are significant problems in patients with liver cirrhosis (LC). Although furosemide and spironolactone are commonly used as treatment, they are often insufficient to treat hyponatremia and renal insufficiency in patients with LC. Tolvaptan (TVP) could provide an effective treatment alternative. However, predictive factors of a therapeutic response to TVP are unclear. Our aim was to examine clinical predictors of the response to TVP in patients with LC and water retention.

METHODS

Fifty-two patients were treated with TVP, with therapeutic effects judged by a decrease in body weight (≥2 kg) and increase in urinary volume (≥500 mL) within 7 days. Blood biochemical tests were carried out at baseline and post-treatment, including serum soluble CD14 (sCD14) and urinary aquaporin 2 (AQP2) levels. Clinical and laboratory predictive factors of a TVP response were evaluated by univariate and multivariate analyses.

RESULTS

The overall response to TVP was 55.8%. On univariate analyses, serum C-reactive protein (CRP) level, the neutrophil-to-lymphocyte ratio, urinary blood urea nitrogen, and urinary AQP2 were predictors of the TVP response, with only serum CRP retained on multivariate analysis. A higher serum sCD14 level was strongly associated with a non-response to TVP. A decrease in urinary AQP2 to undetectable level was associated with a response.

CONCLUSION

Tolvaptan provides a rapid and strong effect to improve water retention in patients with LC. Baseline serum sCD14 and CRP levels are useful predictors of a response to TVP, with a decrease in urinary AQP2 during treatment indicating an early response.

Good response to tolvaptan shortens hospitalization in patients with congestive heart failure

Tolvaptan has been gradually spread to use as a potent diuretic for congestive heart failure in the limited country. However, the response to this aquaretic drug still is unpredictable. A total of 92 patients urgently hospitalized due to congestive heart failure and treated with tolvaptan in addition to standard treatment was retrospectively analyzed. Responder of tolvaptan treatment was defined as a patient with peak negative fluid balance greater than 500 mL/day, and clinical profiles were compared between 76 responders and 16 non-responders. Responders started to increase daily urine volume (UV) from Day 1 through Day 3. In contrast, non-responders showed no significant increase in daily UV from the baseline up to Day 5. Time between admission and tolvaptan administration was shorter in responders, even without statistical significance (3.3 vs. 4.6 days, p = 0.053). Multivariate analysis revealed that blood urea nitrogen (BUN) [cutoff: 34 mg/dL, odds ratio (OR) 9.0, 95% confidence interval (CI) 1.42-57.3, p < 0.01] and plasma renin activity (PRA) (cutoff: 4.7 ng/mL/h, OR 6.1, 95% CI 1.01-36.4, p < 0.01) at baseline were independent predictors for tolvaptan responsiveness. It suggests that renal perfusion may affect tolvaptan-induced UV. Finally, durations of stay in intensive care unit and total hospitalization were significantly shorter in responders (median: 6.0 vs. 13.0 days, p = 0.022; 15.0 vs. 25.0 days, p = 0.016, respectively). Responders of tolvaptan have lower BUN and renin activity at baseline, and shorten hospitalization period. Trial Registration The study was registered at University Hospital Medical Information Network Clinical Trials Registry (UMIN-CTR) with the identifier UMIN000023594. https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000024988.

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.

Response to tolvaptan and its effect on prognosis in cirrhotic patients with ascites

AIM

The vasopressin V2 receptor antagonist tolvaptan has been used for the treatment of cirrhotic patients with ascites; however, no predictor of efficacy and prognosis has been developed. We evaluated candidate predictors of response to tolvaptan treatment.

METHODS

This was a single-center retrospective study. Overall, 97 Japanese cirrhotic patients (60 men, median age 63 years), who were hospitalized for ascites treatment including oral tolvaptan coupled with conventional diuretics, were enrolled. The efficacy of tolvaptan was defined as a urination increase of ≥500 mL or a urine volume ≥2000 mL/day on the day following treatment. The prognosis of tolvaptan treatment was evaluated by the post-treatment survival time by Kaplan-Meier analysis.

RESULTS

Tolvaptan therapy was effective in 67% of cirrhotic patients. Patients showed -1.5 (-17.2 to +6.2) kg change in body weight and 40% achieved ≥2.0 kg reduction in body weight after 1 week of treatment. Platelet counts, urine sodium (Na) level, and urine Na/potassium (Na/K) ratio were higher, and the blood urea nitrogen (BUN)/creatinine (Cr) ratio was lower, in cases showing a response to tolvaptan. The combination of a BUN/Cr ratio ≥17.5 and urine Na/K ratio <3.09 was predictive of being non-responsive to tolvaptan, and the response rate in these patients was only 39% (P < 0.01). The mean post-treatment survival duration was significantly longer in patients who responded to tolvaptan therapy.

CONCLUSIONS

Urinary BUN and Na excretion were predictive of a response to tolvaptan, and tolvaptan treatment may improve the prognosis of cirrhotic patients.

Predictive parameter of tolvaptan effectiveness in cirrhotic ascites

AIMS

The efficacy of the vasopressin V2 receptor antagonist tolvaptan for difficult-to-treat cirrhotic ascites has recently been reported. However, its effect is variable among patients. This study aimed to clarify the predictive factors for obtaining a good response to tolvaptan in patients with difficult-to-treat ascites.

METHODS

Data were collected from 50 patients with liver cirrhosis having ascites (hepatitis B, n = 1; hepatitis C, n = 22; alcoholism, n = 11; and others, n = 16) after treatment with tolvaptan (3.75-7.5 mg/day) in addition to conventional diuretics. A follow-up assessment was carried out after 7-day tolvaptan treatment for all patients.

RESULTS

After an uneventful 7-day tolvaptan treatment, 18 patients (36.0%) lost more than 2 kg of their body weight (responders). Twenty-six patients (52.0%) showed an increase in urine volume (>300 mL) on day 2. Tolvaptan was also effective for patients with pleural effusion, portal vein thrombosis, and hepatocellular carcinoma. Basal blood urea nitrogen (BUN) levels, plasma renin activity, and aldosterone levels were significantly higher in the poor responders (<2 kg weight loss), who were considered to be in the relative vascular underfilling state, than in the responders. Basal BUN was extracted as a predictive factor of responsiveness by multivariate logistic regression analysis.

CONCLUSIONS

Tolvaptan is useful and safe for the treatment of cirrhotic ascites. This report showed that BUN will predict the response of tolvaptan even when measured before tolvaptan treatment.

Impact of chronic kidney disease on the diuretic response of tolvaptan in acute decompensated heart failure

Aim

This study investigated the relationship between the initial diuretic response to tolvaptan and clinical predictors for tolvaptan responders in patients with acute decompensated heart failure (ADHF).

Methods and results

Patients (153) with ADHF (clinical scenario 2 or 3 with signs of fluid retention) who were administered tolvaptan were enrolled. Tolvaptan (15 or 7.5 mg) was administered for at least 7 days to those patients in whom fluid retention was observed even after standard treatment. The maximum urine volume immediately after tolvaptan administration showed good correlations with the ejection fraction and estimated glomerular filtration rate that were independent predictors of the urine volume (UV) responders (≥1500 mL increase in urine volume). The diuretic response (in terms of maximum diuresis) diminished with advancing chronic kidney disease (CKD) stage and concomitant deterioration of the renal function. Furthermore, advanced CKD was a significant negative predictor for the body weight (BW) responders (2.0% decrease in the body weight within 1 week after starting tolvaptan). As compared with non‐CKD, the presence of advanced CKD predicts poor diuretic response for both UV and BW responders.

Conclusions

The diuretic response following tolvaptan administration gradually diminished with progressive deterioration of the CKD stage. Worsening renal function was not observed. Tolvaptan is effective in treating CS2 or CS3 ADHF patients who present fluid retention and congestion, suggesting its potential efficacy for fluid management in the ADHF patients with CKD without worsening the renal function.

Comparison of the Effects of Carperitide and Tolvaptan on Patients with Left Ventricular Dysfunction: A Two-Center Retrospective Study

In patients with left ventricular (LV) dysfunction, diuretics can reduce blood pressure and lead to electrolyte abnormalities. The aim of this study was to compare the effects of tolvaptan (T group) and carperitide (C group) in these patients. Sixty-one consecutive patients admitted to the Iwate Prefectural Kuji Hospital or the Emergency Center of the Iwate Medical University between July 2011 and April 2015 were included in this study. These patients had acute heart failure (HF) and were initially treated with furosemide. Patients were excluded from the study if they received combined carperitide and tolvaptan, if they received tolvaptan or cardiotonic drugs prior to the study period, if their LV ejection fraction was ≥40%, and if they had renal dysfunction (serum creatinine > 2.0 mg/dL). There were no differences in the change in serum electrolytes in both groups, and none of the patients in the T group received supplementary dobutamine therapy. Oxygen administration was stopped successfully after a significantly shorter treatment period in the T group. These findings suggest that patients treated with tolvaptan did not require dobutamine as frequently as those treated with carperitide and indicated that tolvaptan may improve respiratory function more rapidly in patients with LV dysfunction.

Successful Treatment of Congestive Heart Failure Due to Severe Aortic Valve Stenosis With Low Dose Tolvaptan in Elderly Patients

Medical therapy for severe aortic valve stenosis (AS) is necessary for inoperable patients due to comorbid conditions. Tolvaptan (TLV), unlike other diuretics, resulted in modest changes in filling pressures associated with an increase in urine output, suggesting that TLV improves congestive heart failure (CHF) due to severe AS without hemodynamic instability.We retrospectively investigated 14 consecutive patients ≥ 80 years of age admitted due to decompensated CHF with severe AS at Juntendo University Hospital from April 2014 to November 2015. Seven of the 14 patients were treated with TLV. We examined the safety and efficacy of TLV treatment for severe AS.Mean age was 90.0 ± 6.3 years and mean aortic valve area was 0.57 ± 0.22 cm². Urine volume at day 1 of TLV treatment was increased and urine osmolality significantly decreased at day 1 of TLV treatment (all P < 0.05). New York Heart Association classification and brain natriuretic peptide levels significantly improved 1 week after treatment and at discharge (all P < 0.05) whereas brain natriuretic peptide levels did not improve in the patients without TLV. Severe adverse events did not occur during TLV treatment. During the first 3 days, blood pressure and heart rate were relatively stable. TLV treatment did not affect serum creatinine, blood urea nitrogen, or the estimated glomerular filtration rate.In elderly patients with severe AS, TLV treatment improved CHF without hemodynamic instability. Further prospective studies are needed to assess the safety and efficacy of TLV in decompensated heart failure due to severe AS.