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

Relationship between BUN/Cr and Prognosis of HF Across the Full Spectrum of Ejection Fraction

BACKGROUND

In patients with heart failure (HF), due to the relative deficiency of blood volume, neurohormone system activation leads to renal vasoconstriction, which affects the content of blood urea nitrogen (BUN) and creatinine (Cr) in the body, while BUN and Cr are easily affected by other factors. Therefore, BUN/Cr can be used as another marker for the prognosis of HF.

OBJECTIVE

Explore the prognosis of adverse outcome of HF in the high BUN/Cr group compared with the low BUN/Cr group across the full spectrum of ejection fraction.

METHODS

From 2014 to 2016, symptomatic hospitalized HF patients were recruited and followed up to observe adverse cardiovascular outcomes. Logistic analysis and COX analysis were performed to determine significance. p-values <0.05 were considered statistically significant.

RESULTS

In the univariate logistic regression analysis, the high BUN/Cr group had a higher risk of adverse outcome in heart failure with reduced ejection fraction (HFrEF) and heart failure with preserved ejection fraction (HFpEF). Multivariate logistic regression analysis showed that the risk of cardiac death in the HFrEF group was higher than that in the low BUN/Cr group, while the risk of all-cause death was significant only in 3 months (p<0.05) (Central Illustration). The risk of all-cause death in the high BUN/Cr in the HFpEF group was significantly higher than that in the low BUN/Cr group at two years.

CONCLUSION

The high BUN/Cr group is related to the risk of poor prognosis of HFpEF, and is not lower than the predictive value of left ventricular ejection fraction (LVEF).

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.

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 factors of the pharmacological action of tolvaptan in patients with liver cirrhosis: a post hoc analysis

BACKGROUND

Tolvaptan has been approved in Japan for the treatment of hepatic edema. An important consideration in providing a clinical benefit to patients with liver cirrhosis is the improvement of ascites-related clinical symptoms. In the present post hoc analysis, we aimed to identify factors that were predictive of the potency of tolvaptan, and to examine the relationship between changes in initial urine volume and improvement in ascites-related clinical symptoms.

METHODS

This post hoc analysis was based on three previous phase 2 and 3 clinical trials of tolvaptan in patients with liver cirrhosis. Predictive factors associated with a change in initial urine volume were identified. A change of ≥500 mL from baseline confirmed the pharmacological action of tolvaptan treatment. The relationship between the change in initial urine volume and improvement in ascites-related clinical symptoms was also examined.

RESULTS

A total of 152 patients were enrolled in this study. Body weight and BUN were identified as predictive parameters. Among patients with a change in initial urine volume of ≥500 mL, 75 % demonstrated improvement in ascites-related clinical symptoms, while no improvement was seen in those with a change of <500 mL. None of the patients with initial urine volume of <500 mL showed resolution of symptoms.

CONCLUSIONS

Change in urine volume was affected by both baseline body weight and BUN in tolvaptan-treated subjects. Higher urine output was associated with improvements in ascites-related clinical symptoms.

Predictors of the Effect of Tolvaptan on the Prognosis of Cirrhosis

Objective Tolvaptan was first approved for use for cirrhosis in Japan in September 2013. The aim of the study was to examine the effect of tolvaptan, a vasopressin V2 receptor antagonist, on the prognosis of cirrhosis. Methods The effect of tolvaptan was evaluated in 26 patients with cirrhosis treated at our hospital from September 2013 to April 2015. Results The primary disease was hepatitis C in 20 patients, hepatitis B in 2, nonalcoholic steatohepatitis in 2 and others in 2; and 12 had hepatocellular carcinoma. The Child-Pugh score was 9.7±1.6 and the serum albumin level was 2.53±0.44 g/dL. Body weight decreased from 55.5±11.8 kg before administration to 52.1±14.7 kg after 7 days of tolvaptan treatment. After 7 days, patients with weight loss ≥2 kg (n=16, mean decrease of 4.3±2.3 kg) had significantly lower blood urea nitrogen (24.2±14.4 vs. 36.1±11.4 mg/dL) and serum creatinine (1.1±0.5 vs. 1.5±0.7 mg/dL) levels and decreased urine osmolality 4 h after the administration of tolvaptan (236±96 vs. 364±122 mOsm/kg) compared with patients with weight loss <2 kg (n=10, mean increase of +0.7±2.1 kg) (all p<0.05). The prognosis was significantly better in the group with weight loss ≥2 kg. Conclusion The effect of tolvaptan on the renal function is likely to improve the prognosis of patients with cirrhosis if the drug is started at a stage in which the renal function is maintained.