Tolvaptan in reversing worsening acute heart failure: A systematic review and meta-analysis

Tolvaptan for the treatment of the syndrome of inappropriate antidiuresis (SIAD)

The syndrome of inappropriate antidiuresis (SIAD), the commonest cause of hyponatraemia, is associated with significant morbidity and mortality. Tolvaptan, an oral vasopressin V2-receptor antagonist, leads through aquaresis to an increase in serum sodium concentration and is the only medication licenced in Europe for the treatment of euvolaemic hyponatraemia. Randomised controlled trials have shown that tolvaptan is highly efficacious in correcting SIAD-related hyponatraemia. Real-world data have confirmed the marked efficacy of tolvaptan, but they have also reported a high risk of overly rapid sodium increase in patients with a very low baseline serum sodium. The lower the baseline serum sodium, the higher the tolvaptan-induced correction rate occurs. Therefore, a lower starting tolvaptan dose of 7.5 mg has been evaluated in small cohort studies, demonstrating its efficacy, but it still remains unclear as to whether it can reduce the risk of overcorrection. Most international guidelines, except for the European ones, recommend tolvaptan as second-line treatment for SIAD after fluid restriction. However, the risk of unduly rapid sodium correction in combination with its high cost have limited its routine use. Prospective controlled studies are warranted to evaluate whether tolvaptan-related sodium increase can improve patient-related clinical outcomes, such as mortality and length of hospital stay in the acute setting or neurocognitive symptoms and quality of life in the chronic setting. In addition, the potential role of a low tolvaptan starting dose needs to be further explored. Until then, tolvaptan should mainly be used as second-line treatment for SIAD, especially when there is a clinical need for prompt restoration of normonatraemia. Tolvaptan should be used with specialist input according to a structured clinical pathway, including rigorous monitoring of electrolyte and fluid balance and, if needed, implementation of appropriate measures to prevent, or when necessary reverse, overly rapid hyponatraemia correction.

Hyponatremia Associated with Congestive Heart Failure: Involvement of Vasopressin and Efficacy of Vasopressin Receptor Antagonists

Hyponatremia is frequently found in patients with congestive heart failure. A reduction in effective circulatory blood volume in a volume-expanded patient with decreased cardiac output is linked to a baroreceptor-mediated non-osmotic release of arginine vasopressin (AVP). The increased production of AVP and salt and water retention in the proximal and distal tubules of the kidney by humoral, hemodynamic, and neural mechanisms increase circulatory blood volume and contribute to hyponatremia. Recent studies have indicated that hyponatremia predicts the short-term and long-term prognosis of heart failure by increasing cardiac death and rehospitalization. In addition, the early development of hyponatremia in acute myocardial infarction also predicts the long-term prognosis of worsening heart failure. AVP V2 receptor antagonism may relieve water retention, but it is unknown whether the V2 receptor inhibitor, tolvaptan, improves the long-term prognosis of congestive heart failure. The newly identified natriuretic factor in renal salt wasting has the potential of improving clinical outcomes when combined with a distal diuretic.

The Efficacy and Safety of Short-Term Tolvaptan Usage in Patients with Acute Decompensated Heart Failure

BACKGROUND

Patients admitted with acute decompensated heart failure (ADHF) have a poor prognosis and poor quality of life due to dyspnea and edema. Tolvaptan, a vasopressin V2 receptor antagonist, is an effective water diuretic. This study aimed to evaluate the efficacy and safety of a short course of tolvaptan to treat volume overload in patients with ADHF.

METHODS

We conducted a phase III, multicenter, randomized, double-blind, placebo-controlled study to evaluate the efficacy and safety of a short course of tolvaptan (15 mg/day for 4 days) in hospitalized ADHF patients with volume overload despite the use of conventional diuretics. The primary end-point was the change in body weight after 4 days of treatment. The secondary end-points were the change in intake/output balance, change in serum sodium/potassium concentrations, physician/patient assessed signs and symptoms of heart failure after 4 days of treatment, and all-cause mortality in 1 month.

RESULTS

A total of 110 patients were screened, and 91 were randomized to receive 15 mg/day of tolvaptan for 4 days (n = 46) or matching placebo (n = 45). Compared to the placebo-treated patients, tolvaptan significantly reduced body weight (-1.36 ± 2.13 kg in the tolvaptan group vs. -0.59 ± 1.27 kg in the placebo group, p = 0.0394). The tolvaptan group also had a negative intake/urine volume balance compared to the placebo group (-509.3 ± 2788.2 ml vs. 975.5 ± 1903.1 ml, p = 0.0059). The safety profile of tolvaptan was acceptable.

CONCLUSIONS

Tolvaptan significantly reduced volume overload in hospitalized ADHF patients with volume overload despite the use of conventional diuretics.

Benefits of tolvaptan on early dyspnea relief in patients with acute heart failure: A meta-analysis

Considering the prevalence of dyspnea in acute heart failure (AHF), its reduction is important to both patients and caregivers. This meta‐analysis was performed to determine the efficacy and safety of tolvaptan on early dyspnea relief in patients with AHF. A systematic search was made of PubMed, Embase, Web of Science, Cochrane Library, and clinicaltrials.gov, without language restrictions. Randomized controlled trials (RCTs) on treatment of AHF with tolvaptan, compared with placebo or blank, were reviewed. Studies were pooled to relative risk (RR), with 95% confidence interval (CI). Five RCTs (enrolling 4857 participants) met the inclusion criteria. Tolvaptan presented significant effects on 12 h dyspnea relief (RR: 1.98; 95% CI: 1.24−3.15; p = .004), 24 h/day 1 dyspnea relief (RR: 1.15; 95% CI: 1.07−1.24; p = .0003), 48 h dyspnea relief (RR: 1.20; 95% CI: 1.06−1.36; p = .004), and 72 h dyspnea relief (RR: 1.18; 95% CI: 1.02−1.37; p = .03). No significant increase was noticed in the incidence of worsening renal function in tolvaptan group (RR: 1.10; 95% CI: 0.87−1.39; p = .43). Tolvaptan treatment significantly improved patient‐assessed dyspnea early and persistently in patients with AHF.

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.

Efficacy and safety of tolvaptan in acute heart failure patients during long-distance transportation

AIMS

Treating patients with acute heart failure is difficult at the local hospitals in medically depopulated areas where cardiologists are generally absent. These patients require long-distance and time-consuming transportation to the intensive care units. It is well known that tolvaptan is effective for the treatment of congestive heart failure, but the effect of prehospital tolvaptan use in patients is not well evaluated. The aim of this study was to evaluate the efficacy and safety of prehospital tolvaptan use in patients with acute congestive heart failure who require long-distance and time-consuming transportation.

METHODS

This retrospective study included 30 patients who were newly diagnosed with acute heart failure at Wakkanai City Hospital and transported to Nayoro City General Hospital between January 2013 and May 2020. The patients were classified into those who received tolvaptan (tolvaptan group, n = 18) and did not receive tolvaptan (control group, n = 12).

RESULTS

The percentage of patient survival at discharge did not show a statistically significant difference between the groups (100% [tolvaptan] vs. 91% [control], p = 0.414). During transportation, the percentage of patients in the tolvaptan group who required increased oxygen doses was statistically significantly lower than that in the control group (0% vs. 36%, p = 0.0181). Patients in the tolvaptan group had statistically significantly shorter intensive care unit stays (median: 2 days vs. 6 days, p = 0.0376), less days to discontinuation of oxygen (median: 2.8 days vs. 6.9 days, p < 0.00125), and less days to ambulation (median: 1.5 days vs. 7.5 days, p = 0.0362) compared with the control group. In the tolvaptan group, blood pressure was not different; however, heart rate was statistically significantly reduced (99 ± 21 vs. 88 ± 21 beats per minute, p = 0.016) during transportation.

CONCLUSION

The use of tolvaptan in patients with acute heart failure requiring long-distance transport is safe and may show better clinical course compared with conventional therapies.

Cardiovascular Neuroendocrinology: Emerging Role for Neurohypophyseal Hormones in Pathophysiology

Arginine vasopressin (AVP) and oxytocin (OXY) are released by magnocellular neurosecretory cells that project to the posterior pituitary. While AVP and OXY currently receive more attention for their contributions to affiliative behavior, this mini-review discusses their roles in cardiovascular function broadly defined to include indirect effects that influence cardiovascular function. The traditional view is that neither AVP nor OXY contributes to basal cardiovascular function, although some recent studies suggest that this position might be re-evaluated. More evidence indicates that adaptations and neuroplasticity of AVP and OXY neurons contribute to cardiovascular pathophysiology.