Mechanisms and management of diuretic resistance in congestive heart failure

Discovery of BMS-986308: A Renal Outer Medullary Potassium Channel Inhibitor for the Treatment of Heart Failure

Recent literature reports highlight the importance of the renal outer medullary potassium (ROMK) channel in renal sodium and potassium homeostasis and emphasize the potential impact that ROMK inhibitors could have as a novel mechanism diuretic in heart failure patients. A series of piperazine-based ROMK inhibitors were designed and optimized to achieve excellent ROMK potency, hERG selectivity, and ADME properties, which led to the identification of compound 28 (BMS-986308). BMS-986308 demonstrated efficacy in the volume-loaded rat diuresis model as well as promising in vitro and in vivo profiles and was therefore advanced to clinical development.

Diuretic resistance and the role of albumin in congestive heart failure

Diuresis with loop diuretics is the mainstay treatment for volume optimization in patients with congestive heart failure, in which perfusion and volume expansion play a crucial role. There are robust guidelines with extensive evidence for the management of heart failure; however, clear guidance is needed for patients who do not respond to standard diuretic treatment. Diuretic resistance (DR) can be defined as an insufficient quantity of natriuresis with proper diuretic therapy. A combination of diuretic regimens is used to overcome DR and, more recently, SGLT2 inhibitors have been shown to improve diuresis. Despite DR being relatively common, it is challenging to treat and there remains a notable lack of substantial data guiding its management. Moreover, DR has been linked with poor prognosis. This review aims to expose the multiple approaches for treatment of patients with DR and the importance of intravascular volume expansion in the response to therapy.

Effects of Triamterene in Hospitalized Patients with Heart Failure and Diuretic Resistance: A Randomized Clinical Trial

Due to the potential benefits of triamterene in diuretic resistance, this study was performed to assess whether triamterene add-on to the standard treatment of heart failure (HF)-related diuretic resistance improves outcomes. A randomized clinical trial was performed on 45 hospitalized patients with HF with reduced ejection fraction who had diuretic resistance. Patients were randomized to receive either triamterene 50 mg plus hydrochlorothiazide 25 mg (n = 23) or hydrochlorothiazide 50 mg alone (n = 22) until hospital discharge. The primary outcomes were changes in weight and fluid input-to-output ratio. Secondary outcomes were respiratory rate, hospitalization duration, serum sodium and potassium, estimated glomerular filtration rate, creatinine, and blood urea nitrogen levels during the study period. The mean (standard deviation) of weight changes was not significantly different in the intervention and the control groups (-6.3 [4.8] vs -4.8 [2.4] kg, respectively; P = .1). No significant differences were shown in input-to-output changes between the 2 groups (208.0 [243.4] in the intervention and 600.2 [250.3] in the control group; P = .4). Although the respiratory rate of triamterene-treated patients decreased, the difference did not reach statistical significance (P = .2). Other secondary outcomes were also similar in both groups. This study did not support the use of triamterene as an add-on therapy for patients with HF-related diuretic resistance.

Natriuretic Peptide Receptors (NPRs) as a Potential Target for the Treatment of Heart Failure

PURPOSE OF REVIEW

Heart failure is defined as a complex clinical syndrome that results from any structural or functional impairment of ventricular filling or ejection of blood. The natriuretic peptide is known to exert its biological action on the kidney, heart, blood vessels, renin-angiotensin system, autonomous nervous system, and central nervous system. The natriuretic peptide-natriuretic receptor system plays an important role in the regulation of blood pressure and body fluid volume through its pleiotropic effects.

RECENT FINDINGS

The clinical and animal studies suggest that natriuretic peptide-natriuretic receptors are important targets for the treatment of heart failure and other cardiovascular diseases. Even though attempts targeting natriuretic peptide receptors are underway for heart failure treatment, they seem insufficient despite the receptor systems' potential. This review summarizes natriuretic peptide-natriuretic receptor system's physiological actions and potential target for the treatment of heart failure. Natriuretic peptides play multiple roles in different parts of the body, almost all of the activities related to this receptor system appear to have the potential to be harnessed to treat heart failure or symptoms associated with heart failure.

Combination Diuretic Therapy With Thiazides: A Systematic Review on the Beneficial Approach to Overcome Refractory Fluid Overload in Heart Failure

Heart failure (HF) is a notable public health issue, and intravenous loop diuretics are frequently employed to address acute decompensated heart failure (ADHF) and alleviate symptoms of congestion. However, prolonged use of loop diuretics can lead to drug resistance, and some patients experience refractory volume overload that does not respond to treatment. Sequential nephron blockade, which involves combining loop and thiazide diuretics, has been proposed as a strategy to overcome diuretic resistance and improve fluid overload management. This systematic review aims to critically evaluate the effectiveness and safety of this combination diuretic therapy. Following the directives detailed in the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a comprehensive search was conducted. Eligibility criteria were established to select relevant studies, including the requirement for studies to be conducted on human subjects and published as free full-text papers in English within the last 10 years. Several databases were searched using a combination of Medical Subject Heading (MeSH) phrases and keywords related to heart failure, loop diuretics, and thiazide diuretics. The search yielded 948 references, and after screening titles, abstracts, and full-text papers, eight final studies (five observational studies and three randomized control trials) were included in the review. Based on the findings of this systematic review, there is substantial evidence to endorse the efficacy of combination diuretic therapy of loop and thiazide diuretics in augmenting diuresis and enhancing outcomes for patients who exhibit insufficient responses to single-agent diuretics. Additionally, the review provides valuable insights about the timing and type of diuretics to use, helping clinicians make informed therapeutic decisions. However, to ensure patient safety and well-being, it is imperative to take into account the potential for electrolyte disturbances and impacts on renal function, necessitating diligent and vigilant monitoring as well as effective management strategies. In light of these findings, further research is warranted to optimize the dosing regimens and to delve deeper into the long-term safety and efficacy of combination therapy. Such research endeavors will undoubtedly contribute to refining treatment approaches and advancing patient care in the field of HF management.

Diuretic-resistant heart failure and the role of ultrafiltration: A proposed protocol

Acute heart failure (HF) decompensation generally manifests with signs and symptoms of congestion that strongly predict poor poor patient outcome. Loop diuretics are the cornerstone of therapy to counteract fluid overload and are widely used for acute management and chronic stabilization of HF. However, a diminished response to loop diuretics is a common problem, affecting the patient's clinical course and potentially prolonging hospitalization. Diuretic resistance is defined as failure to decongest despite appropriate and escalating loop diuretic therapy. We propose a protocol for the management of diuretic resistance. The initial approach should include an assessment of causes of pseudo-diuretic resistance. Adjustments to loop diuretic therapy, such as increasing doses and frequency of administration and sequential nephron blockade, may be successful. For hospitalized patients with progressive disease there are more invasive methods for fluid removal. Switching from oral to intravenous loop diuretics is essential to avoid variable absorption and for symptomatic relief. Extracorporeal ultrafiltration is also an option since this technique is highly effective at removing plasma fluid from blood. While extracorporeal ultrafiltration is an invasive solution, peritoneal dialysis is a home-based, intermittent therapeutic option that can enable efficient management of fluid overload, preventing HF-related hospital admission, and improving quality of life. As a last resort for fluid removal, a peritoneal dialysis regimen should fully exploit its decongestive properties and should be tailored to the patient's characteristics and clinical needs.

Diuretic resistance in patients with kidney disease: Challenges and opportunities

Edema caused by kidney disease is called renal edema. Edema is a common symptom of many human kidney diseases. Patients with renal edema often need to take diuretics.However, After taking diuretics, patients with kidney diseases are prone to kidney congestion, decreased renal perfusion, decreased diuretics secreted by renal tubules, neuroendocrine system abnormalities, abnormal ion transporter transport, drug interaction, electrolyte disorder, and hypoproteinemia, which lead to ineffective or weakened diuretic use and increase readmission rate and mortality. The main causes and coping strategies of diuretic resistance in patients with kidney diseases were described in detail in this report. The common causes of DR included poor diet (electrolyte disturbance and hypoproteinemia due to patients' failure to limit diet according to correct sodium, chlorine, potassium, and protein level) and poor drug compliance (the patient did not take adequate doses of diuretics. true resistance occurs only if the patient takes adequate doses of diuretics, but they are not effective), changes in pharmacokinetics and pharmacodynamics, electrolyte disorders, changes in renal adaptation, functional nephron reduction, and decreased renal blood flow. Common treatment measures include increasing in the diuretic dose and/or frequency, sequential nephron blockade,using new diuretics, ultrafiltration treatment, etc. In clinical work, measures should be taken to prevent or delay the occurrence and development of DR in patients with kidney diseases according to the actual situation of patients and the mechanism of various causes. Currently, there are many studies on DR in patients with heart diseases. Although the phenomenon of DR in patients with kidney diseases is common, there is a relatively little overview of the mechanism and treatment strategy of DR in patients with kidney diseases. Therefore, this paper hopes to show the information on DR in patients with kidney diseases to clinicians and researchers and broaden the research direction and ideas to a certain extent.

New Strategies for Volume Control in Patients with Diabetes Mellitus, a Narrative Review

Sodium is reabsorbed all along the renal tubules. The positive impacts of sodium-glucose cotransporter-2 inhibitors (SGLT2i), angiotensin receptor neprilysin inhibitor (ARNI) and mineralocorticoid receptor antagonists (MRA) on hard renal and/or cardiac endpoints calls for the role of diuretics in nephroprotection and cardioprotection in patients with diabetes mellitus to be reviewed. Here, we review: (a) the mechanisms of action of the available natriuretics; (b) the physiological adaptations to chronic loop diuretic usage that lead to increased sodium reabsorption in the proximal and distal convoluted tubules; (c) the physiology of sodium retention in patients with diabetes mellitus; and (d) the mechanisms of aldosterone breakthrough. We show the rationale for combined diuretics to target not only the loop of Henle, but also the proximal and distal convoluted tubules. Indeed, higher residual proteinuria in patients treated with renin-angiotensin-aldosterone system (RAAS) blockers portends poorer renal and cardiovascular outcomes. Diuretics are known to optimize the reduction of proteinuria, in addition to RAAS blockers, but may favor aldosterone breakthrough in the absence of MRA. The aim of our study is to support a combined diuretics strategy to improve the management of patients with diabetes mellitus and chronic kidney disease or heart failure.

Efficacy of tolvaptan on advanced chronic kidney disease with heart failure: a randomized controlled trial

Background

Tolvaptan (TLV) is reported to improve diuretic effects in patients with chronic kidney disease (CKD) when furosemide (FUR) is not sufficiently effective. However, it is not clear whether TLV addition is effective for advanced CKD patients with heart failure.

Methods

An open-label, parallel-group randomized trial was performed. The subjects were 33 patients with CKD stage G3–G5 who had fluid overload despite taking 20–100 mg/day FUR. They were divided into two groups: a group administered 15 mg/day TLV plus their original FUR dose for 7 days (TLV group), and a group administered 120–200 mg/day FUR (i.e., 100 mg/day over their previous dose) for 7 days (FUR group).

Results

The mean change in urine volume was significantly higher in the TLV group compared to the FUR group (637 ml vs 119 ml; p < 0.05). The difference was greater when the urine osmolality before treatment was high. Serum creatinine was increased only in the FUR group. The incidence of worsening renal function (WRF) was significantly lower in the TLV group (18.8% vs 58.8%; p < 0.05). Serum sodium decreased significantly in the FUR group, but did not change in the TLV group.

Conclusions

In patients with advanced CKD with fluid overload, the addition of TLV achieved a significantly higher urine volume with less adverse effects on renal function compared with increasing the dose of FUR. The efficacy and safety of TLV were higher in patients who had higher urine osmolality and lower serum sodium before treatment.

Clinical trial registration

UMIN000014763.

Diuretic therapy in congestive heart failure

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

Improving Diuretic Response in Heart Failure by Implementing a Patient-Tailored Variability and Chronotherapy-Guided Algorithm

Heart failure is a major public health problem, which is associated with significant mortality, morbidity, and healthcare expenditures. A substantial amount of the morbidity is attributed to volume overload, for which loop diuretics are a mandatory treatment. However, the variability in response to diuretics and development of diuretic resistance adversely affect the clinical outcomes. Morevoer, there exists a marked intra- and inter-patient variability in response to diuretics that affects the clinical course and related adverse outcomes. In the present article, we review the mechanisms underlying the development of diuretic resistance. The role of the autonomic nervous system and chronobiology in the pathogenesis of congestive heart failure and response to therapy are also discussed. Establishing a novel model for overcoming diuretic resistance is presented based on a patient-tailored variability and chronotherapy-guided machine learning algorithm that comprises clinical, laboratory, and sensor-derived inputs, including inputs from pulmonary artery measurements. Inter- and intra-patient signatures of variabilities, alterations of biological clock, and autonomic nervous system responses are embedded into the algorithm; thus, it may enable a tailored dose regimen in a continuous manner that accommodates the highly dynamic complex system.

Association between intestinal oedema and oral loop diuretic resistance in hospitalized patients with acute heart failure

AIMS

Intestinal oedema is one of the manifestations associated with right-sided heart failure (HF), which is known to be associated with poorer patient outcomes. We attempted to reveal the association between intestinal oedema and diuretic resistance in hospitalized patients with acute HF.

METHODS AND RESULTS

Among 213 hospitalized patients with acute HF, abdominal ultrasonography was performed under clinically stable conditions after initial HF treatments. The association among abdominal ultrasonographic parameters, maintenance doses of loop diuretics, and responsiveness to initial loop diuretic treatment was evaluated. Higher mean colon wall thickness (CWT) independently correlated with a higher dose of loop diuretics at enrolment (adjusted β = 0.198, P = 0.0004). Increased mean CWT also correlated with poor response to oral loop diuretics as an initial treatment, whereas it did not correlate with the response to intravenous loop diuretics. Discrimination of non-responders to initial oral loop diuretics resulted in a sensitivity of 0.772 and a specificity of 0.733 using a mean CWT cut-off value of ≥3 mm.

CONCLUSIONS

In hospitalized patients with acute HF, a strong correlation was identified among the severity of intestinal oedema, required quantities as maintenance loop diuretic doses, and poor responsiveness to oral loop diuretics at admission.

Pathophysiology and Therapeutic Approaches to Acute Decompensated Heart Failure

Acute decompensated heart failure (ADHF) is one of the leading admission diagnoses worldwide, yet it is an entity with incompletely understood pathophysiology and limited therapeutic options. Patients admitted for ADHF have high in-hospital morbidity and mortality, as well as frequent rehospitalizations and subsequent cardiovascular death. This devastating clinical course is partly due to suboptimal medical management of ADHF with persistent congestion upon hospital discharge and inadequate predischarge initiation of life-saving guideline-directed therapies. While new drugs for the treatment of chronic HF continue to be approved, there has been no new therapy approved for ADHF in decades. This review will focus on the current limited understanding of ADHF pathophysiology, possible therapeutic targets, and current limitations in expanding available therapies in light of the unmet need among these high-risk patients.

The pathophysiology and management of diuretic resistance in patients with heart failure

OBJECTIVES

The objectives of the study are to investigate the causes of diuretic resistance in patients with advanced congestive heart failure (CHF), since diuretics are the cornerstone of treatment of these patients. Several studies have shown that diuretic resistance in patients with advanced CHF is common, ranging from 25% to 50% in hospitalized patients.

METHODS

In order to get a current perspective as to the magnitude of diuretic resistance in such patients, a focused Medline search of the English language literature was conducted between 2015 and 2020 using the search terms, CHF, diuretics, treatment, resistance, frequency, and 30 papers with pertinent information were selected.

RESULTS

The analysis of data from the selected papers demonstrated that diuretic resistance is common in hospitalized patients with advanced CHF and frequently associated with renal failure, which is secondary to CHF.

CONCLUSIONS

Diuretic resistance appears to be common in patients with advanced CHF and it is mostly due to decreased cardiac output, low blood pressure, decreased glomerular filtration rate, decreased filtration of sodium, and increased tubular reabsorption of sodium. Diuretic resistance in such patients can be overcome with the combination of loop diuretics with thiazide and thiazide-like diuretics, aldosterone antagonists, as well as other agents. The data from these studies in combination with collateral literature will be discussed in this review.

Management of the Patient with Heart Failure and an Implantable Pulmonary Artery Hemodynamic Sensor

Purpose of Review

Heart failure (HF) management guided by hemodynamics obtained from an implantable pulmonary artery pressure (PAP) sensor (CardioMEMS) improves symptoms and reduces HF hospitalizations (HFH). This paper reviews the theoretical basis of pulmonary vascular physiology, summarizes recently published data about CardioMEMS, and provides practical guidelines for patient selection and management.

Recent Findings

Compared to patients managed by standard care, HF patients randomized to PAP-guided treatment have a higher frequency of medication adjustments, resulting in lower PAP and fewer HFH. Real-world analyses further support associations between implant of the CardioMEMS sensor with reductions in PAP, hospitalizations, and mortality.

Summary

Implantable, wireless hemodynamic sensor technology is a promising remote monitoring platform for chronic HF. A phased approach using a treatment algorithm may improve the efficiency and effectiveness of pressure-guided therapy.

A narrative review of pharmacologic de-resuscitation in the critically ill

Despite evidence highlighting harms of fluid overload, minimal guidance exists on counteraction via utilization of diuretics in the de-resuscitation phase. While diuretics have been shown to decrease net volume and improve clinical outcomes in the critically ill, a lack of standardization surrounding selection of diuretic regimen or monitoring of de-resuscitation exists. Current monitoring parameters of de-resuscitation often rely on clinical signs of fluid overload, end organ recovery and other biochemical surrogate markers which are often deemed unreliable. The majority of evidence suggests that achieving a net-negative fluid balance within 72 h after shock resolution may be of benefit; however, approaches to such goal are uncertain. Loop diuretics are a widely available type of diuretic for removal of volume in patients with sufficient kidney function, with the potential for adjunct diuretics in special circumstances. At present, administration of diuretics within the broad critically ill population fails to find uniformity and often efficacy. Given the lack of randomized controlled trials in this susceptible population, we aim to provide a thorough therapeutic understanding of diuretic pharmacotherapy which is necessary in order to achieve desired goal of fluid balance and improve overall outcomes.

Diuretic Resistance in Heart Failure

Decompensated heart failure accounts for approximately 1 million hospitalizations in the United States annually, and this number is expected to increase significantly in the near future. Diuretics provide the initial management in most patients with fluid overload. However, the development of diuretic resistance remains a significant challenge in the treatment of heart failure. Due to the lack of a standard definition, the prevalence of this phenomenon remains difficult to determine, with some estimates suggesting that 25-30% of patients with heart failure have diuretic resistance. Certain characteristics, including low systolic blood pressures, renal impairment, and atherosclerotic disease, help predict the development of diuretic resistance. The underlying pathophysiology is likely multifactorial, with pharmacokinetic alterations, hormonal dysregulation, and the cardiorenal syndrome having significant roles. The therapeutic approach to this common problem typically involves increases in the diuretic dose and/or frequency, sequential nephron blockade, and mechanical fluid movement removal with ultrafiltration or peritoneal dialysis. Paracentesis is potentially useful in patients with intra-abdominal hypertension.

Heart failure and acute renal dysfunction in the cardiorenal syndrome

Just under 1 million people in the UK have symptomatic heart failure. Decompensated heart failure is associated with a particularly poor prognosis with in-hospital mortality at around 10%. Over the last 30 years renin-angiotensin-aldosterone system antagonists have been shown to have incremental benefit on improved quality of life, reduced hospitalisation and mortality rates in those with heart failure with reduced ejection fraction. Concomitant chronic kidney disease and 'acute kidney injury' are common and associated with adverse outcomes.In patients with decompensated heart failure, congestion is a key driver of deterioration in renal function. Decongestion is fundamental to successful management. Yet it is not uncommon to see prognostically important medication (such as angiotensin converting enzyme inhibitors and mineralocorticoid antagonists) inappropriately stopped, along with under-diuresis of the patient. This leaves the patient still in a state of congestion without the prognostic medication at discharge, with resultant adverse outcome. The British Society for Heart Failure and the Renal Association have produced consensus guidance to help guide management in a more consistent fashion based on heart failure classification, whether the patient is congested and the degree of renal impairment. Early heart failure specialist review is associated with improved patient outcomes.

Lower-Dose, Intravenous Chlorothiazide Is an Effective Adjunct Diuretic to Furosemide Following Pediatric Cardiac Surgery

OBJECTIVES

Postoperative fluid overload is ubiquitous in neonates and infants following operative intervention for congenital heart defects; ineffective diuresis is associated with poor outcomes. Diuresis with furosemide is widely used, yet there is often resistance at higher doses. In theory, furosemide resistance may be overcome with chlorothiazide; however, its efficacy is unclear, especially in lower doses and in this population. We hypothesized the addition of lower-dose, intravenous chlorothiazide following surgery in patients on high-dose furosemide would induce meaningful diuresis with minimal side effects.

METHODS

This was a retrospective, cohort study. Postoperative infants younger than 6 months, receiving high-dose furosemide, and given lower-dose chlorothiazide (1-2 mg/kg every 6-12 hours) were identified. Diuretic doses, urine output, fluid balance, vasoactive-inotropic scores, total fluid intake, and electrolyte levels were recorded.

RESULTS

There were 73 patients included. The addition of lower-dose chlorothiazide was associated with a significant increase in urine output (3.8 ± 0.18 vs 5.6 ± 0.27 mL/kg/hr, p < 0.001), more negative fluid balance (16.1 ± 4.2 vs -25.0 ± 6.3 mL/kg/day, p < 0.001), and marginal changes in electrolytes. Multivariate analysis was performed, demonstrating that increased urine output and more negative fluid balance were independently associated with addition of chlorothiazide. Subgroup analysis of 21 patients without a change in furosemide dose demonstrated the addition of chlorothiazide significantly increased urine output (p = 0.03) and reduced fluid balance (p < 0.01), further validating the adjunct effects of chlorothiazide.

CONCLUSION

Lower-dose, intravenous chlorothiazide is an effective adjunct treatment in postoperative neonates and infants younger than 6 months following cardiothoracic surgery.

Prevalence and outcome of diuretic resistance in heart failure

Diuretic resistance (DR) is common in patients with decompensated heart failure (HF), and is associated with adverse outcomes. To determine the prevalence of DR and its impact on survival among patients with decompensated HF, we prospectively evaluated the prevalence and influence on prognosis of DR (defined as persistent congestion despite ≥ 80 mg of furosemide per day) in a cohort of elderly patients from the Spanish HF registry (RICA) admitted for an acute decompensation of HF. Patients with new-onset HF were excluded. From the global cohort of 2067 patients, 435 (21%; 95% CI 19.3%-22.7%) patients met criteria for DR. Patients with DR had more comorbidities (hypercholesterolemia, diabetes mellitus, valvular disease, chronic kidney disease, and cancer) and a worse functional status compared to patients without DR. In addition, patients with DR had a higher proportion of ischemic etiology, more advanced functional class and lower left ventricular ejection fraction values. After 1 year of follow-up, all-cause mortality was higher in patients with DR with an adjusted hazard ratio of 1.37 (95% CI 1.06-1.79; p = 0.018). The prevalence of DR in a cohort of elderly patients admitted for acute HF decompensation is 21%. DR is an independent predictor of 1-year mortality.

Advanced Heart Failure Therapies and Cardiorenal Syndrome

Heart failure (HF) is extremely prevalent and for those with end-stage (stage D) disease, 1-year survival is only 25-50%. Several studies have captured the mortality impact of kidney disease on patients with HF, and measures of kidney function are a component of many HF risk stratification scores. The management of advanced HF complicated by cardiorenal syndrome (CRS) is challenging, and irreversible kidney failure often limits patient candidacy for advanced HF therapies, such as transplant or left ventricular assist device therapy. Thus, prompt institution of aggressive therapy is warranted in stage D HF patients with CRS to prevent irreversible kidney failure. In this chapter, we discuss the assessment and management of patients with CRS with end-stage HF. In addition to discussing medical therapy aimed at decongestion and increased cardiac inotropy, we provide a summary of temporary circulatory support devices that can be considered for those whom hospice is not desired. In all circumstances, a close collaboration between the advanced HF specialist and nephrologist is needed to achieve the best patient outcomes.

Utilization and budget impact of tolvaptan in the inpatient setting among patients with heart failure and hyponatremia

OBJECTIVE

Assess characteristics of patients with heart failure (HF) and hyponatremia (HN) using tolvaptan, a selective vasopressin V2-receptor antagonist, for sodium correction, and estimate the budget impact of tolvaptan use in a hospital.

METHODS

The Premier hospital database was analyzed to assess the utilization of tolvaptan, characteristics of users and non-users, and hospitalization costs among patients with HF and HN. Using these findings, a model was developed to estimate tolvaptan costs in proportion to total medical costs of managing patients with HF and HN, and the budget impact of tolvaptan use. Results were regenerated using data from the Healthcare Cost and Utilization Project (HCUP) database, and robustness was assessed in sensitivity analyses.

RESULTS

Tolvaptan was used in 4.96% of inpatient visits among patients with HF and HN, more commonly among sicker patients as reflected in high utilization during intensive care stays (30.46%). Additionally, utilization increased by length of stay, which can serve as a proxy for disease severity. The model estimated that tolvaptan costs accounted for 0.3% of total hospitalization-related costs for patients with HF and HN, and the budget impact was $52.42 per visit.

CONCLUSIONS

Results demonstrate that tolvaptan is used infrequently among patients with HF and HN, and is utilized among sicker patients. Tolvaptan accounted for 0.3% of total spending on management of inpatient visits with HF and HN, and had a marginal impact on hospital budget when compared with fluid restriction for HN correction. Availability of tolvaptan can provide an additional therapeutic option for sodium correction.

Tolvaptan for Heart Failure in Chronic Kidney Disease Patients: A Systematic Review and Meta-Analysis

BACKGROUND

Heart failure (HF) is frequently associated with renal impairment. Tolvaptan is reported to be effective in treating congestion in HF without significant electrolyte loss compared to conventional diuretics. However, the safety and efficacy of its use in patients with chronic kidney disease (CKD) is uncertain. This systematic review and meta-analysis evaluated the efficacy and safety outcomes of tolvaptan for HF management in patients with CKD, with a focus at a physiologic basis related to safety.

METHODS

We searched for observational studies and randomised clinical trials (RCTs) that assessed the effects of tolvaptan against placebo or standard care in adult patients with HF and CKD. Our protocol was registered with PROSPERO (number CRD42017052775).

RESULTS

Seventeen studies were included in the qualitative review and six in the meta-analysis involving 1597 patients. Tolvaptan was associated with an increase in sodium concentration. No significant differences in change of eGFR and serum creatinine were found between tolvaptan and control groups. Urine flow rate appears to increase significantly with tolvaptan compared to baseline (p<0.0001). The meta-analysis demonstrated no heterogeneity between studies but the possibility of publication bias due to incomplete reporting in excluded studies and lack of RCTs.

CONCLUSIONS

The safety profile of tolvaptan appears acceptable for patients with HF and CKD. There is evidence for an improvement in serum sodium and reduction in body water without deterioration in renal function. Further research is needed to elucidate the long-term benefits of tolvaptan as an adjunct or alternative to diuretics in such patients.

Discovery and in Vitro Optimization of 3-Sulfamoylbenzamides as ROMK Inhibitors

Inhibitors of the renal outer medullary potassium channel (ROMK) show promise as novel mechanism diuretics, with potentially lower risk of diuretic-induced hypokalemia relative to current thiazide and loop diuretics. Here, we report the identification of a novel series of 3-sulfamoylbenzamide ROMK inhibitors. Starting from HTS hit 4, this series was optimized to provide ROMK inhibitors with good in vitro potencies and well-balanced ADME profiles. In contrast to previously reported small-molecule ROMK inhibitors, members of this series were demonstrated to be highly selective for inhibition of human over rat ROMK and to be insensitive to the N171D pore mutation that abolishes inhibitory activity of previously reported ROMK inhibitors.

A perspective on diuretic resistance in chronic congestive heart failure

Chronic congestive heart failure (CHF) is a complex disorder characterized by inability of the heart to keep up the demands on it, followed by the progressive pump failure and fluid accumulation. Although the loop diuretics are widely used in heart failure (HF) patients, both pharmacodynamic and pharmacokinetic alterations are thought to be responsible for diuretic resistance in these patients. Strategies to overcome diuretic resistance include sodium intake restriction, changes in diuretic dose and route of administration and sequential nephron diuretic therapy. In this review, we discuss the definition, prevalence, mechanism of development and management strategies of diuretic resistance in HF patients.

Acetazolamide and Hydrochlorothiazide Followed by Furosemide Versus Furosemide and Hydrochlorothiazide Followed by Furosemide for the Treatment of Adults With Nephrotic Edema: A Randomized Trial

BACKGROUND

Nephrotic edema is considered refractory if it does not respond to maximum or near-maximum doses of loop diuretics. This condition can be treated with loop diuretics and thiazides. However, animal studies show that the simultaneous downregulation of pendrin with acetazolamide and inhibition of the sodium-chloride cotransporter with hydrochlorothiazide generates significant diuresis, and furosemide administration following a pendrin inhibitor potentiates furosemide's diuretic effect. Therefore, we performed this study to compare the efficacy of acetazolamide and hydrochlorothiazide followed by furosemide versus furosemide and hydrochlorothiazide followed by furosemide for treatment of refractory nephrotic edema.

STUDY DESIGN

Randomized, double-blind, 2-arm, parallel trial.

SETTING & PARTICIPANTS

20 patients with refractory nephrotic edema despite treatment with 80mg of furosemide daily and creatinine clearance > 60mL/min.

INTERVENTION

Patients were randomly assigned to 2 groups: group 1 (n=10) received 250mg of acetazolamide and 50mg of hydrochlorothiazide daily and group 2 (n=10) received 40mg of furosemide and 50mg of hydrochlorothiazide daily for 1 week in phase 1. In phase 2, both groups received 40mg of furosemide daily for 2 weeks.

OUTCOMES

The primary outcome was absolute change in weight before and at the end of each phase.

MEASUREMENTS

Weight and 24-hour urine volume at baseline and the end of each phase.

RESULTS

The mean weight decrease was of significantly larger magnitude in group 1 compared with group 2 at the end of phase 1 (-1.4±0.52 [SD] vs -0.65±0.41kg; P=0.001) and phase 2 (-1.6±0.84 vs -0.5±0.47kg; P=0.005). The increase in 24-hour urine volume was also significantly higher in group 1 at the end of phase 2.

LIMITATIONS

Small sample size, short follow-up duration, and lack of serum bicarbonate and chloride measurement.

CONCLUSIONS

Acetazolamide and hydrochlorothiazide followed by furosemide is more effective than furosemide and hydrochlorothiazide followed by furosemide for the treatment of refractory nephrotic edema.

Acute Decompensated Heart Failure

Heart failure (HF) is a societal burden due to its high prevalence, frequent admissions for acute decompensated heart failure (ADHF), and the economic impact of direct and indirect costs associated with HF and ADHF. Common etiologies of ADHF include medication and diet noncompliance, arrhythmias, deterioration in renal function, poorly controlled hypertension, myocardial infarction, and infections. Appropriate medical management of ADHF in patients is guided by the identification of signs and symptoms of fluid overload or low cardiac output and utilization of evidence-based practices. In patients with fluid overload, various strategies for diuresis or ultrafiltration may be considered. Depending on hemodynamics and patient characteristics, vasodilator, inotropic, or vasopressor therapies may be of benefit. Upon ADHF resolution, patients should be medically optimized, have lifestyle modifications discussed and implemented, and medication concierge service considered. After discharge, a multidisciplinary HF team should follow up with the patient to ensure a safe transition of care. This review article evaluates the management options and considerations when treating a patient with ADHF.

Ultrafiltration in patients with decompensated heart failure and diuretic resistance: an Asian centre's experience

INTRODUCTION

Diuretics are the mainstay of therapy for restoring the euvolaemic state in patients with decompensated heart failure. However, diuretic resistance remains a challenge.

METHODS

We conducted a retrospective cohort study to examine the efficacy and safety of ultrafiltration (UF) in 44 hospitalised patients who had decompensated heart failure and diuretic resistance between October 2011 and July 2013.

RESULTS

Among the 44 patients, 18 received UF (i.e. UF group), while 26 received diuretics (i.e. standard care group). After 48 hours, the UF group achieved lower urine output (1,355 mL vs. 3,815 mL, p = 0.0003), greater fluid loss (5,058 mL vs. 1,915 mL, p < 0.0001) and greater weight loss (5.0 kg vs. 1.0 kg, p < 0.0001) than the standard care group. The UF group also had a shorter duration of hospitalisation (5.0 days vs. 9.5 days, p = 0.0010). There were no differences in the incidence of 30-day emergency department visits and rehospitalisations for heart failure between the two groups. At 90 days, the UF group had fewer emergency department visits (0.2 vs. 0.8, p = 0.0500) and fewer rehospitalisations for heart failure (0.3 vs. 1.0, p = 0.0442). Reduction in EQ-5D™ scores was greater in the UF group, both at discharge (2.7 vs. 1.4, p = 0.0283) and 30 days (2.5 vs. 0.3, p = 0.0033). No adverse events were reported with UF.

CONCLUSION

UF is an effective and safe treatment that can improve the health outcomes of Asian patients with decompensated heart failure and diuretic resistance.

Intra-abdominal Hypertension: An Important Consideration for Diuretic Resistance in Acute Decompensated Heart Failure

Fluid accumulation is the hallmark of heart failure decompensation. Fluid overload and congestion are associated with recurrent hospitalizations, poor quality of life, and increased mortality in heart failure. Despite the use of high-dose intravenous loop diuretic therapy, acutely decompensated heart failure patients may develop diuretic resistance. Diuretic refractoriness can be a result of elevated intra-abdominal pressure (IAP) in acutely decompensated heart failure. Increased renal venous and interstitial pressures in patients with elevated IAP may lead to renal impairment and diuretic resistance. Routine approaches such as sequential nephron blockade with a combination of loop and thiazide or thiazide-like diuretics, continuous diuretic infusion, and ultrafiltration may not be sufficient. Presented here is a case illustrating the importance of recognizing intra-abdominal hypertension in patients with diuretic resistance. Lowering IAP improves renal perfusion, renal filtration, and diuresis. When elevated, IAP is an easily reversible cause of diuretic resistance. Additionally, abdominal perfusion pressure can be used to guide therapy to reverse end-organ damage and avoid permanent renal replacement therapy.

Management of Patients Admitted with Acute Decompensated Heart Failure

BACKGROUND

Hospital admission for the treatment of acute decompensated heart failure is an unfortunate certainty in the vast majority of patients with heart failure. Regardless of the etiology, inpatient treatment for acute decompensated heart failure portends a worsening prognosis.

METHODS

This review identifies patients with heart failure who need inpatient therapy and provides an overview of recommended therapies and management of these patients in the hospital setting.

RESULTS

Inpatient therapy for patients with acute decompensated heart failure should be directed at decongestion and symptom improvement. Clinicians should also treat possible precipitating events, identify comorbid conditions that may exacerbate heart failure, evaluate and update current guideline-directed medical therapy, and perform risk stratification for all patients. Finally, efforts should be made to educate patients about the importance of restricting salt and fluid, monitoring daily weights, and adhering to a graded exercise program.

CONCLUSION

Early discharge follow-up and continued optimization of guideline-directed medical therapy are key to preventing future heart failure readmissions.

Comparison of bumetanide- and metolazone-based diuretic regimens to furosemide in acute heart failure

INTRODUCTION

Limited data exist comparing the efficacy and safety of bumetanide- or metolazone-based diuretic regimens to furosemide in acute heart failure (HF). Our purpose was to evaluate the comparative effect on urine output (UO) and renal function between these regimens.

METHODS

A retrospective study of hospitalized HF patients treated with continuous infusion furosemide (CIF), combination furosemide plus metolazone (F + M), or continuous infusion bumetanide (CIB). Primary end points were between regimen comparisons for change in mean hourly UO versus baseline and incidence of worsening renal function.

RESULTS

Data on 242 patients with acute HF (age 58 ± 12 years, 63% male, left ventricular ejection fraction 38% ± 17%) were analyzed (160 CIF, 42 F + M, 40 CIB). The mean duration of diuretic regimens was 41 ± 32 hours. Compared to baseline, all regimens increased mean hourly UO (P < .0001 for all), with greater increases with F + M (109 ± 171 mL) and CIB (90 ± 90 mL) compared to CIF (48 ± 103 mL; P = .009). Incidence of worsening renal function was not different between regimens; however, blood urea nitrogen (BUN) tended to increase more with F + M (4.4 ± 9.8 mg/dL) and CIB (4.3 ± 9.7 mg/dL) than CIF (1.8 ± 10.8 mg/dL), P = .09. The incidence of hyponatremia was higher with F + M and CIB. Differences in UO, BUN, and hyponatremia were retained in the subgroup analysis limited to patients with baseline serum creatinine <1.5 mg/dL, where renal function between the groups was not different.

CONCLUSION

Compared to CIF, F + M or CIB was associated with greater increases in UO. No difference in the incidence of worsening renal function was found; however, electrolyte abnormalities may be more prevalent when furosemide is combined with metolazone or when bumetanide is used. These therapeutic differences warrant prospective study.

The kidney in heart failure: friend or foe?

Heart failure constitutes a significant source of morbidity and mortality in the United States and its incidence and prevalence continue to grow, increasing its burden on the health care system. Renal dysfunction in patients with heart failure is common and has been associated with adverse clinical outcomes. This complex interaction is characterized by a pathophysiological disequilibrium between the heart and the kidney, in which cardiac malfunction promotes renal impairment, which in turn feeds back for further deterioration of cardiovascular function. Multiple neurohumoral and hemodynamic mechanisms are involved in this cardiorenal dyshomeostasis, including the deficiency of and/or resistance to compensatory natriuretic peptides, leading to sodium retention, volume overload and organ remodeling. Management of patients with cardiorenal dysfunction can be challenging and should be individualized. Emerging therapies must address the impairment of both organs to secure better clinical outcomes. To this end, a multidisciplinary approach is warranted to achieve optimal results.

The added-up albumin enhances the diuretic effect of furosemide in patients with hypoalbuminemic chronic kidney disease: a randomized controlled study

Background

Chronic kidney disease (CKD) with edema is a common clinical problem resulting from defects in water and solute excretion. Furosemide is the drug of choice for treatment. In theory, good perfusion and albumin are required for the furosemide to be secreted at the tubular lumen. Thus, in the situation of low glomerular filtration rate (GFR) and hypoalbuminemia, the efficacy of furosemide alone might be limited. There has been no study to validate the effectiveness of the combination of furosemide and albumin in this condition.

Methods

We conducted a randomized controlled crossover study to compare the efficacy of diuretics between furosemide alone and the combination of furosemide plus albumin in stable hypoalbuminemic CKD patients by measuring urine output and sodium. The baseline urine output/sodium at 6 and 24 hours were recorded. The increment of urine output/sodium after treatment at 6 and 24 hours were calculated by using post-treatment minus baseline urine output/sodium at the corresponding period.

Results

Twenty-four CKD patients (GFR = 31.0 ± 13.8 mL/min) with hypoalbuminemia (2.98 ± 0.30 g/dL) were enrolled. At 6 hours, there were significant differences in the increment of urine volume (0.47 ± 0.40 vs 0.67 ± 0.31 L, P < 0.02) and urine sodium (37.5 ± 29.3 vs 55.0 ± 26.7 mEq, P < 0.01) between treatment with furosemide alone and with furosemide plus albumin. However, at 24 hours, there were no significant differences in the increment of urine volume (0.49 ± 0.47 vs 0.59 ± 0.50 L, P = 0.46) and urine sodium (65.3 ± 47.5 vs 76.1 ± 50.1 mEq, P = 0.32) between the two groups.

Conclusion

The combination of furosemide and albumin has a superior short-term efficacy over furosemide alone in enhancing water and sodium diuresis in hypoalbuminemic CKD patients.

Trial registration

The Australian New Zealand Clinical Trials Registration (ANZCTR12611000480987)

Diuretics and ultrafiltration in acute decompensated heart failure

Congestion and volume overload are the hallmarks of acute decompensated heart failure (ADHF), and loop diuretics have historically been the cornerstone of treatment. The demonstrated efficacy of loop diuretics in managing congestion is balanced by the recognized limitations of diuretic resistance, neurohormonal activation, and worsening renal function. However, the recently published DOSE (Diuretic Optimization Strategies Evaluation) trial suggests that previous concerns about the safety of high-dose diuretics may not be valid. There has been a growing interest in alternative strategies to manage volume retention in ADHF with improved efficacy and safety profiles. Peripheral venovenous ultrafiltration (UF) represents a potentially promising approach to volume management in ADHF. Small studies suggest that UF may allow for more effective fluid removal compared with diuretics, with improved quality of life and reduced rehospitalization rates. However, further investigation is needed to completely define the role of UF in patients with ADHF. This review summarizes available data on the use of both diuretics and UF in ADHF patients and identifies challenges and unresolved questions for each approach.

[Acute heart failure]

Acute decompensated heart failure (ADHF) is a major public health problem throughout the world and its importance is continuing to grow. More than 50% of ADHF patients have coronary artery disease, which is generally associated with a history of hypertension. Recent data suggest that half of the patients presenting with acute heart failure have preserved left ventricular systolic function. The diagnosis of ADHF may be difficult at times, and the clinical assessment and patient profiling is essential for appropriate therapy. Immediate therapeutic goals are not only to improve symptoms, restore oxygenation and stabilize hemodynamic conditions, but also to improve short- and long-term survival. In addition to general supportive measures such as oxygen supplementation, noninvasive ventilation, analgesia, diuretics, vasodilators together with inotropic agents and/or vasopressors remain the cornerstone of therapy in patients with ADHF.