Determinants of Diuretic Responsiveness and Associated Outcomes During Acute Heart Failure Hospitalization: An Analysis From the NHLBI Heart Failure Network Clinical Trials

Basal natriuresis as a predictor of diuretic resistance and clinical evolution in acute heart failure

BACKGROUND

Some clinical guidelines recommend serial measurement of natriuresis to detect diuretic resistance (DR) in acute heart failure (AHF) patients, but it adds complexity to the management.

OBJECTIVES

To correlate a single measurement of basal natriuresis (BN) on admission with the development of DR and clinical evolution in AHF hospitalized patients.

METHODS

Prospective and multicenter study included AHF hospitalized patients, without shock or creatinine >2.5mg%. Patients received 40mg of intravenous furosemide on admission, then BN was measured, and diuretic treatment was guided by protocol. BN was considered low if <70 meq/L. DR was defined as the need of furosemide >240mg/day, tubular blockade (TB), hypertonic saline solution (HSS) or renal replacement therapy (RRT). In-hospital cardiovascular (CV) mortality, CV mortality and AHF readmissions at 60-day post-discharge were evaluated.

RESULTS

157 patients were included. BN was low in 22%. DR was development in 19% (12.7% furosemide >240mg/day, 8% TB, 4% RRT). Low NB was associated with DR (44% vs 12%; p 0.0001), persistence of congestion (26.5% vs 11.4%; p 0.05), furosemide >240 mg/day (29% vs 8%; p 0.003), higher cumulative furosemide dose at 72 hours (220 vs 160mg; p 0.0001), TB (20.6 vs 4.9%; p 0.008), RRT (11.8 vs 1.6%; p 0.02), worsening of AHF (27% vs 9%; p 0.01), inotropes use (21% vs 7%; p 0.48), respiratory assistance (12% vs 2%; p 0.02) and a higher in-hospital CV mortality (12% vs 4%; p 0.1). No association was demonstrated with post-discharge endpoints.

CONCLUSIONS

In AHF patients, low BN was associated with DR, persistent congestion, need for aggressive decongestion strategies, and worse in-hospital evolution.

Epidemiology and Management of Patients With Kidney Disease and Heart Failure With Preserved Ejection Fraction

Heart failure with preserved ejection fraction (HFpEF) comprises approximately one-half of all diagnoses of heart failure. There is significant overlap of this clinical syndrome with chronic kidney disease (CKD), with many shared comorbid conditions. The presence of CKD in patients with HFpEF is one of the most powerful risk factors for adverse clinical outcomes, including death and heart failure hospitalization. The pathophysiology linking HFpEF and CKD remains unclear, but it is postulated to consist of numerous bidirectional pathways, including endothelial dysfunction, inflammation, obesity, insulin resistance, and impaired sodium handling. The diagnosis of HFpEF requires certain criteria to be satisfied, including signs and symptoms consistent with volume overload caused by structural or functional cardiac abnormalities and evidence of increased cardiac filling pressures. There are numerous overlapping metabolic clinical syndromes in patients with HFpEF and CKD that can serve as targets for intervention. With an increasing number of therapies available for HFpEF and CKD as well as for obesity and diabetes, improved recognition and diagnosis are paramount for appropriate management and improved clinical outcomes in patients with both HFpEF and CKD.

Integration of implantable device therapy in patients with heart failure. A clinical consensus statement from the Heart Failure Association (HFA) and European Heart Rhythm Association (EHRA) of the European Society of Cardiology (ESC)

Implantable devices form an integral part of the management of patients with heart failure (HF) and provide adjunctive therapies in addition to cornerstone drug treatment. Although the number of these devices is growing, only few are supported by robust evidence. Current devices aim to improve haemodynamics, improve reverse remodelling, or provide electrical therapy. A number of these devices have guideline recommendations and some have been shown to improve outcomes such as cardiac resynchronization therapy, implantable cardioverter-defibrillators and long-term mechanical support. For others, more evidence is still needed before large-scale implementation can be strongly advised. Of note, devices and drugs can work synergistically in HF as improved disease control with devices can allow for further optimization of drug therapy. Therefore, some devices might already be considered early in the disease trajectory of HF patients, while others might only be reserved for advanced HF. As such, device therapy should be integrated into HF care programmes. Unfortunately, implementation of devices, including those with the greatest evidence, in clinical care pathways is still suboptimal. This clinical consensus document of the Heart Failure Association (HFA) and European Heart Rhythm Association (EHRA) of the European Society of Cardiology (ESC) describes the physiological rationale behind device-provided therapy and also device-guided management, offers an overview of current implantable device options recommended by the guidelines and proposes a new integrated model of device therapy as a part of HF care.

Current Approaches to Worsening Heart Failure: Pathophysiological and Molecular Insights

Worsening heart failure (WHF) is a severe and dynamic condition characterized by significant clinical and hemodynamic deterioration. It is characterized by worsening HF signs, symptoms and biomarkers, despite the achievement of an optimized medical therapy. It remains a significant challenge in cardiology, as it evolves into advanced and end-stage HF. The hyperactivation of the neurohormonal, adrenergic and renin-angiotensin-aldosterone system are well known pathophysiological pathways involved in HF. Several drugs have been developed to inhibit the latter, resulting in an improvement in life expectancy. Nevertheless, patients are exposed to a residual risk of adverse events, and the exploration of new molecular pathways and therapeutic targets is required. This review explores the current landscape of WHF, highlighting the complexities and factors contributing to this critical condition. Most recent medical advances have introduced cutting-edge pharmacological agents, such as guanylate cyclase stimulators and myosin activators. Regarding device-based therapies, invasive pulmonary pressure measurement and cardiac contractility modulation have emerged as promising tools to increase the quality of life and reduce hospitalizations due to HF exacerbations. Recent innovations in terms of WHF management emphasize the need for a multifaceted and patient-centric approach to address the complex HF syndrome.

Predictors of a Good Diuretic Response and Administration Methods for Carperitide in Patients With Acute Heart Failure

PURPOSE

In Japan, carperitide has been recommended for the treatment of pulmonary congestion in patients with acute heart failure. Identifying useful indicators to support the decision to administer carperitide and the optimal timing of administration may lead to better improvement of pulmonary congestion. Therefore, we investigated the factors associated with good diuretic response to carperitide in patients with acute heart failure and the optimal timing of carperitide administration.

METHODS

This retrospective cohort study investigated 293 hospitalized patients who were diagnosed with acute heart failure and treated with carperitide at the Department of Cardiology, Showa University Fujigaoka Hospital. The primary endpoint was the diuretic response to carperitide. Patients with urine output ≥100 mL/h were defined as the good diuretic response group, and those with a urine output <100 mL/h during the first 6 hours of carperitide administration were defined as the poor diuretic response group. Multivariate analysis was used to examine the predictors of good diuretic response. The relationship between the time from intravenous furosemide to carperitide administration and urine output was also investigated.

FINDINGS

The patients' median age was 77 (range: 28-99) years, and 75.5% had New York Heart Association stage IV acute heart failure. The median urine output within 6 hours of carperitide administration was 104.5 (range: 6.6-1571.3) mL/h, and 118 patients (53.6%) showed a good diuretic response. Significant predictors of good diuretic response were age < 75 years [odds ratio (OR) 4.186; 95% confidence interval (CI), 2.129-8.230; P < 0.001], no prior use of loop diuretics (OR 2.155; 95% CI, 1.104-4.207; P = 0.024), blood urea nitrogen <20 mg/dL (OR 2.637; 95% CI, 1.340-5.190; P = 0.005), and white blood cell count <8.6 × 109/L (OR 3.162; 95% CI, 1.628-6.140; P = 0.001). The median urine output in the group with <2 hours between intravenous furosemide and carperitide administration was significantly higher than that in the group with an interval >6 hours [127.3; interquartile range (IQR), 77.6-216.2 mL/h vs. 66.2; IQR. 51.8-114.8 mL/h; P = 0.012).

IMPLICATIONS

The 4 predictors (age, no prior use of loop diuretics, blood urea nitrogen, and white blood cell count) of good diuretic response are useful indicators to support decision-making for carperitide administration. Additionally, the administration of carperitide within 2 hours of intravenous furosemide may lead to the improvement of pulmonary congestion.

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.

Cardiorenal Syndrome in the Hospital

The cardiorenal syndrome refers to a group of complex, bidirectional pathophysiological pathways involving dysfunction in both the heart and kidney. Upward of 60% of patients admitted for acute decompensated heart failure have CKD, as defined by an eGFR of <60 ml/min per 1.73 m 2 . CKD, in turn, is one of the strongest risk factors for mortality and cardiovascular events in acute decompensated heart failure. Although not well understood, the mechanisms in the cardiorenal syndrome include venous congestion, arterial underfilling, neurohormonal activation, inflammation, and endothelial dysfunction. Arterial underfilling may lead to activation of the renin-angiotensin-aldosterone system and sympathetic nervous system, leading to sodium reabsorption and vasoconstriction. Venous congestion likely also mediates and perpetuates these maladaptive pathways. To rule out intrinsic kidney disease that is distinct from the cardiorenal syndrome, one should obtain a careful history, review longitudinal eGFR trends, assess albuminuria and proteinuria, and review the urine sediment and kidney imaging. The hallmark of the cardiorenal syndrome is intense sodium avidity and diuretic resistance, often requiring a combination of diuretics with varying pharmacological targets, and monitoring of urinary response to guide escalations in therapy. Invasive means of decongestion may be required including ultrafiltration or KRT such as peritoneal dialysis, which is often better tolerated from a hemodynamic perspective than intermittent hemodialysis. Strategies for increasing forward perfusion in states of low cardiac output and cardiogenic shock may include afterload reduction and inotropes and, in the most severe cases, mechanical circulatory support devices, many of which have kidney-specific considerations.

Extracorporeal veno-venous ultrafiltration in congestive heart failure: What’s the state of the art? A mini-review

Hospitalizations for heart failure exceed 1 million per year in both the United States and Europe and more than 90% are due to symptoms and signs of fluid overload. Rates of rehospitalizations or emergency department visit at 60 days are remarkable regardless of whether loop diuretics were administered at low vs high doses or by bolus injection vs continuous infusion. Ultrafiltration (UF) has been considered a promising alternative to stepped diuretic therapy and it consists in the mechanical, adjustable removal of iso-tonic plasma water across a semipermeable membrane with the application of hydrostatic pressure gradient generated by a pump. Fluid removal with ultrafiltration presents several advantages such as elimination of higher amount of sodium with less neurohormonal activation. However, the conflicting results from UF studies highlight that patient selection and fluid removal targets are not completely understood. The best way to assess fluid status and therefore establish the fluid removal target is also still a matter of debate. Herein, we provide an up-to-date systematic review about the role of ultrafiltration among patients with fluid overload and its gaps in daily practice.

A second-generation artificial intelligence-based therapeutic regimen improves diuretic resistance in heart failure: Results of a feasibility open-labeled clinical trial

INTRODUCTION

Diuretics are a mainstay therapy for congestive heart failure (CHF); however, over one-third of patients develop diuretic resistance. Second-generation artificial intelligence (AI) systems introduce variability into treatment regimens to overcome the compensatory mechanisms underlying the loss of effectiveness of diuretics. This open-labeled, proof-of-concept clinical trial sought to investigate the ability to improve diuretic resistance by implementing algorithm-controlled therapeutic regimens.

METHODS

Ten CHF patients with diuretic resistance were enrolled in an open-labeled trial where the Altus Care™ app managed diuretics' dosage and administration times. The app provides a personalized therapeutic regimen creating variability in dosages and administration times within pre-defined ranges. Response to therapy was measured by the Kansas City Cardiomyopathy Questionnaire (KCCQ) score, 6-minute walk test (SMW), N-terminal pro-brain natriuretic peptide (NT-proBNP) levels, and renal function.

RESULTS

The second-generation, AI-based, personalized regimen alleviated diuretic resistance. All evaluable patients demonstrated clinical improvement within ten weeks of intervention. A dose reduction (based on a three-week average before and last three weeks of intervention) was achieved in 7/10 patients (70 %, p = 0.042). The KCCQ score improved in 9/10 (90 %, p = 0.002), the SMW improved in 9/9 (100 %, p = 0.006), NT-proBNP was decreased in 7/10 (70 %, p = 0.02), and serum creatinine was decreased in 6/10 (60 %, p = 0.05). The intervention was associated with reduced number of emergency room visits and the number of CHF-associated hospitalizations.

SUMMARY

The results support that the randomization of diuretic regimens guided by a second-generation personalized AI algorithm improves the response to diuretic therapy. Prospective controlled studies are needed to confirm these findings.

Management of Hyponatremia in Heart Failure: Practical Considerations

Hyponatremia is commonly encountered in the setting of heart failure, especially in decompensated, fluid-overloaded patients. The pathophysiology of hyponatremia in patients with heart failure is complex, including numerous mechanisms: increased activity of the sympathetic nervous system and the renin-angiotensin-aldosterone system, high levels of arginine vasopressin and diuretic use. Symptoms are usually mild but hyponatremic encephalopathy can occur if there is an acute decrease in serum sodium levels. It is crucial to differentiate between dilutional hyponatremia, where free water excretion should be promoted, and depletional hyponatremia, where administration of saline is needed. An inappropriate correction of hyponatremia may lead to osmotic demyelination syndrome which can cause severe neurological symptoms. Treatment options for hyponatremia in heart failure, such as water restriction or the use of hypertonic saline with loop diuretics, have limited efficacy. The aim of this review is to summarize the principal mechanisms involved in the occurrence of hyponatremia, to present the main guidelines for the treatment of hyponatremia, and to collect and analyze data from studies which target new treatment options, such as vaptans.

Efficacy of tolvaptan on the short and mid-term prognosis in elderly patients with acute heart failure coexisting with oliguria: A retrospective cohort study

Background

In patients with acute heart failure (AHF) coexisting with oliguria, high doses of loop diuretics are often ineffective in increasing urine output and may adversely affect the patient's prognosis, especially in elderly patients. We investigated the efficacy of adding tolvaptan (TLV) on improving the prognosis in elderly patients with AHF coexisting with oliguria.

Methods

All data for this retrospective cohort study were extracted from the electronic medical record system of the Second Medical Center of Chinese PLA General Hospital from January 2018 to December 2020. Patients diagnosed with AHF coexisting with oliguria were enrolled in this study and were divided into TLV and non-TLV groups based on the use of TLV. The primary outcome was all-cause mortality at 7 and 90-day. The secondary outcomes were the remission of AHF within 7 and 30 days or continued progression of AHF, and new-onset chronic kidney disease (CKD) after 90 days. Cox proportional hazards regression was used to assess the relationships between all-cause mortality and diuretic regimens, demographics, laboratory parameters, comorbidities, and medications.

Results

A total of 308 patients met the study criteria for the final statistical analysis, and they had a median age of 91 years (88, 95). The results showed that the addition of TLV was associated with a decreased risk of the 7 and 90-day all-cause mortality in patients with AHF with oliguria [adjusted HR, 95% CI: 0.60 (0.37, 0.98), p = 0.042; 0.56 (0.41, 0.75), p < 0.001, respectively]. Adding TLV significantly increased urine output and decreased N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels in 7 days, and alleviated the progression of AHF within 30 days. There were no statistically significant differences between the patients with or without TLV in terms of the occurrence of hypernatremia, the development of hepatic impairment within 30 days, and new-onset CKD after 90 days.

Conclusions

This study demonstrated that the addition of TLV was clinically effective in increasing urine output, and had favorable effects on alleviating AHF progression and may reduce the risk of all-cause mortality at 7 and 90-day in elderly patients with AHF with oliguria, and TLV had a good safety profile.

Trial registration

http://www.chictr.org.cn/showprojen.aspx?proj=148046, identifier: ChiCTR2200055518.

Nalfurafine, a G-Protein-Biased KOR (Kappa Opioid Receptor) Agonist, Enhances the Diuretic Response and Limits Electrolyte Losses to Standard-of-Care Diuretics

Nalfurafine is a G-protein-biased KOR (kappa opioid receptor) agonist that produces analgesia and lacks central nervous system adverse effects. Here, we examined the cardiovascular and renal responses to intravenous and oral nalfurafine alone and in combination with furosemide, hydrochlorothiazide, or amiloride. We hypothesized that nalfurafine, given its distinct mechanism of vasopressin inhibition, would increase urine output to these diuretics and limit electrolyte loss. Following catheterization, conscious Sprague-Dawley rats received an isotonic saline infusion and were then administered an intravenous bolus of nalfurafine, a diuretic, or a combination. Mean arterial pressure, heart rate, and urine output were recorded for 90 minutes. In another study, rats were placed in metabolic cages and administered drug in an oral volume load. Hourly urine samples were then collected for 5 hours. Intravenous and oral nalfurafine produced a marked diuresis, antinatriuresis, antikaliuresis, and a decrease in mean arterial pressure. Compared with diuretic treatment alone, intravenous coadministration with nalfurafine significantly increased urine output to furosemide and hydrochlorothiazide and decreased sodium and potassium excretion. Notably, mean arterial pressure was reduced with nalfurafine/diuretic combination therapy compared to diuretics alone. Similarly, oral coadministration of nalfurafine significantly increased urine output to hydrochlorothiazide and decreased sodium and potassium excretion, whereas combination with furosemide only limited the amount of sodium excreted. Further, both intravenous and oral coadministration of nalfurafine enhanced the diuresis to amiloride and decreased sodium excretion. Together, these findings demonstrate that nalfurafine enhances the diuresis to standard-of-care diuretics without causing an excessive loss of electrolytes, offering a new approach to treat several cardiovascular conditions.

Dose of furosemide before admission predicts diuretic efficiency and long-term prognosis in acute heart failure

AIMS

The outpatient diuretic dose is a marker of diuretic resistance and prognosis in chronic heart failure (HF). Still, the impact of the preadmission dose on diuretic efficiency (DE) and prognosis in acute HF is not fully known.

METHODS AND RESULTS

We conducted an observational and prospective study. All patients admitted for acute HF treated with intravenous diuretic and at least one criterion of congestion on admission were evaluated. Decongestion [physical examination, hemoconcentration, N-terminal pro-brain natriuretic peptide (NT-proBNP) change, and lung ultrasound], DE (weight loss and urine output per unit of 40 mg furosemide), and urinary sodium were monitored on the fifth day of admission. DE was dichotomized into high-low based on the median value. A multivariate Cox regression analysis was conducted to find predictors of HF readmission or mortality. A total of 105 patients were included between July 2017 and July 2019. Mean age was 74.5 ± 12.0 years, 64.8% were male, 33.3% had de novo HF, and mean left ventricular ejection fraction was 46 ± 17%. Median follow-up was 26 [15-35] months. Low DE based on weight loss was associated with a higher previous dose of furosemide (odds ratio [OR] 1.01 [1.00-1.02]), thiazide treatment before admission (OR 9.37 [2.19-40.14]), and lower diastolic blood pressure (OR 0.95 [0.91-0.98]) in the multivariate regression model. Only previous dose of furosemide (OR 1.01 [1.00-1.02]) and haemoglobin at admission (OR 0.76 [0.58-0.99]) were associated with low DE based on urine output in the multivariate analysis. The correlation between the previous dose of furosemide and DE based on weight loss was poor (r = -0.12; P = 0.209) and with DE based on urine output was weak to moderate (r = -0.33; P < 0.001). Low DE based on weight loss and urine output was associated with lesser decongestion measured by NT-proBNP (P = 0.011; P = 0.007), hemoconcentration (P = 0.006; P = 0.044), and lung ultrasound (P = 0.034; P = 0.029), but not by physical examination (P = 0.506; P = 0.560). Survival and event-free survival in acute decompensated HF (ADHF) were lower than in de novo HF; a preadmission dose of furosemide > 80 mg in ADHF identified patients with particularly poor prognosis (log-rank < 0.001). In ADHF, the preadmission dose of furosemide (hazard ratio [HR] 1.34 [1.08-1.67] per 40 mg) and NT-proBNP at admission (HR 1.03 [1.01-1.06] per 1000 pg/mL) were independently associated with mortality or HF readmission in the multivariate Cox regression analysis.

CONCLUSIONS

The outpatient dose of furosemide before acute HF admission predicts DE and must be taken into account when deciding on the initial diuretic dose. In ADHF, the outpatient dose of furosemide can predict long-term prognosis better than DE during hospitalization.

Tolvaptan Add-on Therapy to Overcome Loop Diuretic Resistance in Acute Heart Failure With Renal Dysfunction (DR-AHF): Design and Rationale

Background

Diuretic Resistance in Acute Heart Failure (DR-AHF) was designed to demonstrate the effectiveness of the early tolvaptan (a vasopressin-2 receptor antagonist) add-on therapy in patients with AHF with renal dysfunction and to provide clinical evidence of loop diuretic resistance.

Methods and Results

This single-centered, open-labeled, randomized, and controlled trial enrolled 128 patients hospitalized with AHF, as participants. These patients with a wet-warm phenotype, whose estimated glomerular filtration rates are of ≥15 ml/min/1.73 m² and ≤ 60 ml/min/1.73 m², with a cumulative urine output of <300 ml 2 h after the first dose of intravenous furosemide, will be randomly assigned 1:1 to receive standard care with an uptitrating intravenous furosemide alone, or a combination therapy with 15 mg of tolvaptan administered once daily for 2 days. The standard furosemide treatment will follow the latest position statements of the Heart Failure Association. The primary endpoint is the cumulative urine output at 48 h. The key secondary endpoints include the improvement of fractional excretion of sodium at 6 h, the total dose of furosemide, and the incidence of worsening renal function (WRF) at 48 h.

Conclusions

Although the combination of diuretic treatment has recently gained more attention due to its physiologically synergistic action, its advantages may be outweighed by the substantial risk of electrolyte disturbances and severe WRF. Further, there is no consensus on the time point for early starting of add-on therapy and for the preferred diuretic combination.

Trial registration

NCT04331132.

Compensatory post-diuretic renal sodium reabsorption is not a dominant mechanism of diuretic resistance in acute heart failure

AIMS

In healthy volunteers, the kidney deploys compensatory post-diuretic sodium reabsorption (CPDSR) following loop diuretic-induced natriuresis, minimizing sodium excretion and producing a neutral sodium balance. CPDSR is extrapolated to non-euvolemic populations as a diuretic resistance mechanism; however, its importance in acute decompensated heart failure (ADHF) is unknown.

METHODS AND RESULTS

Patients with ADHF in the Mechanisms of Diuretic Resistance cohort receiving intravenous loop diuretics (462 administrations in 285 patients) underwent supervised urine collections entailing an immediate pre-diuretic spot urine sample, then 6-h (diuretic-induced natriuresis period) and 18-h (post-diuretic period) urine collections. The average spot urine sodium concentration immediately prior to diuretic administration [median 15 h (13-17) after last diuretic] was 64 ± 33 mmol/L with only 4% of patients having low (<20 mmol/L) urine sodium consistent with CPDSR. Paradoxically, greater 6-h diuretic-induced natriuresis was associated with larger 18-h post-diuretic spontaneous natriuresis (r = 0.7, P < 0.001). Higher pre-diuretic urine sodium to creatinine ratio (r = 0.37, P < 0.001) was the strongest predictor of post-diuretic spontaneous natriuresis. In a subgroup of patients (n = 43) randomized to protocol-driven intensified diuretic therapies, the mean diuretic-induced natriuresis increased three-fold. In contrast to the substantial decrease in spontaneous natriuresis predicted by CPDSR, no change in post-diuretic spontaneous natriuresis was observed (P = 0.47).

CONCLUSION

On a population level, CPDSR was not an important driver of diuretic resistance in hypervolemic ADHF. Contrary to CPDSR, a greater diuretic-induced natriuresis predicted a larger post-diuretic spontaneous natriuresis. Basal sodium avidity, rather than diuretic-induced CPDSR, appears to be the predominant determinate of both diuretic-induced and post-diuretic natriuresis in hypervolemic ADHF.

Multinephron Segment Diuretic Therapy to Overcome Diuretic Resistance in Acute Heart Failure: A Single-Center Experience

BACKGROUND

The concept of multinephron segment diuretic therapy (MSDT) has been recommended in severe diuretic resistance with only expert opinion and case-level evidence. The purpose of this study was to investigate the safety and efficacy of MSDT, combining 4 diuretic classes, in acute heart failure (AHF) complicated by diuretic resistance.

METHODS AND RESULTS

A retrospective analysis was conducted in patients hospitalized with AHF at a single medical center who received MSDT, including concomitant carbonic anhydrase inhibitor, loop, thiazide, and mineralocorticoid receptor antagonist diuretics. Subjects served as their own controls with efficacy evaluated as urine output and weight change before and after MSDT. Serum chemistries, renal replacement therapies, and in-hospital mortality were evaluated for safety. Patients with severe diuretic resistance before MSDT were analyzed as a subcohort. A total of 167 patients with AHF and diuretic resistance received MSDT. MSDT was associated with increased median 24-hour urine output in the first day of therapy compared with the previous day (2.16 L [0.95-4.14 L] to 3.08 L [1.74-4.86 L], P = .003) in the total cohort and in the Severe diuretic resistance cohort (0.91 L [0.43-1.43 L] to 2.08 L [1.13-3.96 L], P < .001). The median cumulative weight loss at day 7 or discharge was -7.4 kg (-15.3 to -3.4 kg) (P = .02). Neither serum sodium, chloride, potassium, bicarbonate, or creatinine changed significantly relative to baseline (P > .05 for all).

CONCLUSIONS

In an AHF cohort with diuretic resistance, MSDT was associated with increased diuresis without changes in serum chemistries or kidney function. Prospective studies of MSDT in AHF and diuretic resistance are warranted.

[The use of diuretics in chronic heart failure. Position paper of the Russian Heart Failure Society]

The document focuses on key issues of diuretic therapy in CHF from the standpoint of current views on the pathogenesis of edema syndrome, its diagnosis, and characteristics of using diuretics in various clinical situations.

Levosimendan Plus Dobutamine in Acute Decompensated Heart Failure Refractory to Dobutamine

Randomized studies showed that Dobutamine and Levosimendan have similar impact on outcome but their combination has never been assessed in acute decompensated heart failure (ADHF) with low cardiac output. This is a retrospective, single-center study that included 89 patients (61 ± 15 years) admitted for ADHF requiring inotropic support. The first group consisted of patients treated with dobutamine alone (n = 42). In the second group, levosimendan was administered on top of dobutamine, when the superior vena cava oxygen saturation (ScVO2) remained <60% after 3 days of dobutamine treatment (n = 47). The primary outcome was the occurrence of major cardiovascular events (MACE) at 6 months, defined as all cause death, heart transplantation or need for mechanical circulatory support. Baseline clinical characteristics were similar in both groups. At day-3, the ScVO2 target (>60%) was reached in 36% and 32% of patients in the dobutamine and dobutamine-levosimendan group, respectively. After adding levosimendan, 72% of the dobutamine-levosimendan-group reached the ScVO2 target value at dobutamine weaning. At six months, 42 (47%) patients experienced MACE (n = 29 for death). MACE was less frequent in the dobutamine-levosimendan (32%) than in the dobutamine-group (64%, p = 0.003). Independent variables associated with outcome were admission systolic blood pressure and dobutamine-levosimendan strategy (OR = 0.44 (0.23–0.84), p = 0.01). In conclusion, levosimendan added to dobutamine may improve the outcome of ADHF refractory to dobutamine alone.

Prediction and measurement of diuretic responsiveness after oral administration of furosemide to healthy dogs and dogs with congestive heart failure

Background

In human patients, cumulative urine volume (uVol) and urine sodium (uNa) can be predicted using spot urine samples and these quantitative measures help detect low diuretic responsiveness (LDR).

Hypothesis/objectives

Formulas using spot urine samples predict cumulative uVol and uNa output after oral administration of furosemide to dogs.

Animals

Eight healthy dogs, 6 dogs with congestive heart failure (CHF).

Methods

Prospective interventional study. Spot urine samples at 180 and 270 minutes after furosemide (3 mg/kg PO) were used to predict cumulative uVol and uNa output over 7 hours. Differentiation of dogs fulfilling predefined criteria for LDR was examined using receiver operating characteristic (ROC) curves.

Results

Predicted uNa output at 180 minutes (r_s = 0.763, [95% confidence interval [CI], 0.375‐0.923], P = .002) and 270 minutes (r = 0.816, [95% CI, 0.503‐0.940], P < .001) was highly correlated to 7‐hour uNa output. Predicted uVol at 180 minutes (r = 0.598, [95% CI, 0.098‐0.857], P = .02) and 270 minutes (r = 0.791, [95% CI, 0.450‐0.931], P < .001) was moderately correlated to 7‐hour uVol. Predicted uNa using 180‐minute (area under the curve [AUC], 0.933 [95% CI, 0.804‐1.000]) and 270‐minute (AUC, 0.911 [95% CI, 0.756‐1.000]) samples identified dogs with LDR (n = 5) with high accuracy.

Conclusions and Clinical Importance

Urinary Na excretion and uVol are complementary but distinct aspects of diuretic responsiveness in dogs. Quantification of diuretic responsiveness in the clinical setting opens new diagnostic, treatment, and monitoring strategies.

Soluble ST2 and Diuretic Efficiency in Acute Heart Failure and Concomitant Renal Dysfunction

BACKGROUND

Identifying patients at risk of poor diuretic response in acute heart failure (AHF) is critical to make prompt adjustments in therapy. The objective of this study was to investigate whether the circulating levels of soluble ST2 predict the cumulative diuretic efficiency (DE) at 24 and 72 hours in patients with AHF and concomitant renal dysfunction.

METHODS AND RESULTS

This is a post hoc analysis of the IMPROVE-HF trial, in which we enrolled 160 patients with AHF and renal dysfunction (estimated glomerular filtrate rate of <60 mL/min/1.73 m²). DE was calculated as the net fluid output produced per 40 mg of furosemide equivalents. The association between sST2 and DE was evaluated by using multivariate linear regression analysis. The median cumulative DE at 24 and 72 hour was 747 mL (interquartile range 490-1167 mL) and 1844 mL (interquartile range 1142-2625 mL), respectively. The median sST2 and mean estimated glomerular filtrate rate were 72 ng/mL (interquartile range 47-117 ng/mL), and 34.0 ± 8.5 mL/min/1.73 m², respectively. In a multivariable setting, higher sST2 were significant and nonlinearly related to lower DE both at 24 and 72 hours (P = .002 and P = .019, respectively).

CONCLUSIONS

In patients with AHF and renal dysfunction at presentation, circulating levels of sST2 were independently and negatively associated with a poor diuretic response, both at 24 and 72 hours.

Pathophysiology of Diuretic Resistance and Its Implications for the Management of Chronic Heart Failure

Diuretic resistance implies a failure to increase fluid and sodium (Na+) output sufficiently to relieve volume overload, edema, or congestion, despite escalating doses of a loop diuretic to a ceiling level (80 mg of furosemide once or twice daily or greater in those with reduced glomerular filtration rate or heart failure). It is a major cause of recurrent hospitalizations in patients with chronic heart failure and predicts death but is difficult to diagnose unequivocally. Pharmacokinetic mechanisms include the low and variable bioavailability of furosemide and the short duration of all loop diuretics that provides time for the kidneys to restore diuretic-induced Na+ losses between doses. Pathophysiological mechanisms of diuretic resistance include an inappropriately high daily salt intake that exceeds the acute diuretic-induced salt loss, hyponatremia or hypokalemic, hypochloremic metabolic alkalosis, and reflex activation of the renal nerves. Nephron mechanisms include tubular tolerance that can develop even during the time that the renal tubules are exposed to a single dose of diuretic, or enhanced reabsorption in the proximal tubule that limits delivery to the loop, or an adaptive increase in reabsorption in the downstream distal tubule and collecting ducts that offsets ongoing blockade of Na+ reabsorption in the loop of Henle. These provide rationales for novel strategies including the concurrent use of diuretics that block these nephron segments and even sequential nephron blockade with multiple diuretics and aquaretics combined in severely diuretic-resistant patients with heart failure.

Comparing Diuresis Patterns in Hospitalized Patients With Heart Failure With Reduced Versus Preserved Ejection Fraction: A Retrospective Analysis

BACKGROUND

Congestion predominates in exacerbations of heart failure with reduced ejection fraction (HFrEF) or preserved ejection fraction (HFpEF), but evidence suggests that excess volume may be distributed differently in these 2 subgroups.

METHODS AND RESULTS

In this retrospective study, diuretic efficiency (DE, or net urine output per 40-mg of intravenous furosemide equivalent) during the first 72 hours was compared between patients hospitalized with HFrEF (n = 121) versus HFpEF (n = 120). Multivariate analysis was used to compare the 2 groups based on expected baseline differences (e.g., demographics, heart failure etiology, concomitant therapy). During the first 72 hours, mean daily diuretic doses were higher in patients with HFpEF versus HFrEF (172.0 vs. 159.9 mg, respectively, P = 0.026) but urine output was not significantly different (2603.3 mL vs. 2667.5 mL, respectively, adjusted P = 0.100). Similarly, mean cumulative DE did not differ (-673.5 vs. -637.8 mL/40-mg in the HFrEF and HFpEF groups, respectively, adjusted P = 0.884). An exploratory analysis of propensity-matched cohorts yielded similar findings. Correlations between the components of DE varied considerably and only became weak to moderately correlated toward the end of the observation period.

CONCLUSIONS

Although cumulative DE did not differ between patients with HFrEF and HFpEF, variable correlations in the components of DE suggest there may be differences in diuretic response that warrant future analysis.

Racial Differences in Diuretic Efficiency, Plasma Renin, and Rehospitalization in Subjects With Acute Heart Failure

BACKGROUND

Black patients have higher rates of hospitalization for acute heart failure than other race/ethnic groups. We sought to determine whether diuretic efficiency is associated with racial differences in risk for rehospitalization after acute heart failure.

METHODS

A post hoc analysis was performed on 721 subjects (age, 68±13 years; 22% black) enrolled in 3 acute heart failure clinical trials: ROSE-AHF (Renal Optimization Strategies Evaluation in Acute Heart Failure), DOSE-AHF (Diuretic Optimization Strategy Evaluation in Acute Decompensated Heart Failure), and CARRESS-HF (Cardiorenal Rescue Study in Acute Decompensated Heart Failure). Repeated-measures ANOVA was used to test for a race×time effect on measures of decongestion. Diuretic efficiency was calculated as net fluid balance per total furosemide equivalents. In a subset of subjects, Cox regression was used to examine the association between race and rehospitalization according to plasma renin activity (PRA).

RESULTS

Compared with nonblack patients, black patients were younger and more likely to have nonischemic heart failure. During the first 72 to 96 hours, there was greater fluid loss (P=0.001), decrease in NT-proBNP (N-terminal pro-B-type natriuretic peptide; P=0.002), and lower levels of PRA (P<0.0001) in black patients. Diuretic efficiency was higher in black than in nonblack patients (403 [interquartile range, 221-795] versus 325 [interquartile range, 154-698]; P=0.014). However, adjustment for baseline PRA attenuated the association between black race and diuretic efficiency. Over a median follow-up of 68 (interquartile range, 56-177) days, there was an increased risk of all-cause and heart failure-specific rehospitalization in nonblack patients with increasing levels of PRA, while the risk of rehospitalization was relatively constant across levels of PRA in black patients.

CONCLUSIONS

Higher diuretic efficiency in black patients with acute heart failure may be related to racial differences in activity of the renin-angiotensin-aldosterone system.

Conceptual Considerations for Device-Based Therapy in Acute Decompensated Heart Failure

Acute decompensated heart failure remains the most common cause of hospitalization in older adults, and studies of pharmacological therapies have yielded limited progress in improving outcomes for these patients. This has prompted the development of novel device–based interventions, classified mechanistically based on the way in which they intend to improve central hemodynamics, increase renal perfusion, remove salt and water from the body, and result in clinically meaningful degrees of decongestion. In this review, we provide an overview of the pathophysiology of acute decompensated heart failure, current management strategies, and failed pharmacological therapies. We provide an in depth description of seven investigational device classes designed to target one or more of the pathophysiologic derangements in acute decompensated heart failure, denoted by the acronym DRI 2 P 2 S. Dilators decrease central pressures by increasing venous capacitance through splanchnic nerve modulation. Removers remove excess fluid through peritoneal dialysis, aquaphoresis, or hemodialysis. Inotropes directly modulate the cardiac nerve plexus to enhance ventricular contractility. Interstitial devices enhance volume removal through lymphatic duct decompression. Pushers are novel descending aorta rotary pumps that directly increase renal artery pressure. Pullers reduce central venous pressures or renal venous pressures to increase renal perfusion. Selective intrarenal artery catheters facilitate direct delivery of short acting vasodilator therapy. We also discuss challenges posed in clinical trial design for these novel device–based strategies including optimal patient selection and appropriate end points to establish efficacy.

Diuretic Strategies for Loop Diuretic Resistance in Acute Heart Failure: The 3T Trial

OBJECTIVES

This study compared combination diuretic strategies in acute heart failure (AHF) complicated by diuretic resistance (DR).

BACKGROUND

Combination diuretic regimens to overcome loop DR are commonly used but with limited evidence.

METHODS

This study was a randomized, double-blinded trial in 60 patients hospitalized with AHF and intravenous (IV) loop DR. Patients were randomized to oral metolazone, IV chlorothiazide, or tolvaptan therapy. All patients received concomitant high-dose IV infusions of furosemide. The primary outcome was 48-h weight loss.

RESULTS

The cohort exhibited DR prior to enrollment, producing 1,188 ± 476 ml of urine in 12 h during high-dose loop diuretic therapy (IV furosemide: 612 ± 439 mg/day). All 3 interventions significantly improved diuretic efficacy (p < 0.001). Compared to metolazone (4.6 ± 2.7 kg), neither IV chlorothiazide (5.8 ± 2.7 kg; 1.2 kg [95% confidence interval (CI)]: -2.9 to 0.6; p = 0.292) nor tolvaptan (4.1 ± 3.3 kg; 0.5 kg [95% CI: -1.5 to 2.4; p = 0.456) resulted in more weight loss at 48 h. Median (interquartile range [IQR]) cumulative urine output increased significantly and did not differ among those receiving metolazone (7.78 [IQR: 6.59 to 10.10] l) and chlorothiazide (8.77 [IQR: 7.37 to 10.86] l; p = 0.245) or tolvaptan (9.70 [IQR: 6.36 to 13.81] l; p = 0.160). Serum sodium decreased less with tolvaptan than with metolazone (+4 ± 5 vs. -1 ± 3 mEq/l; p = 0.001), but 48-h spot urine sodium was lower with tolvaptan (58 ± 25 mmol/l) than with metolazone (104 ± 16 mmol/l; p = 0.002) and with chlorothiazide (117 ± 14 mmol/l; p < 0.001).

CONCLUSIONS

In this moderately sized DR trial, weight loss was excellent with the addition of metolazone, IV chlorothiazide, or tolvaptan to loop diuretics, without a detectable between-group difference. (Comparison of Oral or Intravenous Thiazides vs. tolvaptan in Diuretic Resistant Decompensated Heart Failure [3T]; NCT02606253).

Diuretic Responsiveness and Its Prognostic Significance in Children With Heart Failure

BACKGROUND

Loop diuretics are considered first-line therapy for congestion in children with heart failure, although some patients remain volume overloaded during treatment. We sought to characterize loop diuretic responsiveness (DR) in children hospitalized with acute decompensated failure and to determine whether a decreased response was associated with worse outcomes.

METHODS AND RESULTS

DR was calculated for 108 consecutive children ˂21 years of age who were hospitalized with acute decompensated heart failure. DR was defined as net fluid (mL) output per 1 mg of furosemide equivalents during the first 72 hours of treatment with a loop diuretic. The primary outcome was the composite end point of inpatient death or use of mechanical circulatory support. The median DR was 6.0 mL/mg (interquartile range -2.4 to 15.7 mL/mg). Thirty-two percent of patients remained in a positive fluid balance after 72 hours of treatment with a loop diuretic. Death or use of mechanical circulatory support occurred in 29 patients (27%). Low DR was associated with the composite end point, even after adjusting for net urine output and loop diuretic dose indexed to weight (odds ratio 5.3; P = .003). Patients with low DR also experienced longer length of hospital stay than patients with greater DR (median 33 days vs 11 days; P = .002).

CONCLUSION

In children hospitalized with acute decompensated heart failure, early diminished loop DR during decongestion therapy is common and portends a poor prognosis.

Diuretic Resistance in Heart Failure

PURPOSE OF REVIEW

Diuretic resistance (DR) occurs along a spectrum of relative severity and contributes to worsening of acute heart failure (AHF) during an inpatient stay. This review gives an overview of mechanisms of DR with a focus on loop diuretics and summarizes the current literature regarding the prognostic value of diuretic efficiency and predictors of natriuretic response in AHF.

RECENT FINDINGS

The pharmacokinetics of diuretics are impaired in chronic heart failure, but little is known about mechanisms of DR in AHF. Almost all diuresis after administration of a loop diuretic dose occurs in the first few hours after administration and within-dose DR can develop. Recent studies suggest that DR at the level of the nephron may be more important than defects in diuretic delivery to the tubule. Because loop diuretics induce natriuresis, urine sodium (UNa) concentration may serve as a functional, physiological, and direct measure for diuretic responsiveness to a given loop diuretic dose. Identifying and targeting individuals with DR for more aggressive, tailored therapy represents an important opportunity to improve outcomes. A better understanding of the mechanistic underpinnings of DR in AHF is needed to identify additional biomarkers and guide future trials and therapies.