Spot urine sodium excretion as prognostic marker in acutely decompensated heart failure: the spironolactone effect

Effects of early initiation of mineralocorticoid receptor antagonist therapy in acute decompensated heart failure: a systematic review and meta-analysis

BACKGROUND

Acute heart failure (AHF) is a major cause of hospitalization, with high morbidity and mortality. Mineralocorticoid receptor antagonists (MRAs) improve outcomes in chronic heart failure, but their role and optimal timing in AHF remain unclear. Early initiation may enhance hemodynamic stability, yet concerns about hyperkalemia and renal dysfunction limit their use. This meta-analysis evaluates the efficacy and safety of early MRA initiation in AHF.

METHODS

A systematic search of PubMed, SCOPUS, and Cochrane databases identified studies comparing early in-hospital MRA therapy plus standard care versus standard care alone in AHF patients. Pooled odds ratios (OR) with 95 % confidence intervals (CI) were calculated using a random-effects model. Primary outcomes included cardiovascular and all-cause mortality, heart failure rehospitalizations, and safety outcomes (hyperkalemia, renal deterioration, hypotension, and hypokalemia).

RESULTS

Six studies (N = 11,039) were included. Early MRA initiation reduced cardiovascular mortality (OR 0.73, 95 % CI 0.59-0.92; p = 0.007), heart failure rehospitalizations (OR 0.56, 95 % CI 0.40-0.78; p = 0.0008), and renal deterioration (OR 0.78, 95 % CI 0.66-0.92; p = 0.003). No significant effect on all-cause mortality was observed (OR 0.88, 95 % CI 0.62-1.24; p = 0.46). A non-significant trend toward increased hyperkalemia emerged (OR 1.45, 95 % CI 0.57-3.68; p = 0.43).

CONCLUSION

This meta-analysis suggests that early MRA initiation in AHF improves cardiovascular outcomes and reduces rehospitalizations with an acceptable safety profile. Further large-scale randomized controlled studies are needed to confirm its long-term clinical impact.

AKR1D1 suppresses liver cancer progression by promoting bile acid metabolism-mediated NK cell cytotoxicity

Bile acid metabolism and antitumor immunity are both disrupted during liver cancer progression. However, the complex regulatory relationship between them remains largely unclear. Here, we find that loss of aldo-keto reductase 1D1 (AKR1D1) promotes the accumulation of isolithocholic acid (iso-LCA) through gut microbiome dysregulation, thereby impairing the cytotoxic function of natural killer (NK) cells and leading to the accelerated development of hepatocellular carcinoma (HCC). Mechanistically, AKR1D1 deficiency leads to an increased proportion of Bacteroidetes ovatus (B. ovatus), which breaks down chenodeoxycholic acid (CDCA) into iso-LCA. Moreover, accumulated iso-LCA impairs the antitumor activity of hepatic NK cells in a phosphorylated-CREB1 (p-CREB1)-dependent manner. The potassium-sparing diuretic spironolactone treatment significantly enhances the inhibitory effect of anti-PD1 antibody on HCC progression by targeting iso-LCA-mediated tumor immune escape. Taken together, our results uncover a previously unappreciated link between AKR1D1 and HCC and suggest that targeting iso-LCA produced by B. ovatus might be a promising strategy to activate NK cell cytotoxicity to treat HCC.

The role of urine sodium in acutely decompensated heart failure

Background

Diuretic resistance is common and results in poor outcome. Spot urine sodium (UrNa) is suggested as a tool to tailor diuretics and improve efficacy of therapy. We prospectively evaluate the prevalence of diuretic resistance, predictors of low spot-UrNa and the prognostic value of spot-UrNa in an unselected ADHF population.

Methods

Patients admitted for ADHF and treated with iv diuretics were included. Spot-UrNa was collected 2 h after administration of an IV diuretic bolus. The main endpoint was a composite of HF re-hospitalizations and all-cause mortality at 90 days follow-up.

Results

143 patients were included in this study (median age 81 [75 - 85] years, 55 % male), of which 50 % were newly diagnosed with HF. Low spot-UrNa was independently associated with worse renal function, low serum sodium, and systolic blood pressure, previous loop diuretic and SGLT2i use and loop diuretic administered dose. Both absolute spot-UrNa (HR 0.87, 95 % CI 0.79 - 0.95, P=0.003 per 10 mmol/L increase) and a urinary sodium ≥ 100 mmol/l (HR=0.51, 95 % CI 0.27 - 0.97, P=0.04) significantly predicted the composite endpoint. This association was no longer significant after correction for confounders. Patients with low spot-UrNa attained longer IV diuretic treatment and a higher cumulative IV diuretic dose.

Conclusions

Spot-UrNa is prevalent and occurs more often in patients with more progressed cardio-renal disease. Spot-UrNa significantly predicts 90-day HF hospital-free survival in ADHF. Further studies are needed evaluating the effect of UrNa guided diuretic treatment on clinical endpoints.

Mineralocorticoid Receptor Antagonists in Heart Failure: An Update

Spironolactone, a steroidal mineralocorticoid receptor antagonist (MRA), has been used to treat patients with heart failure (HF) for more than half a century. Spironolactone improved outcomes in patients with severely symptomatic HF with reduced ejection fraction, and later, eplerenone expanded the benefits to patients with mildly symptomatic HF with reduced ejection fraction and myocardial infarction complicated by HF. Spironolactone reduced HF events in some patients with HF with preserved ejection fraction, but the results were not generalizable to all patients with HF with preserved ejection fraction. More recently, the nonsteroidal MRA finerenone improved the HF outcomes of patients with HF with preserved ejection fraction, expanding the benefits previously seen among patients with diabetes and albuminuric chronic kidney disease. The use of MRAs has been limited due to excessive concern about hyperkalemia. Education about the limited true risk associated with hyperkalemia, and about how to predict, prevent, and manage hyperkalemia, may lead to wider acceptability and use of these agents. Several ongoing trials are testing steroidal and nonsteroidal MRAs in HF populations. In this review, we perform a critical appraisal of MRA use in HF populations and point toward future directions.

The utility of urine sodium-guided diuresis during acute decompensated heart failure

Diuresis to achieve decongestion is a central aim of therapy in patients hospitalized for acute decompensated heart failure (ADHF). While multiple approaches have been tried to achieve adequate decongestion rapidly while minimizing adverse effects, no single diuretic strategy has shown superiority, and there is a paucity of data and guidelines to utilize in making these decisions. Observational cohort studies have shown associations between urine sodium excretion and outcomes after hospitalization for ADHF. Urine chemistries (urine sodium ± urine creatinine) may guide diuretic titration during ADHF, and multiple randomized clinical trials have been designed to compare a strategy of urine chemistry-guided diuresis to usual care. This review will summarize current literature for diuretic monitoring and titration strategies, outline evidence gaps, and describe the recently completed and ongoing clinical trials to address these gaps in patients with ADHF with a particular focus on the utility of urine sodium-guided strategies.

The role of urine chloride in acute heart failure

In our retrospective study, we aimed to investigate the relationship between urinary chloride (uCl-) and selected clinical and laboratory biomarkers, renal function, and patient outcomes in the acute heart failure (AHF) population. We divided 248 adult patients (≥ 18 years) with AHF into two groups: low uCl- (< 115 mmol/L) and high uCl-. The mean age of the patient group was 70.2 ± 12.6, and 182 patients were male (73.4%). Clinical endpoints included in-hospital mortality, one-year mortality, and a composite endpoint of one-year mortality and rehospitalization for heart failure. Patients were followed up for at least one year. Relevant clinical and baseline biomarker data were collected, including markers concerning inflammation, liver and kidney function, perfusion and congestion, iron status, cardiac remodeling, gasometry, renin and aldosterone. Low uCl- was associated with worse in-hospital outcomes, including higher in-hospital mortality (7.7% vs. 1.4%, p = 0.014), the need for inotropic support (20.19% vs. 2.08%, p ≤ 0.001), worsening of HF during therapy (17.31% vs. 4.86%, p ≤ 0.001), and the need for treatment in an intensive cardiac care unit (33.65% vs. 15.28%, p ≤ 0.001). Low uCl- was a significant predictor of one-year mortality (40.4% vs. 16.7%, p < 0.05) and the composite outcome (HR 2.42, 95% CI 1.43-4.08, p < 0.001). In the multivariable analysis, uCl- was independently associated with the risk of one-year mortality (HR 0.92, 95% CI 0.87-0.98, p < 0.05) and the composite outcome (HR 0.95, 95% CI 0.92-0.99, p < 0.05). Our findings suggest that low uCl- is a marker of more advanced heart failure, activation of the renin-angiotensin-aldosterone system and is related to worse one-year outcomes.

Patient Selection and End Point Definitions for Decongestion Studies in Acute Decompensated Heart Failure: Part 1

Despite recent advances in the treatment of patients with chronic heart failure, acute decompensated heart failure remains associated with significant mortality and morbidity because many novel therapies have failed to demonstrate meaningful benefit. Persistent congestion in the setting of escalating diuretic therapy has been repeatedly shown to be a marker of poor prognosis and is currently being targeted by various emerging device-based therapies. Because these therapies inherently carry procedural risk, patient selection is key in the future trial design. However, it remains unclear which patients are at a higher risk of residual congestion or adverse outcomes despite maximally tolerated decongestive therapy. In the first part of this 2-part review, we aimed to outline patient risk factors and summarize current evidence for early recognition of high-risk profile for residual congestion and adverse outcomes. These factors are classified as relating to the following: (1) previous clinical course, (2) severity of congestion, (3) diuretic response, and (4) degree of renal impairment. We also aimed to provide an overview of key inclusion criteria in recent acute decompensated heart failure trials and investigational device studies and propose potential criteria for selection of high-risk patients in future trials.

Spot Urinary Sodium Measurements: the Future Direction of the Treatment and Follow-up of Patients with Heart Failure

PURPOSE OF REVIEW

Heart failure is characterized by episodes of congestion with need for hospitalization. The current metrics lack the accuracy to predict and prevent episodes of congestion and to guide diuretic titration to reach euvolemia in case of decompensation. This article aims to provide answers to the role of urinary sodium measurements in acute and chronic heart failure.

RECENT FINDINGS

In acute heart failure, urinary sodium concentrations at the moment of admission and after diuretic administration are correlated with short- and long-term outcome. As this is a reflection of the degree of sodium retention, it can be used as a guide in the diuretic titration. In chronic heart failure, it might be used to predict and consequently prevent episodes of decompensation. Urinary sodium measurements hold great promises to be a novel diagnostic and therapeutic parameter in patients with acute and chronic heart failure. However, more research is needed.

Toward quantification of loop diuretic responsiveness for congestive heart failure

Diuretics, such as furosemide, are routinely administered to dogs with congestive heart failure (CHF). Traditionally, dose and determination of efficacy primarily are based on clinical signs rather than quantitative measures of drug action. Treatment of human CHF patients increasingly is guided by quantification of urine sodium concentration (uNa) and urine volume after diuretic administration. Use of these and other measures of diuretic responsiveness is associated with decreased duration of hospitalization, complication rates, future rehospitalization, and mortality. At their core, loop diuretics act through natriuresis, and attention to body sodium (Na) stores and handling offers insight into the pathophysiology of CHF and pharmacology of diuretics beyond what is achievable from clinical signs alone. Human patients with low diuretic responsiveness or diuretic resistance are at risk for difficult or incomplete decongestion that requires diuretic intensification or other remedial strategies. Identification of the specific etiology of resistance in a patient can help tailor personalized interventions. In this review, we advance the concept of loop diuretic responsiveness by highlighting Na and natriuresis. Specifically, we review body water homeostasis and congestion in light of the increasingly recognized role of interstitial Na, propose definitions for diuretic responsiveness and resistance in veterinary subjects, review relevant findings of recent studies, explain how the particular cause of resistance can guide treatment, and identify current knowledge gaps. We believe that a quantitative approach to loop diuretic usage primarily involving natriuresis will advance our understanding and care of dogs with CHF.

Urinary sodium concentration predicts time to major adverse coronary events and all-cause mortality in men with heart failure over a 28–33-year period: a prospective cohort study

Background

Lower urinary sodium concentrations (UNa) may be a biomarker for poor prognosis in chronic heart failure (HF). However, no data exist to determine its prognostic association over the long-term. We investigated whether UNa predicted major adverse coronary events (MACE) and all-cause mortality over 28–33 years.

Methods

One hundred and eighty men with chronic HF from the Kuopio Ischaemic Heart Disease Risk Factor Study (KIHD) were included. Baseline data was collected between 1984 and 1989. MACE and all-cause outcomes were obtained using hospital linkage data (1984–2017) with a follow-up of 28–33 years. Cox proportional hazards models were generated using 24-h UNa tertiles at baseline (1 ≤ 173 mmol/day; 2 = 173-229 mmol/day; 3 = 230-491 mmol/day) as a predictor of time-to-MACE outcomes, adjusted for relevant covariates.

Results

Overall, 63% and 83% of participants (n = 114 and n = 150) had a MACE event (median 10 years) and all-cause mortality event (median 19 years), respectively. On multivariable Cox Model, relative to the lowest UNa tertile, no significant difference was noted in MACE outcome for individuals in tertiles 2 and 3 with events rates of 28% (HR:0.72; 95% CI: 0.46–1.12) and 21% (HR 0.79; 95% CI: 0.5–1.25) respectively.. Relative to the lowest UNa tertile, those in tertile 2 and 3 were 39% (HR: 0.61; 95% CIs: 0.41, 0.91) and 10% (HR: 0.90; 95% CIs: 0.62, 1.33) less likely to experience to experience all-cause mortality. The multivariable Cox model had acceptable prediction precision (Harrell's C concordance measure 0.72).

Conclusion

UNa was a significant predictor of all-cause mortality but not MACE outcomes over 28–33 years with 173–229 mmol/day appearing to be the optimal level. UNa may represent an emerging long-term prognostic biomarker that warrants further investigation.

Early urinary sodium trajectory and risk of adverse outcomes in acute heart failure and renal dysfunction

INTRODUCTION AND OBJECTIVES

Urinary sodium (UNa⁺) has emerged as a useful biomarker of poor clinical outcomes in acute heart failure (AHF). Here, we sought to evaluate: a) the usefulness of a single early determination of UNa⁺ for predicting adverse outcomes in patients with AHF and renal dysfunction, and b) whether the change in UNa⁺ at 24hours (ΔUNa24h) adds any additional prognostic information over baseline values.

METHODS

This is a post-hoc analysis of a multicenter, open-label, randomized clinical trial (IMPROVE-HF) (ClinicalTrials.gov NCT02643147) that randomized 160 patients with AHF and renal dysfunction on admission to a) the standard diuretic strategy, or b) a carbohydrate antigen 125-guided diuretic strategy. The primary end point was all-cause mortality and total all-cause readmissions.

RESULTS

The mean age was 78±8 years, and the mean glomerular filtration rate was 34.0±8.5mL/min/1.73 m². The median UNa⁺ was 90 (65-111) mmol/L. At a median follow-up of 1.73 years [interquartile range, 0.48-2.35], 83 deaths (51.9%) were registered, as well as 263 all-cause readmissions in 110 patients. UNa⁺ was independently associated with mortality (HR, 0.75; 95%CI, 0.65-0.87; P <.001) and all-cause readmissions (HR, 0.92; 95%CI, 0.88-0.96; P <.001). The prognostic usefulness of the ΔUNa24h varied according to UNa⁺ at admission (P for interaction <.05). The ΔUNa24h was inversely associated with both end points only in the group with UNa⁺ ≤ 50 mmol/L. Conversely, no effect was found in the group with UNa⁺> 50 mmol/L.

CONCLUSIONS

In patients with AHF and renal dysfunction, a single early determination of UNa⁺ ≤ 50 mmol/L identifies patients with a higher risk of all-cause mortality and readmission. The ΔUNa24h adds prognostic information over baseline values only when UNa⁺ at admission is ≤ 50 mmol/L.

The value of urinary sodium assessment in acute heart failure

Acute heart failure (AHF) is a frequent medical condition that needs immediate evaluation and appropriate treatment. Patients with signs and symptoms of volume overload mostly require intravenous loop diuretics in the first hours of hospitalization. Some patients may develop diuretic resistance, resulting in insufficient and delayed decongestion, with increased mortality and morbidity. Urinary sodium measurement at baseline and/or during treatment has been proposed as a useful parameter to tailor diuretic therapy in these patients. This systematic review discusses the current sum of evidence regarding urinary sodium assessment to evaluate diuretic efficacy in AHF. We searched Medline, Embase, and Cochrane Clinical Trials Register for published studies that tested urinary sodium assessment in patients with AHF.

Natriuretic Equation to Predict Loop Diuretic Response in Patients With Heart Failure

BACKGROUND

Most acute decompensated heart failure admissions are driven by congestion. However, residual congestion is common and often driven by the lack of reliable tools to titrate diuretic therapy. The authors previously developed a natriuretic response prediction equation (NRPE), which predicts sodium output using a spot urine sample collected 2 h after loop diuretic administration.

OBJECTIVES

The purpose of this study was to validate the NRPE and describe proof-of-concept that the NRPE can be used to guide diuretic therapy.

METHODS

Two cohorts were assembled: 1) the Diagnosing and Targeting Mechanisms of Diuretic Resistance (MDR) cohort was used to validate the NRPE to predict 6-h sodium output after a loop diuretic, which was defined as poor (<50 mmol), suboptimal (<100 mmol), or excellent (>150 mmol); and 2) the Yale Diuretic Pathway (YDP) cohort, which used the NRPE to guide loop diuretic titration via a nurse-driven automated protocol.

RESULTS

Evaluating 638 loop diuretic administrations, the NRPE showed excellent discrimination with areas under the curve ≥0.90 to predict poor, suboptimal, and excellent natriuretic response, and outperformed clinically obtained net fluid loss (p < 0.05 for all cutpoints). In the YDP cohort (n = 161) using the NRPE to direct therapy mean daily urine output (1.8 ± 0.9 l vs. 3.0 ± 0.8 l), net fluid output (-1.1 ± 0.9 l vs. -2.1 ± 0.9 l), and weight loss (-0.3 ± 0.3 kg vs. -2.5 ± 0.3 kg) improved substantially following initiation of the YDP (p < 0.001 for all pre-post comparisons).

CONCLUSIONS

Natriuretic response can be rapidly and accurately predicted by the NRPE, and this information can be used to guide diuretic therapy during acute decompensated heart failure. Additional study of diuresis guided by the NRPE is 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.

The impact of the glucagon-like peptide-1 receptor agonist liraglutide on natriuretic peptides in heart failure patients with reduced ejection fraction with and without type 2 diabetes

AIM

To assess the effect of liraglutide, a glucagon-like peptide-1 receptor agonist, on urinary sodium excretion as well as on circulating adrenomedullin and copeptin levels in patients with type 2 diabetes (T2D).

MATERIALS AND METHODS

In the LIVE study, patients (n = 241) with left ventricular ejection fraction ≤45% were randomized to liraglutide 1.8 mg daily or placebo for 24 weeks, and 30% had a concomitant diagnosis of T2D. Plasma levels of N-terminal brain-natriuretic-peptide (NT-proBNP) (a predefined secondary endpoint), midregional pro-atrial-natriuretic-peptide (MR-proANP), midregional pro-adrenomedullin (MR-proADM) and copeptin were measured at baseline and after 24 weeks in this substudy. The potential effect modification of T2D was assessed.

RESULTS

In the eligible subgroup of 231 patients with available biomarkers (115 randomized to liraglutide and 116 to placebo), MR-proANP decreased by 12% (P = .002) and NT-proBNP by 9% (P = .009) during liraglutide treatment compared with placebo at week 24. Interaction with T2D for the treatment effect of change in MR-proANP and NT-proBNP levels was P = .003 and P = .03, respectively. Consequently, in patients with T2D, liraglutide decreased MR-proANP by 27% (P < .001) and NT-proBNP by 25% (P = .02) compared with placebo, whereas no change was observed in patients without T2D. There was no effect of liraglutide on MR-proADM (P = .10) or copeptin (P = .52).

CONCLUSION

Liraglutide decreased the A- and B-type natriuretic peptides significantly in patients with heart failure with reduced ejection fraction (HFrEF) and concomitant T2D, suggesting a beneficial mechanism of liraglutide in T2D patients with HFrEF.

Early Spot Urinary Sodium and Diuretic Efficiency in Acute Heart Failure and Concomitant Renal Dysfunction

OBJECTIVE

In acute heart failure (AHF), early assessment of spot urinary sodium (UNa) has emerged as a useful biomarker for risk stratification and monitoring. The objective of this study was to investigate (a) whether early spot UNa predicts 24-h diuretic efficiency and (b) the clinical factors associated with early spot UNa in patients with AHF and concomitant renal dysfunction (RD).

METHODS

This is a post hoc analysis of the IMPROVE-HF trial, in which 160 patients with AHF and RD (estimated glomerular filtrate rate [eGFR] <60 mL/min/1.73 m2) were included. Diuretic efficiency was calculated as the net fluid output produced per 40 mg of furosemide equivalents in 24 h. The association between early spot UNa and diuretic efficiency and clinical variables associated with UNa were evaluated using multivariate linear regression analysis. The contribution of the exposures in the predictability of the models was assessed with the coefficient of determination (R2).

RESULTS

The mean age of the study population was 78 ± 8 years. The median (interquartile range) diuretic efficiency, early spot UNa, aminoterminal pro-brain natriuretic peptide, and eGFR were 747 (490-1,167) mL, 90 mmol/L (65-111), 7,765 pg/mL (3,526-15,369), and 33.7 ± 11.3 mL/min/1.73 m2, respectively. In a multivariate setting, lower UNa was significantly and nonlinearly associated with lower diuretic efficiency (p = 0.001), explaining the 44.4% of the model predictability. Natremia and surrogates of congestion emerged as the main factors related to UNa.

CONCLUSIONS

In patients with AHF and RD at presentation, early spot UNa was inversely related to 24-h diuretic efficiency.

Spot urinary sodium in acute decompensation of advanced heart failure and dilutional hyponatremia: insights from DRAIN trial

BACKGROUND

Diuretic resistance portends a poor prognosis in acute heart failure, especially in advanced stages. Early identification of a poor response to diuretics may help to improve treatment and outcomes. Spot natriuresis (UNa⁺) at 2 h from the start of intravenous furosemide has been proposed as an early indicator of diuretic response. Our paper aimed to determine the role of early natriuresis in patients hospitalized with advanced chronic heart failure (ACHF) and high risk of diuretic resistance.

METHODS AND RESULTS

We performed a sub-analysis of the DRAIN trial, a randomized clinical trial on 80 patients with acute decompensation of ACHF (NYHA IV, EF ≤ 30%) with low systolic blood pressure (≤ 110 mmHg) and dilutional hyponatremia (sodium ≤ 135 mMol/L) at admission. Patients were divided into two groups according to spot urinary sodium excretion (high: UNa⁺  > 50 or low: ≤ 50 mEq/L) at 2 h from furosemide administration. Twenty-eight patients (35%) showed a low natriuretic response. As compared to the other patients, this group showed lower daily urinary output (2275 ± 790 vs 3849 ± 2034 mL, p < 0.001), lower body weight reduction after 48 h (1.55 ± - 1.66 vs - 3.55 ± - 2.93 kg, p < 0.001), higher incidence of worsening renal function (32% vs 10%, p 0.02) and increasing rather than reducing NT-proBNP at 72 h (p 0.02).

CONCLUSIONS

In patients with ACHF and dilutional hyponatremia, low natriuresis after furosemide is an early marker of poor diuretic response and correlates with higher NT-proBNP and higher incidence of worsening renal function at 72 h.

Role of electrolyte concentrations and renin-angiotensin-aldosterone activation in the staging of canine heart disease

Background

Refractory congestive heart failure (CHF) and associated diuretic resistance are not well defined.

Objectives

To characterize renal function, electrolyte concentrations, indices of diuretic efficacy, and renin‐angiotensin‐aldosterone system (RAAS) activation in dogs with naturally occurring heart disease (HD) in American College of Veterinary Internal Medicine stages B1, B2, C, and D and to determine their usefulness in defining HD stages.

Animals

Group 1:149 dogs with HD stages B1, B2, C, and D. Group 2:22 dogs with HD stages C and D.

Methods

Group 1: Renal parameters, serum and urine electrolyte and diuretic concentrations, and urine aldosterone concentrations were measured. Medication dosages and measured variables were compared among stages. Correlation of furosemide dosages to serum concentrations was explored. Group 2: Angiotensin‐converting enzyme activity and RAAS components were measured and compared among CHF stages.

Results

Serum chloride concentration was the best differentiator of HD stage. Furosemide PO dosages (≤6 mg/kg/day) were weakly correlated with serum furosemide concentrations, whereas higher dosages were not significantly correlated. Angiotensin‐converting enzyme inhibitor dosage and RAAS inhibition were greater in stage D, compared to stage C dogs.

Conclusions and Clinical Importance

Hypochloremia is a useful marker for stage D HD in dogs. Poor furosemide dosage correlation to serum concentration may indicate variable and poor absorption, especially at higher dosages, advanced disease, or both. A small number of stage D dogs met proposed criteria for diuretic resistance. Greater RAAS inhibition in stage D versus stage C indicates effectiveness of RAAS‐suppressive treatments in this group of dogs with refractory CHF.

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.

Early urine electrolyte patterns in patients with acute heart failure

Aims

We conducted a prospective study of emergency department (ED) patients with acute heart failure (AHF) to determine if worsening HF (WHF) could be predicted based on urinary electrolytes during the first 1–2 h of ED care. Loop diuretics are standard therapy for AHF patients. A subset of patients hospitalized for AHF will develop a blunted natriuretic response to loop diuretics, termed diuretic resistance, which often leads to WHF. Early detection of diuretic resistance could facilitate escalation of therapy and prevention of WHF.

Methods and results

Patients were eligible if they had an ED AHF diagnosis, had not yet received intravenous diuretics, had a systolic blood pressure > 90 mmHg, and were not on dialysis. Urine electrolytes and urine output were collected at 1, 2, 4, and 6 h after diuretic administration. Worsening HF was defined as clinically persistent or WHF requiring escalation of diuretics or administration of intravenous vasoactives after the ED stay. Of the 61 patients who qualified in this pilot study, there were 10 (16.3%) patients who fulfilled our definition of WHF. At 1 h after diuretic administration, patients who developed WHF were more likely to have low urinary sodium (9.5 vs. 43.0 mmol; P < 0.001) and decreased urine sodium concentration (48 vs. 80 mmol/L; P = 0.004) than patients without WHF. All patients with WHF had a total urine sodium of <35.4 mmol at 1 h (100% sensitivity and 60% specificity).

Conclusions

One hour after diuretic administration, a urine sodium excretion of <35.4 mmol was highly suggestive of the development of WHF. These relationships require further testing to determine if early intervention with alternative agents can prevent WHF.

Hyponatremia in Acute Heart Failure in Relation to Hematocrit Levels: Clinical Relevance and Prognostic Implication

BACKGROUND

Hyponatremia is the most common electrolyte abnormality found in hospitalized patients with acute heart failure (AHF) and is related to poor prognosis. This study sought to evaluate: (1) the different prognostic impact of dilutional versus depletional hyponatremia, evaluating short- and long-term outcome; (2) the relationship between both types of hyponatremia and intravenous furosemide dose, renal function changes, and persistent congestion at discharge.

METHODS

This retrospective single-center study included 233 consecutive patients with a primary diagnosis of AHF. Hyponatremia was defined as serum sodium < 135 mEq/L, which could be either dilutional (hematocrit < 35%) or depletional (hematocrit ≥35%). Persistent congestion was defined as a congestion score ≥2 at discharge. Patients were followed 180 days for occurrence of death or rehospitalization for AHF.

RESULTS

Hyponatremia was present in 68/233 patients with 27 cases classified as dilutional hyponatremia versus 41 as depletional. The proportion of patients with persistent congestion was higher in the dilutional hyponatremia group, but similar in the depletional hyponatremia group (52 vs. 81 vs. 58%; p = 0.02). After adjustment for important baseline characteristics, dilutional hyponatremia was significantly associated with the risk of death or rehospitalization for AHF at 60 days (HR 2.17 [1.08-4.37]; p = 0.03) and 180 days (HR 1.88 [1.10-3.21]; p = 0.02). In contrast, depletional hyponatremia was only significantly associated with the same endpoint at 180 days (HR 1.64 [1.05-2.57]; p = 0.03).

CONCLUSIONS

Low hematocrit levels in AHF patients with hyponatremia characterize a population that is more difficult to decongest and has poor clinical outcome. In contrast, patients with hyponatremia but normal hematocrit are better decongested and have better short-term outcome.

[Update on heart failure]

Heart failure is one of the leading diseases in internal medicine worldwide. Because of the increase in population aging, the incidence and prevalence of heart insufficiency is rising annually and is now the most frequent individual diagnosis among hospitalized patients in Germany. The mortality rate has recently been reduced, since new pharmacological options, especially the inhibition of neprilysin, have been developed; however, heart failure is still associated with a high mortality and morbidity rate. Thus, guideline-conform treatment is of crucial importance. This review highlights and summarizes the current scientific knowledge on heart failure from 2017 and 2018 based on the guidelines of the European Society of Cardiology. New aspects about heart failure with middle grade limitations of ejection fraction are firstly presented. Subsequently, innovative diagnostic and therapeutic strategies, new pharmacological developments and handling of frequent comorbidities in patients with heart failure are discussed.

Pharmacodynamic assessment of diuretic efficacy and braking in a furosemide continuous infusion model

INTRODUCTION

Diuretic failure is a potential life-ending event but is unpredictable and poorly understood. The objectives of this study were to evaluate pharmacodynamic markers of furosemide-induced diuresis and to investigate mechanisms of diuretic braking in dogs receiving constant rate infusion (CRI) of furosemide.

ANIMALS

Six healthy male dogs.

METHODS

Raw data and stored samples from one arm of a previously published study were further analyzed to mechanistically investigate causes of diuretic braking in these dogs. Urine volume was recorded hourly during a 5-h furosemide CRI. Urine and blood samples were collected hourly to measure serum and urine electrolytes, urine aldosterone, and plasma and urine furosemide. Serum electrolyte fractional excretion was calculated. Urine sodium concentration was indexed to urine potassium (uNa:uK) and urine furosemide (uNa:uFur) concentrations, plasma furosemide concentration was indexed to urine furosemide concentration (pFur:uFur), and urine aldosterone was indexed to urine creatinine (UAldo:C). Temporal change and the relationship to urine volume were evaluated for these measured and calculated variables.

RESULTS

Urine volume was significantly correlated with urine electrolyte amounts and with uNa:uK. The ratio of pFur:uFur decreased during the infusion, whereas furosemide excretion was unchanged.

CONCLUSIONS

There was a strong relationship between urine volume and absolute urine electrolyte excretion. Urine volume was strongly correlated to uNa:uK, giving it potential as a spot indicator of urine production during diuresis. The decrease in uNa:uK over time during the infusion is consistent with mineralocorticoid modification of urinary electrolyte excretion, supporting renin-angiotensin-aldosterone activation as a cause of diuretic braking in this model.

Association between hypo- and hyperkalemia and outcome in acute heart failure patients: the role of medications

BACKGROUND

The interaction between chronic medications on admission and the association between serum potassium level and outcome in patients with acute heart failure (AHF) are unknown.

METHODS

Observational intercontinental study of patients admitted with AHF. 15954 patients were included from 12 cohorts in 4 continents. Main outcome was 90-day mortality. Clinical presentation (medication use, hemodynamics, comorbidities), demographic, echocardiographic, and biochemical data on admission were recorded prospectively in each cohort, with prospective adjudication of outcomes.

RESULTS

Positive and negative linear relationships between 90-day mortality and sK+ above 4.5 mmol/L (hyperkalemia) and below 3.5 mmol/L (hypo-kalemia) were observed. Hazard ratio for death was 1.46 [1.34-1.58] for hyperkalemia and 1.22 [1.06-1.40] for hypokalemia. In a fully adjusted model, only hyperkalemia remained associated with mortality (HR 1.03 [1.02-1.04] for each 0.1 mmol/l change of sK+ above 4.5 mmol/L). Interaction tests revealed that the association between hyperkalemia and outcome was significantly affected by chronic medications. The association between hyperkalemia and mortality was absent for patients treated with beta blockers and in those with preserved renal function.

CONCLUSIONS

In patients with AHF, sK+ > 4.5 mmol/L appears to be associated with 90-day mortality. B-blockers have potentially a protective effect in the setting of hyperkalemia.

Impact of a Telehealth Program With Voice Recognition Technology in Patients With Chronic Heart Failure: Feasibility Study

Background

Despite the advances in the diagnosis and treatment of heart failure (HF), the current hospital-oriented framework for HF management does not appear to be sufficient to maintain the stability of HF patients in the long term. The importance of self-care management is increasingly being emphasized as a promising long-term treatment strategy for patients with chronic HF.

Objective

The objective of this study was to evaluate whether a new information communication technology (ICT)–based telehealth program with voice recognition technology could improve clinical or laboratory outcomes in HF patients.

Methods

In this prospective single-arm pilot study, we recruited 31 consecutive patients with chronic HF who were referred to our institute. An ICT-based telehealth program with voice recognition technology was developed and used by patients with HF for 12 weeks. Patients were educated on the use of this program via mobile phone, landline, or the Internet for the purpose of improving communication and data collection. Using these systems, we collected comprehensive data elements related to the risk of HF self-care management such as weight, diet, exercise, medication adherence, overall symptom change, and home blood pressure. The study endpoints were the changes observed in urine sodium concentration (uNa), Minnesota Living with Heart Failure (MLHFQ) scores, 6-min walk test, and N-terminal prohormone of brain natriuretic peptide (NT-proBNP) as surrogate markers for appropriate HF management.

Results

Among the 31 enrolled patients, 27 (87%) patients completed the study, and 10 (10/27, 37%) showed good adherence to ICT-based telehealth program with voice recognition technology, which was defined as the use of the program for 100 times or more during the study period. Nearly three-fourths of the patients had been hospitalized at least once because of HF before the enrollment (20/27, 74%); 14 patients had 1, 2 patients had 2, and 4 patients had 3 or more previous HF hospitalizations. In the total study population, there was no significant interval change in laboratory and functional outcome variables after 12 weeks of ICT-based telehealth program. In patients with good adherence to ICT-based telehealth program, there was a significant improvement in the mean uNa (103.1 to 78.1; P=.01) but not in those without (85.4 to 96.9; P=.49). Similarly, a marginal improvement in MLHFQ scores was only observed in patients with good adherence (27.5 to 21.4; P=.08) but not in their counterparts (19.0 to 19.7; P=.73). The mean 6-min walk distance and NT-proBNP were not significantly increased in patients regardless of their adherence.

Conclusions

Short-term application of ICT-based telehealth program with voice recognition technology showed the potential to improve uNa values and MLHFQ scores in HF patients, suggesting that better control of sodium intake and greater quality of life can be achieved by this program.

Early treatment with tolvaptan improves diuretic response in acute heart failure with renal dysfunction

BACKGROUND

Poor response to diuretics is associated with worse prognosis in patients with acute heart failure (AHF). We hypothesized that treatment with tolvaptan improves diuretic response in patients with AHF.

METHODS

We performed a secondary analysis of the AQUAMARINE open-label randomized study in which a total of 217 AHF patients with renal impairment (eGFR < 60 mL/min/1.73 m²) were randomized to either tolvaptan or conventional treatment. We evaluated diuretic response to 40 mg furosemide or its equivalent based on two different parameters: change in body weight and net fluid loss within 48 h.

RESULTS

The mean time from patient presentation to randomization was 2.9 h. Patients with a better diuretic response showed greater relief of dyspnea and less worsening of renal function. Tolvaptan patients showed a significantly better diuretic response measured by diuretic response based both body weight [-1.16 (IQR -3.00 to -0.57) kg/40 mg vs. -0.51 (IQR -1.13 to -0.20) kg/40 mg; P < 0.001] and net fluid loss [2125.0 (IQR 1370.0-3856.3) mL/40 mg vs. 1296.3 (IQR 725.2-1726.5) mL/40 mg; P < 0.001]. Higher diastolic blood pressure and use of tolvaptan were independent predictors of a better diuretic response.

CONCLUSIONS

Better diuretic response was associated with greater dyspnea relief and less WRF. Early treatment with tolvaptan significantly improved diuretic response in AHF patients with renal dysfunction.