Early urine electrolyte patterns in patients with acute heart failure

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.

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.

Urine sodium concentration after intravenous furosemide in dogs with acute congestive heart failure and correlation with treatment efficacy

BACKGROUND

Poor natriuresis is a potential marker of diuretic resistance in dogs with acute congestive heart failure (CHF) but little is known about the relationship between urine sodium concentration (uNa) and frequency of successful decongestion. Supplemental O2 is a common treatment in dogs with severe CHF. The time from start to discontinuation of supplemental O2 therapy (DCSO2 ) typically reflects the time course and ease of decongestion.

HYPOTHESIS/OBJECTIVES

Urine Na concentration after IV administration of furosemide will be correlated with duration of treatment with supplemental O2 (timeO2 ) and the cumulative frequency of successful DCSO2 during hospitalization.

ANIMALS

Fifty-one dogs with acute CHF.

METHODS

Retrospective observational single center study.

RESULTS

Dogs with low uNa had significantly longer mean timeO2 than dogs with high uNa (uNa <87 mmol/L, 24.2 ± 2.6 hours vs uNa ≥87 mmol/L, 16.6 ± 1.7 hours; P = .02). Low uNa was correlated with lower cumulative frequency of DCSO2 (12 hour, 28%; 24 hour, 42%; 36 hour, 73%) compared to high uNa (12 hour, 28%; 24 hour, 88%; 36 hour, 96%; P = .005). History of PO loop diuretics, low serum chloride concentration (sCl), and high PCV were associated with low uNa. Urine Na concentration outperformed other metrics of diuretic responsiveness including weight loss.

CONCLUSIONS AND CLINICAL IMPORTANCE

Urine Na concentration after IV furosemide predicted timeO2 and cumulative frequency of DCSO2 in dogs with acute CHF, which likely reflects important aspects of diuretic responsiveness. Urine Na can assess diuretic responsiveness and treatment efficacy in dogs with CHF.

Spot urinary sodium as a prognostic marker for mortality in patients with acute decompensated heart failure

Introduction. Urinary sodium has been proposed as a prognostic marker and indicator of the diuretic response in patients with heart failure. However, study results are heterogeneous. Objective. To evaluate the spot urinary sodium level as a risk factor for mortality in patients with decompensated heart failure. Materials and methods. We conducted a case-control study nested in a prospective cohort of patients with decompensated heart failure. The primary outcome was mortality at 180 days. The risk factors associated with mortality were evaluated through a bivariate analysis. Differences in clinical variables between groups with urinary sodium greater than or lesser than 70 mEq/L were analyzed. Results. The study included 79 patients; 15 died at 180 days. Their mean age was 68.9 years (SD=± 13.8); 30 were women (38%), and 15 (18.9%) had urinary sodium <70 mEq/L. In the bivariate analysis, a significant association was found between mortality and past medical history of hospitalizations, SBP<90 mm Hg, the use of inotropes, and urinary sodium <70 mEq/L. Regarding clinical characteristics, patients with low urinary sodium level in the last year were hospitalized more frequently with hyponatremia and hypotension at admission. Conclusion. Patients with urinary sodium <70 mEq/L had more severe signs. In a bivariate analysis, urinary sodium was associated with mortality at 180 days.

Randomized controlled trial of urinE chemiStry guided aCute heArt faiLure treATmEnt (ESCALATE): Rationale and design

Diuresis to achieve decongestion is a central aim of therapy in patients hospitalized for acute decompensated heart failure (ADHF). While multiple clinical trials have investigated initial diuretic strategies for a designated period of time, there is a paucity of evidence to guide diuretic titration strategies continued until decongestion is achieved. The use of urine chemistries (urine sodium and creatinine) in a natriuretic response prediction equation accurately estimates natriuresis in response to diuretic dosing, but a randomized clinical trial is needed to compare a urine chemistry-guided diuresis strategy with a strategy of usual care. The urinE chemiStry guided aCute heArt faiLure treATmEnt (ESCALATE) trial is designed to test the hypothesis that protocolized diuretic therapy guided by spot urine chemistry through completion of intravenous diuresis will be superior to usual care and improve outcomes over the 14 days following randomization. ESCALATE will randomize and obtain complete data on 450 patients with acute heart failure to a diuretic strategy guided by urine chemistry or a usual care strategy. Key inclusion criteria include an objective measure of hypervolemia with at least 10 pounds of estimated excess volume, and key exclusion criteria include significant valvular stenosis, hypotension, and a chronic need for dialysis. Our primary outcome is days of benefit over the 14 days after randomization. Days of benefit combines patient symptoms captured by global clinical status with clinical state quantifying the need for hospitalization and intravenous diuresis. CLINICAL TRIAL REGISTRATION: NCT04481919.

Cardiovascular and renal effects of SGLT2 inhibitor initiation in acute heart failure: a meta-analysis of randomized controlled trials

BACKGROUND

We sought to compare cardiovascular outcomes, renal function, and diuresis in patients receiving standard diuretic therapy for acute heart failure (AHF) with or without the addition of SGLT2i.

METHODS AND RESULTS

Systematic search of three electronic databases identified nine eligible randomized controlled trials involving 2,824 patients. The addition of SGLT2i to conventional therapy for AHF reduced all-cause death (odds ratio [OR] 0.75; 95% CI 0.56-0.99; p = 0.049), readmissions for heart failure (HF) (OR 0.54; 95% CI 0.44-0.66; p < 0.001), and the composite of cardiovascular death and readmissions for HF (hazard ratio 0.71; 95% CI 0.60-0.84; p < 0.001). Furthermore, SGLT2i increased mean daily urinary output in liters (mean difference [MD] 0.45; 95% CI 0.03-0.87; p = 0.035) and decreased mean daily doses of loop diuretics in mg of furosemide equivalent (MD -34.90; 95% CI [- 52.58, - 17.21]; p < 0.001) without increasing the incidence worsening renal function (OR 0.75; 95% CI 0.43-1.29; p = 0.290).

CONCLUSION

SGLT2i addition to conventional diuretic therapy reduced all-cause death, readmissions for HF, and the composite of cardiovascular death or readmissions for HF. Moreover, SGLT2i was associated with a higher volume of diuresis with a lower dose of loop diuretics.

Natriuretic Response to Acetazolamide in Patients With Acute Heart Failure and Volume Overload

BACKGROUND

Acetazolamide facilitates decongestion in acute decompensated heart failure (ADHF).

OBJECTIVES

This study sought to investigate the effect of acetazolamide on natriuresis in ADHF and its relationship with outcomes.

METHODS

Patients from the ADVOR (Acetazolamide in Decompensated Heart Failure with Volume Overload) trial with complete data on urine output and urine sodium concentration (UNa) were analyzed. Predictors of natriuresis and its relationship with the main trial endpoints were evaluated.

RESULTS

This analysis included 462 of 519 patients (89%) from the ADVOR trial. During 2 days after randomization, UNa was 92 ± 25 mmol/L on average, and total natriuresis was 425 ± 234 mmol. Allocation to acetazolamide strongly and independently predicted natriuresis with a 16 mmol/L (19%) increase in UNa and 115 mmol (32%) greater total natriuresis. Higher systolic blood pressure, better renal function, higher serum sodium levels, and male sex also independently predicted both a higher UNa and greater total natriuresis. A stronger natriuretic response was associated with faster and more complete relief of signs of volume overload, and this effect was already significant on the first morning of assessment (P = 0.022). A significant interaction was observed between the effect of allocation to acetazolamide and UNa on decongestion (P = 0.007). Stronger natriuresis with better decongestion translated into a shorter hospital stay (P < 0.001). After multivariable adjustments, every 10 mmol/L UNa increase was independently associated with a lower risk of all-cause death or heart failure readmission (HR: 0.92; 95% CI: 0.85-0.99).

CONCLUSIONS

Increased natriuresis is strongly related to successful decongestion with acetazolamide in ADHF. UNa may be an attractive measure of effective decongestion for future trials. (Acetazolamide in Decompensated Heart Failure with Volume Overload [ADVOR]; NCT03505788).

The Prognostic Role of Spot Urinary Sodium and Chloride in a Cohort of Hospitalized Advanced Heart Failure Patients: A Pilot Study

Recent studies have demonstrated the prognostic value of spot urinary sodium (UNa+) in acutely decompensated chronic HF (ADCHF) patients. However, data on the prognostic role of UNa+ and spot urinary chloride (UCl-) in patients with advanced HF are limited. In the present prospective pilot study, we examined the predictive value of UNa+ and UCl- concentration at baseline, at 2 h and at 24 h after admission for all-cause mortality and HF rehospitalization up to 3 months post-discharge. Consecutive advanced HF patients (n = 30) admitted with ADCHF and aged > 18 years were included in the study. Loop diuretics were administered based on the natriuresis-guided algorithm recommended by the recent HF guidelines. Exclusion criteria were cardiogenic shock, acute coronary syndrome, estimated glomerular filtration rate < 15 mL/min/1.73 m2, severe hepatic dysfunction (Child-Pugh category C), and sepsis. UNa+ at baseline (Area Under the Curve (AUC) = 0.75, 95% Confidence Interval (CI) (0.58-0.93), p = 0.019) and at 2 h after admission (AUC = 0.80, 95% CI: 0.64-0.96, p = 0.005) showed good and excellent discrimination, respectively. UCl- at 2 h after admission (AUC = 0.75, 95%CI (0.57-0.93), p = 0.017) demonstrated good discrimination. In the multivariate logistic regression analysis, UNa+ at 2 h (p = 0.02) and dose of loop diuretics at admission (p = 0.03) were the only factors independently associated with the study outcome. In conclusion, UNa+ and UCl- may have a prognostic role in hospitalized advanced HF patients.

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.

The association between urinary sodium concentration (UNa) and outcomes of acute heart failure: a systematic review and meta-analysis

AIMS

Urinary sodium concentration (UNa) is a simple test advocated to assess diuretics efficacy and predict outcomes in acute heart failure (AHF). We performed a systematic review and meta-analysis to examine the association of UNa with outcomes of AHF.

METHODS AND RESULTS

We searched Embase and Medline for eligible studies that reported the association between UNa and outcomes of urinary output, weight loss, worsening renal function, length of hospital stay, re-hospitalization, worsening heart failure, and all-cause mortality in AHF. Nineteen observational studies out of 1592 screened records were included. For meta-analyses of outcomes, we grouped patients into high vs. low UNa, with most studies defining high UNa as &gt;48-65 mmol/L. In the high UNa group, pooled data showed a higher urinary output (mean difference 502 mL, 95% CI 323-681, P &lt; 0.01), greater weight loss (mean difference 1.6 kg, 95% CI 0.3-2.9, P = 0.01), and a shorter length of stay (mean difference -1.4 days, 95% CI -2.8 to -0.1, P = 0.03). There was no significant difference in worsening kidney function (OR 0.54, 95% CI 0.25-1.16, P = 0.1). Due to the small number of studies, we did not report pooled estimates for re-hospitalization and worsening heart failure. High UNa was associated with lower odds of 30-day (OR 0.27; 95% CI 0.14-0.49, P &lt; 0.01), 90-day (OR 0.39,95% CI 0.25-0.59, P &lt; 0.01) and 12-month (OR 0.35; 95% CI 0.20-0.61, P &lt; 0.01) mortality.

CONCLUSION

High UNa after diuretic administration is associated with higher urinary output, greater weight loss, shorter length of stay, and lower odds of death. UNa is a promising marker of diuretic efficacy in AHF which should be confirmed in randomized trials.

Role of Early Assesment of Diuresis and Natriuresis in Detecting In-Hospital Diuretic Resistance in Acute Heart Failure

Background and Purpose: European Guidelines recommend early evaluation of diuresis and natriuresis after the first administration of diuretic to identify patients with insufficient diuretic response during acute heart failure. The aim of this work is to evaluate the prevalence and characteristics of patients with insufficient diuretic response according to this new algorithm.

Methods: Prospective observational single centre study of consecutive patients with acute heart failure and congestive signs. Clinical evaluation, echocardiography and blood tests were performed. Diuretic naïve patients received 40 mg of intravenous furosemide. Patients on an oupatient diuretic regimen received 2 times the ambulatory dose. The diuresis volume was assessed 6 h after the first loop diuretic administration, and a spot urinary sample was taken after 2 h. Insufficient diuretic response was defined as natriuresis <70 mEq/L or diuresis volume <600 ml.

Results: From January 2020 to December 2021, 73 patients were included (59% males, median age 76 years). Of these, 21 patients (28.8%, 95%CI 18.4; 39.2) had an insufficient diuretic response. Diuresis volume was <600 ml in 13 patients (18.1%), and 12 patients (16.4%) had urinary sodium <70 mEq/L. These patients had lower systolic blood pressure, worse glomerular filtration rate, and higher aldosterone levels. Ambulatory furosemide dose was also higher. These patients required more frequently thiazides and inotropes during admission.

Conclusion: The diagnostic algorithm based on diuresis and natriuresis was able to detect up to 29% of patients with insufficient diuretic response, who showed some characteristics of more advanced disease.

Classic and Novel Mechanisms of Diuretic Resistance in Cardiorenal Syndrome

Despite the incompletely understood multiple etiologies and underlying mechanisms, cardiorenal syndrome is characterized by decreased glomerular filtration and sodium avidity. The underlying level of renal sodium avidity is of primary importance in driving a congested heart failure phenotype and ultimately determining the response to diuretic therapy. Historically, mechanisms of kidney sodium avidity and resultant diuretic resistance were primarily extrapolated to cardiorenal syndrome from non-heart failure populations. Yet, the mechanisms appear to differ between these populations. Recent literature in acute decompensated heart failure has refuted several classically accepted diuretic resistance mechanisms and reshaped how we conceptualize diuretic resistance mechanisms in cardiorenal syndrome. Herein, we propose an anatomically based categorization of diuretic resistance mechanisms to establish the relative importance of specific transporters and translate findings toward therapeutic strategies. Within this categorical structure, we discuss classic and novel mechanisms of diuretic resistance.

Efficacy and safety of dapagliflozin in acute heart failure: Rationale and design of the DICTATE-AHF trial

BACKGROUND

Dapagliflozin, a sodium-glucose cotransporter-2 inhibitor, reduces cardiovascular death and worsening heart failure in patients with chronic heart failure and reduced ejection fraction. Early initiation during an acute heart failure (AHF) hospitalization may facilitate decongestion, improve natriuresis, and facilitate safe transition to a beneficial outpatient therapy for both diabetes and heart failure.

OBJECTIVE

The objective is to assess the efficacy and safety of initiating dapagliflozin within the first 24 hours of hospitalization in patients with AHF compared to usual care.

METHODS

DICTATE-AHF is a prospective, multicenter, open-label, randomized trial enrolling a planned 240 patients in the United States. Patients with type 2 diabetes hospitalized with hypervolemic AHF and an estimated glomerular filtration rate of at least 30 mL/min/1.73m² are eligible for participation. Patients are randomly assigned 1:1 to dapagliflozin 10 mg once daily or structured usual care until day 5 or hospital discharge. Both treatment arms receive protocolized diuretic and insulin therapies. The primary endpoint is diuretic response expressed as the cumulative change in weight per cumulative loop diuretic dose in 40 mg intravenous furosemide equivalents. Secondary and exploratory endpoints include inpatient worsening AHF, 30-day hospital readmission for AHF or diabetic reasons, change in NT-proBNP, and measures of natriuresis. Safety endpoints include the incidence of hyper/hypoglycemia, ketoacidosis, worsening kidney function, hypovolemic hypotension, and inpatient mortality.

CONCLUSIONS

The DICTATE-AHF trial will establish the efficacy and safety of early initiation of dapagliflozin during AHF across both AHF and diabetic outcomes in patients with diabetes.

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.

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.

Usefulness of natriuresis to predict in-hospital diuretic resistance

BACKGROUND

Urinary sodium excretion predicts long-term adverse events after discharge in patients with acute heart failure (AHF). The role of natriuresis as an early marker of poor diuretic response during an AHF episode has been scarcely investigated. We sought to evaluate whether early natriuresis or its change during heart failure hospitalization is associated with the development of in-hospital diuretic resistance (DR).

METHODS

This was a prospective, observational single center study of consecutive patients with AHF. Urine electrolytes were estimated from a spot urine sample within the first 6 hours following the first diuretic dose and 48 hours after admission. In-hospital DR was defined as poor diuretic response based on diuretic efficiency metrics and persistent congestion despite an intensive diuretic protocol.

RESULTS

Between January and December 2018, 143 patients were admitted for AHF. Of these, 102 fulfilled the inclusion criteria (60% males, median age 77 years [interquartile range [IQR]: 69-83), and 20 patients (19.6%) met the definition of DR. Early natriuresis was lower in patients with DR than in non-resistant patients (46 mEq/L [IQR: 38.5-80.0] vs 97.5 mEq/L [IQR: 70.5-113.5], P<0.001). Urinary sodium <50 mEq/L increased the risk of developing in-hospital DR (risk ratio: 5.011 [95% confidence interval 2.408-10.429], P<0.001). The area under the receiver operating characteristic curve for early natriuresis to predict DR was 0.791 (95% confidence interval 0.681-0.902, P<0.001).

CONCLUSIONS

Initial natriuresis can predict in-hospital DR. Patients with urinary sodium <50 mEq/L have an increased risk of early resistance to diuretic treatment.

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.

Utility of Urine Biomarkers and Electrolytes for the Management of Heart Failure

PURPOSE OF REVIEW

To provide insight into the role of urine biomarkers and electrolytes for the management of heart failure.

RECENT FINDINGS

The age-dependent decrease in glomerular filtration rate due to loss of functional nephrons occurs at a faster pace in heart failure, potentially exacerbated by episodes of acute kidney injury. Urine biomarkers have not convincingly demonstrated to improve detection of irreversible renal damage and predict long-term renal trajectories, compared with serial creatinine measurements. Recent data show that natriuresis and diuretic response track poorly with glomerular filtration, but strongly with prognosis. Urine sodium concentration > 50-70 mmol/L was recently put forward through expert consensus as an adequate diuretic response. The value of urine biomarkers to detect structural renal damage in heart failure remains unsure and the latter is probably uncommon, especially over short-term follow-up. Urine electrolytes on the other hand predict diuretic response accurately and may allow better diuretic titration.

Bioanalytical Assessment of Plasma Concentrations of Angiotensin-Converting Enzyme II Inhibitors and Angiotensin Receptor Blockers: A Pilot Study Among Patients Hospitalized With Acute Heart Failure

BACKGROUND

Although angiotensin-converting enzyme II inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs) improve chronic heart failure (HF) outcomes, their potential harms and benefits in acute HF (AHF) is less clear.

STUDY QUESTION

We explored the relationship between ACEI or ARB plasma concentrations among patients with AHF with in-hospital change in estimated glomerular filtration rate (eGFR).

DATA SOURCES AND STUDY DESIGN

From August 2016-June 2017, patients with AHF prescribed an outpatient ACEI or ARB were enrolled before AHF treatment. All patients were given twice their home dose of diuretic intravenously and received clinical care at the discretion of the medical team. Of 61 patients in the parent study, saved plasma from 34 who were prescribed an outpatient ACEI or ARB was included in this substudy.

MEASURES AND OUTCOMES

Liquid chromatography-tandem mass spectrometry was performed to assess ACEI or ARB plasma concentrations before AHF treatment. Change in eGFR was computed using the Chronic Kidney Disease Epidemiology Collaboration equation, which adjusts for age, sex, and race; diuretic dose and enrollment eGFR were used to adjust for HF severity. Multiple linear regression adjusting for enrollment eGFR and diuretic dose was performed to examine the relationship between drug concentration (undetectable/low vs. in/above-range) and in-hospital change in eGFR.

RESULTS

Of 34 patients with AHF, median age was 63 years (interquartile range, 58-78 years), 19 (55.9%) were women, median eGFR at enrollment was 55.6 mL/min (interquartile range, 35.2-75.3 mL/min), and for 11 (32.4%), no ACEI or ARB was detectable in plasma. Medication concentrations in- or above-reference range were associated with in-hospital decrease in eGFR of 8.3 mL/min (95% confidence interval, 15.3-1.3 mL/min decrease), after adjusting for enrollment eGFR and diuretic treatment.

CONCLUSIONS

Bioanalytical assessment of medication levels may be useful to guide in-hospital ACEI and ARB therapy for patients with AHF.

Lower urine sodium predicts longer length of stay in acute heart failure patients: Insights from the ROSE AHF trial

Background

In patients hospitalized with acute heart failure (AHF), low urine sodium concentration (U_Na) after diuretic treatment may identify patients at risk for longer length of stay (LOS) and adverse events. We investigated the prognostic significance of 24‐hour cumulative postdiuretic urine sodium concentration in a multicenter clinical trial population.

Methods

The Renal Optimization Strategies Evaluation AHF (ROSE AHF) trial randomized 360 patients with AHF and renal dysfunction receiving intravenous diuretic to dopamine, nesiritide, or placebo. Sodium concentration was measured in cumulative urine sample collected during the first 24 hours after randomization in 298 patients. Based on prior studies, lower U_Na was defined as ≤60 mmol/L.

Results

Lower U_Na was present in 142 (48%) patients, who had longer LOS (7 days vs 5 days, P < .001) and less 72‐hour weight loss (5.7 lb vs 9.0 lb, P < .001). These associations persisted after controlling for baseline estimated glomerular filtration rate and outpatient furosemide dose. Lower U_Na did not modify the null effects of dopamine or nesiritide on clinical outcomes. Results were similar for spot rather than cumulative 24‐hour U_Na concentration.

Conclusion

In patients hospitalized for AHF and renal dysfunction, U_Na ≤ 60 mmol/L during the first 24 hours of diuresis identifies patients at risk for prolonged hospitalization but does not provide an indication for adjunctive dopamine or nesiritide.

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.