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

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.

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.

Comparative effectiveness and safety of bolus vs. continuous infusion of loop diuretics: Results from the MIMIC-III Database

BACKGROUND

It is unclear whether fluid management goals are best achieved by bolus injection or continuous infusion of loop diuretics. In this study, we compared the effectiveness and safety of a continuous infusion with that of a bolus injection when an increased loop diuretic dosage is required in intensive care unit (ICU) patients.

METHODS

We obtained data from the MIMIC-III database for patients who were first-time ICU admissions and required an increased diuretic dosage. Patients were excluded if they had an estimated glomerular filtration rate <15 ml/min/1.73 m², were receiving renal replacement therapy, had a baseline systolic blood pressure <80 mmHg, or required a furosemide dose <120 mg. The patients were divided into a continuous group and a bolus group. Propensity score matching was used to balance patients' background characteristics.

RESULTS

The final dataset included 807 patients (continuous group, n = 409; bolus group, n = 398). After propensity score matching, there were 253 patients in the bolus group and 231 in the continuous group. The 24 h urine output per 40 mg of furosemide was significantly greater in the continuous group than in the bolus group (234.66 ml [95% confidence interval (CI) 152.13-317.18, p < 0.01]). There was no significant between-group difference in the incidence of acute kidney injury (odds ratio 0.96, 95% CI 0.66-1.41, p = 0.85).

CONCLUSIONS

Our results indicate that a continuous infusion of loop diuretics may be more effective than a bolus injection and does not increase the risk of acute kidney injury in patients who need an increased diuretic dosage in the ICU.

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.

Natriuresis as a Way to Assess the Effectiveness of Diuretic Therapy for Acute Decompensated Heart Failure: Data from a Pilot Study

Aim. To analyze the clinical significance of the sodium level in a single urine test obtained 2 hours after the first dose of a loop diuretic was administered in patients with acute decompensation of chronic heart failure (ADHF).

Material and methods. An observational study was conducted on the basis of a rapid-care hospital. The concentration of sodium in urine analysis obtained 2 hours after intravenous administration of the first dose of loop diuretic and natriuresis for the first day of hospitalization were evaluated. The development of resistance to diuretics was taken as the primary endpoint (the need to increase the daily dose of furosemide by more than 2 times compared to the initial one or the addition of another class of diuretic drugs).

Results. 25 patients with ADHF were included. The average age of patients was 69.0±14.8 years, 16 (64%) of them were men. The average left ventricular ejection fraction was 49.0±13.5%. The level of the N‐terminal fragment of the brain natriuretic peptide (NT-proBNP) was 3416 (2128; 5781) pg/ml. The average sodium concentration in the urine analysis obtained 2 hours after the start of treatment was 100.6±41.0 mmol / l. The concentration of sodium in urine for the first day was 102.2±39.0 mmol/l. 2 hours after the start of treatment, the sodium concentration in a single urine test was less than 50 mmol/l in 5 (20%) patients. Upon further observation, oligoanuria (defined as diuresis of less than 400 ml within 24 hours) developed in 2 of them. Oligoanuria was not detected among patients whose sodium concentration was more than 50 mmol/l. The need for escalation (any increase in the dose of a loop diuretic and/or the addition of another class of diuretic drugs) arose in 7 (28%) patients; at the same time, we diagnosed the development of resistance to diuretics in 5 (20%) of them. Resistance to diuretics was more common among patients with a sodium concentration in a single urine test obtained 2 hours after the start of furosemide administration, less than 50 mmol/l (p=0.037); when dividing the recruited patient population into subgroups with a sodium concentration in a single urine test ≥50 mmol/l and <50 mmol/l there was no significant difference in the need for any escalation of diuretic therapy [3 (60%) vs 4 (20%), p=0.07].

Conclusion. Resistance to diuretics is more common among patients with a sodium concentration in a single urine test obtained 2 hours after the first dose of furosemide, less than 50 mmol / l. Evaluation of natriuresis allows to identify insufficient effectiveness of diuretic therapy already at the beginning of treatment.

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.

Urine biochemistry assessment in the sequential evaluation of renal function: Time to think outside the box

Urine biochemistry (UB) remains a controversial tool in acute kidney injury (AKI) monitoring, being considered to be of limited value both in terms of AKI diagnosis and prognosis. However, many criticisms can be made to the studies that have established the so called “pre-renal paradigm” (used for decades as the essential physiological basis for UB assessment in AKI) as well as to more recent studies suggesting that UB has no utility in daily clinical practice. The aim of this article is to describe our hypothesis on how to interpret simple and widely recognized urine biochemical parameters from a novel perspective, propose the rationale for their sequential assessment and demonstrate their usefulness in AKI monitoring, especially in the critical care setting.

Rationale and Design of the Efficacy of a Standardized Diuretic Protocol in Acute Heart Failure Study

AIMS

Although acute heart failure (AHF) with volume overload is treated with loop diuretics, their dosing and type of administration are mainly based upon expert opinion. A recent position paper from the Heart Failure Association (HFA) proposed a step-wise pharmacologic diuretic strategy to increase the diuretic response and to achieve rapid decongestion. However, no study has evaluated this protocol prospectively.

METHODS AND RESULTS

The Efficacy of a Standardized Diuretic Protocol in Acute Heart Failure (ENACT-HF) study is an international, multicentre, non-randomized, open-label, pragmatic study in AHF patients on chronic loop diuretic therapy, admitted to the hospital for intravenous loop diuretic therapy, aiming to enrol 500 patients. Inclusion criteria are as follows: at least one sign of volume overload (oedema, ascites, or pleural effusion), use ≥ 40 mg of furosemide or equivalent for >1 month, and a BNP > 250 ng/L or an N-terminal pro-B-type natriuretic peptide > 1000 pg/L. The study is designed in two sequential phases. During Phase 1, all centres will treat consecutive patients according to the local standard of care. In the Phase 2 of the study, all centres will implement a standardized diuretic protocol in the next cohort of consecutive patients. The protocol is based upon the recently published HFA algorithm on diuretic use and starts with intravenous administration of two times the oral home dose. It includes early assessment of diuretic response with a spot urinary sodium measurement after 2 h and urine output after 6 h. Diuretics will be tailored further based upon these measurements. The study is powered for its primary endpoint of natriuresis after 1 day and will be able to detect a 15% difference with 80% power. Secondary endpoints are natriuresis and diuresis after 2 days, change in congestion score, change in weight, in-hospital mortality, and length of hospitalization.

CONCLUSIONS

The ENACT-HF study will investigate whether a step-wise diuretic approach, based upon early assessment of urinary sodium and urine output as proposed by the HFA, is feasible and able to improve decongestion in AHF with volume overload.

Renoprotection by long-term low-dose tolvaptan in patients with heart failure and hyponatremia

AIMS

In previous randomized controlled trials, the use of tolvaptan (TLV) at a fixed dose of 30 mg/day for 1 year did not provide renal benefits in patients with heart failure (HF). This retrospective, cohort study examined the renoprotective effects of long-term, flexible-dose, and lower-dose TLV use.

METHODS AND RESULTS

Tolvaptan users were defined as patients receiving TLV for at least 180 consecutive days or those who continued it until death, any cardiac events, or renal replacement therapy even if it was taken for <180 days. Of a total of 584 HF patients, 78 TLV users were identified. The median age, baseline B-type natriuretic peptide, and estimated glomerular filtration rate (eGFR) were 71 years, 243 pg/mL, and 54 mL/min/1.73 m² , respectively. During follow-up (median, 461 days), TLV use (median average dose, 7.5 mg/day) was associated with frequent dose reductions of loop diuretics (incidence rate ratio [IRR], 1.5; 95% confidence interval [CI], 1.1-2.2), particularly in patients with serum sodium ≤135 mEq/L (IRR, 2.9; 95% CI, 1.5-5.7) (P_interaction  = 0.04). In a mixed effects model, propensity score (PS)-matched TLV users had higher eGFRs over time than PS-matched never-users (P < 0.01). The entire cohort analyses (N = 584) yielded similar results. The renal benefit of TLV in terms of annualized eGFR slope was more pronounced in patients with lower sodium levels (P_interaction  = 0.03). This effect modification was extinguished when patients who underwent a loop diuretic dose reduction during the follow-up period were excluded from the analysis.

CONCLUSIONS

Long-term, flexible-dose, and low-dose TLV use was associated with better renal function, particularly in hyponatremic HF, possibly due to its loop diuretic dose-sparing effect in the long term.

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.

Intensification of pharmacological decongestion but not the actual daily loop diuretic dose predicts worse chronic heart failure outcome: insights from TIME-CHF

BACKGROUND

Both loop diuretics (LDs) and congestion have been related to worse heart failure (HF) outcome. The relationship between the cause and effect is unknown. The aim of this study was to investigate the interaction between congestion, diuretic use and HF outcome.

METHODS

Six hundred and twenty-two chronic HF patients from TIME-CHF were studied. Congestion was measured by means of a clinical congestion index (CCI). Loop diuretic dose was considered at baseline and month 6. Treatment intensification was defined as the increase in LD dose over 6 months or loop diuretic and thiazide or thiazide-like diuretic co-administration. The end-points were survival and HF hospitalisation-free survival.

RESULTS

High-LD dose at baseline and month 6 (≥ 80 mg of furosemide per day) was not identified as an independent predictor of outcome. CCI at baseline remained independently associated with impaired survival [hazard ratio (HR) 1.34, (95% confidence interval) (95% CI) (1.20-1.50), p < 0.001] and HF hospitalisation-free survival [HR 1.09, 95% CI (1.02-1.17), p = 0.015]. CCI at month 6 was independently associated with HF hospitalisation-free survival [HR 1.24, 95% CI (1.11-1.38), p < 0.001]. Treatment intensification was independently associated with survival [HR 1.75, 95% CI (1.19-1.38), p = 0.004] and HF hospitalisation-free survival [HR 1.69, 95% CI (1.22-2.35), p = 0.002]. Patients undergoing treatment intensification resulting in decongestion had better outcome than patients with persistent (worsening) congestion despite LD dose up-titration (p < 0.001).

CONCLUSION

Intensification of pharmacological decongestion but not the actual LD dose was related to poor outcome in chronic HF. If treatment intensification translated into clinical decongestion, outcome was better than in case of persistent or worsening congestion.