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

Contemporary Decongestive Strategies in Acute Heart Failure

Congestion is the primary driver of hospital admissions in patients with heart failure and the key determinant of their outcome. Although intravenous loop diuretics remain the predominant agents used in the setting of acute heart failure, the therapeutic response is known to be variable, with a significant subset of patients discharged from the hospital with residual hypervolemia. In this context, urinary sodium excretion has gained attention both as a marker of response to loop diuretics and as a marker of prognosis that may be a useful clinical tool to guide therapy. Several decongestive strategies have been explored to improve diuretic responsiveness and removal of excess fluid. Sequential nephron blockade through combination diuretic therapy is one of the most used methods to enhance natriuresis and counter diuretic resistance. In this article, I provide an overview of the contemporary decongestive approaches and discuss the clinical data on the use of add-on diuretic therapy. I also discuss mechanical removal of excess fluid through extracorporeal ultrafiltration with a brief review of the results of landmark studies. Finally, I provide a short overview of the strategies that are currently under investigation and may prove helpful in this setting.

Renal Sodium Avidity in Heart Failure

BACKGROUND

Increased renal sodium avidity is a hallmark feature of the heart failure syndrome.

SUMMARY

Increased renal sodium avidity refers to the inability of the kidneys to elicit potent natriuresis in response to sodium loading. This eventually causes congestion, which is a major contributor to hospital admissions and mortality in heart failure.

KEY MESSAGES

Important novel concepts such as the renal tamponade hypothesis, accelerated nephron loss, and the role of hypochloremia, the sympathetic nervous system, inflammation, the lymphatic system, and interstitial sodium buffers are involved in the pathophysiology of renal sodium avidity. A good understanding of these concepts is crucially important with respect to treatment recommendations regarding dietary sodium restriction, fluid restriction, rapid up-titration of guideline-directed medical therapies, combination diuretic therapy, natriuresis-guided diuretic therapy, use of hypertonic saline, and ultrafiltration.

Evaluation and estimation of diuretic activity of the linalyl acetate in the rats

This study aimed to explore the diuretic activity of linalyl acetate (LA). LA is an essential oil, it is an integral phyto-constituent of various plants. In this study, acute and chronic diuretic activities were explored by measuring the levels of different electrolytes and pH in the urine of experimental rats. Rats were divided into five groups. The control group was given 10 mg/kg normal saline, the treated group was given 10 mg/kg furosemide, and the remaining 3 groups received different doses of LA including 25, 50, and 75 mg/kg through intraperitoneal route, to determine its diuretic potential. Urine volume for acute diuretic activity was measured for 6 hours however for chronic diuretic activity was measured for 6 days. For a comparative study of LA with a control group and treated group with reference drug, diuretic index was used. Moreover, the underlying mechanism of the diuretic activity was also explored by comparing atropine, L-NAME, and indomethacin. The results of each group with 6 rats in each group were obtained by ± standard error of the mean of every group. Analysis of Variance (ANOVA) was used for statistical analysis. Results revealed that the LA 75 mg/kg dose showed comparable results as of furosemide. Moreover, this study revealed the involvement of muscarinic receptors to produce diuresis in comparison with atropine with very little involvement of prostanoids and no effect on NO pathway induced by indomethacin and L-NAME respectively. It is concluded that LA possess anti-diuretic potential. Muscarinic receptors might be involved in producing diuretic effects.

Prognostic Impact of Induced Natriuresis in Acute Decompensated Heart Failure and Its Association with Intraabdominal Pressure and Other Congestion Markers: A Multimodal Approach to Congestion Assessment

BACKGROUND

Congestion is an essential issue in patients with heart failure (HF). Standard treatments do not usually achieve decongestion, and various strategies have been proposed to guide treatment, such as determination of natriuresis. After starting treatment with loop diuretics, we postulate that initial natriuresis might help treatment titration, decongestion, and improve prognosis.

METHODS

It was a prospective and observational study. Patients admitted with the diagnosis of HF decompensation were eligible. An assessment of congestion was performed during the first 48 h.

RESULTS

A total of 113 patients were included. A poor diuretic response was observed in 39.8%. After the first 48 h, patients with a greater diuretic response on admission (NaU > 80 mmol/L) showed fewer pulmonary b lines (12 vs. 15; p = 0.084), a lower IVC diameter (18 mm vs. 22 mm; p = 0.009), and lower IAP figures (11 mmHg vs. 13 mmHg; p = 0.041). Survival analysis tests demonstrated significant differences showing a higher proportion of all-cause mortality (ACM) and HF rehospitalization in the poor-diuretic-response group (log-rank test = 0.020).

CONCLUSIONS

Up to 40% of the patients presented a poorer diuretic response at baseline, translating into worse outcomes. Patients with an optimal diuretic response showed significantly higher abdominal decongestion at 48 h and a better prognosis regarding ACM and/or HF rehospitalizations.

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.

Serial evaluation of loop diuretic efficiency following left ventricular assist device implantation

More than 50% of heart failure (HF) patients require diuretic therapy after left ventricular assist device (LVAD). Although few data related to diuretic response (DR) exist in stage D patients, tubular sodium reabsorption may be clinically prognostic independent of estimated glomerular filtration rate (eGFR) and proteinuria within this cohort. We aimed to characterize DR serially before and after LVAD implantation in a stage D population. We conducted a prospective, observational cohort study of HF patients receiving diuretics with plans to undergo LVAD implantation. We measured urine sodium (UNa) and creatinine (UCr) at three points after diuretic therapy: pre-LVAD, post-LVAD prior to discharge, and as an outpatient. Prior to LVAD, patients (N = 19) had an average eGFR of 54.0 ± 18.0 mL/min/1.73 m2, spot UNa of 74.8 ± 28.0 mmol/L, and fractional excretion of sodium (FENa) of 3.1 ± 2.7%. Pre-LVAD, eGFR did not correlate with spot UNa nor FENa (p > 0.05 for both). LVAD implantation did not improve DR post-LVAD (mean change FENa per 40 mg IV furosemide 0.5 ± 1.0%; p = 0.84), and 90% of patients required loop diuretics at 90 days post-surgery. Improved hemodynamics following LVAD may not improve DR or tubular function; larger studies are needed to confirm our results and assess the utility of DR to predict post-LVAD outcomes.

Natriuresis-guided diuretic therapy in acute heart failure: a pragmatic randomized trial

Measurement of natriuresis has been suggested as a reliable, easily obtainable biomarker for assessment of the response to diuretic treatment in patients with acute heart failure (AHF). Here, to assess whether natriuresis-guided diuretic therapy in patients with AHF improves natriuresis and clinical outcomes, we conducted the pragmatic, open-label Pragmatic Urinary Sodium-based algoritHm in Acute Heart Failure trial, in which 310 patients (45% female) with AHF requiring treatment with intravenous loop diuretics were randomly assigned to natriuresis-guided therapy or standard of care (SOC). In the natriuresis-guided arm, natriuresis was determined at set timepoints, prompting treatment intensification if spot urinary sodium levels were <70 mmol l-1. The dual primary endpoints were 24 h urinary sodium excretion and a combined endpoint of time to all-cause mortality or adjudicated heart failure rehospitalization at 180 days. The first primary endpoint was met, as natriuresis in the natriuresis-guided and SOC arms was 409 ± 178 mmol arm versus 345 ± 202 mmol, respectively (P = 0.0061). However, there were no significant differences between the two arms for the combined endpoint of time to all-cause mortality or first heart failure rehospitalization, which occurred in 46 (31%) and 50 (31%) of patients in the natriuresis-guided and SOC arms, respectively (hazard ratio 0.92 [95% confidence interval 0.62-1.38], P = 0.6980). These findings suggest that natriuresis-guided therapy could be a first step towards personalized treatment of AHF. ClinicalTrials.gov registration: NCT04606927 .

Combination Diuretic Therapy to Counter Renal Sodium Avidity in Acute Heart Failure: Trials and Tribulations

In contrast to significant advances in the management of patients with chronic heart failure over the past few years, there has been little change in how patients with acute heart failure are treated. Symptoms and signs of fluid overload are the primary reason for hospitalization of patients who experience acute decompensation of heart failure. Intravenous loop diuretics remain the mainstay of therapy in this patient population, with a significant subset of them showing suboptimal response to these agents leading to incomplete decongestion at the time of discharge. Combination diuretic therapy, that is, using loop diuretics along with an add-on agent, is a widely applied strategy to counter renal sodium avidity through sequential blockade of sodium absorption within renal tubules. The choice of the second diuretic is affected by several factors, including the site of action, the anticipated secondary effects, and the available evidence on their efficacy and safety. While the current guidelines recommend combination diuretic therapy as a viable option to overcome suboptimal response to loop diuretics, it is also acknowledged that this strategy is not supported by strong evidence and remains an area of uncertainty. The recent publication of landmark studies has regenerated the interest in sequential nephron blockade. In this article, we provide an overview of the results of the key studies on combination diuretic therapy in the setting of acute heart failure and discuss their findings primarily with regard to the effect on renal sodium avidity and cardiorenal outcomes.

In-Hospital Observation on Oral Diuretics After Treatment for Acute Decompensated Heart Failure: Evaluating the Utility

BACKGROUND

Following treatment for acute decompensated heart failure, in-hospital observation on oral diuretics (OOD) is recommended, assuming it provides actionable information on discharge diuretic dosing and thus reduces readmissions.

METHODS

In the Mechanisms of Diuretic Resistance (MDR) cohort, we analyzed in-hospital measures of diuretic response, provider's decisions, and diuretic response ≈30 days postdischarge. In a Yale multicenter cohort, we assessed if in-hospital OOD was associated with 30-day readmission risk. The main objective of this study was to evaluate the utility of in-hospital OOD.

RESULTS

Of the 468 patients in the MDR cohort, 57% (N=265) underwent in-hospital OOD. During the OOD, weight change and net fluid balance correlated poorly with each other (r=0.36). Discharge diuretic dosing was similar between patients who had increased, stable, or decreased weight (decreased discharge dose from OOD dose in 77% versus 72% versus 70%, respectively), net fluid status (decreased discharge dose from OOD dose in 100% versus 69% versus 74%, respectively), and urine output (decreased discharge dose from OOD dose in 69% versus 79% versus 72%, respectively) during the 24-hour OOD period (P>0.27 for all). In participants returning at 30 days for formal quantification of outpatient diuretic response (n=98), outpatient and inpatient OOD natriuresis was poorly correlated (r=0.26). In the Yale multicenter cohort (n=18 454 hospitalizations), OOD occurred in 55% and was not associated with 30-day hospital readmission (hazard ratio, 0.98 [95% CI, 0.93-1.05]; P=0.51).

CONCLUSIONS

In-hospital OOD did not provide actionable information on diuretic response, was not associated with outpatient dose selection, did not predict subsequent outpatient diuretic response, and was not associated with lower readmission rate. Additional research is needed to replicate these findings and understand if these resources could be better allocated elsewhere.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT02546583.

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.

A Machine Learning Model to Predict Diuretic Resistance

BACKGROUND

Volume overload is a common complication encountered in hospitalized patients, and the mainstay of therapy is diuresis. Unfortunately, the diuretic response in some individuals is inadequate despite a typical dose of loop diuretics, a phenomenon called diuretic resistance. An accurate prediction model that predicts diuretic resistance using predosing variables could inform the right diuretic dose for a prospective patient.

METHODS

Two large, deidentified, publicly available, and independent intensive care unit (ICU) databases from the United States were used-the Medical Information Mart for Intensive Care III (MIMIC) and the Philips eICU databases. Loop diuretic resistance was defined as <1400 ml of urine per 40 mg of diuretic dose in 24 hours. Using 24-hour windows throughout admission, commonly accessible variables were obtained and incorporated into the model. Data imputation was performed using a highly accurate machine learning method. Using XGBoost, several models were created using train and test datasets from the eICU database. These were then combined into an ensemble model optimized for increased specificity and then externally validated on the MIMIC database.

RESULTS

The final ensemble model was composed of four separate models, each using 21 commonly available variables. The ensemble model outperformed individual models during validation. Higher serum creatinine, lower systolic blood pressure, lower serum chloride, higher age, and female sex were the most important predictors of diuretic resistance (in that order). The specificity of the model on external validation was 92%, yielding a positive likelihood ratio of 3.46 while maintaining overall discrimination (C-statistic 0.69).

CONCLUSIONS

A diuretic resistance prediction model was created using machine learning and was externally validated in ICU populations. The model is easy to use, would provide actionable information at the bedside, and would be ready for implementation in existing electronic medical records. This study also provides a framework for the development of future machine learning models.

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.

Multimodal Strategies for the Diagnosis and Management of Refractory Congestion. An Integrated Cardiorenal Approach

Refractory congestion is common in acute and chronic heart failure, and it significantly impacts functional class, renal function, hospital admissions, and survival. In this paper, the pathophysiological mechanisms involved in cardiorenal syndrome and the interplay between heart failure and chronic kidney disease are reviewed. Although the physical exam remains key in identifying congestion, new tools such as biomarkers or lung, vascular, and renal ultrasound are currently being used to detect subclinical forms and can potentially impact its management. Thus, an integrated multimodal diagnostic algorithm is proposed. There are several strategies for treating congestion, although data on their efficacy are scarce and have not been validated. Herein, we review the optimal use and monitorization of different diuretic types, administration route, dose titration using urinary volume and natriuresis, and a sequential diuretic scheme to achieve a multitargeted nephron blockade, common adverse events, and how to manage them. In addition, we discuss alternative strategies such as subcutaneous furosemide, hypertonic saline, and albumin infusions and the available evidence of their role in congestion management. We also discuss the use of extracorporeal therapies, such as ultrafiltration, peritoneal dialysis, or conventional hemodialysis, in patients with normal or impaired renal function. This review results from a multidisciplinary view involving both nephrologists and cardiologists.

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.

Impact of Loop Diuretic on Outcomes in Patients with Heart Failure and Reduced Ejection Fraction

PURPOSE OF REVIEW

Loop diuretics are the cornerstone of the treatment of congestion in heart failure patients. The manuscript aims to summarize the most updated information regarding the use of loop diuretics in heart failure.

RECENT FINDINGS

Diuretic response can be highly variable between patients and needs to be carefully evaluated during and after the hospitalization. Diuretic resistance can lead to residual congestion which affects prognosis and can be difficult to detect. The effect of loop diuretics on long-term prognosis remains uncertain but patients with advanced heart failure typically have renal dysfunction and are more inclined to develop loop diuretic resistance, which may lead to an incomplete decongestion and thus to a worse prognosis. Loop diuretics are the most potent diuretics available and their use is recommended in order to alleviate symptoms, improve exercise capacity, and reduce hospitalizations in patients with heart failure. Their use should be limited to the lowest dose necessary to maintain euvolemia because a low dose does not increase the risk of decompensation but reduce the risk of adverse effects and allow the up-titration of disease-modifying drugs.

Estimating urine volume from the urine creatinine concentration

Spot determinations of the urine creatinine concentration are widely used as a substitute for 24-hour urine collections. Expressed as the amount excreted per gram of creatinine, urine concentrations in a single-voided sample are often used to estimate 24-hour excretion rates of protein, sodium, potassium, calcium, magnesium, urea, and uric acid. These estimates are predicated on the assumption that daily creatinine excretion equals 1 gm (and that a urine creatinine concentration of 100 mg/dl reflects a 1 Liter 24-hour urine volume). Such estimates are invalid if the serum creatinine concentration is rising or falling. In addition, because creatinine excretion is determined by muscle mass, the assumption that 24-hour urine creatinine excretion equals 1 gm yields a misleading estimate at the extremes of age and body size. In this review we evaluate seven equations for the accuracy of their estimates of urine volume based on urine creatinine concentrations in actual and idealized patients. None of the equations work well in patients who are morbidly obese or in patients with markedly decreased muscle mass. In other patients, estimates based on a reformulation of the Cockroft-Gault equation are reasonably accurate. A recent study based on this relationship found a high strength of correlation between estimated and measured urine output with chronic kidney disease (CKD) studied in the African American Study of Kidney Disease (AASK) trial and for the patients studied in the CKD Optimal Management with Binders and NictomidE (COMBINE) trial. However, the equation systematically underestimated urine output in the AASK trial. Hence, an intercept was added to account for the bias in estimated output. A more rigorous equation, derived from an ambulatory Swiss population, that includes body mass index and models the non-linear accelerated decline in creatinine excretion with age, could potentially be more accurate in overweight and elderly patients. In addition to extremes of body weight and muscle mass, decreased dietary intake or reduced hepatic synthesis of creatine, a precursor of creatinine, or ingestion of creatine supplements will also result in inaccurate estimates. These limitations must be appreciated to rationally use predictive equations to estimate urine volume. If the baseline urine creatinine concentration is determined in a sample of known volume, subsequent urine creatinine concentrations will reveal actual urine output as well as the change in urine output. Given the constraints of the various estimating equations, a single baseline timed collection may be more useful strategy for monitoring urine volume than entering anthropomorphic data into a calculator.

Natriuresis guided therapy in acute heart failure: rationale and design of the Pragmatic Urinary Sodium-based Treatment algoritHm in Acute Heart Failure (PUSH-AHF) trial

Aims

Insufficient diuretic response frequently occurs in patients admitted for acute heart failure (HF) and is associated with worse clinical outcomes. Recent studies have shown that measuring natriuresis early after hospital admission could reliably identify patients with a poor diuretic response during hospitalization who might require enhanced diuretic treatment. This study will test the hypothesis that natriuresis‐guided therapy in patients with acute HF improves natriuresis and clinical outcomes.

Methods

The Pragmatic Urinary Sodium‐based treatment algoritHm in Acute Heart Failure (PUSH‐AHF) is a pragmatic, single‐centre, randomized, controlled, open‐label study, aiming to recruit 310 acute HF patients requiring treatment with intravenous loop diuretics. Patients will be randomized to natriuresis‐guided therapy or standard of care. Natriuresis will be determined at set time points after initiation of intravenous loop diuretics, and treatment will be adjusted based on the urinary sodium levels in the natriuresis‐guided group using a pre‐specified stepwise approach of increasing doses of loop diuretics and the initiation of combination diuretic therapy. The co‐primary endpoint is 24‐h urinary sodium excretion after start of loop diuretic therapy and a combined endpoint of all‐cause mortality or first HF rehospitalization at 6 months. Secondary endpoints include 48‐ and 72‐h sodium excretion, length of hospital stay, and percentage change in N‐terminal pro brain natriuretic peptide at 48 and 72 h.

Conclusion

The PUSH‐AHF study will investigate whether natriuresis‐guided therapy, using a pre‐specified stepwise diuretic treatment approach, improves natriuresis and clinical outcomes in patients with acute HF.

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

BACKGROUND

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

METHODS AND RESULTS

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

CONCLUSIONS

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