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

Management of patients with heart failure and chronic kidney disease

Chronic kidney disease (CKD) and heart failure are often co-existing conditions due to a shared pathophysiological process involving neurohormonal activation and hemodynamic maladaptation. A wide range of pharmaceutical and interventional tools are available to patients with CKD, consisting of traditional ones with decades of experience and newer emerging therapies that are rapidly reshaping the landscape of medical care for this population. Management of patients with heart failure and CKD requires a stepwise approach based on renal function and the clinical phenotype of heart failure. This is often challenging due to altered drug pharmacokinetics interactions with various degrees of kidney function and frequent adverse effects from the therapy that lead to poor patient tolerance. Despite a great body of clinical evidence and guidelines that have offered various treatment options for patients with heart failure and CKD, respectively, patients with CKD are still underrepresented in heart failure clinical trials, especially for those with advanced CKD and end-stage renal disease (ESRD). Future studies are needed to better understand the generalizability of these therapeutic options among heart failures with different stages of CKD.

Rationale and Design of the DECONGEST (Diuretic Treatment in Acute Heart Failure with Volume Overload Guided by Serial Spot Urine Sodium Assessment) Study

AIMS

To evaluate whether early combination diuretic therapy guided by serial post-diuretic urine sodium concentration (UNa+) assessments in acute heart failure (AHF) facilitates safe and effective decongestion.

METHODS

The Diuretic Treatment in Acute Heart Failure with Volume Overload Guided by Serial Spot Urine Sodium Assessment (DECONGEST) study is a pragmatic, 2-centre, randomized, parallel-arm, open-label study, aiming to enrol 104 patients with AHF and clinically evident fluid overload, requiring treatment with intravenous loop diuretics. Patients are randomized to receive standard of care or a bundled approach comprising: (1) systematic post-diuretic UNa+ assessments until successful decongestion, defined as no remaining clinical signs of fluid overload with a post-diuretic UNa+ ≤80 mmol/L; (2) thrice-daily intravenous loop diuretic bolus therapy, with dosing according to estimated glomerular filtration rate; (3) upfront use of intravenous acetazolamide (500 mg OD); and (4) full nephron blockade with high-dose oral chlorthalidone (100 mg OD) and intravenous canreonate (200 mg OD) for diuretic resistance, defined as persisting signs of fluid overload with a post-diuretic UNa+ ≤80 mmol/L. The primary endpoint of the DECONGEST study is a hierarchical composite of (1) survival at 30 days; (2) days alive and out of hospital or care facility up to 30 days; and (3) greater relative decrease in natriuretic peptide levels from baseline to day 30.

CONCLUSION

The DECONGEST study aims to determine whether an intensive diuretic regimen focused on early combination therapy, guided by serial post-diuretic UNa+ assessments, safely enhances decongestion, warranting further evaluation in a larger trial powered for clinical events.

Role of spot urinary sodium in outpatients with heart failure

INTRODUCTION AND OBJECTIVES

Spot determination of urinary sodium (UNa+) has emerged as a useful tool for monitoring diuretic response in patients with acute heart failure (AHF). However, the evidence in outpatients is scarce. We aimed to examine the relationship between spot UNa+ levels and the risk of mortality and worsening heart failure (WHF) events in individuals with chronic HF.

METHODS

This observational and ambispective study included 1145 outpatients with chronic HF followed in a single center specialized HF clinic. UNa+ assessment was carried out 1-5 days before each visit. The endpoints of the study were the association between UNa+ and risk of a) long-term death and b) AHF-hospitalization and total WHF events (including AHF-hospitalization, emergency department visits or parenteral loop-diuretic administration in HF clinic), assessed by multivariate Cox and negative binomial regressions.

RESULTS

The mean±standard deviation of age was 73±11 years, 670 (58.5%) were men, 902 (78.8%) were on stable NYHA class II, and 595 (52%) had LFEF ≥50%. The median (interquartile range) UNa+ was 72 (51-94) mmol/L. Over a median follow-up of 2.63 (1.70-3.36) years, there were 293 (25.6%) deaths and 382 WHF events (244 AHF-admissions) in 233 (20.3%) patients. After multivariate adjustment, baseline UNa+ was inverse and linearly associated with the risk of total WHF (IRR, 1.07; 95%CI, 1.02-1.12; P=.007) and AHF-admissions (IRR, 1.08; 95%CI, 1.02-1.14; P=.012) and borderline associated with all-cause mortality (HR, 1.04; 95%CI, 0.99-1.09; P=.068).

CONCLUSIONS

In outpatients with chronic HF, lower UNa+ was associated with a higher risk of recurrent WHF events.

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.

Post-diuretic spot urine sodium assessment in acute heart failure: a retrospective analysis

AIMS

To provide real-world data on post-diuretic spot urine sodium concentration (UNa) assessment in acute heart failure (AHF) and its implications for treatment.

METHODS AND RESULTS

Automated query of the electronic medical record identified patients admitted to the cardiac intensive care unit of a single tertiary care hospital between November 2018 and December 2021, who received intravenous loop diuretics. Detailed manual chart review confirmed the AHF diagnosis. Stratification was performed based on whether post-diuretic UNa was assessed within 24 h of admission. AHF was confirmed in 340/380 identified patients. Post-diuretic UNa was assessed in 117 (34%), more frequently when ejection fraction was reduced and heart failure more advanced. Patients with versus without post-diuretic UNa assessment received higher doses of intravenous loop diuretics and more frequently acetazolamide and thiazide-like diuretics (p < 0.001 for all), resulting in similar urine output despite more advanced heart failure [2,488 mL (1,740-4,033 mL) vs. 2,400 mL (1,553-3,250 mL), respectively; p = 0.170]. Diuretic therapy remained more intense at discharge in the post-diuretic UNa group, with also a higher prescription rate of angiotensin-neprilysin inhibitors (p = 0.021). Serum creatinine increases/decreases were similarly frequent irrespectively from UNa assessment, with more dynamic changes observed in patients with UNa ≤ 80 mmol/L versus ≥ 81 mmol/L. After adjustments for baseline characteristics, the risk for death or heart failure readmission was similar in patients with versus without UNa assessment [HR (95%CI) = 1.43 (0.88-2.32); p = 0.150].

CONCLUSION

Post-diuretic UNa assessment in AHF was associated with more intense diuretic regimens, preserving urine output despite its use in a sicker population.

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).

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.

Fluid management in acute kidney injury: from evaluating fluid responsiveness towards assessment of fluid tolerance

Despite the widespread use of intravenous fluids in acute kidney injury (AKI), solid evidence is lacking. Intravenous fluids mainly improve AKI due to true hypovolaemia, which is difficult to discern at the bedside unless it is very pronounced. Empiric fluid resuscitation triggered only by elevated serum creatinine levels or oliguria is frequently misguided, especially in the presence of fluid intolerance syndromes such as increased extravascular lung water, capillary leak, intra-abdominal hypertension, and systemic venous congestion. While fluid responsiveness tests clearly identify patients who will not benefit from fluid administration (i.e. those without an increase in cardiac output), the presence of fluid responsiveness does not guarantee that fluid therapy is indicated or even safe. This review calls for more attention to the concept of fluid tolerance, incorporating it into a practical algorithm with systematic venous Doppler ultrasonography assessment to use at the bedside, thereby lowering the risk of detrimental kidney congestion in AKI.

Vitamin D Binding Protein and Renal Injury in Acute Decompensated Heart Failure

Background

Renal function in acute decompensated heart faiulre (ADHF) is a strong predictor of disease evolution and poor outcome. Current biomarkers for early diagnostic of renal injury in the setting of ADHF are still controversial, and their association to early pathological changes needs to be established. By applying a proteomic approach, we aimed to identify early changes in the differential urine protein signature associated with development of renal injury in patients hospitalised due to ADHF.

Materials and Methods

Patients (71 [64–77] years old) admitted at the emergency room with ADHF and hospitalised were investigated (N = 64). Samples (urine/serum) were collected at hospital admission (day 0) and 72 h later (day 3). Differential serum proteome was analysed by two-dimensional electrophoresis and matrix-assisted laser desorption/ionisation-time of flight (MALDI-ToF/ToF). Validation studies were performed using ELISA.

Results

Proteomic analysis depicted urinary vitamin D binding protein (uVDBP) as a two spots protein with increased intensity in ADHF and significant differences depending on the glomerular filtration rate (GFR). Urinary VDBP in patients with ADHF at hospitalisation was &gt; threefold higher than in healthy subjects, with the highest levels in those patients with ADHF already presenting renal dysfunction. At day 3, urine VDBP levels in patients maintaining normal renal function dropped to normal values (P = 0.03 vs. day 0). In contrast, urine VDBP levels remained elevated in the group developing renal injury, with values twofold above the normal range (P &lt; 0.05), while serum creatinine and GF levels were within the physiological range in this group. Urinary VDBP in ADHF positively correlated with markers of renal injury such as cystatin C and Kidney Injury Molecule 1 (KIM-1). By ROC analysis, urinary VDBP, when added to cystatin C and KIM-1, improved the prediction of renal injury in patients with ADHF.

Conclusion

We showed increased urine VDBP in patients with ADHF at hospital admission and a differential uVDBP evolution pattern at early stage of renal dysfunction, before pathological worsening of GFR is evidenced.

Hyponatraemia in heart failure: time for new solutions?

Hyponatraemia is very common in heart failure (HF), especially in decompensated patients. It is associated with increased mortality and morbidity and considered a marker of advanced disease. Recognition of hyponatraemia and its causes may help guide treatment strategy. Historically, therapy has primarily focused on water restriction, decongestion with loop diuretics in case of volume overload (dilutional hyponatraemia) and sodium repletion in case of depletion. In this review, we summarise the potential benefits of established and emerging HF therapies on sodium homeostasis, with a focus on dual vasopressin antagonists, angiotensin receptor-neprilysin inhibitors, sodium-glucose cotransporter 2 inhibitors and hypertonic saline, and propose a potential therapeutic approach for hyponatraemia in HF.

Inpatient Diuretic Management of Acute Heart Failure: A Practical Review

The inpatient treatment of acute heart failure (AHF) is aimed at achieving euvolemia, relieving symptoms, and reducing rehospitalization. Adequate treatment of AHF is rooted in understanding the pharmacokinetics and pharmacodynamics of select diuretic agents used to achieve decongestion. While loop diuretics remain the primary treatment of AHF, the dosing strategies of loop diuretics and the use of adjunct diuretic classes to augment clinical response can be complex. This review examines the latest strategies for diuretic management in patients with AHF, including dosing and monitoring strategies, interaction of diuretics with other medication classes, use adjunctive therapies, and assessing endpoints for diuretic. The goal of the review is to guide the reader through commonly encountered clinical scenarios and pitfalls in the diuretic management of patients with AHF.

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.

Altered Hemodynamics and End-Organ Damage in Heart Failure: Impact on the Lung and Kidney

Heart failure is characterized by pathologic hemodynamic derangements, including elevated cardiac filling pressures ("backward" failure), which may or may not coexist with reduced cardiac output ("forward" failure). Even when normal during unstressed conditions such as rest, hemodynamics classically become abnormal during stressors such as exercise in patients with heart failure. This has important upstream and downstream effects on multiple organ systems, particularly with respect to the lungs and kidneys. Hemodynamic abnormalities in heart failure are affected by processes that extend well beyond the cardiac myocyte, including important roles for pericardial constraint, ventricular interaction, and altered venous capacity. Hemodynamic perturbations have widespread effects across multiple heart failure phenotypes, ranging from reduced to preserved ejection fraction, acute to chronic disease, and cardiogenic shock to preserved perfusion states. In the lung, hemodynamic derangements lead to the development of abnormalities in ventilatory control and efficiency, pulmonary congestion, capillary stress failure, and eventually pulmonary vascular disease. In the kidney, hemodynamic perturbations lead to sodium and water retention and worsening renal function. Improved understanding of the mechanisms by which altered hemodynamics in heart failure affect the lungs and kidneys is needed in order to design novel strategies to improve clinical outcomes.

Cardiac biomarkers of heart failure in chronic kidney disease

Heart failure remains a continuing threat to patients with chronic kidney disease (CKD). Although various heart failure biomarkers have been applied for early detection, diagnosis and prognosis in CKD, these are easily affected by renal insufficiency thus limiting use in these patients. In this review, the major four groups of heart failure biomarkers are explored. These include those associated with: myocardial stretch, ie, brain natriuretic peptide (BNP), N-terminal pro-BNP (NT-proBNP) and mid-regional proatrial natriuretic peptide (MR-proANP); myocyte injury, ie, high-sensitivity troponin T (hsTnT), heart-type fatty acid-binding protein (H-FABP); fibrosis, matrix remodelling and inflammation, ie, soluble growth stimulating gene 2 (sST2), galectin-3 (Gal-3), growth differentiation factor-15 (GDF-15); and renal function, ie, neutrophil gelatinase-associated lipocalin (NGAL) kidney injury molecule-1 (KIM-1), cystatin C (CysC), urinary sodium and urinary albumin. This review highlights classic heart failure biomarkers with critical values adjusted to glomerular filtration rate, summarizes research progress of new heart failure biomarkers and future research directions. Because diagnostic and prognostic usefulness of a single time point biomarker is limited, biomarkers should be combined and monitored at multiple times for optimal clinical impact.