Hypochloremia, Diuretic Resistance, and Outcome in Patients With Acute Heart Failure

Admission and discharge sodium: Chloride ratio in acute heart failure - The importance of electrolytes

BACKGROUND

Chloride has prognostic implications in heart failure (HF). The sodium:chloride (Na:Cl) ratio gathers information of both ions.

OBJECTIVES

To study the prognostic impact of Na:Cl ratio in acute HF.

METHODS

We retrospectively analysed patients included in an acute HF cohort in 2009-2010.

PRIMARY ENDPOINT

all-cause mortality.

FOLLOW-UP

1-year from admission to study the impact of admission Na:Cl ratio; 1-year post-discharge to study the discharge ratio impact. ROC curves of the association of Na, Cl, and the Na:Cl ratio with 1-year mortality were determined and the AUC compared. The association of Na:Cl ratio with mortality was assessed in multivariate analyses.

RESULTS

We studied 616 patients. Median admission Na:Cl ratio = 1.34 (1.31-1.38). During 1-year since admission, 229 patients died, AUC for death-association of admission Na, Cl and Na:Cl ratio = 0.42 (0.38-0.47), 0.39 (0.35-0.44) and 0.58 (0.53-0.63), respectively, with significant difference between Na:Cl ratio curve and the others. When admission Na:Cl ratio ≥ 1.34, the multivariate-adjusted death-risk was 1.41 (1.04-1.89); 1.32 (1.04-1.68), per each 0.1 increase in ratio. In-hospital death rate was 4.1 %, median discharge Na:Cl ratio = 1.40 (1.37-1.45). During 1-year post-discharge, 205 patients (34.9 %) died; AUC for Na, Cl and Na:Cl ratio: 0.45 (0.40-0.50), 0.41 (0.36-0.46) and 0.57 (0.52-0.62), with differences between Na:Cl ratio curve and the others. When discharge Na:Cl ratio ≥ 1.43 (percentile 66.7), the adjusted-HR of death was 1.43 (1.04-1.97), p = 0.03, 1.54 (1.23-1.92) per 0.1 increase.

CONCLUSIONS

Elevated Na:Cl ratio is independently associated with all-cause death. Per each 0.1 increase in Na:Cl ratio at admission and discharged, there was a 32 % and 54 % higher risk, respectively.

Association between serum chloride levels and estimated glomerular filtration rate among US adults: evidence from NHANES 1999-2018

PURPOSE

Chloride, the predominant anion in extracellular fluid from humans, is essential to maintaining homeostasis. One important metric for thoroughly assessing kidney function is the estimated glomerular filtration rate (eGFR). However, the relationship between variations in serum chloride concentration and eGFR in general populations has been poorly studied. Therefore, the purpose of this study is to elucidate the correlation between serum chloride levels and eGFR within the United States' adult population.

METHODS

This cohort study was conducted using data from the National Health and Nutrition Examination Survey (NHANES), which covered the years 1999-2018. We employed multiple linear regression analysis and subgroup analysis to evaluate the correlation between serum chloride concentration and eGFR. To examine the nonlinear association between serum chloride levels and eGFR, restricted cubic spline analyses were employed.

RESULTS

Data from 49,008 participants in this cohort study were used for the chloride analysis. In the comprehensively adjusted model, a noteworthy inverse relationship was discovered between chloride plasma concentration and eGFR. Restricted cubic spline analyses revealed a significant nonlinear relationship between chloride levels and eGFR (P for overall < 0.001 and P for nonlinear < 0.001). A significant interaction was observed between eGFR and plasma chloride concentration (all P < 0.001 for interaction) among the subgroups characterized by sex, household income to poverty ratio, BMI, hypertension, and diabetes.

CONCLUSION

Our findings suggest that higher levels of chloride plasma concentration were linked to decreased eGFR. These findings underscore the significance of monitoring chloride plasma concentration as a potential indicator for identifying individuals at risk of developing chronic kidney disease (CKD).

Evaluation and Management of Kidney Dysfunction in Advanced Heart Failure: A Scientific Statement From the American Heart Association

Early identification of kidney dysfunction in patients with advanced heart failure is crucial for timely interventions. In addition to elevations in serum creatinine, kidney dysfunction encompasses inadequate maintenance of sodium and volume homeostasis, retention of uremic solutes, and disrupted endocrine functions. Hemodynamic derangements and maladaptive neurohormonal upregulations contribute to fluctuations in kidney indices and electrolytes that may recover with guideline-directed medical therapy. Quantifying the extent of underlying irreversible intrinsic kidney disease is crucial in predicting whether optimization of congestion and guideline-directed medical therapy can stabilize kidney function. This scientific statement focuses on clinical management of patients experiencing kidney dysfunction through the trajectory of advanced heart failure, with specific focus on (1) the conceptual framework for appropriate evaluation of kidney dysfunction within the context of clinical trajectories in advanced heart failure, including in the consideration of advanced heart failure therapies; (2) preoperative, perioperative, and postoperative approaches to evaluation and management of kidney disease for advanced surgical therapies (durable left ventricular assist device/heart transplantation) and kidney replacement therapies; and (3) the key concepts in palliative care and decision-making processes unique to individuals with concomitant advanced heart failure and kidney disease.

Serum Chloride and the Response to Acetazolamide in Patients With Acute Heart Failure and Volume Overload: A Post Hoc Analysis From the ADVOR Trial

BACKGROUND

Chloride plays a crucial role in renal salt sensing. This study investigates whether serum chloride is associated with clinical outcomes and decongestive response to acetazolamide in patients with acute decompensated heart failure.

METHODS

This post hoc analysis includes all 519 patients from the ADVOR trial (Acetazolamide in Decompensated Heart Failure With Volume Overload), randomized to intravenous acetazolamide or matching placebo on top of intravenous loop diuretics. The impact of baseline serum chloride on the main trial end points and the treatment effect of acetazolamide was assessed, as was the evolution of serum chloride under decongestive treatment.

RESULTS

Hypochloremia (<96 mmol/L) and hyperchloremia (>106 mmol/L) were present in 80 (15%) and 53 (10%), respectively, at baseline. Hypochloremia was associated with significantly slower decongestion, a longer length of hospital stay, and increased risk of all-cause mortality and heart failure readmissions. Acetazolamide increased the odds of successful decongestion and reduced length of stay irrespectively of baseline serum chloride levels. No statistically significant interaction between serum chloride levels and the effect of acetazolamide on death or heart failure readmissions was observed. The placebo group exhibited a progressive decline in serum chloride, which was effectively prevented by acetazolamide (P<0.001).

CONCLUSIONS

Hypochloremia is associated with diuretic resistance and worse clinical outcomes. Add-on acetazolamide therapy improves decongestion across the entire range of serum chloride and prevents the drop in chloride levels caused by loop diuretic monotherapy.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03505788.

Prevalence and prognostic role of hypochloremia in patients with acute heart failure in Ethiopia: A single-center retrospective analysis

BACKGROUND

In patients with heart failure (HF), multiple electrolyte disorders are common, and recent studies have shown that chloride disorders play a significant role in the prognosis of HF. Data about the prevalence and prognostic role of hypochloremia in patients with acute HF (AHF) are scarce in African nations, including Ethiopia. Hence, this study aimed to assess the prevalence, associated factors, and prognostic role of hypochloremia in patients with AHF in Ethiopia.

METHODS

This was a single-center retrospective analysis of AHF patients, aged ≥15 years, with chloride determination upon admission to the medical wards and medical ICU of Yekatit 12 Hospital Medical College, Addis Ababa, Ethiopia, from July 1, 2022, to July 1, 2023. Statistical Package for Social Sciences, version 26, was used to enter and analyze the data. Descriptive analysis was used to summarize clinical profiles, laboratory data, and outcomes of AHF patients stratified by the presence and absence of hypochloremia. Logistic regression analysis was used to determine the factors associated with hypochloremia and to assess the association of hypochloremia and other factors with in-hospital mortality in patients with AHF. A two-tailed P value <0.05 was regarded as statistically significant.

RESULTS

A total of 267 AHF patients who had chloride determination on admission were included in this study; the mean age was 56.7 years (standard deviation: 18.6), and the gender-based distribution of the patients was nearly equal. The prevalence of hypochloremia was 36.7%. Diastolic blood pressure <60 mm Hg [adjusted odds ratio (AOR) = 3.63, 95% confidence interval (CI), 1.04, 12.72] and hyponatremia (AOR = 29.20, 95% CI, 13.21, 64.56) were significantly associated with hypochloremia. The in-hospital mortality rate was higher in AHF patients with hypochloremia (16.3%) compared to those without hypochloremia (4.7%). The odds of in-hospital mortality among AHF patients with hypochloremia were 2.8 times higher compared to patients without hypochloremia (AOR = 2.82, 95% CI: 1.08, 7.04) after adjusting for ICU admission, systolic blood pressure < 120 mm Hg and diastolic blood pressure < 60 mm Hg.

CONCLUSIONS

This study revealed a high prevalence of hypochloremia among patients with AHF. Low diastolic blood pressure and hyponatremia were significantly associated with the development of hypochloremia. Most importantly, AHF patients with hypochloremia had a higher in-hospital mortality rate compared to those without hypochloremia. Hence, hypochloremia on admission should be considered a potential prognostic factor in patients with AHF, and further research with a larger sample size is needed to support the findings of this study.

Inverse association between serum chloride levels and the risk of atrial fibrillation in chronic kidney disease patients

Background

Electrolyte abnormalities are common symptoms of chronic kidney disease (CKD), but previous studies have mainly focussed on serum potassium and sodium levels. Chloride is an important biomarker for the prognosis of various diseases. However, the relationship between serum chloride levels and atrial fibrillation (AF) in CKD patients is unclear.

Objective

In this study, we sought to determine the association between serum chloride homeostasis and AF in CKD patients.

Methods

In this retrospective cohort study, we included patients who met the diagnostic criteria for CKD in China between 2000 and 2021. Competing risk regression for AF was performed. The associations of the baseline serum chloride concentration with heart failure (HF) and stroke incidence were also calculated by competing risk regression. The association of baseline serum chloride levels with all-cause death was determined by a Cox regression model.

Results

The study cohort comprised 20 550 participants. During a median follow-up of 350 days (interquartile range, 123-730 days), 211 of the 20 550 CKD patients developed AF. After multivariable adjustment, every decrease in the standard deviation of serum chloride (5.02 mmol/l) was associated with a high risk for AF [sub-hazard ratio (sHR) 0.78, 95% confidence interval (CI) 0.65-0.94, P = .008]. These results were also consistent with those of the stratified and sensitivity analyses. According to the fully adjusted models, the serum chloride concentration was also associated with a high risk for incident HF (sHR 0.85, 95% CI 0.80-0.91, P < .001), a high risk for incident stroke (sHR 0.87, 95% CI 0.81-0.94, P < .001), and a high risk for all-cause death [hazard ratio (HR) 0.82, 95% CI 0.73-0.91, P < .001].

Conclusion

In this CKD population, serum chloride levels were independently and inversely associated with the incidence of AF. Lower serum chloride levels were also associated with an increased risk of incident HF, stroke, and all-cause death.

Prognostic value of hypochloremia on mortality in patients with heart failure: a systematic review and meta-analysis

AIMS

Electrolyte imbalances are common in patients with heart failure. Several studies have shown that a low serum chloride level is associated with adverse outcomes in hospitalized patients with acute heart failure and in outpatients with chronic heart failure. We performed a systematic review and meta-analysis to assess the association of hypochloremia with all-cause mortality in patients with heart failure.

METHODS

Data search was conducted from inception through 1 February 2023, using the following MeSH terms: ('chloride' OR 'hypochloremia') AND 'heart failure'. Studies evaluating the association between serum chloride and all-cause mortality in patients with heart failure were included. The predefined primary outcome was all-cause mortality. Pooled hazard ratios and 95% confidence intervals (CIs) were used as effect estimates and calculated with a random-effects model; fixed-effects model and leave-one-out sensitivity analyses were also performed.

RESULTS

A total of 15 studies, involving 25 848 patients, were included. The prevalence of hypochloremia ranged from 8.6 to 31.5%. Follow-up time ranged from 6 to 67 months. Hypochloremia as a categorical variable was associated with an increased risk of all-cause mortality [hazard ratio 1.56; 95% confidence interval (CI) 1.38-1.75; P  < 0.001]. As a continuous variable, serum chloride was associated with all-cause mortality (hazard ratio per mmol/l decrease in serum chloride: 1.06; 95% CI 1.05-1.07; P  < 0.001). Results were confirmed by using several sensitivity analyses.

CONCLUSION

Hypochloremia exhibits a significant prognostic value in patients with heart failure. Serum chloride can be used as an effective tool for risk stratifying in patients with heart failure.

Predictive value of the prognostic nutritional index combined with serum chloride levels for the prognosis of patients with acute decompensated heart failure

BACKGROUND

The prognostic nutritional index (PNI) and serum chloride level are related to adverse outcomes in patients with heart failure. However, little is known about the relationship between the PNI and serum chloride level in predicting the poor prognosis of patients with acute decompensated heart failure (ADHF).

METHODS AND RESULTS

We reviewed 1221 consecutive patients with ADHF admitted to the First Affiliated Hospital of Kunming Medical University from January 2017 to October 2021. After excluding patients with in hospital death, missing follow-up data, missing chloride data, missing lymphocyte (LYM) count data, or missing serum albumin data, 805 patients were included. PNI was calculated using the formula: serum albumin (ALB) (g/L) + 5 × LYM count (10^9/L). Patients were divided into 4 groups according to the quartiles of the PNI, and the highest PNI quartile (PNI Q4: PNI ≥ 47.3) was set as the reference group. The patients in the lowest PNI quartile (PNI Q1: PNI < 40.8) had the lowest cumulative survival rate, and mortality risk decreased progressively through the quartiles (log-rank χ2 142.283, P < 0.0001). Patients with ADHF were divided into 8 groups by quartiles of PNI and median levels of serum chloride. After adjustment, the hazard ratio (HR) for all-cause mortality in ADHF patients in Group 1 was 8.7 times higher than that in the reference Group 8. Furthermore, the addition of serum chloride level and PNI quartile to the Cox model increased the area under the Receiver operating characteristic (ROC) curve by 0.05, and the area under the ROC curve of the new model was higher than that of the original model with traditional risk factors.

CONCLUSIONS

Both the lowest PNI quartiles and low chloride level indicate a higher risk of all-cause death in patients with ADHF.

Acetazolamide Tolerance in Acute Decompensated Heart Failure: An Observational Study

Objectives: This real-life study aimed to evaluate the safety of acetazolamide (ACZ), a carbonic anhydrase inhibitor with diuretic effects. ACZ has recently been proven to improve decongestion in the context of patients hospitalized for acute heart failure (HF). However, data in terms of safety are lacking. Methods: We conducted a monocentric observational prospective study from November 2023 to February 2024 in a 12-bed cardiology department, recording adverse events (hypotension, severe metabolic acidosis, severe hypokalemia and renal events) during in-hospital HF treatment. All patients hospitalized for acute HF during the study period treated with ACZ (500 mg IV daily for 3 days) on top of IV furosemide (n = 28, 48.3%) were compared with patients who have been treated with IV furosemide alone (n = 30, 51.7%). Results: The patients treated with ACZ were younger than those without (median age 78 (range 67-86) vs. 85 (79-90) years, respectively, p = 0.01) and had less frequent chronic kidney disease (median estimated glomerular fraction rate (60 (35-65) vs. 38 (26-63) mL/min, p = 0.02). As concerned adverse events during HF treatment, there were no differences in the occurrences of hypotension (three patients [10.7%] in the ACZ group vs. four [13.3%], p = 0.8), renal events (four patients [14.3%] in the ACZ group vs. five [16.7%], p = 1) and severe hypokalemia (two [7.1%] in the ACZ group vs. three [10%], p = 1). No severe metabolic acidosis occurred in either group. Conclusions: Although the clinical characteristics differed at baseline, with younger age and better renal function in patients receiving ACZ, the tolerance profile did not significantly differ from patients receiving furosemide alone. Additional observational data are needed to further assess the safety of ACZ-furosemide combination in the in-hospital management of HF, especially in older, frail populations.

Design and baseline characteristics of SALT-HF trial: hypertonic saline therapy in ambulatory heart failure

AIMS

Hypertonic saline solution (HSS) plus intravenous (IV) loop diuretic appears to enhance the diuretic response in patients hospitalized for heart failure (HF). The efficacy and safety of this therapy in the ambulatory setting have not been evaluated. We aimed to describe the design and baseline characteristics of the SALT-HF trial participants.

METHODS AND RESULTS

'Efficacy of Saline Hypertonic Therapy in Ambulatory Patients with HF' (SALT-HF) trial was a multicenter, double-blinded, and randomized study involving ambulatory patients who experienced worsening heart failure (WHF) without criteria for hospitalization. Enrolled patients had to present at least two signs of volume overload, use ≥ 80 mg of oral furosemide daily, and have elevated natriuretic peptides. Patients were randomized 1:1 to treatment with a 1-h infusion of IV furosemide plus HSS (2.6-3.4% NaCl depending on plasmatic sodium levels) versus a 1-h infusion of IV furosemide at the same dose (125-250 mg, depending on basal loop diuretic dose). Clinical, laboratory, and imaging parameters were collected at baseline and after 7 days, and a telephone visit was planned after 30 days. The primary endpoint was 3-h diuresis after treatment started. Secondary endpoints included (a) 7-day changes in congestion data, (b) 7-day changes in kidney function and electrolytes, (c) 30-day clinical events (need of IV diuretic, HF hospitalization, cardiovascular mortality, all-cause mortality or HF-hospitalization).

RESULTS

A total of 167 participants [median age, 81 years; interquartile range (IQR), 73-87, 30.5% females] were randomized across 13 sites between December 2020 and March 2023. Half of the participants (n = 82) had an ejection fraction >50%. Most patients showed a high burden of comorbidities, with a median Charlson index of 3 (IQR: 2-4). Common co-morbidities included diabetes mellitus (41%, n = 69), atrial fibrillation (80%, n = 134), and chronic kidney disease (64%, n = 107). Patients exhibited a poor functional NYHA class (69% presenting NYHA III) and several signs of congestion. The mean composite congestion score was 4.3 (standard deviation: 1.7). Ninety per cent of the patients (n = 151) presented oedema and jugular engorgement, and 71% (n = 118) showed lung B lines assessed by ultrasound. Median inferior vena cava diameter was 23 mm, (IQR: 21-25), and plasmatic levels of N-terminal-pro-B-type natriuretic peptide (NTproBNP) and antigen carbohydrate 125 (CA125) were increased (median NT-proBNP 4969 pg/mL, IQR: 2508-9328; median CA125 46 U/L, IQR: 20-114).

CONCLUSIONS

SALT-HF trial randomized 167 ambulatory patients with WHF and will determine whether an infusion of hypertonic saline therapy plus furosemide increases diuresis and improves decongestion compared to equivalent furosemide administration alone.

Chloride ions in health and disease

Chloride is a key anion involved in cellular physiology by regulating its homeostasis and rheostatic processes. Changes in cellular Cl- concentration result in differential regulation of cellular functions such as transcription and translation, post-translation modifications, cell cycle and proliferation, cell volume, and pH levels. In intracellular compartments, Cl- modulates the function of lysosomes, mitochondria, endosomes, phagosomes, the nucleus, and the endoplasmic reticulum. In extracellular fluid (ECF), Cl- is present in blood/plasma and interstitial fluid compartments. A reduction in Cl- levels in ECF can result in cell volume contraction. Cl- is the key physiological anion and is a principal compensatory ion for the movement of the major cations such as Na+, K+, and Ca2+. Over the past 25 years, we have increased our understanding of cellular signaling mediated by Cl-, which has helped in understanding the molecular and metabolic changes observed in pathologies with altered Cl- levels. Here, we review the concentration of Cl- in various organs and cellular compartments, ion channels responsible for its transportation, and recent information on its physiological roles.

Clinical characteristics, treatment patterns, and outcomes of hospitalized patients with acute heart failure in central Ethiopia: a retrospective observational study

BACKGROUND

Acute heart failure is the rapid onset of new or worsening symptoms and signs of heart failure. Despite the increasing burden of heart failure in developing countries like Ethiopia, there is a paucity of comprehensive data regarding the clinical characteristics, treatment patterns, and outcomes of acute heart failure, especially in the selected study area. Therefore, this study aimed to assess the clinical characteristics, treatment patterns, and outcomes of hospitalized patients with acute heart failure at Yekatit 12 Hospital Medical College, Addis Ababa, Ethiopia.

METHODS

This is a retrospective cross-sectional study of 303 acute heart failure patients who were admitted to the medical wards and intensive care unit of Yekatit 12 Hospital Medical College, Addis Ababa, central Ethiopia, from July 1, 2022, to July 1, 2023. A pretested data abstraction format was used for data extraction from electronic medical records, and SPSS version 26 was used for data analysis. Descriptive analysis was used to summarize sociodemographic data, clinical characteristics, treatment patterns, and outcomes of acute heart failure. Bivariate and multivariate logistic regression models were fitted to identify factors associated with in-hospital mortality. The odds ratio (OR) with the corresponding 95% confidence interval (CI) was calculated to show the strength of the association.

RESULTS

Of the 303 patients, 51.5% were females, and the mean age was 56.7 years. The most frequent symptom and sign were dyspnea (98.7%) and peripheral edema (79%), respectively. The commonest underlying cause and precipitating factor of acute heart failure were cor pulmonale (22.8%) and pneumonia (35.3%), respectively. The commonest anti-remodeling medications prescribed on discharge were beta-blockers (47.9%), followed by mineralocorticoid receptor antagonists (42.8%) and angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (38.6%), and the least prescribed were sodium-glucose cotransporter 2 inhibitors (8.3%). The in-hospital mortality rate was 8.6%, and the median length of hospital stay was 9 days. Based on the multivariate logistic regression analysis, the most important predictors of in-hospital mortality were systolic blood pressure (SBP) < 115 mmHg (adjusted odds ratio [AOR] = 6.28; 95% CI: 1.99, 19.78), chloride level < 96 mg/dL (AOR = 4.88; 95% CI: 1.30, 18.33), blood urea nitrogen (BUN) > 20 mg/dl (AOR = 5.48; 95% CI: 1.47, 20.49), and presence of dyslipidemia (AOR = 3.73, 95% CI: 1.15, 12.07).

CONCLUSIONS

This study has shown that systolic blood pressure (SBP) < 115 mmHg, blood urea nitrogen (BUN) > 20 mg/dL, chloride (Cl) level < 96 mg/dL, and the presence of dyslipidemia were statistically significant factors associated with in-hospital mortality among patients with acute heart failure. Hence, healthcare providers should stratify patients with acute heart failure upon admission based on their risk of in-hospital mortality and address those potential negative prognostic indicators accordingly.

Impact of hypochloremia as a prognostic factor in patients with heart failure, a retrospective cohort study

BACKGROUND

some studies suggest that hypochloremia is a risk factor in the prognosis of heart failure (HF) in patients with recent decompensation.

MATERIALS AND METHODS

retrospective cohort study of patients discharged due to HF decompensation who began follow-up in a specialized clinic. Two groups are defined: patients with hypochloremia (chloride < 98 mmol/L) and normochloremic patients (chloride > 98 mmol/L) in the initial assessment within the first month after discharge. The rate of intravenous diuretic rescue, emergency department visits, readmission for HF and cardiovascular (CV) death are compared using a Cox proportional hazards model.

RESULTS

165 patients were included (59% women, mean age 85 years), with 60 (36%) having hypochloremia. Both groups were comparable in terms of baseline characteristics, except for female sex, presence of peripheral artery disease, moderate-to-severe liver disease (more prevalent in the hypochloremia group), PROFUND index, and baseline furosemide dose (higher in patients with hypochloremia). The incidence of the primary event was higher in subjects with hypochloremia than in normochloremic subjects (HR: 1.59, 95% CI 0.97-2.62), mainly due to the need for intravenous diuretic rescue (HR: 1.86, 95% CI 1.07-3.24).

CONCLUSIONS

hypochloremia following admission for HF decompensation is associated with a greater need for intravenous diuretic rescue therapy and probably worse overall prognosis across the spectrum of the disease, regardless of left ventricular ejection fraction (LVEF).

Serial direct sodium removal in patients with heart failure and diuretic resistance

AIMS

Loop diuretics may exacerbate cardiorenal syndrome (CRS) in heart failure (HF). Direct sodium removal (DSR) using the peritoneal membrane, in conjunction with complete diuretic withdrawal, may improve CRS and diuretic resistance.

METHODS AND RESULTS

Patients with HF requiring high-dose loop diuretics were enrolled in two prospective, single-arm studies: RED DESERT (n = 8 euvolaemic patients), and SAHARA (n = 10 hypervolaemic patients). Loop diuretics were withdrawn, and serial DSR was utilized to achieve and maintain euvolaemia. At baseline, participants required a median 240 mg (interquartile range [IQR] 200-400) oral furosemide equivalents/day, which was withdrawn in all participants during DSR (median time of DSR 4 weeks [IQR 4-6]). Diuretic response (queried by formal 40 mg intravenous furosemide challenge and 6 h urine sodium quantification) increased substantially from baseline (81 ± 37 mmol) to end of DSR (223 ± 71 mmol, p < 0.001). Median time to re-initiate diuretics was 87 days, and the median re-initiation dose was 8% (IQR 6-10%) of baseline. At 1 year, diuretic dose remained substantially below baseline (30 [IQR 7.5-40] mg furosemide equivalents/day). Multiple dimensions of kidney function such as filtration, uraemic toxin excretion, kidney injury, and electrolyte handling improved (p < 0.05 for all). HF-related biomarkers including N-terminal pro-B-type natriuretic peptide, carbohydrate antigen-125, soluble ST2, interleukin-6, and growth differentiation factor-15 (p < 0.003 for all) also improved.

CONCLUSIONS

In patients with HF and diuretic resistance, serial DSR therapy with loop diuretic withdrawal was feasible and associated with substantial and persistent improvement in diuretic resistance and several cardiorenal parameters. If replicated in randomized controlled studies, DSR may represent a novel therapy for diuretic resistance and CRS.

CLINICAL TRIAL REGISTRATION

RED DESERT (NCT04116034), SAHARA (NCT04882358).

Positive association between sodium-to-chloride ratio and in-hospital mortality of acute heart failure

Previous studies have suggested that levels of sodium and chloride in the blood may be indicative of the prognosis of different medical conditions. Nevertheless, the assessment of the prognostic significance of the sodium-to-chloride (Na/Cl) ratio in relation to in-hospital mortality among individuals suffering from acute heart failure (AHF) remains unexplored. In this study, the participants were selected from the Medical Information Mart for Intensive Care IV database and divided into three groups based on the Na/Cl ratio level upon admission. The primary results were the mortality rate within the hospital. Cox regression, Kaplan-Meier curves, receiver operator characteristic (ROC) curve analysis and subgroup analyses were utilized to investigate the correlation between the admission Na/Cl ratio and outcomes in critically ill patients with AHF. A total of 7844 patients who met the selection criteria were included in this study. After adjusting for confounders, the multivariable Cox regression analysis revealed that the baseline Na/Cl ratio significantly elevated the risk of in-hospital mortality among critically ill patients with AHF (HR = 1.34, 95% CI 1.21-1.49). Furthermore, when the Na/Cl ratio was converted into a categorical factor and the initial tertile was taken as a point of comparison, the hazard ratios (HRs) and 95% confidence intervals (CIs) for the second and third tertiles were 1.27 (1.05-1.54) and 1.53 (1.27-1.84), respectively. Additionally, a P value indicating a significant trend of < 0.001 was observed. ROC curve analysis showed that Na/Cl ratio had a more sensitive prognostic value in predicting in-hospital mortality of AHF than the sodium or chloride level alone (0.564 vs. 0.505, 0.544). Subgroup examinations indicated that the association between the Na/Cl ratio upon admission and the mortality rate of critically ill patients with AHF remained consistent in the subgroups of hyponatremia and hypochlorhydria (P for interaction > 0.05). The linear relationship between the Na/Cl ratio and in-hospital mortality in AHF patients indicates a positive association.

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.

The association between serum chloride and mortality in ICU patients with heart failure: The impact of bicarbonate

OBJECTIVE

To assess whether serum chloride predicts risk of death in intensive care unit (ICU) patients with heart failure (HF) and the effect of bicarbonate on the efficacy of serum chloride in predicting risk of death in ICU patients.

METHODS

A total of 9364 HF patients hospitalized in the ICU were enrolled. Patients were divided into hypochloremia (< 96 mEq/L), normal chloride (96-108 mEq/L), and hyperchloremia (> 108 mEq/L) groups. Similarly, we divided the serum bicarbonate level into three groups: low bicarbonate (< 22 mEq/L), medium bicarbonate (22-26 mEq/L), and high bicarbonate (> 26 mEq/L). The outcome of this study was in-hospital mortality. Then, we analyzed the association between abnormal serum chloride and mortality according to the category of serum bicarbonate and assessed the interaction effect. Restricted cubic spline (RCS) was used to show possible nonlinear associations.

RESULTS

In the overall study population, hypochloremia was associated with a higher risk of in-hospital mortality than normal chloride (odds ratio [OR] 1.54, 95% confidence interval [CI] 1.26-1.86, P < 0.001), hyperchloremia was not significantly related to in-hospital mortality (OR 1.00, 95% CI 0.85-1.19, P = 0.962). However, a linear association between serum chloride and in-hospital mortality was found in the low and normal bicarbonate groups (all P for nonlinear >0.05).

CONCLUSIONS

Hypochloremia is associated with in-hospital mortality and longer hospital stay in critically ill patients with HF. In addition, risk of death in the low and medium serum bicarbonate groups decreased with increasing serum chloride level.

U-Shaped Association between Serum Chloride Levels and In-Hospital Mortality in Patients with Congestive Heart Failure in Intensive Care Units

Serum chloride level has clinical significance in the prognosis of heart failure. Little is known regarding the association between serum chloride levels and in-hospital mortality in patients with heart failure.This retrospective study used clinical data obtained from the Medical Information Mart for Intensive Care Database. The study cohort comprised patients who were categorized on the basis of their serum chloride levels, and the primary endpoint was in-hospital mortality. To assess the impact of serum chloride levels at the time of intensive care unit admission on in-hospital mortality, we used various statistical approaches, including multivariable logistic regression models, a generalized additive model, and a two-piecewise linear regression model. In addition, subgroup analysis was conducted to examine the robustness of the main findings.This study comprised 15,983 participants. When compared with the reference group (Q5), the groups with the highest (Q7) and lowest (Q1) blood chloride levels exhibited increased in-hospital mortality, with fully adjusted odds ratios (ORs) of 1.36 [95% confidence interval (CI): 1.08-1.71] and 1.25 (95% CI: 1-1.56), respectively. A U-shaped relationship was observed between blood chloride levels and in-hospital mortality, with the lowest risk observed at a threshold of 105.017 mmol/L. The effect sizes and corresponding CIs below and above the threshold were 0.969 (95% CI: 0.957-0.982) and 1.039 (95% CI: 1.002-1.076), respectively. Stratified analyses demonstrated the robustness of this correlation.The relationship between serum chloride levels and in-hospital mortality in patients with heart failure was U-shaped, with an inflection point of 105.017 mmol/L.

Associations between serum electrolyte and short-term outcomes in patients with acute decompensated heart failure

INTRODUCTION

There is a dearth of comprehensive studies on the association between serum electrolyte and adverse short-term prognosis of Chinese patients with acute decompensated heart failure (ADHF).

PATIENTS AND METHODS

A total of 5166 patients with ADHF were divided into four serum electrolyte-related study populations (potassium (n = 5145), sodium (n = 5135), chloride (n = 4966), serum total calcium (STC) (n = 4143)) under corresponding exclusions. Different logistic regression models were utilized to gauge the association between these electrolytes or the number of electrolyte abnormalities and the risk of a composite of all-cause mortality or 30-day heart failure (HF) readmission.

RESULTS

In multivariable adjusted analysis, patients with potassium below 3.5 mmol/L (odds ratios (ORs) 1.45; 95% confidence interval (CI):1.07-1.95), 4.01-4.50 mmol/L (OR: 1.29, CI: 1.02-1.62), 4.51-5.00 mmol/L (OR: 1.43, CI: 1.08-1.90) and above 5.00 mmol/L (OR: 1.74, CI: 1.21-2.51) had an increased risk of outcome when compared with potassium at 3.50-4.00 mmol/L. Sodium levels were inversely related to the risk of a composite outcome (<130 mmol/L: OR: 2.73 (95% CI, 1.81-4.12); 130-134 mmol/L: OR, 1.97 (CI, 1.45-2.68); 135-140 mmol/L: OR, 1.45 (CI, 1.17-1.81); p for trend < 0.001) in comparison with sodium at 141-145 mmol/L. Chloride < 95 mmol/L corresponded to a higher risk of a composite outcome with an OR of 1.65 (95% CI, 1.16-2.37) in contrast to chloride levels at 101-105 mmol/L. In addition, the adjusted ORs (95% CI) for a composite outcome comparing the STC < 2.00 and 2.00-2.24 vs. 2.25-2.58 mmol/L were 0.98 (0.69-1.43) and 1.13 (0.89-1.44), respectively. Besides that, the number of electrolyte abnormalities was positively related to the risk of a composite outcome (N = 1, OR 1.40, 95% CI: 1.13-1.73; N = 2, OR 2.51, 95% CI: 1.85-3.42; N = 3, OR 2.47, 95% CI: 1.45-4.19; p for trend < 0.001) in comparison with N = 0.

CONCLUSIONS

A deviation of potassium levels from 3.50 to 4.00 mmol/L, lower sodium levels and hypochloremia were associated with poorer short-term prognosis of ADHF. Furthermore, the number of electrolyte abnormalities positively correlated with adverse short-term prognosis of patients with ADHF. Key MessagesADHF patients with baseline serum potassium at first half part of normal range (3.50-4.00 mmol/L) may herald the lowest risk of recent cardiovascular events.Serum sodium and chloride levels exhibit discrepancies in terms of risk of short-term adverse events of ADHF patients.The number of electrolyte abnormalities is a significant predictor of poor short-term prognosis in patients with ADHF.

CLINICAL TRIAL REGISTRATION URL

http://www.chictr.org.cn/showproj.aspx?proj=23139. Unique identifier: ChiCTR-POC-17014020.

Hyponatraemia and changes in natraemia during hospitalization for acute heart failure and associations with in-hospital and long-term outcomes - from the ESC-HFA EORP Heart Failure Long-Term Registry

AIMS

To comprehensively assess hyponatraemia in acute heart failure (AHF) regarding prevalence, associations, hospital course, and post-discharge outcomes.

METHODS AND RESULTS

Of 8298 patients in the European Society of Cardiology Heart Failure Long-Term Registry hospitalized for AHF with any ejection fraction, 20% presented with hyponatraemia (serum sodium <135 mmol/L). Independent predictors included lower systolic blood pressure, estimated glomerular filtration rate (eGFR) and haemoglobin, along with diabetes, hepatic disease, use of thiazide diuretics, mineralocorticoid receptor antagonists, digoxin, higher doses of loop diuretics, and non-use of angiotensin-converting enzyme inhibitors/angiotensin receptor blockers and beta-blockers. In-hospital death occurred in 3.3%. The prevalence of hyponatraemia and in-hospital mortality with different combinations were: 9% hyponatraemia both at admission and discharge (hyponatraemia Yes/Yes, in-hospital mortality 6.9%), 11% Yes/No (in-hospital mortality 4.9%), 8% No/Yes (in-hospital mortality 4.7%), and 72% No/No (in-hospital mortality 2.4%). Correction of hyponatraemia was associated with improvement in eGFR. In-hospital development of hyponatraemia was associated with greater diuretic use and worsening eGFR but also more effective decongestion. Among hospital survivors, 12-month mortality was 19% and adjusted hazard ratios (95% confidence intervals) were for hyponatraemia Yes/Yes 1.60 (1.35-1.89), Yes/No 1.35 (1.14-1.59), and No/Yes 1.18 (0.96-1.45). For death or heart failure hospitalization they were 1.38 (1.21-1.58), 1.17 (1.02-1.33), and 1.09 (0.93-1.27), respectively.

CONCLUSION

Among patients with AHF, 20% had hyponatraemia at admission, which was associated with more advanced heart failure and normalized in half of patients during hospitalization. Admission hyponatraemia (possibly dilutional), especially if it did not resolve, was associated with worse in-hospital and post-discharge outcomes. Hyponatraemia developing during hospitalization (possibly depletional) was associated with lower risk.

Critical Analysis of the Effects of SGLT2 Inhibitors on Renal Tubular Sodium, Water and Chloride Homeostasis and Their Role in Influencing Heart Failure Outcomes

SGLT2 (sodium-glucose cotransporter 2) inhibitors interfere with the reabsorption of glucose and sodium in the early proximal renal tubule, but the magnitude and duration of any ensuing natriuretic or diuretic effect are the result of an interplay between the degree of upregulation of SGLT2 and sodium-hydrogen exchanger 3, the extent to which downstream compensatory tubular mechanisms are activated, and (potentially) the volume set point in individual patients. A comprehensive review and synthesis of available studies reveals several renal response patterns with substantial variation across studies and clinical settings. However, the common observation is an absence of a large acute or chronic diuresis or natriuresis with these agents, either when given alone or combined with other diuretics. This limited response results from the fact that renal compensation to these drugs is rapid and nearly complete within a few days or weeks, preventing progressive volume losses. Nevertheless, the finding that fractional excretion of glucose and lithium (the latter being a marker of proximal sodium reabsorption) persists during long-term treatment with SGLT2 inhibitors indicates that pharmacological tolerance to the effects of these drugs at the level of the proximal tubule does not meaningfully occur. This persistent proximal tubular effect of SGLT2 inhibitors can be hypothesized to produce a durable improvement in the internal set point for volume homeostasis, which may become clinically important during times of fluid expansion. However, it is difficult to know whether a treatment-related change in the volume set point actually occurs or contributes to the effect of these drugs to reduce the risk of major heart failure events. SGLT2 inhibitors exert cardioprotective effects by a direct effect on cardiomyocytes that is independent of the presence of or binding to SGLT2 or the actions of these drugs on the proximal renal tubule. Nevertheless, changes in the volume set point mediated by SGLT2 inhibitors might potentially act cooperatively with the direct favorable molecular and cellular effects of these drugs on cardiomyocytes to mediate their benefits on the development and clinical course of heart failure.

Pre-discharge and early post-discharge management of patients hospitalized for acute heart failure: A scientific statement by the Heart Failure Association of the ESC

Acute heart failure is a major cause of urgent hospitalizations. These are followed by marked increases in death and rehospitalization rates, which then decline exponentially though they remain higher than in patients without a recent hospitalization. Therefore, optimal management of patients with acute heart failure before discharge and in the early post-discharge phase is critical. First, it may prevent rehospitalizations through the early detection and effective treatment of residual or recurrent congestion, the main manifestation of decompensation. Second, initiation at pre-discharge and titration to target doses in the early post-discharge period, of guideline-directed medical therapy may improve both short- and long-term outcomes. Third, in chronic heart failure, medical treatment is often left unchanged, so the acute heart failure hospitalization presents an opportunity for implementation of therapy. The aim of this scientific statement by the Heart Failure Association of the European Society of Cardiology is to summarize recent findings that have implications for clinical management both in the pre-discharge and the early post-discharge phase after a hospitalization for acute heart failure.

Prognostic impact of serum chloride concentrations in acute heart failure patients: A systematic Rreview and meta-analysis

OBJECTIVE

Acute heart failure (AHF) is a common disease in the emergency departments. Its occurrence is often accompanied by electrolyte disorders, but little attention is paid to chloride ion. Recent studies have shown that hypochloremia was associated with poor prognosis of AHF. Therefore, this meta-analysis aimed to assess the incidence of hypochloremia and the impact of the reduction of serum chloride on the prognosis of AHF patients.

METHODS

We searched Cochrane Library, Web of science, PubMed, Embase databases and searched the relevant studies on chloride ion and AHF prognosis. The search time is from the establishment of the database to December 29, 2021. Two researchers screened the literature and extracted data independently. The quality of the included literature was evaluated using Newcastle-Ottawa Scale (NOS) scale. The effect amount is expressed as hazard ratio (HR) or relative risk (RR) and 95% confidence interval (CI). Review Manager 5.4.1 software for was used to perform the meta-analysis.

RESULTS

Seven studies involving 6787 AHF patients were included in meta-analysis. Meta-analysis revealed that the incidence of hypochloremia in AHF patients at admission was 17% (95% CI: 0.11-0.22); One mmol /L decrease in serum chloride at admission was associated with 6% increased risk of all-cause death of AHF patients (HR = 1.06, 95% CI: 1.04-1.08, P < 0.00001); Compared with the non-hypochloremia group, the risk of all-cause death in the hypochloremia group increased by 1.71 times (RR = 1.71, 95% CI: 1.45-2.02, P < 0.00001), the risk of all-cause death in the progressive hypochloremia(development of hypochloremia after admission) group increased by 2.24 times (HR = 2.24, 95% CI: 1.72-2.92, P < 0.00001), and the risk of all-cause death in the persistent hypochloremia (hypochloremia both on admission and at discharge) group increased by 2.80 times (HR = 2.80, 95% CI: 2.10-3.72, P < 0.00001).

CONCLUSION

The available evidence shows that the decrease of chloride ion at admission is associated with poor prognosis of AHF patients, and the prognosis of persistent hypochloremia is worse.Some outcome indicators(progressive hypochloremia, persistent hypochloremia, and composite of death + HF hospitalization)are as few as 2 studies in the literature, and the results should be interpreted carefully.

Serum Chloride and Heart Failure

Despite significant advances in management, heart failure continues to impose a significant epidemiologic burden with high prevalence and mortality rates. For decades, sodium has been the serum electrolyte most commonly associated with outcomes; however, challenging the conventional paradigm of sodium's influence, recent studies have identified a more prominent role in serum chloride in the pathophysiology of heart failure. More specifically, hypochloremia is associated with neurohumoral activation, diuretic resistance, and a worse prognosis in patients with heart failure. This review examines basic science, translational research, and clinical studies to better characterize the role of chloride in patients with heart failure and additionally discusses potential new therapies targeting chloride homeostasis that may impact the future of heart failure care.

Effect of renal function on the prognostic importance of chloride in patients with heart failure

Hypochloremia has recently gained interest as a potential marker of outcomes in patients with heart failure (HF). The exact pathophysiologic mechanism linking hypochloremia to HF is unclear but is thought to be mediated by chloride-sensitive proteins and channels located in kidneys. This analysis aimed to understand whether renal dysfunction (RD) affects the association of hypochloremia with mortality in patients with HF. Using data from a nationwide registry, 438 cases with complete data on serum chloride concentration and 1-year survival were included in the analysis. Patients with an estimated glomerular filtration rate of <60 mL/min/m² at baseline were accepted as having RD. Hypochloremia was defined as a chloride concentration <96 mEq/L at baseline. For HF patients without RD at baseline, patients with hypochloremia had a significantly higher 1-year all-cause mortality than those without hypochloremia (41.6% vs 13.0%, log-rank p < 0.001) and the association remained significant after multivariate adjustment (odds ratio (OR): 2.55, 95% confidence interval (CI): 1.25-5.21). The evidence supporting the association was very strong in this subgroup (Bayesian Factor (BF)₁₀: 48.25, log OR: 1.56, 95% CI: 0.69-2.43). For patients with RD at baseline, there was no statistically significant difference for 1-year mortality for patients with or without hypochloremia (36.3% vs 29.7, log-rank p = 0.35) and there was no evidence to support an association between hypochloremia and mortality (BF₁₀: 1.18, log OR :0.66, 95% CI: -0.02 to 1.35). In patients with HF, the association between low chloride concentration and mortality is limited to those without RD at baseline.

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.

Etiology and Management of Edema: A Review

The development of peripheral edema can often pose a significant diagnostic and therapeutic challenge for practitioners due to its association with a wide variety of underlying disorders ranging in severity. Updates to the original Starling's principle have provided new mechanistic insights into edema formation. Additionally, contemporary data highlighting the role of hypochloremia in the development of diuretic resistance provide a possible new therapeutic target. This article reviews the pathophysiology of edema formation and discusses implications for treatment.

Co-Administration of Albumin and Furosemide in Acute Heart Failure with Diuretics Resistance

Acute heart failure is a frequent cause of hospital admission in Portugal, and has an increasing tendency given the aging population. Although most admissions for acute heart failure are caused by congestive conditions, not all patients have a congestive phenotype, reflecting the complexity of a process with multiple pathophysiological pathways. The use of diuretics, usually loop diuretics, is the mainstay of treatment for congestion. However, many patients develop resistance, thus constituting a challenge with no consensual solution to date, despite extensive debate over the years. Despite its frequent use in clinical practice, the co-administration of albumin and furosemide remains controversial in the management of patients with acute heart failure, hypoalbuminemia, and diuretic resistance. This review addresses the pathophysiological mechanisms of congestion in patients with acute heart failure and explores the theoretical basis that supports the co-administration of albumin and furosemide in this clinical context. It is intended to clarify the potential benefit of the combined approach in this specific population and identify possible gaps in the literature that could be the subject of future studies.

Persistent Hypochloremia Is Associated with Adverse Prognosis in Patients Repeatedly Hospitalized for Heart Failure

BACKGROUND

Hypochloremia reflects neuro-hormonal activation in patients with heart failure (HF). However, the prognostic impact of persistent hypochloremia in those patients remains unclear.

METHODS

We collected the data of patients who were hospitalized for HF at least twice between 2010 and 2021 (n = 348). Dialysis patients (n = 26) were excluded. The patients were divided into four groups based on the absence/presence of hypochloremia (<98 mmol/L) at discharge from their first and second hospitalizations: Group A (patients without hypochloremia at their first and second hospitalizations, n = 243); Group B (those with hypochloremia at their first hospitalization and without hypochloremia at their second hospitalization, n = 29); Group C (those without hypochloremia at their first hospitalization and with hypochloremia at their second hospitalization, n = 34); and Group D (those with hypochloremia at their first and second hospitalizations, n = 16).

RESULTS

a Kaplan-Meier analysis revealed that all-cause mortality and cardiac mortality were the highest in Group D compared to the other groups. A multivariable Cox proportional hazard analysis revealed that persistent hypochloremia was independently associated with both all-cause death (hazard ratio 3.490, p < 0.001) and cardiac death (hazard ratio 3.919, p < 0.001).

CONCLUSIONS

In patients with HF, prolonged hypochloremia over two hospitalizations is associated with an adverse prognosis.

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.

Serum chloride and serum sodium derangements in children on prolonged furosemide therapy and their effect on diuretic response

Background

Electrolyte disturbances are not uncommon in patients on chronic furosemide therapy. We hypothesized that serum chloride (Cl) and serum sodium (Na) abnormalities may occur in children on prolonged furosemide therapy affecting the diuretic response in these children.

Methods

The study included 45 children, with congenital left to right shunts causing chronic congestive state which necessitated chronic furosemide therapy. Patients in need to an increase of their furosemide dose were recruited in the study. We assessed serum Cl and serum Na as well as parameters of diuretic responsiveness; net fluid output and change in body weight/40 mg furosemide, and change in urinary Na/K ratio. These parameters were assessed initially and at day 3 after increasing furosemide dose.

Results

According to serum levels of Cl and Na, patients were divided into four groups: isolated hyponatremia (15 patients, 33.3%), isolated hypochloremia (9 patients, 20%), combined hypochloremia and hyponatremia (12 patients, 26.7%), and normal serum electrolytes (9 patients, 20%). Patients with combined hyponatremia and hypochloremia and those with isolated hypochloremia showed minimal clinical and radiological signs of decongestion as well as lowest changes in urinary Na/K ratio, fluid output and weight change/40 mg furosemide on augmenting the diuretic dose, unlike the hyponatremic patients who had near normal parameters with no evidence of diuretic resistance.

Conclusion

Both hypochloremia and hyponatremia are common in patients on prolonged furosemide therapy. Hypochloremia is associated with a poor diuretic response, unlike isolated hyponatremia which does not seem to affect the diuretic response. Concomitant occurrence of hyponatremia and hypochloremia is associated with poor diuretic response as well which can be worse than that seen in isolated hypochloremia.

U-Shaped Relationship of Sodium-to-chloride Ratio on admission and Mortality in Elderly Patients with Heart Failure

AIMS

Serum sodium and chloride have clinical significance in the prognosis of heart failure. Little is known regarding the prognostic value of sodium-to-chloride (Na/Cl) ratio in patients with heart failure. This study sought to investigate the association between Na/Cl ratio on admission and mortality risk of elderly patients with acute heart failure in a retrospective cohort.

METHODS AND RESULTS

We included 1819 patients (aged over 60) from the Zigong Heart Failure Study. Patients were grouped according to Na/Cl ratio and followed up for all-cause mortality at 3 months. Restricted cubic spline, cox proportional hazard regression and Kaplan-Meier curve were used to examine the correlation between serum Na/Cl ratio on admission and mortality risk. Restricted cubic spline analysis suggested a U-shaped association between Na/Cl ratio on admission and 3 months mortality risk (p _nonlinearity <0.001), with the nadir of risk at 1.34. After adjustment for multivariate, patients with Na/Cl ratio <1.3 or ≥ 1.4 had hazard ratios for mortality of 3.58 (95% CI, 1.63-7.84) and 2.66 (95% CI, 1.23-5.72) compared with those with Na/Cl ratio of 1.3-1.4. The cumulative hazard of mortality estimates significantly differed across Na/Cl ratio groups (log-rank p<0.001). Subgroup analysis showed there were no interactions with absent or present of hyponatremia and hypochloremia (p for interaction all >0.05).

CONCLUSIONS

Both low and high Na/Cl ratios were associated with an increased mortality risk in elderly patients with acute heart failure. Further studies need to verify these two biochemical phenotypes and develop corresponding treatment strategies.

Relation of Low Chloride Concentration to Diuretic Efficiency and Transplant-Free Survival in Children Hospitalized With Heart Failure

Serum chloride plays an important role in fluid homeostasis and is associated with impaired diuretic responsiveness and mortality in adults with heart failure (HF). We sought to characterize the relationship of serum chloride and diuretic efficiency (DE) and to determine its prognostic importance in children hospitalized with acute decompensated HF (ADHF). We studied DE, defined as net fluid output/kg+constant per mg of loop diuretic/kg, in 200 children hospitalized with ADHF. Median serum chloride at admission was 102 mmol/L (interquartile range 99 to 105 mmol/L), and hypochloremia (chloride ≤96 mmol/L) was present in 16% of the population at admission. Serum chloride correlated with serum sodium (r = 0.66; p < 0.001) and bicarbonate (r = -0.39; p < 0.001). In the adjusted analysis, lower chloride was associated with reduced DE (p < 0.001). Serum sodium was associated with DE on the unadjusted analysis; however, the association was eliminated when added to the model with chloride (p = 0.442). Lower chloride was also associated with features of inadequate decongestion during hospitalization: a positive fluid balance (p = 0.003), greater cumulative loop diuretic dose per weight (p = 0.001), addition of a thiazide diuretic during hospitalization (p < 0.001), less weight loss (p = 0.025), and longer length of stay (p = 0.003). Chloride concentration was independently associated with death or transplant 1 year after admission (hazard ratio 0.94; p < 0.001). As a dichotomous variable, hypochloremia was independently associated with reduced DE (p < 0.001) and decreased 1-year transplant-free survival (hazard ratio 2.3, p < 0.001). Lower serum chloride at hospital admission is strongly and independently associated with impaired DE and reduced transplant-free survival in children hospitalized with ADHF.

Serum Chloride Is Inversely Associated With 3 Months Outcomes in Chinese Patients With Heart Failure, a Retrospective Cohort Study

Background

Serum chloride was recently found to be associated with prognosis of heart failure in western countries. However, the evidence was scarce in Asia. We aimed to investigated the relationship between serum chloride and clinical outcomes in a Chinese cohort with hospitalized heart failure.

Methods

We retrospectively analyzed the data from PhysioNet, involving 1996 patients who were admitted with heart failure between December 2016 and June 2019. Outcome was a composite endpoint of all-cause death or rehospitalization at 3 months.

Results

The incidence of the composite endpoint was 26.8% (535/1,996); it was 32.2% (213/662), 25.0% (165/661), and 23.3% (157/673) by chloride tertiles (from the lowest to the highest), respectively. The serum chloride at admission was independently and inversely associated with the composite endpoint risk (hazard ratio: 0.967; 95% confidence interval: 0.939 to 0.996; p = 0.026) in contrast to sodium, which was no longer significant (p > 0.05) after multivariable adjustment. Pearson correlation between serum chloride and sodium was 0.747 (p < 0.001). However, an increased AUC was not observed by adding sodium to model composed of age, sex, NYHA class, diabetes, log BNP and chloride (0.620 vs. 0.612, p = 0.132). Subgroup analysis showed the presence or absence of hyponatremia did not affect the association between chloride and composite endpoint risk.

Conclusions

Low serum chloride at admission was associated with poor outcomes in Chinese hospitalized patients with heart failure. These findings warrant future studies for tackling the potential pathophysiological mechanisms and correction methods of hypochloremia in heart failure.

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.

Prognostic significance of serum chloride level in heart failure patients with preserved ejection fraction

Aims

The prognostic value of serum chloride level has been reported primarily in patients with heart failure with reduced ejection fraction, and hence, there is limited evidence in patients of heart failure with preserved ejection fraction (HFpEF). This study was conducted to clarify the relationship between serum chloride level and clinical outcomes in patients with HFpEF with acute decompensated heart failure (ADHF).

Methods and results

Patient data were extracted from The Prospective mUlticenteR obServational stUdy of patIenTs with Heart Failure with Preserved Ejection Fraction (PURSUIT HFpEF) study, a prospective multicentre observational registry for ADHF‐HFpEF in Osaka. The data of 870 patients were analysed after excluding patients with in‐hospital death, missing follow‐up data, missing data of serum chloride level, or on chronic dialysis therapy. The primary endpoint of this study was all‐cause mortality. At discharge, right ventricular systolic dysfunction was significantly associated with the lowest tertile of serum chloride level after multivariable adjustment (P = 0.0257). During a mean follow‐up period of 1.8 ± 1.0 years, 186 patients died. Cox multivariable analysis showed that serum chloride level at discharge (P = 0.0017) was independently associated with all‐cause mortality after multivariable adjustment of major confounders, whereas serum sodium level was no longer significant (P = 0.6761). Kaplan–Meier survival curve analysis revealed a significantly increased risk of mortality stratified by the tertile of serum chloride level [29% vs. 19% vs. 16%, P = 0.0002; hazard ratio (HR): 2.09 (95% confidence interval, CI: 1.31 to 3.34), HR: 1.03 (95% CI: 0.65 to 1.64)].

Conclusions

Serum chloride level was useful for the prediction of poor outcome in ADHF patients with preserved ejection fraction.

Molecular Probes, Chemosensors, and Nanosensors for Optical Detection of Biorelevant Molecules and Ions in Aqueous Media and Biofluids

Synthetic molecular probes, chemosensors, and nanosensors used in combination with innovative assay protocols hold great potential for the development of robust, low-cost, and fast-responding sensors that are applicable in biofluids (urine, blood, and saliva). Particularly, the development of sensors for metabolites, neurotransmitters, drugs, and inorganic ions is highly desirable due to a lack of suitable biosensors. In addition, the monitoring and analysis of metabolic and signaling networks in cells and organisms by optical probes and chemosensors is becoming increasingly important in molecular biology and medicine. Thus, new perspectives for personalized diagnostics, theranostics, and biochemical/medical research will be unlocked when standing limitations of artificial binders and receptors are overcome. In this review, we survey synthetic sensing systems that have promising (future) application potential for the detection of small molecules, cations, and anions in aqueous media and biofluids. Special attention was given to sensing systems that provide a readily measurable optical signal through dynamic covalent chemistry, supramolecular host-guest interactions, or nanoparticles featuring plasmonic effects. This review shall also enable the reader to evaluate the current performance of molecular probes, chemosensors, and nanosensors in terms of sensitivity and selectivity with respect to practical requirement, and thereby inspiring new ideas for the development of further advanced systems.

2021 ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure: Developed by the Task Force for the diagnosis and treatment of acute and chronic heart failure of the European Society of Cardiology (ESC). With the special contribution of the Heart Failure Association (HFA) of the ESC

Document Reviewers: Rudolf A. de Boer (CPG Review Coordinator) (Netherlands), P. Christian Schulze (CPG Review Coordinator) (Germany), Magdy Abdelhamid (Egypt), Victor Aboyans (France), Stamatis Adamopoulos (Greece), Stefan D. Anker (Germany), Elena Arbelo (Spain), Riccardo Asteggiano (Italy), Johann Bauersachs (Germany), Antoni Bayes-Genis (Spain), Michael A. Borger (Germany), Werner Budts (Belgium), Maja Cikes (Croatia), Kevin Damman (Netherlands), Victoria Delgado (Netherlands), Paul Dendale (Belgium), Polychronis Dilaveris (Greece), Heinz Drexel (Austria), Justin Ezekowitz (Canada), Volkmar Falk (Germany), Laurent Fauchier (France), Gerasimos Filippatos (Greece), Alan Fraser (United Kingdom), Norbert Frey (Germany), Chris P. Gale (United Kingdom), Finn Gustafsson (Denmark), Julie Harris (United Kingdom), Bernard Iung (France), Stefan Janssens (Belgium), Mariell Jessup (United States of America), Aleksandra Konradi (Russia), Dipak Kotecha (United Kingdom), Ekaterini Lambrinou (Cyprus), Patrizio Lancellotti (Belgium), Ulf Landmesser (Germany), Christophe Leclercq (France), Basil S. Lewis (Israel), Francisco Leyva (United Kingdom), AleVs Linhart (Czech Republic), Maja-Lisa Løchen (Norway), Lars H. Lund (Sweden), Donna Mancini (United States of America), Josep Masip (Spain), Davor Milicic (Croatia), Christian Mueller (Switzerland), Holger Nef (Germany), Jens-Cosedis Nielsen (Denmark), Lis Neubeck (United Kingdom), Michel Noutsias (Germany), Steffen E. Petersen (United Kingdom), Anna Sonia Petronio (Italy), Piotr Ponikowski (Poland), Eva Prescott (Denmark), Amina Rakisheva (Kazakhstan), Dimitrios J. Richter (Greece), Evgeny Schlyakhto (Russia), Petar Seferovic (Serbia), Michele Senni (Italy), Marta Sitges (Spain), Miguel Sousa-Uva (Portugal), Carlo G. Tocchetti (Italy), Rhian M. Touyz (United Kingdom), Carsten Tschoepe (Germany), Johannes Waltenberger (Germany/Switzerland) All experts involved in the development of these guidelines have submitted declarations of interest. These have been compiled in a report and published in a supplementary document simultaneously to the guidelines. The report is also available on the ESC website www.escardio.org/guidelines For the Supplementary Data which include background information and detailed discussion of the data that have provided the basis for the guidelines see European Heart Journal online.

Hypochloraemia following admission to hospital with heart failure is common and associated with an increased risk of readmission or death: a report from OPERA-HF

AIMS

Hypochloraemia is common in patients hospitalized with heart failure (HF) and associated with a high risk of adverse outcomes during admission and following discharge. We assessed the significance of changes in serum chloride concentrations in relation to serum sodium and bicarbonate concentrations during admission in a cohort of 1002 consecutive patients admitted with HF and enrolled into an observational study based at a single tertiary centre in the UK.

METHODS AND RESULTS

Hypochloraemia (<96 mmol/L), hyponatraemia (<135 mmol/L), and metabolic alkalosis (bicarbonate >32 mmol/L) were defined by local laboratory reference ranges. Outcomes assessed were all-cause mortality, all-cause mortality or all-cause readmission, and all-cause mortality or HF readmission. Cox regression and Kaplan-Meier curves were used to investigate associations with outcome. During a median follow-up of 856 days (interquartile range 272-1416), discharge hypochloraemia, regardless of serum sodium, or bicarbonate levels was associated with greater all-cause mortality [hazard ratio (HR) 1.44, 95% confidence interval (CI) 1.15-1.79; P = 0.001], all-cause mortality or all-cause readmission (HR 1.26, 95% CI 1.04-1.53; P = 0.02), and all-cause mortality or HF readmission (HR 1.41, 95% CI 1.14-1.74; P = 0.002) after multivariable adjustment. Patients with concurrent hypochloraemia and natraemia had lower haemoglobin and haematocrit, suggesting congestion; those with hypochloraemia and normal sodium levels had more metabolic alkalosis, suggesting decongestion.

CONCLUSION

Hypochloraemia is common at discharge after a hospitalization for HF and is associated with worse outcome subsequently. It is an easily measured clinical variables that is associated with morbidity or mortality of any cause.

Prevalence and Mortality of Hypochloremia Among Patients Suffering From Coronary Artery Disease and Congestive Heart Failure: An Analysis of Patients in CIN-I and MIMIC-III Databases

Background: Hypochloremia is an independent predictor for mortality in patients with coronary artery disease (CAD) but whether the same correlation exists in CAD patients with congestive heart failure (CHF) is unclear. Methods: This is an analysis of data stored in the databases of the CIN-I [a registry of Cardiorenal Improvement (NCT04407936) in China from January 2007 to December 2018] and Medical Information Mart for Intensive Care (MIMIC)-III. CAD patients with CHF were included. The outcome measures were 90-day all-cause mortality (ACM) and long-term ACM. Results: Data from 8,243 CAD patients with CHF were analyzed. We found that 10.2% of the study population had hypochloremia (Cl- <98 mmol/L) in CIN-I (n = 4,762) and 20.1% had hypochloremia in MIMIC-III (n = 3,481). Patients suffering from hypochloremia were, in general, older and had a higher prevalence of comorbidities. After adjustment for confounders, hypochloremia remained a significant predictor of short-term mortality risk [90-day ACM: adjusted hazard ratio (aHR), 1.69; 95% CI, 1.27-2.25; P < 0.001 in CIN-I, and 1.36 (1.17-1.59); P < 0.001 in MIMIC-III]. Hypochloremia was also associated with long-term mortality [aHR, 1.26; 95% CI, 1.06-1.50; P = 0.009 in CIN-I, and 1.48 (1.32-1.66); P < 0.001 in MIMIC-III]. Prespecified subgroup analyses revealed an association of hypochloremia with long-term ACM to be attenuated slightly in the women of the two databases (P interaction < 0.05). Conclusions: Hypochloremia is independently associated with higher short-term and long-term ACM. Further studies are needed to determine if early preventive measurements and active intervention of hypochloremia can reduce the mortality risk of CAD patients with CHF.

Chloride in Heart Failure: The Neglected Electrolyte

The increasing burden of heart failure (HF) and emerging knowledge regarding chloride as a prognostic marker in HF have increased the interest in the pathophysiology and interactions of chloride abnormalities with HF-related factors and treatments. Chloride is among the major electrolytes that play a unique role in fluid homeostasis and is associated with cardiorenal and neurohormonal systems. This review elucidates the role of chloride in the pathophysiology of HF, evaluates the effects of treatment on chloride (eg, diuretic agents cause higher urinary chloride excretion and consequently serum hypochloremia), and discusses recent evidence for the association between chloride levels and mortality.

Electrolyte and renal disorders in patients with newly diagnosed glioblastoma

Purpose: Disturbances of electrolytes and renal function have been linked to the prognosis of critically ill patients and recently also of cancer patients. This study aimed to assess electrolyte and renal disorders in glioblastoma patients and evaluate their prognostic effect. Methods: Medical records of patients with newly diagnosed glioblastoma between 2005 and 2018 were retrospectively reviewed for electrolyte and renal function parameters and for demographic, clinical and outcome parameters. Results: Electrolyte and renal function disorders were associated with poorer survival in univariate and Kaplan-Meier analysis. Multivariate analysis revealed hypochloremia as an independent prognostic factor for overall and 1-year survival. Conclusion: Only hypochloremia showed an association with glioblastoma prognosis, independent of other known prognostic factors, as age or molecular status.

Sodium Bicarbonate Prescription and Extracellular Volume Increase: Real-world Data Results from the AlcalUN Study

Oral alkalization with sodium bicarbonate (NaHCO₃ ) or citrate is prescribed for conditions ranging from metabolic acidosis to nephrolithiasis. Although most nephrologists/urologists use this method routinely, extracellular volume (ECV) increase is the main feared adverse event reported for NaHCO₃ . Thus far, no trial has specifically studied this issue in a real-world setting. AlcalUN (NCT03035812) is a multicentric, prospective, open-label cohort study with nationwide (France) enrollment in 18 (public and private) nephrology/urology units. Participants were adult outpatients requiring chronic (>1 month) oral alkalization by either NaHCO₃ -containing or no-NaHCO₃ -containing agents. The ECV increase (primary outcome) was judged based on body weight increase (ΔBW), blood pressure increase (ΔBP), and/or new-onset edema at the first follow-up visit (V1). From February 2017 to February 2020, 156 patients were enrolled. After a median 106 days of treatment, 91 (72%) patients reached the primary outcome. They had lower systolic (135 (125, 141) vs. 141 (130, 150), P = 0.02) and diastolic (77 (67, 85) vs. 85 (73, 90), P = 0.03) BP values, a higher plasma chloride (106.0 (105.0, 109.0) vs. 105.0 (102.0, 107.0), P = 0.02) at baseline, and a less frequent history of nephrolithiasis (32 vs. 56%, P = 0.02). Patients experienced mainly slight ΔBP (< 10 mmHg). The primary outcome was not associated (P = 0.79) with the study treatment (129 received NaHCO₃ and 27 received citrate). We subsequently developed three different models of propensity score matching; each confirmed our results. Chronic oral alkalization with NaHCO₃ is no longer associated with an ECV increase compared to citrate in real-life settings.