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

Lowering mean pulmonary arterial pressure (mPAP) without reducing cardiac output is essential in treating pulmonary hypertension (PH). Isosorbide dinitrate (ISDN) potentially achieves this in post-capillary PH but can decrease cardiac output and blood pressure (BP), especially in pre-capillary PH. However, post-capillary PH and pre-capillary PH can overlap, and their clear discrimination is difficult. The aim of the study was to examine to what extent bolus ISDN injection reduces mPAP and BP, and changes mixed venous oxygen saturation (SvO2), an indicator of cardiac output in PH with various cardiopulmonary comorbidities in the context of treatment modifications. We retrospectively examined the hemodynamic effects of bolus ISDN injection in patients with PH who underwent right heart catheterization and their subsequent treatment modification. Our sample comprised 13 PH patients. In seven with pre-capillary PH, ISDN significantly lowered mPAP from the median 34 (interquartile range 32-39) to 28 (28-30) mmHg and the mean BP (mBP) from 90 (79-92) to 72 (68-87) mmHg. In six with post-capillary PH, ISDN lowered mPAP from 40 (29-44) to 27 (23-31) mmHg and mBP from 91 (87-110) to 87 (82-104) mmHg. There was a significant decrease in SvO2 from 69.8% (64.9%-78.1%) to 63.9% (60.5%-71.5%) in pre-capillary PH, but not in post-capillary PH including combined post- and pre-capillary PH and some patients showed a large increase in SvO2. In all patients showing an SvO2 increase, diuretics or hemodialysis were up-titrated or continued. Bolus ISDN injection lowered mPAP. However, in pre-capillary PH, it caused a significant decrease in SvO2 and a notable reduction in blood pressure. In post-capillary PH, including combined post- and pre-capillary PH, it clarified whether systemic preload and afterload reduction increased or decreased SvO2 in each patient, which may aid in treatment modification.

Congestion and fluid retention are the hallmarks of decompensated heart failure and the major reason for the hospitalization of patients with heart failure. Diuretics have been used in heart failure for decades, and they remain the backbone of the contemporary management of heart failure. Loop diuretics is the preferred diuretic, and it has been given a class I recommendation by clinical guidelines for the relief of congestion symptoms. Although loop diuretics have been used virtually among all patients with acute decompensated heart failure, there is still very limited clinical evidence to guide the optimized diuretics use. This is a sharp contrast to the rapidly growing evidence of the rest of the guideline-directed medical therapy of heart failure and calls for further studies. The loop diuretics possess a unique pharmacology and pharmacokinetics that lay the ground for different strategies to increase diuretic efficiency. However, many of these approaches have not been evaluated in randomized clinical trials. In recent years, a stepped and protocolized diuretics dosing has been suggested to have superior benefits over an individual clinician-based strategy. Diuretic resistance has been a major challenge to decongestion therapy for patients with heart failure and is associated with a poor clinical prognosis. Recently, therapy options have emerged to help overcome diuretic resistance to loop diuretics and have been evaluated in randomized clinical trials. In this review, we aim to provide a comprehensive review of the pharmacology and clinical use of loop diuretics in the context of heart failure, with attention to its side effects, and adjuncts, as well as the challenges and future direction.

BACKGROUND: Baccharis milleflora (Less.) DC. is a plant native to Brazil that is frequently used in traditional medicine as a diuretic and antihypertensive. However, even though it is traditionally used for these purposes, its diuretic and hypotensive effects have not been fully elucidated.
OBJECTIVE: Investigate the cardiorenal effects of the ethanol-soluble fraction (ESBM) of Baccharis milleflora in normotensive rats.
METHODS: Cladodes of B. milleflora were analyzed using light and scanning electron microscopy to provide anatomical data to support quality control. Subsequently, the ESBM was obtained and analyzed using LC-DAD-MS, and its components were annotated. The acute toxicity of ESBM was assessed in female Wistar rats. The acute and prolonged diuretic and hypotensive effects were then studied in Wistar rats. Finally, we assessed the mechanisms responsible for the diuretic effects of ESBM, including the activity of renal Na+/K+/ATPase, angiotensin-converting enzyme, and erythrocyte carbonic anhydrase. Additionally, we also investigated the involvement of bradykinin, prostaglandins, and nitric oxide.
RESULTS: From LC-DAD-MS data, thirty-three metabolites were identified from ESBM, including chlorogenic acids, glycosylated phenolic derivatives, C-glycosylated flavones, and O-glycosylated flavonols. No signs of acute toxicity were observed in female rats. The findings showed that ESBM had significant diuretic and natriuretic effects, as well as a potassium-sparing effect. The treatment with ESBM was able to significantly decrease serum levels of creatinine and malondialdehyde, and also significantly increase levels of nitrite, an indirect marker of nitric oxide bioavailability. Furthermore, pre-treatment with L-NAME abolished all diuretic effects induced by ESBM.
CONCLUSIONS: This study presented important morpho-anatomical and phytochemical data that support the quality control of Baccharis milleflora. The ESBM exhibited a significant diuretic and natriuretic effect following acute and seven-days repeated treatment in Wistar rats, without affecting renal potassium elimination. These effects appear to be dependent on the activation of the nitric oxide-cyclic GMP pathway. This study suggests the potential use of B. milleflora preparations in clinical situations where a diuretic effect is needed.

Hyponatremia is the most common disorder of electrolyte imbalances. It is necessary to develop new type of diuretics to treat hyponatremia without losing electrolytes. Urea transporters (UT) play an important role in the urine concentrating process and have been proved as a novel diuretic target. In this study, rat and mouse syndromes of inappropriate antidiuretic hormone secretion (SIADH) models were constructed and analyzed to determine if UTs are a promising drug target for treating hyponatremia. Experimental results showed that 100 mg/kg UT inhibitor 25a significantly increased serum osmolality (from 249.83 ± 5.95 to 294.33 ± 3.90 mOsm/kg) and serum sodium (from 114 ± 2.07 to 136.67 ± 3.82 mmol/L) respectively in hyponatremia rats by diuresis. Serum chemical examination showed that 25a neither caused another electrolyte imbalance nor influenced the lipid metabolism. Using UT-A1 and UT-B knockout mouse SIADH model, it was found that serum osmolality and serum sodium were lowered much less in UT-A1 knockout mice than in UT-B knockout mice, which suggest UT-A1 is a better therapeutic target than UT-B to treat hyponatremia. This study provides a proof of concept that UT-A1 is a diuretic target for SIADH-induced hyponatremia and UT-A1 inhibitors might be developed into new diuretics to treat hyponatremia.

OBJECTIVE: The TRANSFORM-HF trial demonstrated no significant outcome differences between torsemide and furosemide following hospitalization for heart failure (HF), but may have been impacted by non-adherence to the randomized diuretic. The current study sought to determine the treatment effect of torsemide versus furosemide using an on-treatment analysis inclusive of all randomized patients except those confirmed non-adherent to study diuretic.
RESULTS: TRANSFORM-HF was an open-label, pragmatic randomized trial of 2859 patients hospitalized for HF from June 2018 through March 2022. Patients were randomized to a loop diuretic strategy of torsemide versus furosemide with investigator-selected dosage. This post-hoc on-treatment analysis included all patients alive with either known or unknown diuretic status, and excluded patients confirmed to be non-adherent to study diuretic. This modified on-treatment definition was applied separately at time of hospital discharge and 30-day follow-up. All-cause mortality and hospitalization outcomes were assessed over 12 months. Overall, 2570 (89.9%) and 2374 (83.0%) patients were included in on-treatment analyses at discharge and 30-day follow-up, respectively. There was no significant difference in all-cause mortality between torsemide and furosemide in patients on-treatment at discharge (17.5% vs. 17.8%; hazard ratio [HR] 1.01 [95% confidence interval [CI] 0.83-1.22], p = 0.96) and at 30-day follow-up (14.5% vs. 15.0%; HR 1.02 [95% CI 0.81-1.27], p = 0.90). All-cause mortality or all-cause hospitalization was similar between torsemide and furosemide in patients who were on-treatment at discharge (58.3% vs. 61.3%; HR 0.92 [95% CI 0.82-1.03]) and 30-day follow-up (60.9% vs. 64.4%; HR 0.93 [95% CI 0.82-1.05]). In patients who were on-treatment at 30-day follow-up, there were 677 total hospitalizations in the torsemide group and 686 total hospitalizations in the furosemide group (rate ratio 0.99 [95% CI 0.86-1.14], p = 0.87).
CONCLUSIONS: In TRANSFORM-HF, a post-hoc on-treatment analysis did not meaningfully differ from the original trial results. Among those deemed compliant with the assigned diuretic, there remained no significant difference in mortality or hospitalization after HF hospitalization with a strategy of torsemide versus furosemide.
BACKGROUND: ClinicalTrials.gov Identifier: NCT03296813.

Understanding the function of the kappa opioid receptor (KOP) is crucial for the development of novel therapeutic interventions that target KOP for the treatment of pain, stress-related disorders and other indications. Activation of KOP produces diuretic effects in rodents and man. Sex is a vital factor to consider when assessing drug response in pre-clinical and clinical studies. In this study, the diuretic effect of the KOP agonist, U50488 (1-10 mg/kg), was investigated in both adult female and male Wistar rats that were either normally hydrated or water-loaded. The KOP antagonist norbinaltorphimine (norBNI, 10 mg/kg) was administered 24 h prior to U50488 to confirm the involvement of KOP. U50488 elicited a significant diuretic response at doses ≥ 3 mg/kg in both female and male rats independent of hydration status. U50488 diuretic effects were inhibited by norBNI pre-administration. Water-loading reduced data variability for urine volume in males, but not in females, compared with normally hydrated rats. Sex differences were also evident in U50488 eliciting a significant increase in sodium and potassium ion excretion only in males. This may suggest different mechanisms of U50488 diuretic action in males where renal excretion mechanisms are directly affected more than in females.

OBJECTIVE: 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.
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.
BACKGROUND: RED DESERT (NCT04116034), SAHARA (NCT04882358).

Previous work comparing safety and effectiveness outcomes for new initiators of angiotensin converting-enzyme inhibitors (ACEi) and thiazides demonstrated more favorable outcomes for thiazides, although cohort definitions allowed for addition of a second antihypertensive medication after a week of monotherapy. Here, we modify the monotherapy definition, imposing exit from cohorts upon addition of another antihypertensive medication. We determine hazard ratios (HR) for 55 safety and effectiveness outcomes over six databases and compare results to earlier findings. We find, for all primary outcomes, statistically significant differences in effectiveness between ACEi and thiazides were not replicated (HRs: 1.11, 1.06, 1.12 for acute myocardial infarction, hospitalization with heart failure and stroke, respectively). While statistical significance is similarly lost for several safety outcomes, the safety profile of thiazides remains more favorable. Our results indicate a less striking difference in effectiveness of thiazides compared to ACEi and reflect some sensitivity to the monotherapy cohort definition modification.

Heart failure (HF) is the common final pathway of several conditions and is characterized by hyperactivation of numerous neurohumoral pathways. Cardiorenal interaction plays an essential role in the progression of the disease, and the use of diuretics is a cornerstone in the treatment of hypervolemic patients, especially in acute decompensated HF (ADHF). The management of congestion is complex and, to avoid misinterpretations and errors, one must understand the interface between the heart and the kidneys in ADHF. Congestion itself may impair renal function and must be treated aggressively. Transitory elevations in serum creatinine during decongestion is not associated with worse outcomes and diuretics should be maintained in patients with clear hypervolemia. Monitoring urinary sodium after diuretic administration seems to improve the response to diuretics as it allows for adjustments in doses and a personalized approach. Adequate assessment of volemia and the introduction and titration of guideline-directed medical therapy are mandatory before discharge. An early visit after discharge is highly recommended, to assess for residual congestion and thus avoid readmissions.