Loop diuretic down-titration at discharge in patients hospitalized for acute heart failure

AIMS

The current literature provides limited guidance on the best diuretic strategy post-hospitalization for acute heart failure (AHF). It is postulated that the efficacy and safety of the outpatient diuretic regimen may be significantly influenced by the degree of fluid overload (FO) encountered during hospitalization. We hypothesize that in patients with more pronounced FO, reducing their regular oral diuretic dosage might be associated with an elevated risk of unfavourable clinical outcomes.

METHODS AND RESULTS

It was a retrospective observational study of 410 patients hospitalized for AHF in which the dose of furosemide at admission and discharge was collected. Patients were categorized across diuretic dose status into two groups: (i) the down-titration group and (ii) the stable/up-titration group. FO status was evaluated by a clinical congestion score and circulating biomarkers. The endpoint of interest was the composite of time to all-cause death and/or heart failure readmission. A multivariable Cox proportional hazard regression model was constructed to analyse the endpoints. The median age was 86 (78-92) years, 256 (62%) were women, and 80% had heart failure with preserved ejection fraction. After multivariate adjustment, the down-titration furosemide equivalent dose remained not associated with the risk of the combined endpoint in the whole sample (hazard ratio 1.34, 95% confidence interval 0.86-2.06, P = 0.184). The risk of the combination of death and/or worsening heart failure associated with the diuretic strategy at discharge was significantly influenced by FO status, including clinical congestion scores and circulating proxies of FO like BNP and cancer antigen 125.

CONCLUSIONS

In patients hospitalized for AHF, furosemide down-titration does not imply an increased risk of mortality and/or heart failure readmission. However, FO status modifies the effect of down-titration on the outcome. In patients with severe congestion or residual congestion at discharge, down-titration was associated with an increased risk of mortality and/or heart failure readmission.

Diuretic Treatment in Patients with Heart Failure: Current Evidence and Future Directions-Part II: Combination Therapy

PURPOSE OF REVIEW

Fluid retention or congestion is a major cause of symptoms, poor quality of life, and adverse outcome in patients with heart failure (HF). Despite advances in disease-modifying therapy, the mainstay of treatment for congestion-loop diuretics-has remained largely unchanged for 50 years. In these two articles (part I: loop diuretics and part II: combination therapy), we will review the history of diuretic treatment and current trial evidence for different diuretic strategies and explore potential future directions of research.

RECENT FINDINGS

We will assess recent trials, including DOSE, TRANSFORM, ADVOR, CLOROTIC, OSPREY-AHF, and PUSH-AHF, and assess how these may influence current practice and future research. There are few data on which to base diuretic therapy in clinical practice. The most robust evidence is for high-dose loop diuretic treatment over low-dose treatment for patients admitted to hospital with HF, yet this is not reflected in guidelines. There is an urgent need for more and better research on different diuretic strategies in patients with HF.

Diuretic Treatment in Patients with Heart Failure: Current Evidence and Future Directions - Part I: Loop Diuretics

PURPOSE OF REVIEW

Fluid retention or congestion is a major cause of symptoms, poor quality of life, and adverse outcome in patients with heart failure (HF). Despite advances in disease-modifying therapy, the mainstay of treatment for congestion-loop diuretics-has remained largely unchanged for 50 years. In these two articles (part I: loop diuretics and part II: combination therapy), we will review the history of diuretic treatment and the current trial evidence for different diuretic strategies and explore potential future directions of research.

RECENT FINDINGS

We will assess recent trials including DOSE, TRANSFORM, ADVOR, CLOROTIC, OSPREY-AHF, and PUSH-AHF amongst others, and assess how these may influence current practice and future research. There are few data on which to base diuretic therapy in clinical practice. The most robust evidence is for high dose loop diuretic treatment over low-dose treatment for patients admitted to hospital with HF, yet this is not reflected in guidelines. There is an urgent need for more and better research on different diuretic strategies in patients with HF.

Hydralazine combined with conventional therapy improved outcomes in severe systolic dysfunction and mitral regurgitation

AIMS

Patients with heart failure (HF) and reduced left ventricular ejection fraction (LVEF) accompanied by significant mitral regurgitation (MR) had poor outcome. Several vasodilator trials showed neutral results. We aimed to investigate the effect of early up-titration of hydralazine combined with conventional treatment in acute HF with severe systolic dysfunction and significant MR.

METHODS AND RESULTS

The study was open-labelled, one-to-one ratio randomized designed. Consecutively hospitalized patients with decompensated HF symptoms, LVEF < 35%, and MR more than moderate severity were enrolled after exclusion. All participants with inadequate preload should have intake promotion with/without fluid supply. Patients receiving evidence-based medications (EBMs) as conventional treatment served as the control. Hydralazine + conventional treatment group received up-titration of hydralazine at Days 1-5 of the index admission combined with EBMs and throughout the course of follow-up. The endpoints included cardiovascular (CV) death and HF rehospitalization. Totally, 408 patients were enrolled (203 in conventional treatment and 205 in hydralazine + conventional treatment). The mean follow-up period was 3.5 years. The mean dose of hydralazine was 191 mg at index admission and 264 mg at study end in hydralazine + conventional treatment group. Both groups did not significantly differ in prescription rates and dosages of EBMs (all P > 0.05) at study end. Side effects did not differ between the two groups. Finally, 51% (104 out of 203 cases) reached endpoints in conventional group and 34.6% (71 out of 205 cases) in hydralazine + conventional treatment group, which had a significant reduction in CV events (hazard ratio 0.613, 95% confidence interval 0.427-0.877, P < 0.001). In-hospital death during the index admission was significantly higher in conventional group (5.4% vs. 0.5%, respectively; P = 0.001).

CONCLUSIONS

When administered without inadequate preload, combining early up-titration of hydralazine with EBMs improves outcome in patients with severe systolic dysfunction and significant MR, and it is safe and well tolerated.

Efficacy of tolvaptan in postoperative volume therapy for acute Stanford type A aortic dissection

BACKGROUND

Despite the increasing application of tolvaptan in cardiac surgery, there is no information on the use of tolvaptan in Stanford patients with type A aortic dissection. This study aimed to evaluate the postoperative clinical effects of tolvaptan in patients with type A aortic dissection  after tafter surgery.

METHODS

A retrospective analysis was performed on 45 patients treated for type A aortic dissection in our hospital from 2018 to 2020. These included 21 patients who were treated with tolvaptan (Group T) and 24 patients who received traditional diuretics (Group L). The hospital's electronic health records were used to obtain perioperative data.

RESULTS

Group T did not differ significantly from Group L in terms of the duration of mechanical ventilation, postoperative blood required, length of catecholamine use, or the amount of intravenous diuretic drugs administered (all P > 0.05). The development of postoperative atrial fibrillation was significantly less in the tolvaptan group (P = 0.023). The urine volumes and change in body weight loss were slightly higher in group T than in group L but the differences were non-significant (P > 0.05). Serum potassium, creatinine, and urea nitrogen levels did not differ between the groups in the week after surgery, At the same time, sodium was significantly higher in the Group T group on day 7 after transfer from the ICU (P = 0.001). In Group L, sodium levels were also elevated by day 7 (P = 0.001). On days 3 and 7, serum creatinine and urea nitrogen levels increased in both groups (both P < 0.05).

CONCLUSIONS

Both tolvaptan and traditional diuretics were found to be effective and safe for patients with acute Stanford type A aortic dissection. Moreover, tolvaptan may be associated with reducing the incidence of postoperative atrial fibrillation.

A retrospective study of 14 dogs with advanced heart failure treated with loop diuretics and hydrochlorothiazide

Background:

The use of thiazide diuretics is recommended in the American College of Veterinary Internal Medicine guidelines for advanced heart failure due to mitral insufficiency (MI) in dogs. However, there are no large-scale reports of the use of thiazide diuretics in dogs with advanced heart failure.

Aim:

This retrospective study evaluated the therapeutic effect of concomitant hydrochlorothiazide (HTCZ) with loop diuretics in dogs with heart failure.

Methods:

The study included 14 dogs diagnosed with advanced pulmonary edema with MI at two facilities. In all cases, high-dose loop diuretics (torsemide; 0.78–4 mg/kg/day) did not improve pulmonary edema. The results of the echocardiography and renal function tests before and after the administration of HTCZ (0.2–0.84 mg/kg/day) in addition to torsemide were statistically compared.

Results:

The echocardiographic data demonstrated significant improvement in relation to cardiac stress; left atrium to the aorta ratio, normalized left ventricular internal dimension in diastole, and E wave velocity (m/s) after HTCZ administration. However, blood urea nitrogen and creatinine levels increased, and potassium levels decreased, indicating a decline in renal function following HTCZ administration.

Conclusion:

This study suggests that the administration of HTCZ in combination with loop diuretics may be beneficial during advanced heart failure due to MI in dogs. The results can also be extended to patients who are resistant to loop diuretics, resulting in the improvement of cardiac function. However, as the combination of HTCZ and loop diuretics can deteriorate renal function, caution should be exercised prior to making recommendations regarding its use, and renal function should be monitored.

Pharmacokinetics and diuretic effect of furosemide after single intravenous, oral tablet, and newly developed oral disintegrating film administration in healthy beagle dogs

Background

Furosemide, a diuretic that acts on the loop of Henle, is commonly used to treat congestive heart failure in veterinary medicine. Some owners have difficulty in administering oral tablet medication to animal patients, which leads to noncompliance, especially during long-term administration. Oral disintegrating film (ODF) has the advantages of easy administration via a non-invasive route, rapid dissolution, and low suffocating risk. The objective of this study was to research the pharmacokinetic (PK) profiles and diuretic effect of furosemide after intravenous (IV), orally uncoated tablet (OUT), and newly developed ODF administration in healthy beagle dogs. In this study, a furosemide-loaded ODF (FS-ODF) formulation was developed and five beagle dogs were administered a single dose (2 mg/kg) of furosemide via each route using a cross-over design.

Results

The most suitable film-forming agent was sodium alginate; thus, this was used to develop an ODF for easy drug administration. No significant differences were detected in the PK profiles between OUT and FS-ODF. In the blood profiles, the concentration of total protein was significantly increased compared to the baseline (0 h), whereas no significant difference was detected in the concentration of creatinine and hematocrit compared to the baseline. FS-ODF resulted in a similar hourly urinary output to OUT during the initial 2 h after administration. The urine specific gravity was significantly decreased compared to the baseline in each group. The peak times of urine electrolyte (sodium and chloride) excretion per hour were 1 h (IV), 2 h (OUT), and 2 h (FS-ODF).

Conclusions

These results suggest that the PK/PD of furosemide after administration of newly developed FS-ODF are similar to those of OUT in healthy dogs. Therefore, the ODF formulation has the benefits of ease and convenience, which would be helpful to owners of companion animals, such as small dogs (< 10 kg), for the management of congestive heart failure.

Diuretic strategies in patients with resistance to loop-diuretics in the intensive care unit: A retrospective study from the MIMIC-III database

PURPOSE

To investigate various diuretic strategies to alleviate loop-diuretics resistance in critically ill patients.

MATERIALS AND METHOD

ICU adults requiring more than 1 mg/kg/day of furosemide, from the MIMIC-III database. Four diuretic strategies were investigated: incremental dose of loop diuretics, continuous infusion, combinations with a second class of diuretics and administration of intravenous albumin. A generalized estimating equation was used to investigate the associations between these strategies and endpoints. The primary outcome was the 24-h urine output and secondary endpoints included fluid balance, weight change, electrolyte and acid-base abnormalities, kidney replacement therapy initiation, and mortality.

RESULTS

A total of 7645 ICU stays from 6358 patients were included. After adjustment, the use of continuous loop-diuretic infusion was associated with a higher 24-h urine output (β: 732, 95% CI:669-795, p < 0.001), lower 24-h fluid balance (p < 0.001) and greater weight loss at 48-h (p < 0.001). Thiazide- and carbonic anhydrase inhibitor combinations were both associated with higher urine output (p < 0.001) and weight loss at 48-h (p < 0.01), while intravenous albumin was associated with fluid gain (p < 0.001). Risks of electrolyte and metabolic disturbances varied across diuretic strategies.

CONCLUSIONS

Continuous loop-diuretic infusion and thiazide- or acetazolamide-loop diuretic combinations increased urine output significantly, leading to a negative fluid balance and weight loss.

Proposal for New Classification and Practical Use of Diuretics According to Their Effects on the Serum Chloride Concentration: Rationale Based on the "Chloride Theory"

Currently, diuretic therapy for heart failure (HF) pathophysiology is primarily focused on the sodium and water balance. Over the last several years, however, chloride (Cl) has been recognized to have an important role in HF pathophysiology, as both a prognostic marker and a possible central factor regulating the body fluid status. I recently proposed a unifying hypothesis for HF pathophysiology, called the "chloride theory", during HF worsening and recovery, as follows. Chloride is the key electrolyte for regulating both reabsorption of tubular electrolytes and water in the kidney through the renin-angiotensin-aldosterone system and distributing body fluid in each compartment of the body. As changes between the serum Cl concentration and plasma volume are intimately associated with worsening HF and its recovery after decongestive therapy, modulation of the serum Cl concentration by careful selection and combination of various diuretics and their doses could become an attractive therapeutic option for HF. In this review, I will propose a new classification and practical use of diuretics according to their effects on the serum Cl concentration. Diuretic use according to this classification is expected to be a useful strategy for the treatment of patients with HF.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

DRESS syndrome following furosemide administration: An unusual association

INTRODUCTION

Drug reaction with eosinophilia and systemic symptoms (DRESS) is a severe and rare adverse drug reaction. Several drugs are known to induce DRESS. Furosemide, a sulfonamide loop diuretic drug, is known to induce hypersensitive reactions such as bullous eruptions, acute generalized exanthematous pustulosis and lichenoid eruptions, but rarely DRESS. We describe herein a case of furosemide-induced DRESS that recurred after bumetanide administration.

CASE REPORT

A 67-year-old man was admitted to the nephrology department for hypertension, gout and chronic renal failure. He received a multidrug therapy including captopril, nifedipine, allopurinol and furosemide. Six weeks after starting this treatment, he developed a maculopapular itchy and edematous skin reaction, facial edemaand fever. The laboratory findings showed 2200/mm³ of eosinophils (20%). Creatinine clearance decreased from 18.9 to 14.4 mL/min. Lactate dehydrogenase was at 600 IU/L (normal range 190-390 IU/L). Chest X-ray showed an interstitial lung injury. Skin biopsy findings were in accordance with a hypersensitive reaction. Furosemide was withdrawn and symptoms resolved completely three weeks later. A patch test with furosemide performed six weeks later was negative. The patient was given bumetanide, another sulfonamide loop diuretic, with recurrence of symptoms two months later. Bumetanide was withdrawn with a complete resolution of both clinical and biological symptoms within three weeks.

CONCLUSION

We add to the literature another case of furosemide-induced DRESS with the particularity of cross reactivity with bumetanide.

Soluble CD146-an underreported novel biomarker of congestion: a comment on a review concerning congestion assessment and evaluation in acute heart failure

In spite of high prevalence, congestion remains a poorly understood phenomenon in heart failure pathophysiology. Its negative impact on outcome has been widely recognised. Still, data from various registries reveal the failure of the contemporary treatment strategies to overcome congestion. This shortcoming is closely related to the fact that there are no universe means for congestion assessment and grading, making it a difficult process to recognise. CD146 is a novel blood biomarker of congestion that has been shown to reflect intravascular fluid accumulation in a number of experimental and clinical studies. This observation deserves special attention, given the huge gap of knowledge about decongestive strategies in acute and chronic heart failure. Randomised clinical trials testing the effect of CD146-guided management intervention are urgently needed to estimate its value in heart failure care.

Renal Nerve Deafferentation Attenuates the Fall in GFR during Intravenous Infusion of Furosemide in Anesthetized Rats

INTRODUCTION

Furosemide reduces the glomerular filtration rate (GFR) and increases the renal vascular resistance (RVR) despite inhibiting tubuloglomerular feedback but increases proximal tubule pressure, renin release, and renal nerve activity.

OBJECTIVE

This study tested the hypothesis that the fall in GFR with furosemide is due to volume depletion or activation of angiotensin type 1 (AT1) receptors or renal nerves.

METHODS

Furosemide was infused for 60 min at 1.0 mg·kg-1·h-1 in groups of 5-8 anesthetized rats. Additional groups received intravenous volume replacement to prevent fluid and Na+ losses or volume replacement plus losartan or plus sham denervation or plus renal denervation or renal nerve deafferentation.

RESULTS

At 60 min of infusion, furosemide alone reduced the GFR (-37 ± 4%; p < 0.01). This fall was not prevented by volume replacement or pretreatment with losartan, although losartan moderated the increase in RVR with furosemide (+44 ± 3 vs. +82 ± 7%; p < 0.01). Whereas the GFR fell after furosemide in rats after sham procedure (-31 ± 2%), it was not changed significantly after prior renal deafferentation. Proximal tubule pressure increased significantly but returned towards baseline over 60 min of furosemide, while urine output remained elevated, and GFR and renal blood flow depressed.

CONCLUSIONS

The fall in GFR over 60 min of furosemide infusion is independent of volume depletion or activation of AT1 receptors but is largely dependent on renal afferent nerves.

The extracellular volume status predicts body fluid response to SGLT2 inhibitor dapagliflozin in diabetic kidney disease

BACKGROUND

Sodium-glucose cotransporter 2 (SGLT2) inhibitors are an antihyperglycemic drug with diuretic action. We recently reported that the SGLT2 inhibitor dapagliflozin ameliorates extracellular volume expansion with a mild increase in urine volume. However, the impact of the pretreatment extracellular volume status on the body fluid response to SGLT2 inhibitors remains unclear.

METHODS

Thirty-six diabetic kidney disease (DKD) patients were treated with dapagliflozin. The body fluid volume, including intracellular water (ICW), extracellular water (ECW) and total body water (TBW), were measured on baseline and day 7 using a bioimpedance analysis (BIA) device. The ECW/TBW and ECW were used as markers of the extracellular volume status. For a comparison, the extracellular volume status responses to loop diuretic furosemide (n = 16) and vasopressin V2 receptor antagonist tolvaptan (n = 13) were analyzed.

RESULTS

The body weight, brain natriuretic peptide and body fluid parameters measured by a BIA (ICW, ECW, TBW, and ECW/TBW) were significantly decreased for 1 week after dapagliflozin administration. The change in the ECW/TBW in the high-ECW/TBW group (over the median value of 0.413) was significantly higher than in the low-ECW/TBW group (- 2.1 ± 0.4 vs. - 0.5 ± 0.4%, p = 0.006). Only with dapagliflozin treatment (not furosemide or tolvaptan treatment) was the baseline ECW/TBW significantly correlated with the changes in the ECW/TBW (r = - 0.590, p < 0.001) and ECW (r = - 0.374, p = 0.025).

CONCLUSIONS

The pretreatment extracellular volume status predicts the body fluid response to the SGLT2 inhibitor dapagliflozin in DKD patients. The diminished extracellular fluid reduction effect of dapagliflozin in patients without severe extracellular fluid retention may contribute to maintaining a suitable body fluid status.

Drugs Causing Bone Loss

Drugs may cause bone loss by lowering sex steroid levels (e.g., aromatase inhibitors in breast cancer, GnRH agonists in prostate cancer, or depot medroxyprogestone acetate - DMPA), interfere with vitamin D levels (liver inducing anti-epileptic drugs), or directly by toxic effects on bone cells (chemotherapy, phenytoin, or thiazolidinedions, which diverts mesenchymal stem cells from forming osteoblasts to forming adipocytes). However, besides effects on the mineralized matrix, interactions with collagen and other parts of the unmineralized matrix may decrease bone biomechanical competence in a manner that may not correlate with bone mineral density (BMD) measured by dual energy absorptiometry (DXA).Some drugs and drug classes may decrease BMD like the thiazolidinediones and consequently increase fracture risk. Other drugs such as glucocorticoids may decrease BMD, and thus increase fracture risk. However, glucocorticoids may also interfere with the unmineralized matrix leading to an increase in fracture risk, not mirrored in BMD changes. Some drugs such as selective serotonin reuptake inhibitors (SSRI), paracetamol, and non-steroidal anti-inflammatory drugs (NSAIDs) may not per se be associated with bone loss, but fracture risk may be increased, possibly stemming from an increased risk of falls stemming from effects on postural balance mediated by effects on the central nervous system or cardiovascular system.This paper performs a systematic review of drugs inducing bone loss or associated with fracture risk. The chapter is organized by the Anatomical Therapeutic Chemical (ATC) classification.

Prognostic Significance of Longitudinal Clinical Congestion Pattern in Chronic Heart Failure: Insights From TIME-CHF Trial

BACKGROUND

The relationship between longitudinal clinical congestion pattern and heart failure outcome is uncertain. This study was designed to assess the prevalence of congestion over time and to investigate its impact on outcome in chronic heart failure.

METHODS

A total of 588 patients with chronic heart failure older than 60 years of age with New York Heart Association (NYHA) functional class ≥II from the TIME-CHF study were included. The endpoints for this study were survival and hospitalization-free heart failure survival. Orthopnea, NYHA ≥III, paroxysmal nocturnal dyspnea, hepatomegaly, peripheral pitting edema, jugular venous distension, and rales were repeatedly investigated and related to outcomes. These congestion-related signs and symptoms were used to design a 7-item Clinical Congestion Index.

RESULTS

Sixty-one percent of patients had a Clinical Congestion Index ≥3 at baseline, which decreased to 18% at month 18. During the median [interquartile range] follow-up of 27.2 [14.3-39.8] months, 17%, 27%, and 47% of patients with baseline Clinical Congestion Index of 0, 1-2, and ≥3 at inclusion, respectively, died (P <.001). Clinical Congestion Index was identified as an independent predictor of mortality at all visits (P <.05) except month 6 and reduced hospitalization-free heart failure survival (P <.05). Successful decongestion was related to better outcome as compared to persistent congestion or partial decongestion (log-rank P <0.001).

CONCLUSIONS

The extent of congestion as assessed by means of clinical signs and symptoms decreased over time with intensified treatment, but it remained present or relapsed in a substantial number of patients with heart failure and was associated with poor outcome. This highlights the importance of appropriate decongestion in chronic heart failure.

Loop diuretic use among patients with heart failure and type 2 diabetes treated with sodium glucose cotransporter-2 inhibitors

AIMS

To compare loop diuretic use in patients with comorbid heart failure (HF) and type 2 diabetes (T2D) newly initiated on sodium glucose cotransporter-2 inhibitors (SGLT2Is) versus other oral anti-glycemic agents (AGAs).

METHODS

This analysis used 2013-2015 MarketScan Medicare Supplemental claims data. HF and T2D patients were identified and SGLT2I users were propensity score matched to other AGA users. The mean daily dose of loop diuretics in furosemide equivalents was ascertained. For those not on baseline loop diuretics, new use was compared between cohorts. For those on baseline loop diuretics, we assessed patterns of use (increased dose, decreased dose, stable dose, no longer using) at 12-months.

RESULTS

A total of 750 SGLT2I users were matched to 750 other AGA users. The distribution of loop diuretic use at mean doses of 0 mg (i.e., no use), ≤20 mg, >20 mg-40 mg, >40 mg-80 mg and >80 mg/day did not differ between cohorts at baseline or 12-months (p > 0.05 for both). SGLT2I use was associated with less new loop diuretic use (22.7% [79/348] vs. 34.0% [132/388]; p = 0.001). For those on loop diuretics at baseline (n = 764), patterns of use at 12-months did not differ between cohorts (p = 0.14).

CONCLUSIONS

New loop diuretic use was less frequent among SGLT2I users; however, patterns of loop diuretic use did not differ between cohorts in those on loop diuretics at baseline.

Comparative Analysis of Long-Term Outcomes of Torasemide and Furosemide in Heart Failure Patients in Heart Failure Registries of the European Society of Cardiology

PURPOSE

Current clinical recommendations do not emphasise superiority of any of diuretics, but available reports are very encouraging and suggest beneficial effects of torasemide. This study aimed to compare the effect of torasemide and furosemide on long-term outcomes and New York Heart Association (NYHA) class change in patients with chronic heart failure (HF).

METHODS

Of 2019 patients enrolled in Polish parts of the heart failure registries of the European Society of Cardiology (Pilot and Long-Term), 1440 patients treated with a loop diuretic were included in the analysis. The main analysis was performed on matched cohorts of HF patients treated with furosemide and torasemide using propensity score matching.

RESULTS

Torasemide was associated with a similar primary endpoint (all-cause death; 9.8% vs. 14.1%; p = 0.13) occurrence and 23.8% risk reduction of the secondary endpoint (a composite of all-cause death or hospitalisation for worsening HF; 26.4% vs. 34.7%; p = 0.04). Treatment with both torasemide and furosemide was associated with the significantly most frequent occurrence of the primary (23.8%) and secondary (59.2%) endpoints. In the matched cohort after 12 months, NYHA class was higher in the furosemide group (p = 0.04), while furosemide use was associated with a higher risk (20.0% vs. 12.9%; p = 0.03) of worsening ≥ 1 NYHA class. Torasemide use impacted positively upon the primary endpoint occurrence, especially in younger patients (aged < 65 years) and with dilated cardiomyopathy.

CONCLUSIONS

Our findings contribute to the body of research on the optimal diuretic choice. Torasemide may have advantageous influence on NYHA class and long-term outcomes of HF patients, especially younger patients or those with dilated cardiomyopathy, but it needs further investigations in prospective randomised trials.

Acute blockade of inner ear marginal and dark cell K+ secretion: Effects on gravity receptor function

Specific pharmacological blockade of KCNQ (Kv7) channels with XE991 rapidly (within 20 min) and profoundly alters inner ear gravity receptor responses to head motion (Lee et al., 2017). We hypothesized that these effects were attributable to the suppression of K⁺ secretion following blockade of KCNQ1-KCNE1 channels in vestibular dark cells and marginal cells. To test this hypothesis, K⁺ secretion was independently inhibited by blocking the Na⁺-K⁺-2Cl^- cotransporter (NKCC1, Slc12a2) rather than KCNQ1-KCNE1 channels. Acute blockade of NKCC1 with ethacrynic acid (40 mg/kg) eliminated auditory responses (ABRs) within approximately 70 min of injection, but had no effect on vestibular gravity receptor function (VsEPs) over a period of 2 h in the same animals. These findings show that, vestibular gravity receptors are highly resistant to acute disruption of endolymph secretion unlike the auditory system. Based on this we argue that acute suppression of K⁺ secretion alone does not likely account for the rapid profound effects of XE991 on gravity receptors. Instead the effects of XE991 likely require additional action at KCNQ channels located within the sensory epithelium itself.

Long-term Stability of a Compounded Suspension of Torsemide (5 mg/mL) for Oral Administration

Background

Torsemide use for congestive heart failure (CHF) has been reported, but prescription frequency is unknown. Commercially available tablet sizes in North America limit dosing precision, indicating a need to evaluate its strength and stability in suspension.

Objectives

To determine the frequency of torsemide prescriptions and to determine a beyond use date (BUD) of a compounded suspension of torsemide for oral administration stored under 2 temperature conditions for 90 days.

Animals

No animals used.

Methods

Pharmacy records were retrospectively reviewed for torsemide and furosemide prescriptions from 2008 to 2015 at 2 veterinary referral centers. After preliminary strength testing, compounded torsemide suspension (5 mg/mL) for oral administration was prepared using torsemide tablets suspended in OraPlus:OraSweet 1:1, buffered to a pH of 8.3 and stored at refrigeration (2–8°C) and room temperature (20–25°C) in 2 oz amber plastic bottles. Samples were analyzed by reverse phase high‐performance liquid chromatography (RP‐HPLC) on days 0, 14, 30, 60, and 90.

Results

Prescriptions for torsemide increased from 2008 to 2015. Analysis of the torsemide 5 mg/mL suspension for oral administration at each time point met United States Pharmacopeia (USP) requirements for torsemide content of 90–110% of label claim. The average strength at 90 days decreased to 92 ± 3% at 2–8°C and 95 ± 2% at 20–25°C. Stability testing did not detect unknown impurities.

Conclusions

Increasing torsemide use warrants availability of a validated and stable compounded formulation. Our results support the assignment of a 90‐day BUD for torsemide 5 mg/mL suspension for oral administration compounded in OraPlus:Sweet 1:1 buffered to a pH of 8.3.

Cardiac Dysfunction, Congestion and Loop Diuretics: their Relationship to Prognosis in Heart Failure

BACKGROUND

Diuretics are the mainstay of treatment for congestion but concerns exist that they adversely affect prognosis. We explored whether the relationship between loop diuretic use and outcome is explained by the underlying severity of congestion amongst patients referred with suspected heart failure.

METHOD AND RESULTS

Of 1190 patients, 712 had a left ventricular ejection fraction (LVEF) ≤50 %, 267 had LVEF >50 % with raised plasma NTproBNP (>400 ng/L) and 211 had LVEF >50 % with NTproBNP ≤400 ng/L; respectively, 72 %, 68 % and 37 % of these groups were treated with loop diuretics including 28 %, 29 % and 10 % in doses ≥80 mg furosemide equivalent/day. Compared to patients with cardiac dysfunction (either LVEF ≤50 % or NT-proBNP >400 ng/L) but not taking a loop diuretic, those taking a loop diuretic were older and had more clinical evidence of congestion, renal dysfunction, anaemia and hyponatraemia. During a median follow-up of 934 (IQR: 513-1425) days, 450 patients were hospitalized for HF or died. Patients prescribed loop diuretics had a worse outcome. However, in multi-variable models, clinical, echocardiographic (inferior vena cava diameter), and biochemical (NTproBNP) measures of congestion were strongly associated with an adverse outcome but not the use, or dose, of loop diuretics.

CONCLUSIONS

Prescription of loop diuretics identifies patients with more advanced features of heart failure and congestion, which may account for their worse prognosis. Further research is needed to clarify the relationship between loop diuretic agents and outcome; imaging and biochemical measures of congestion might be better guides to diuretic dose than symptoms or clinical signs.

The impact of torasemide on haemodynamic and neurohormonal stress, and cardiac remodelling in heart failure - TORNADO: a study protocol for a randomized controlled trial

BACKGROUND

Approximately 50% of heart failure patients are readmitted to hospital within 6 months, owing to deterioration of their condition. Thus, symptomatic treatment of heart failure requires significant improvement. The aim of this study is to compare the effects of torasemide and furosemide on biochemical parameters of haemodynamic and neurohormonal compensation, myocardial remodelling, clinical outcomes and quality of life in patients with chronic heart failure.

METHODS

This is a multicentre, randomized, open, blinded endpoint phase-IV trial. The study includes 120 heart failure patients in NYHA (New York Heart Association) functional class II-IV, treated with optimal heart failure therapy, with indications for use of loop diuretics. At enrolment, patients are stable, with a fixed dose of loop diuretics. Patients are randomized to treatment with furosemide or torasemide (randomization 1:1). After randomization, the current fixed dose of furosemide is continued or is replaced by an equipotential dose of torasemide (4:1). The study consists of two control visits (3 and 6 months after enrolment) with minimal follow-up of 6 months. Assessment involves clinical examination, Quality of Life Questionnaire, laboratory tests, echocardiography, electrocardiography, 24 h Holter-electrocardiography monitoring, 6 -min walk test and assessment of fluid retention. Any need for dose adjustment is assessed during the observation. The primary objective is to compare the effects of torasemide and furosemide on clinical and biochemical parameters of haemodynamic and neurohormonal compensation and myocardial remodelling. Secondary objectives include monitoring of: changes in signs and symptoms of heart failure, NYHA functional class, quality of life, dosage changes, rate of readmissions and mortality.

DISCUSSION

Despite decades of the diuretic's history, knowledge about diuretic therapy is still unsatisfactory. The most widely used diuretic, furosemide, has a stormy pharmacokinetics and pharmacodynamics, and is associated with a high risk of mortality and hospitalization for worsening heart failure. Reports are very encouraging and suggest beneficial effects of torasemide. Hence, there is a need for further studies of the overall effect of torasemide, compared with furosemide. This can translate into improved quality of life and better prognosis of patients with heart failure.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT01942109 . Registered on 24 August 2013.

Dilemmas in the Dosing of Heart Failure Drugs: Titrating Diuretics in Chronic Heart Failure

Despite advances in medical therapy over the past few decades, the incidence of heart failure hospitalisation continues to rise. Diuretics are the most common therapy used to treat heart failure as they relieve congestion. However, there is a lack of guidance on how to best use these medications. Guidelines support the use of diuretics at the lowest clinically effective dose but do not specify a diuretic strategy beyond that. Here we review the diuretics available for treatment, potential mechanisms of diuretic resistance and ways to address this in the ambulatory setting, and review tools that have been developed to help guide diuretic use in the treatment of chronic heart failure.

Diuretic Use and Risk of Vertebral Fracture in Women

BACKGROUND

Vertebral fracture is the most common type of osteoporotic fracture. While thiazide diuretics, which are commonly prescribed for the treatment of hypertension, decrease calciuria, they may also induce hyponatremia, which has been associated with increased vertebral fracture risk. Loop diuretics increase calciuria, which would reduce bone mineral density and increase vertebral fracture risk, but they rarely cause hyponatremia. Recent studies on diuretics and fractures did not include or specifically examine vertebral fracture. The few studies of diuretics and vertebral fracture have been limited by cases defined by self-report or administrative data, relatively small number of cases, study design that was not prospective, and lack of long-term follow-up with updated information on diuretic use.

METHODS

We conducted a prospective cohort study of thiazide diuretic use, loop diuretic use, and risk of incident clinical vertebral fracture in 55,780 women, 55-82 years of age, participating in the Nurses' Health Study, without a prior history of any fracture. Diuretic use was assessed by questionnaire every 4 years. Self-reported vertebral fracture was confirmed by medical record review. Cox proportional-hazards models were used to simultaneously adjust for potential confounders.

RESULTS

Our analysis included 420 incident vertebral fracture cases documented between 2002 and 2012. The multivariate-adjusted relative risk of clinical vertebral fracture for women taking thiazides compared with women not taking thiazides was 1.47 (95% confidence interval, 1.18-1.85). The multivariate adjusted relative risk of vertebral fracture for women taking loop diuretics compared with women not taking loop diuretics was 1.59 (95% confidence interval, 1.12-2.25).

CONCLUSION

Thiazide diuretics and loop diuretics are each independently associated with increased risk of vertebral fracture in women.