Rationale and study design of intravenous loop diuretic administration in acute heart failure: DIUR-AHF

Right Ventricular-Pulmonary Artery Uncoupling and Strain in Acute Heart Failure

BACKGROUND

Assessment of right ventricular-pulmonary artery coupling plays a crucial role in risk stratification, monitoring efficacy, and predicting outcomes in chronic heart failure patients. However, data in acute heart failure (AHF) are still lacking.

METHODS AND RESULTS

This multicenter observational study includes 425 patients with AHF: 248 with reduced left ventricular ejection fraction (<50%) and 177 with preserved left ventricular ejection fraction (≥50%). Pulmonary artery systolic pressure (PASP), tricuspid annular plane systolic excursion (TAPSE), longitudinal 2-dimensional strain of right ventricular (RV) free wall, and the RV end-diastolic diameter were measured by echocardiography. TAPSE/PASP and longitudinal 2-dimensional strain of RV free wall/PASP ratios were calculated as noninvasive surrogates of right ventricular-pulmonary artery coupling. The end point was a composite of all-cause death/HF-related hospitalizations assessed at 180 days. At 180 days, 197 patients (46.4%) reached the end point. After multivariable adjustment for RV end-diastolic diameter, E/e' ratio, left ventricular ejection fraction, and natriuretic peptides, although both TAPSE/PASP (hazard ratio [HR], 0.49 [95% CI, 0.25-0.27]; P=0.042) and longitudinal 2-dimensional strain of RV free wall/PASP (HR, 0.30 [95% CI, 0.13-0.67]; P=0.004) had a statistically significant association with the end point, and longitudinal 2-dimensional strain of RV free wall/PASP better discriminated between patients with and without events compared with TAPSE/PASP (area under the curve, 0.70 versus 0.66; P=0.0041). Interestingly, the superiority of longitudinal 2-dimensional strain of RV free wall/PASP over the TAPSE/PASP ratio was more evident in patients with AHF with preserved ejection fraction (area under the curve, 0.72 versus 0.64; P<0.001) than in those with AHF with reduced ejection fraction (AUC, 0.67 versus 0.64; P=NS).

CONCLUSIONS

In patients with AHF, both TAPSE/PASP and longitudinal 2-dimensional strain of RV free wall/PASP are independent predictor of prognosis. However, longitudinal 2-dimensional strain of RV free wall/PASP showed a superior discriminator capability in identifying patients with events, mainly in the AHF with preserved ejection fraction subgroup.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique Identifier: NCT02638142.

Continuous infusion versus bolus injection of loop diuretics for acute heart failure

BACKGROUND

Acute heart failure (AHF) is new onset of, or a sudden worsening of, chronic heart failure characterised by congestion in about 95% of cases or end-organ hypoperfusion in 5% of cases. Treatment often requires urgent escalation of diuretic therapy, mainly through hospitalisation. This Cochrane review evaluated the efficacy of intravenous loop diuretics strategies in treating AHF in individuals with New York Heart Association (NYHA) classification III or IV and fluid overload.

OBJECTIVES

To assess the effects of intravenous continuous infusion versus bolus injection of loop diuretics for the initial treatment of acute heart failure in adults.

SEARCH METHODS

We identified trials through systematic searches of bibliographic databases and in clinical trials registers including CENTRAL, MEDLINE, Embase, CPCI-S on the Web of Science, ClinicalTrials.gov, the World Health Organization (WHO) International Clinical Trials Registry platform (ICTRP), and the European Union Trials register. We conducted reference checking and citation searching, and contacted study authors to identify additional studies. The latest search was performed on 29 February 2024.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) involving adults with AHF, NYHA classification III or IV, regardless of aetiology or ejection fraction, where trials compared intravenous continuous infusion of loop diuretics with intermittent bolus injection in AHF. We excluded trials with chronic stable heart failure, cardiogenic shock, renal artery stenosis, or end-stage renal disease. Additionally, we excluded studies combining loop diuretics with hypertonic saline, inotropes, vasoactive medications, or renal replacement therapy and trials where diuretic dosing was protocol-driven to achieve a target urine output, due to confounding factors.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened papers for inclusion and reviewed full-texts. Outcomes included weight loss, all-cause mortality, length of hospital stay, readmission following discharge, and occurrence of acute kidney injury. We performed risk of bias assessment and meta-analysis where data permitted and assessed certainty of the evidence.

MAIN RESULTS

The review included seven RCTs, spanning 32 hospitals in seven countries in North America, Europe, and Asia. Data collection ranged from eight months to six years. Following exclusion of participants in subgroups with confounding treatments and different clinical settings, 681 participants were eligible for review. These additional study characteristics, coupled with our strict inclusion and exclusion criteria, improve the applicability of the body of the evidence as they reflect real-world clinical practice. Meta-analysis was feasible for net weight loss, all-cause mortality, length of hospital stay, readmission, and acute kidney injury. Literature review and narrative analysis explored daily fluid balance; cardiovascular mortality; B-type natriuretic peptide (BNP) change; N-terminal-proBNP change; and adverse incidents such as ototoxicity, hypotension, and electrolyte imbalances. Risk of bias assessment revealed two studies with low overall risk, four with some concerns, and one with high risk. All sensitivity analyses excluded trials at high risk of bias. Only narrative analysis was conducted for 'daily fluid balance' due to diverse data presentation methods across two studies (169 participants, the evidence was very uncertain about the effect). Results of narrative analysis varied. For instance, one study reported higher daily fluid balance within the first 24 hours in the continuous infusion group compared to the bolus injection group, whereas there was no difference in fluid balance beyond this time point. Continuous intravenous infusion of loop diuretics may result in mean net weight loss of 0.86 kg more than bolus injection of loop diuretics, but the evidence is very uncertain (mean difference (MD) 0.86 kg, 95% confidence interval (CI) 0.44 to 1.28; 5 trials, 497 participants; P < 0.001, I2 = 21%; very low-certainty evidence). Importantly, sensitivity analysis excluding trials with high risk of bias showed there was insufficient evidence for a difference in bodyweight loss between groups (MD 0.70 kg, 95% CI -0.06 to 1.46; 3 trials, 378 participants; P = 0.07, I2 = 0%). There may be little to no difference in all-cause mortality between continuous infusion and bolus injection (risk ratio (RR) 1.53, 95% CI 0.81 to 2.90; 5 trials, 530 participants; P = 0.19, I2 = 4%; low-certainty evidence). Despite sensitivity analysis, the direction of the evidence remained unchanged. No trials measured cardiovascular mortality. There may be little to no difference in the length of hospital stay between continuous infusion and bolus injection of loop diuretics, but the evidence is very uncertain (MD -1.10 days, 95% CI -4.84 to 2.64; 4 trials, 211 participants; P = 0.57, I2 = 88%; very low-certainty evidence). Sensitivity analysis improved heterogeneity; however, the direction of the evidence remained unchanged. There may be little to no difference in the readmission to hospital between continuous infusion and bolus injection of loop diuretics (RR 0.85, 95% CI 0.63 to 1.16; 3 trials, 400 participants; P = 0.31, I2 = 0%; low-certainty evidence). Sensitivity analysis continued to show insufficient evidence for a difference in the readmission to hospital between groups. There may be little to no difference in the occurrence of acute kidney injury as an adverse event between continuous infusion and bolus injection of intravenous loop diuretics (RR 1.02, 95% CI 0.70 to 1.49; 3 trials, 491 participants; P = 0.92, I2 = 0%; low-certainty evidence). Sensitivity analysis continued to show that continuous infusion may make little to no difference on the occurrence of acute kidney injury as an adverse events compared to the bolus injection of intravenous loop diuretics.

AUTHORS' CONCLUSIONS

Analysis of available data comparing two delivery methods of diuretics in acute heart failure found that the current data are insufficient to show superiority of one strategy intervention over the other. Our findings were based on trials meeting stringent inclusion and exclusion criteria to ensure validity. Despite previous reviews suggesting advantages of continuous infusion over bolus injections, our review found insufficient evidence to support or refute this. However, our review, which excluded trials with clinical confounders and RCTs with high risk of bias, offers the most robust conclusion to date.

Clinical phenotypes according to diuretic combination in acute heart failure

BACKGROUND

The treatment of congestion in heart failure (HF) is a challenge despite the therapeutic arsenal available. The aim of this study was to analyze different combinations of diuretics used to resolve congestion in patients admitted for decompensated HF and to define clinical profiles according to these treatments.

METHODS

Single-center study of 1,559 patients admitted for decompensated HF was done between 2016 and 2020. Patients were grouped according to the diuretic combination that led to clinical stabilization and discharge from the hospital: (1) Loop diuretic. (2) Loop diuretic + distal tubule (antialdosterone ± thiazides). (3) Loop diuretic + distal + proximal tubule (acetazolamide ± SGLT2 inhibitor). (4) Loop diuretic + distal tubule + collecting duct (tolvaptan). (5) Loop diuretic + distal + proximal + collecting duct. Based on these diuretic combinations, profiles with clinical, analytical, and echocardiographic differences were established.

RESULTS

There were more previous hospitalizations in groups 4 and 5 (p = 0.001) with a predominance of pulmonary congestion in profiles 1 and 2 and systemic congestion in 3, 4, and 5. Creatinine and CA125 were higher in profiles 4 and 5 (p = 0.01 and p = 0.0001), with no differences in NT-proBNP. Profiles 4 and 5 had a higher proportion of dilatation and depression of right ventricular (p = 0.0001) and left ventricular (p = 0.003) function. Diuretic therapy-defined groups showed difference in clinical characteristics.

CONCLUSIONS

The diuretic treatment used identifies five clinical profiles according to the degree of congestion, renal function, CA125, and right ventricular functionality. These profiles would guide the best diuretic treatment on admission.

New Miniaturized System for Ultrafiltration: Rationale and Design of a Single-Center, Crossover, Randomized, Open-Label, Pilot Study Protocol

INTRODUCTION

Fluid overload and congestion are common features in patients with heart failure and are associated with negative clinical outcomes. Therapies for these conditions are diuretic-centered but frequently fail to achieve patient-adequate hydration status, prompting the use of extracorporeal ultrafiltration. Artificial Diuresis 1 (AD1) is a miniaturized, portable, and wearable system designed to deliver isolated ultrafiltration with the finest degree of simplicity and practicality.

METHODS/DESIGN

Single-center, crossover, randomized, open-label pilot study to investigate the safety and the efficacy (concerning ultrafiltration accuracy) of extracorporeal ultrafiltration with the device AD1 in comparison to isolated ultrafiltration with a traditional machine (PrisMaX). Patients with chronic kidney disease stage 5D (on hemodialysis) or intensive care patients presenting acute kidney injury stage 3D (requiring hemodialysis) will carry out a single session of isolated ultrafiltration with each of the machines. The safety primary outcomes will be the occurrence of adverse events. The efficacy primary outcome will be the accuracy of ultrafiltration rate (delivered/prescribed) on each of the devices.

CONCLUSION

AD1 is a novel miniaturized device for extracorporeal ultrafiltration. This study will be the first-in-human use of AD1 in patients with fluid overload.

Evaluation of diuretic efficiency of intravenous furosemide in patients with advanced heart failure in a heart failure clinic

INTRODUCTION

Diuretic efficiency (DE) is an independent predictor of all-cause mortality in acute heart failure (HF) at long-term follow-up. The performance of DE in advanced HF and the outpatient scenario is unclear.

METHODS

Survival function analysis on a retrospective cohort of patients with advanced HF followed at the outpatient clinic of Hospital Universitario San Ignacio (Bogotá, Colombia) between 2017 and 2021. DE was calculated as the average of total diuresis in milliliters divided by the dose of IV furosemide in milligrams for each 6-h session, considering all the sessions in which the patient received levosimendan and IV furosemide. We stratified DE in high or low using the median value of the cohort as the cutoff value. The primary outcome was a composite of all-cause mortality and HF hospitalizations during a 12-month follow-up. Kaplan-Meier curves and log-rank test were used to compare patients with high and low DE.

RESULTS

In all, 41 patients (66.5 ± 13.2 years old, 75.6% men) were included in the study, with a median DE of 24.5 mL/mg. In total, 20 patients were categorized as low and 21 as high DE. The composite outcome occurred more often in the high DE group (13 versus 5, log-rank test p = 0.0385); the all-cause mortality rate was 29.2% and was more frequent in the high DE group (11 versus 1, log-rank test p = 0.0026).

CONCLUSION

In patients with advanced HF on intermittent inotropic therapy, a high DE efficiency is associated with a higher risk of mortality or HF hospitalization in a 12-month follow-up period.

Different Renal Function Patterns in Patients With Acute Heart Failure: Relationship With Outcome and Congestion

Background

The role of worsening renal function during acute heart failure (AHF) hospitalization is still debated. Very few studies have extensively evaluated the renal function (RF) trend during hospitalization by repetitive measurements.

Objectives

To investigate the prognostic relevance of different RF trajectories together with the congestion status in hospitalized patients.

Methods

This is a post hoc analysis of a multi-center study including 467 patients admitted with AHF who were screened for the Diur-AHF Trial. We recognized five main RF trajectories based on serum creatinine and estimated glomerular filtration rate (eGFR) behavior. According to the RF trajectories our sample was divided into 1-stable (S), 2-transient improvement (TI), 3-permanent improvement (PI), 4-transient worsening (TW), and 5-persistent worsening (PW). The primary outcome was the combined endpoint of 180 days including all causes of mortality and re-hospitalization.

Results

We recruited 467 subjects with a mean congestion score of 3.5±1.08 and a median creatinine value of 1.28 (1.00-1.70) mg/dl, eGFR 50 (37-65) ml/min/m2 and NTpro B-type natriuretic peptide (BNP) 7,000 (4,200-11,700) pg/ml. A univariate analysis of the RF pattern demonstrated that TI and PW patterns were significantly related to poor prognosis [HR: 2.71 (1.81-4.05); p < 0.001; HR: 1.68 (1.15-2.45); p = 0.007, respectively]. Conversely, the TW pattern showed a significantly protective effect on outcome [HR:0.34 (0.19-0.60); p < 0.001]. Persistence of congestion and BNP reduction ≥ 30% were significantly related to clinical outcome at univariate analysis [HR: 2.41 (1.81-3.21); p < 0.001 and HR:0.47 (0.35-0.67); p < 0.001]. A multivariable analysis confirmed the independently prognostic role of TI, PW patterns, persistence of congestion, and reduced BNP decrease at discharge.

Conclusions

Various RF patterns during AHF hospitalization are associated with different risk(s). PW and TI appear to be the two trajectories related to worse outcome. Current findings confirm the importance of RF evaluation during and after hospitalization.

Ultrafiltration for acute heart failure

BACKGROUND

Pharmacotherapies such as loop diuretics are the cornerstone treatment for acute heart failure (AHF), but resistance and poor response can occur. Ultrafiltration (UF) is an alternative therapy to reduce congestion, however its benefits, efficacy and safety are unclear.

OBJECTIVES

To assess the effects of UF compared to diuretic therapy on clinical outcomes such as mortality and rehospitalisation rates.

SEARCH METHODS

We undertook a systematic search in June 2021 of the following databases: CENTRAL, MEDLINE, Embase, Web of Science CPCI-S and ClinicalTrials.gov. We also searched the WHO ICTRP platform in October 2020.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared UF to diuretics in adults with AHF.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. We contacted study authors for any further information, and language interpreters to translate texts. We assessed risk of bias in included studies using Risk of Bias 2 (RoB2) tool and assessed the certainty of the evidence using GRADE.

MAIN RESULTS

We included 14 trials involving 1190 people. We included people who had clinical signs of acute hypervolaemia. We excluded critically unwell people such as those with ischaemia or haemodynamic instability. Mean age ranged from 57.5 to 75 years, and the setting was a mix of single and multi-centre. Two trials researched UF as a complimentary therapy to diuretics, while the remaining trials withheld diuretic use during UF. There was high risk of bias in some studies, particularly with deviations from the intended protocols from high cross-overs as well as missing outcome data for long-term follow-up.  We are uncertain about the effect of UF on all-cause mortality at 30 days or less (risk ratio (RR) 0.61, 95% confidence interval (CI) 0.13 to 2.85; 3 studies, 286 participants; very low-certainty evidence). UF may have little to no effect on all-cause mortality at the longest available follow-up (RR 1.00, 95% CI 0.73 to 1.36; 9 studies, 987 participants; low-certainty evidence). UF may reduce all-cause rehospitalisation at 30 days or less (RR 0.76, 95% CI 0.53 to 1.09; 3 studies, 337 participants; low-certainty evidence). UF may slightly reduce all-cause rehospitalisation at longest available follow-up (RR 0.91, 95% CI 0.79 to 1.05; 6 studies, 612 participants; low-certainty evidence). UF may reduce heart failure-related rehospitalisation at 30 days or less (RR 0.62, 95% CI 0.37 to 1.04; 2 studies, 395 participants; low-certainty evidence). UF probably reduces heart failure-related rehospitalisation at longest available follow-up, with a number needed to treat for an additional beneficial effect (NNTB) of 10 (RR 0.69, 95% CI 0.53 to 0.90; 4 studies, 636 participants; moderate-certainty evidence).  No studies measured need for mechanical ventilation.  UF may have little or no effect on serum creatinine change at 30 days since discharge (mean difference (MD) 14%, 95% CI -12% to 40%; 1 study, 221 participants; low-certainty evidence). UF may increase the risk of new initiation of renal replacement therapy at longest available follow-up (RR 1.42, 95% CI 0.42 to 4.75; 4 studies, 332 participants; low-certainty evidence).  There is an uncertain effect of UF on the risk of complications from central line insertion in hospital (RR 4.16, 95% CI 1.30 to 13.30; 6 studies, 779 participants; very low-certainty evidence).  AUTHORS' CONCLUSIONS: This review summarises the latest evidence on UF in AHF. Moderate-certainty evidence shows UF probably reduces heart failure-related rehospitalisation in the long term, with an NNTB of 10. UF may reduce all-cause rehospitalisation at 30 days or less and at longest available follow-up. The effect of UF on all-cause mortality at 30 days or less is unclear, and it may have little effect on all-cause mortality in the long-term.  While UF may have little or no effect on serum creatinine change at 30 days, it may increase the risk of new initiation of renal replacement therapy in the long term. The effect on complications from central line insertion is unclear.  There is insufficient evidence to determine the true impact of UF on AHF. Future research should evaluate UF as an adjunct therapy, focusing on outcomes such as heart failure-related rehospitalisation, cardiac mortality and renal outcomes at medium- to long-term follow-up.

Additive harmful effects of acute kidney injury and acute heart failure on mortality in hospitalized patients

Background

Organ crosstalk between the kidney and the heart has been suggested. Acute kidney injury (AKI) and acute heart failure (AHF) are well-known independent risk factors for mortality in hospitalized patients. This study aimed to investigate if these conditions have an additive effect on mortality in hospitalized patients, as this has not been explored in previous studies.

Methods

We retrospectively reviewed the records of 101,804 hospitalized patients who visited two tertiary hospitals in the Republic of Korea over a period of 5 years. AKI was diagnosed using serum creatinine-based criteria, and AHF was classified using International Classification of Diseases codes within 2 weeks after admission. Patients were divided into four groups according to the two conditions. The primary outcome was all-cause mortality.

Results

AKI occurred in 6.8% of all patients (n = 6,920) and AHF in 1.2% (n = 1,244). Three hundred thirty-one patients (0.3%) developed both conditions while AKI alone was present in 6,589 patients (6.5%) and AHF alone in 913 patients (0.9%). Among the 5,181 patients (5.1%) who died, 20.8% died within 1 month. The hazard ratio for 1-month mortality was 29.23 in patients with both conditions, 15.00 for AKI only, and 3.39 for AHF only. The relative excess risk of interaction was 11.85 (95% confidence interval, 2.43‒21.27), and was more prominent in patients aged <75 years and those without chronic heart failure.

Conclusion

AKI and AHF have a detrimental additive effect on short-term mortality in hospitalized patients.

Effects of Metolazone Administration on Congestion, Diuretic Response and Renal Function in Patients with Advanced Heart Failure

Background: Advanced heart failure (HF) is a condition often requiring elevated doses of loop diuretics. Therefore, these patients often experience poor diuretic response. Both conditions have a detrimental impact on prognosis and hospitalization. Aims: This retrospective, multicenter study evaluates the effect of the addition of oral metolazone on diuretic response (DR), clinical congestion, NTproBNP values, and renal function over hospitalization phase. Follow-up analysis for a 6-month follow-up period was performed. Methods: We enrolled 132 patients with acute decompensated heart failure (ADHF) in advanced NYHA class with reduced ejection fraction (EF < 40%) taking a mean furosemide amount of 250 ± 120 mg/day. Sixty-five patients received traditional loop diuretic treatment plus metolazone (Group M). The mean dose ranged from 7.5 to 15 mg for one week. Sixty-seven patients continued the furosemide (Group F). Congestion score was evaluated according to the ESC recommendations. DR was assessed by the formula diuresis/40 mg of furosemide. Results: Patients in Group M and patients in Group F showed a similar prevalence of baseline clinical congestion (3.1 ± 0.7 in Group F vs. 3 ± 0.8 in Group M) and chronic kidney disease (CKD) (51% in Group M vs. 57% in Group F; p = 0.38). Patients in Group M experienced a better congestion score at discharge compared to patients in Group F (C score: 1 ± 1 in Group M vs. 3 ± 1 in Group F p > 0.05). Clinical congestion resolution was also associated with weight reduction (−6 ± 2 in Group M vs. −3 ± 1 kg in Group F, p < 0.05). Better DR response was observed in Group M compared to F (940 ± 149 mL/40 mgFUROSEMIDE/die vs. 541 ± 314 mL/40 mgFUROSEMIDE/die; p < 0.01), whereas median ΔNTproBNP remained similar between the two groups (−4819 ± 8718 in Group M vs. −3954 ± 5560 pg/mL in Group F NS). These data were associated with better daily diuresis during hospitalization in Group M (2820 ± 900 vs. 2050 ± 1120 mL p < 0.05). No differences were found in terms of WRF development and electrolyte unbalance at discharge, although Group M had a significant saline solution administration during hospitalization. Follow-up analysis did not differ between the group but a reduced trend for recurrent hospitalization was observed in the M group (26% vs. 38%). Conclusions: Metolazone administration could be helpful in patients taking an elevated loop diuretics dose. Use of thiazide therapy is associated with better decongestion and DR. Current findings could suggest positive insights due to the reduced amount of loop diuretics in patients with advanced HF.

Impact of loop diuretics on critically ill patients with a positive fluid balance

The impact of the use of loop diuretics to prevent cumulative fluid balance in non-oliguric patients is uncertain. This is a retrospective study to estimate the association of time-averaging loop diuretic exposure in a large population of non-cardiac, critically ill patients with a positive fluid balance (> 5% of body weight). The exposure was loop diuretic and the main outcomes were 28-day mortality, severe acute kidney injury and successful mechanical ventilation weaning. Time-fixed and daily time-varying variables were evaluated with a marginal structural Cox model, adjusting bias for time-varying exposure and the presence of time-dependent confounders. A total of 14,896 patients were included. Patients receiving loop diuretics had better survival (unadjusted hazard ratio 0.56, 95%CI 0.39-0.81 and baseline variables adjusted hazard ratio 0.53, 95%CI 0.45-0.62); after full adjusting, loop diuretics had no association with 28-day mortality (full adjusted hazard ratio 1.07, 95%CI 0.74-1.54) or with reducing severe acute kidney injury occurrence during intensive care unit stay - hazard ratio 1.05 (95%CI 0.78-1.42). However, we identified an association with prolonged mechanical ventilation (hazard ratio 1.59, 95%CI 1.35-1.89). The main results were consistent in the sub-group analysis for sepsis, oliguria and the study period (2002-2007 vs. 2008-2012). Also, equivalent doses of up to 80 mg per day of furosemide had no significant association with mortality. After adjusting for time-varying variables, the time average of loop diuretic exposure in non-cardiac, critically ill patients has no association with overall mortality or severe acute kidney injury; however, prolonged mechanical ventilation is a concern.

Loop Diuretic Administration in Patients with Acute Heart Failure and Reduced Systolic Function: Effects of Different Intravenous Diuretic Doses and Diuretic Response Measurements

Background: Despite the fact that loop diuretics are a landmark in acute heart failure (AHF) treatment, few trials exist that evaluate whether the duration and timing of their administration and drug amount affect outcome. In this study, we sought to evaluate different loop diuretic infusion doses in relation to outcome and to diuretic response (DR), which was serially measured during hospitalization. Methods: This is a post-hoc analysis of a DIUR-HF trial. We divided our sample on the basis of intravenous diuretic dose during hospitalization. Patients taking less than 125 mg of intravenous furosemide (median value) were included in the low dose group (LD), patients with a diuretic amount above this threshold were inserted in the high dose group (HD). The DR formula was defined as weight loss/40 mg daily of furosemide and it was measured during the first 24 h, 72 h, and over the whole infusion period. Outcome was considered as death due to cardiovascular causes or heart failure hospitalization. Results: One hundred and twenty-one AHF patients with reduced ejection fractions (EF) were evaluated. The cardiovascular (CV) death/heart failure (HF) re-hospitalization rate was significantly higher in the HD group compared to the LD group (75% vs. 22%; p < 0.001). Both low DR, measured during the entire infusion period (HR 3.25 (CI: 1.92–5.50); p < 0.001) and the intravenous diuretic HD (HR 5.43 [CI: 2.82–10.45]; p < 0.001) were related to outcome occurrence. Multivariable analysis showed that DR (HR 3.01 (1.36–6.65); p = 0.006), intravenous diuretic HD (HR 2.83 (1.24–6.42); p=0.01) and worsening renal function (WRF) (HR 2.21 (1.14–4.28); p = 0.01) were related to poor prognosis. Conclusions: HD intravenous loop diuretic administration is associated with poor prognosis and less DR. Low DR measured during the whole intravenous administration better predicts outcome compared to DR measured in the early phases. ClinicalTrials.gov Acronym and Identifier Number: DIUR-HF; NCT01441245; registered on 23 September 2011.

Clinical Pharmacodynamics: Principles of Drug Response and Alterations in Kidney Disease

Pharmacokinetics and pharmacodynamics follow the logic of cause and consequence. Receptor-mediated and reversible effects can be distinguished from direct and irreversible effects. Reversible effects are capacity-limited and saturable whereas irreversible effects are limited only by the number of viable targets. In the case of receptor-mediated and reversible effects a threshold and a ceiling concentration can be defined. Antimicrobial drugs with concentration-dependent action are distinguished from drugs with time-dependent action. Concentration-dependent effects are associated with a high ceiling concentration and the target is the high peak. Time-dependent effects are associated with a high threshold concentration and the target is the high trough. During kidney dysfunction, alterations of drug response are usually attributed to pharmacokinetic but rarely to pharmacodynamic changes. Dose adjustment calculations, therefore, tacitly presume that pharmacodynamic parameters remain unchanged while only pharmacokinetic parameters are altered in kidney failure. Kidney dysfunction influences the pharmacokinetic parameters of at least 50% of all essential drugs. Clinicians usually consider pharmacokinetics when kidney disease is found, but pharmacodynamics is as important. Alterations of pharmacodynamic parameters are conceivable but only rarely reported in kidney failure. Sometimes surprising dosing adjustments are needed when pharmacodynamic concepts are brought into the decision process of which dose to choose. Pharmacokinetics and pharmacodynamics should both be considered when any dosing regimen is determined.

Effect of Dynamic Potassium Change on In-Hospital Mortality, Ventricular Arrhythmias, and Long-Term Mortality in STEMI

We evaluated the effect of serum potassium (K) deviation on in-hospital and long-term clinical outcomes in patients with ST-segment elevation myocardial infarction who were normokalemic at admission. A total of 2773 patients with an admission serum K level of 3.5 to 4.5 mEq/L were retrospectively analyzed. The patients were categorized into 3 groups according to their K deviation: normokalemia-to-hypokalemia, normokalemia-to-normokalemia, and normokalemia-to-hyperkalemia. In-hospital mortality, long-term mortality, and ventricular arrhythmias rates were compared among the groups. In a hierarchical multivariable regression analysis, the in-hospital mortality risk was higher in normokalemia-to-hypokalemia (odds ratio [OR] 3.03; 95% confidence interval [CI], 1.72-6.82) and normokalemia-to-hyperkalemia groups (OR 2.81; 95% CI, 1.93-4.48) compared with the normokalemia-to-normokalemia group. In a Cox regression analysis, long-term mortality risk was also higher in normokalemia-to-hypokalemia (hazard ratio [HR] 3.78; 95% CI, 2.07-7.17) and normokalemia-to-hyperkalemia groups (HR, 2.97; 95% CI, 2.10-4.19) compared with the normokalemia-to-normokalemia group. Ventricular arrhythmia risk was also higher in normokalemia-to-hypokalemia group (OR 2.98; 95% CI, 1.41-5.75) compared with normokalemia-to-normokalemia group. The current study showed an increased in-hospital ventricular arrhythmia and mortality and long-term mortality rates with the deviation of serum K levels from normal ranges.

Intermittent furosemide administration in patients with or at risk for acute kidney injury: Meta-analysis of randomized trials

Background

Furosemide is the most common loop diuretic used worldwide. The off-label administration of furosemide bolus(es) for the prevention or to reverse acute kidney injury (AKI) is widespread but not supported by available evidence. We conducted a meta-analysis of randomized trials (RCTs) to investigate whether bolus furosemide to prevent or treat AKI is detrimental on patients’ survival.

Methods

Electronic databases were searched through October 2017 for RCTs comparing bolus furosemide administration versus any comparator in patients with or at risk for AKI. The primary endpoint was all-cause longest follow-up mortality. Secondary endpoints included new or worsening AKI, receipt of renal replacement therapy, length of hospital stay, and peak serum creatinine after randomization.

Results

A total of 28 studies randomizing 3,228 patients were included in the analysis. We found no difference in mortality between the two groups (143/892 [16%] in the furosemide group versus 141/881 [16%] in the control group; odds ratio [OR], 0.84; 95% confidence interval [CI], 0.63 to 1.13; p = 0.25). No significant differences in secondary outcomes were found. A significant improvement in survival was found in the subgroup of patients receiving furosemide bolus(es) as a preventive measure (43/613 [7.0%] versus 67/619 [10.8%], OR 0.62; 95% CI, 0.41 to 0.94; p = 0.03)

Conclusions

Intermittent furosemide administration is not associated with an increased mortality in patients with or at risk for AKI, although it may reduce mortality when used as a preventive measure. Future high-quality RCTs are needed to define the role of loop diuretics in AKI prevention and management.

Trial registration

The study protocol was registered on PROSPERO database for systematic reviews (Registration no. CRD42017078607 – http://www.crd.york.ac.uk/PROSPERO/display_record.php?ID=CRD42017078607).

Rationale and study design of intravenous loop diuretic administration in acute heart failure: DIUR-AHF

AIMS

Although loop diuretics are the most commonly used drugs in acute heart failure (AHF) treatment, their short-term and long-term effects are relatively unknown. The significance of worsening renal function occurrence during intravenous treatment is not clear enough. This trial aims to clarify all these features and contemplate whether continuous infusion is better than an intermittent strategy in terms of decongestion efficacy, diuretic efficiency, renal function, and long-term prognosis.

METHODS AND RESULTS

This is a prospective, multicentre, randomized study that compares continuous infusion to intermittent infusion and a low vs. high diuretic dose of furosemide in patients with a diagnosis of acute heart failure, BNP ≥ 100 pg/mL, and specific chest X-ray signs. Randomization criteria have been established at a 1:1 ratio using a computer-generated scheme of either twice-daily bolus injection or continuous infusion for a time period ranging from 72 to 120 h. The initial dose will be 80 mg/day of intravenous furosemide and, in the case of poor response, will be doubled using an escalation algorithm. A high diuretic dose is defined as a furosemide daily amount >120 mg/day respectively.

CONCLUSIONS

Continuous and high dose groups could reveal a more intensive diuresis and a greater decongestion with respect to intermittent and low dose groups; high dose and poor loop diuretic efficiency should be related to increased diuretic resistance, renal dysfunction occurrence, and greater congestion status. Poor diuretic response will be associated with less decongestion and an adverse prognosis.