Concept: Loop diuretic
Current goals in the acute treatment of heart failure are focused on pulmonary and systemic decongestion with loop diuretics as the cornerstone of therapy. Despite rapid relief of symptoms in patients with acute decompensated heart failure, after intravenous use of loop diuretics, the use of these agents has been consistently associated with adverse events, including hypokalemia, azotemia, hypotension, and increased mortality. Two recent randomized trials have shown that continuous infusions of loop diuretics did not offer benefit but were associated with adverse events, including hyponatremia, prolonged hospital stay, and increased rate of readmissions. This is probably due to the limitations of congestion evaluation as well as to the deleterious effects linked to drug administration, particularly at higher dosage. The impaired renal function often associated with this treatment is not extensively explored and could deserve more specific studies. Several questions remain to be answered about the best diuretic modality administration, global clinical impact during acute and post-discharge period, and the role of renal function deterioration during treatment. Thus, if loop diuretics are a necessary part of the treatment for acute heart failure, then there must be an approach that allows personalization of therapy for optimal benefit and avoidance of adverse events.
: Unfortunately, patients with congestive heart failure suffer frequent admissions for the management of fluid overload. Loop diuretics are pivotal in the management of this common clinical problem. Although loop diuretics have been in clinical use since the 1960s, we still do not understand how to optimally administer these drugs. It is unknown why some decompensated heart failure patients exhibit improvements in renal function with diuresis, whereas others display renal function deterioration, limiting attainment of euvolemia. Here the physiologic interactions between the failing heart and kidneys are reviewed. A conceptual framework is presented that emphasizes the balance between tubuloglomerular feedback and venous congestion in determining renal function during loop diuretic use in heart failure. Within this framework, guidelines are derived that seek to maximize the chance for achieving adequate volume removal while maintaining stable or improved renal function during the treatment of acute decompensated heart failure.
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.
Dapagliflozin inhibits the sodium-glucose-linked transporter 2 in the renal proximal tubule, thereby promoting glycosuria to reduce hyperglycemia in type 2 diabetes mellitus. Because these patients may require loop diuretics, and sodium-glucose-linked transporter 2 inhibition causes an osmotic diuresis, we evaluated the diuretic interaction between dapagliflozin and bumetanide.
The effectiveness of the clinical strategy of empiric potassium supplementation in reducing the frequency of adverse clinical outcomes in patients receiving loop diuretics is unknown. We sought to examine the association between empiric potassium supplementation and 1) all-cause death and 2) outpatient-originating sudden cardiac death (SD) and ventricular arrhythmia (VA) among new starters of loop diuretics, stratified on initial loop diuretic dose.
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.
Background -Worsening renal function (WRF) in the setting of aggressive diuresis for acute heart failure (AHF) treatment may reflect renal tubular injury or simply indicate a hemodynamic or functional change in glomerular filtration. Well-validated tubular injury biomarkers-NAG, NGAL, and KIM-1- are now available that can quantify the degree of renal tubularinjury. The ROSE-AHF trial provides an experimental platform for the study of mechanisms of WRF during aggressive diuresis for AHF, as the ROSE-AHF protocol dictated high dose loop diuretic therapy in all patients. We sought to determine whether tubular injury biomarkers are associated with WRF in the setting of aggressive diuresis and its association with prognosis. Methods -Patients in the multicenter ROSE-AHF trial with baseline and 72-hour urine tubular injury biomarkers were analyzed (N=283). WRF was defined as a ≥20% decrease in glomerular filtration rate estimated using cystatin C. Results -Consistent with protocol driven aggressive dosing of loop diuretics, participants received a median 560 mg of IV furosemide equivalents (IQR 300-815 mg) which induced a urine output of 8425 mL (IQR 6341-10528 ml) over the 72-hour intervention period. Levels of NAG and KIM-1 did not change with aggressive diuresis (P>0.59, both), whereas levels of NGAL decreased slightly [-8.7 ng/mg (-169, 35 ng/mg), P<0.001]. WRF occurred in 21.2% of the population and was not associated with an increase in any marker of renal tubular injury: NGAL (P=0.21), NAG (P=0.46), or KIM-1 (P=0.22). Increases in NGAL, NAG, and KIM-1 were paradoxically associated with improved survival (adjusted HR: 0.80 per 10 percentile increase, 95% CI: 0.69-0.91; P=0.001). Conclusions -Kidney tubular injury does not appear to have an association with WRF in the context of aggressive diuresis of AHF patients. These findings reinforce the notion that the small to moderate deteriorations in renal function commonly encountered with aggressive diuresis are dissimilar from traditional causes of acute kidney injury.
Loop diuretics remain a fundamental pharmacological therapy to remove excess fluid and improve symptom control in acute decompensated heart failure. Several recent randomised controlled trials have examined the clinical benefit of continuous vs. bolus furosemide in acute decompensated heart failure, but have reported conflicting findings. The aim of this review was to compare the effects of continuous and bolus furosemide with regard to mortality, length of hospital stay and its efficacy profile in acute decompensated heart failure. All parallel-arm randomised controlled trials from MEDLINE, EMBASE, PubMed and the Cochrane Database of Systematic Reviews from inception until May 2017 were included. Cross-over randomised controlled trials, observational studies, case reports, case series and non-systematic reviews that involved children were excluded. Eight trials (n = 669) were eligible for inclusion. There was no difference between furosemide continuous infusion and bolus administration for all-cause mortality (four studies; n = 491; I(2) = 0%; OR 1.65; 95%CI 0.93-2.91; p = 0.08) or duration of hospitalisation (six studies; n = 576; I(2) = 71%; mean difference 0.27; 95%CI -1.35 to 1.89 days; p = 0.74). Continuous infusion of intravenous furosemide was associated with increased weight reduction (five studies; n = 516; I(2) = 0%; mean difference 0.70; 95%CI 0.12-1.28 kg; p = 0.02); increased total urine output in 24 h (four studies; n = 390; I(2) = 33%; mean difference 461.5; 95%CI 133.7-789.4 ml; p < 0.01); and reduced brain natriuretic peptide (two studies; n = 390; I(2) = 0%; mean difference 399.5; 95%CI 152.7-646.3 ng.l(-1) ; p < 0.01), compared with the bolus group. There was no difference in the incidence of raised creatinine and hypokalaemia between the two groups. In summary, there was no difference between continuous infusion and bolus of furosemide for all-cause mortality, length of hospital stay and electrolyte disturbance, but continuous infusion was superior to bolus administration with regard to diuretic effect and reduction in brain natriuretic peptide.
Loop diuretics are common therapy for emergency department (ED) patients with acute heart failure (AHF). Diuretic resistance (DR) is a term used to describe blunted natriuretic response to loop diuretics. It would be important to detect DR prior to it becoming clinically apparent, so early interventions can be initiated. However, several definitions have been proposed, and it is not clear if they identify similar patients. We compared these definitions and described the clinical characteristics of patients who fulfilled them.
The effect of a sodium glucose cotransporter 2 inhibitor (SGLT2i) in reducing heart failure hospitalization in the EMPA-REG OUTCOMES trial has raised the possibility of using these agents to treat established heart failure. We hypothesize that osmotic diuresis induced by SGLT2 inhibition, a distinctly different diuretic mechanism than other diuretic classes, results in greater electrolyte-free water clearance, and ultimately in greater fluid clearance from the interstitial fluid (IF) space than from the circulation, potentially resulting in congestion relief with minimal impact on blood volume, arterial filling, and organ perfusion. We utilize a mathematical model to illustrate that electrolyte-free water clearance results in a greater reduction in IF volume compared to blood volume, and that this difference may be mediated by peripheral sequestration of osmotically inactive sodium. By coupling the model with data on plasma and urinary sodium and water in healthy subjects administered either the SGLT2i dapagliflozin or loop diuretic bumetanide, we predict that dapagliflozin produces a 2-fold greater reduction in IF volume compared to blood volume, while the reduction in IF volume with bumetanide is only 78% of the reduction in blood volume. Heart failure is characterized by excess fluid accumulation, in both the vascular compartment and interstitial space, yet many heart failure patients have arterial underfilling due to low cardiac output, which may be aggravated by conventional diuretic treatment. Thus, we hypothesize that by reducing IF volume to a greater extent than blood volume, SGLT2 inhibitors might provide better control of congestion without reducing arterial filling and perfusion.