The vast majority of acute heart failure episodes are characterized by increasing symptoms and signs of congestion with volume overload. The goal of therapy in those patients is the relief of congestion through achieving a state of euvolaemia, mainly through the use of diuretic therapy. The appropriate use of diuretics however remains challenging, especially when worsening renal function, diuretic resistance and electrolyte disturbances occur. This position paper focuses on the use of diuretics in heart failure with congestion. The manuscript addresses frequently encountered challenges, such as (i) evaluation of congestion and clinical euvolaemia, (ii) assessment of diuretic response/resistance in the treatment of acute heart failure, (iii) an approach towards stepped pharmacologic diuretic strategies, based upon diuretic response, and (iv) management of common electrolyte disturbances. Recommendations are made in line with available guidelines, evidence and expert opinion.

Appropriate interpretation of changes in markers of kidney function is essential during the treatment of acute and chronic heart failure. Historically, kidney function was primarily assessed by serum creatinine and the calculation of estimated glomerular filtration rate. An increase in serum creatinine, also termed worsening renal function, commonly occurs in patients with heart failure, especially during acute heart failure episodes. Even though worsening renal function is associated with worse outcome on a population level, the interpretation of such changes within the appropriate clinical context helps to correctly assess risk and determine further treatment strategies. Additionally, it is becoming increasingly recognized that assessment of kidney function is more than just glomerular filtration rate alone. As such, a better evaluation of sodium and water handling by the renal tubules allows to determine the efficiency of loop diuretics (loop diuretic response and efficiency). Also, though neurohumoral blockers may induce modest deteriorations in glomerular filtration rate, their use is associated with improved long‐term outcome. Therefore, a better understanding of the role of cardio–renal interactions in heart failure in symptom development, disease progression and prognosis is essential. Indeed, perhaps even misinterpretation of kidney function is a leading cause of not attaining decongestion in acute heart failure and insufficient dosing of guideline‐directed medical therapy in general. This position paper of the Heart Failure Association Working Group on Cardio‐Renal Dysfunction aims at improving insights into the interpretation of renal function assessment in the different heart failure states, with the goal of improving heart failure care.

BACKGROUNDWhether acetazolamide, a carbonic anhydrase inhibitor that reduces proximal tubular sodium reabsorption, can improve the efficiency of loop diuretics, potentially leading to more and faster decongestion in patients with acute decompensated heart failure with volume overload, is unclear. METHODSIn this multicenter, parallel-group, double-blind, randomized, placebo-controlled trial, we assigned patients with acute decompensated heart failure, clinical signs of volume overload (i.e., edema, pleural effusion, or ascites), and an N-terminal pro-B-type natriuretic peptide level of more than 1000 pg per milliliter or a B-type natriuretic peptide level of more than 250 pg per milliliter to receive either intravenous acetazolamide (500 mg once daily) or placebo added to standardized intravenous loop diuretics (at a dose equivalent to twice the oral maintenance dose). Randomization was stratified according to the left ventricular ejection fraction (≤40% or >40%). The primary end point was successful decongestion, defined as the absence of signs of volume overload, within 3 days after randomization and without an indication for escalation of decongestive therapy. Secondary end points included a composite of death from any cause or rehospitalization for heart failure during 3 months of follow-up. Safety was also assessed. RESULTSA total of 519 patients underwent randomization. Successful decongestion occurred in 108 of 256 patients (42.2%) in the acetazolamide group and in 79 of 259 (30.5%) in the placebo group (risk ratio, 1.46; 95% confidence interval [CI], 1.17 to 1.82; P<0.001). Death from any cause or rehospitalization for heart failure occurred in 76 of 256 patients (29.7%) in the acetazolamide group and in 72 of 259 patients (27.8%) in the placebo group (hazard ratio, 1.07; 95% CI, 0.78 to 1.48). Acetazolamide treatment was associated with higher cumulative urine output and natriuresis, findings consistent with better diuretic efficiency. The incidence of worsening kidney function, hypokalemia, hypotension, and adverse events was similar in the two groups. CONCLUSIONSThe addition of acetazolamide to loop diuretic therapy in patients with acute decompensated heart failure resulted in a greater incidence of successful decongestion. (Funded by the Belgian Health Care Knowledge Center; ADVOR ClinicalTrials.gov number, NCT03505788.

Резюме. Для більшості епізодів гострої серцевої недостатності характерне посилення симптомів та ознак застійних явищ з об'ємним перенавантаженням. Мета терапії в таких пацієнтів полягає в полегшенні застійних явищ шляхом досягнення нормоволемії, головним чином за допомогою терапії діуретиками. Проте належне застосування діуретиків залишається складним, особливо при погіршенні функції нирок, резистентності до діуретиків та порушеннях балансу електролітів. У цій офіційній заяві розглядається застосування діуретиків при застійній серцевій недостатності. У роботі розглядаються поширені проблеми, такі як: 1) оцінка застійних явищ та клінічної нормоволемії; 2) оцінка відповіді на діуретики/резистентності до діуретиків при лікуванні гострої серцевої недостатності; 3) підхід до поетапних фармакологічних стратегій застосування діуретиків на основі відповіді на діуретики; 4) лікування поширених порушень балансу електролітів. Рекомендації наведені відповідно до доступних настанов, свідчень та експертних висновків.