Use of loop diuretics in chronic heart failure: do we adhere to the Hippocratian principle "do no harm"?

Although approaches to optimize volume status, such as modifying fluid and salt intake, are important,1 use of loop diuretics remains the mainstay of treatment for congestion in patients with both acute (AHF) and chronic heart failure (CHF), regardless of the underlying left ventricular ejection fraction.2 Characteristically, more than 80% of patients with CHF receive regular treatment with some kind of oral loop diuretic.3,4 The 2016 European guidelines on heart failure (HF) recommend the use of diuretics for patients with signs and symptoms of congestion (recommendation class I, level of evidence B).5 However, loop diuretics may exert a range of adverse effects including electrolyte depletion, which predispose to life-threatening ventricular arrhythmias, hyperglycaemia, hyperuricaemia, orthostatic hypotension, vestibular symptoms and renal function deterioration.2 Furthermore, they seem to activate the neurohormonal system and hamper the up-titration of guideline-recommended HF treatment.6,7 Thus, current guidelines recommend use of diuretics at the lowest dose needed to achieve and maintain euvolaemia, meaning that reduced loop diuretic dose may often be indicated in stable CHF patients.5 Recently, the Heart Failure Association (HFA) of the European Society of Cardiology (ESC) put together a comprehensive consensus document on the use of diuretics in HF,1 providing, among others, guidance on the challenging task of assessing HF patients’ fluid status. Herein we summarize the existing literature on loop diuretic dose changes in CHF and call for randomized trials. Loop diuretic strategies in AHF are not addressed.