As the number of patients suffering from heart failure is constantly rising worldwide, optimised medical treatment is indispensable to reduce mortality and prevent patients from hospitalisation.1 Despite new drug development in recent years, heart failure is still associated with a poor prognosis: more than every second patient dies within 5 years after diagnosis.2

Mineralocorticoid receptor antagonists (MRA), such as spironolactone, play a key role in the treatment of heart failure as this drug class is pivotal in mitigating the adverse effects of aldosterone, including sodium retention, potassium excretion and myocardial fibrosis. MRAs are an integral part of the standardised treatment for patients with heart failure with reduced ejection fraction. Patients suffering from heart failure with preserved ejection fraction (HFpEF), characterised by myocardial stiffening and impaired relaxation, might also benefit particularly from the drugs’ antifibrotic effects since fibrosis is believed to be a critical pathological mechanism in HFpEF.3 Nevertheless, several large randomised clinical trials, such as …