Guest Editor: Dr Vijay Chopra, Max Super Specialty Hospital in Saket, New Delhi, India

Aldosterone, a steroidal hormone, plays a critical role in maintaining a homeostasis in water and electrolyte balance. These effects are mediated through its action on aldosterone receptors situated in the heart and kidneys. Aldosterone is overactive in several pathological conditions, leading to deleterious effects on the kidneys, heart and vascular system. Aldosterone inhibition in these conditions serves as a key modifier of disease outcomes. 

The use of aldosterone inhibitors has been restricted due to an actual or perceived fear of hyperkalaemia. This is most evident in situations where a patient actually stands to benefit the most. Recent years have seen the emergence of several new strategies to retain the benefit of aldosterone inhibition while reducing the risk of hyperkalaemia and other side-effects. Finerenone, a non-steroidal mineralocorticoid receptor antagonist, has already been shown to be beneficial in diabetic kidney disease and in heart failure with preserved ejection fraction in major clinical trials. Aldosterone synthase inhibition is an exciting field, and several clinical trials are already under way to assess aldosterone inhibitors in heart failure with preserved ejection fraction, heart failure with reduced ejection fraction and renal diseases, alone or in combination with SGLT2 inhibitors. 

This collection focuses on aspects of aldosterone, including strategies to prevent or counter hyperkalaemia, the evidence for the use of non-steroidal mineralocorticoid receptor antagonist and the fast emerging field of aldosterone synthase inhibition. The contributors for these chapters are acknowledged leaders in their fields. It is our earnest hope that the readers will find this information useful.