Heart failure (HF) is a major public health problem characterised by a high rate of hospitalisation and death. The risk is maximal for patients admitted with acute heart failure (AHF). New therapies with solid proof of mortality reduction in both groups of patients with reduced and preserved ejection fraction (EF) are now available (valsartan/sacubitril and SGLT2 inhibitors). The purpose of this article is to review the main data available and to clarify the role of these new therapies in AHF. The precise moment of initiating these therapies is still a matter of debate. This paper presents the recommended criteria for clinical stability that the clinician could use in deciding to initiate therapy. There is a growing amount of evidence that initiating these therapies sooner provides more benefits to patients.