Of note, the WARCEF trial was conducted 20 years ago, when treatment options and recommendations for both DM and HFrEF were different and more limited; therefore, we were unable to explore the effect of potentially interesting drugs (such as sodium-glucose cotransporter-2 inhibitors or glucagon-like peptide-1 receptor agonists) on the relationship between DM and HFrEF. This evidence concerns the gene SLC5A2 and diabetes mellitus.