Reasons for these recommendations are that (1) metformin therapy of people with T2D and HF reduces total mortality and the risk of death or HHF [119], (2) it delays the development of HF in diabetic people in comparison to sulfonylurea monotherapy [119], and (3) metformin therapy is associated with a decreased risk of CV events and death in diabetic people with a clinical CV risk defined by an NT-proBNP level higher than 300 pg/mL [120]. This evidence concerns the gene NPPB and hydrops fetalis.