In the pairwise meta-analysis, significant heterogeneity was found for MACE (I2 = 58%, p = 0.05) in the comparison between GLP-1 RAs vs. placebo, for cardiovascular mortality (I2 = 64%, p = 0.03) and all-cause mortality (I2 = 50%, p = 0.09) in the comparison between SGLT-2 inhibitors vs. placebo, and for hospitalisation for HF (I2 = 54%, p = 0.09) in the comparison between DPP-4 inhibitors vs. placebo. This evidence concerns the gene GCG and hydrops fetalis.