Evaluating cardiovascular safety of novel therapeutic agents for the treatment of type 2 diabetes mellitus.

Type 2 diabetes increases the risk of developing cardiovascular (CV) complications such as myocardial infarction, heart failure, stroke, peripheral vascular disease, and CV-associated mortality. Strict glycemic control in diabetics has shown improvement in microvascular complications related to diabetes but has been unable to demonstrate major effects on macrovascular complications including myocardial infarction and stroke. Conventional therapies for diabetes that include insulin, metformin, sulfonylureas (SU), and alpha-glucosidase inhibitors have limited and/or controversial data on CV safety based on observational studies not designed or powered to assess CV safety of these medications. In 2008, the US Food and Drug Administration (FDA) revised regulations for the approval of medications for type 2 diabetes by requiring that enough CV events are accrued prior to approval to rule out an upper 95 % confidence interval (95 % CI) for HR of 1.8 for CV events, followed by ruling out an upper 95 % CI for HR of 1.3 in the post-approval period. To date, novel diabetes therapies including peroxisome proliferator-activated receptor (PPAR) gamma agonists, dipeptidyl peptidase-4 (DPP4) inhibitors, glucagon-like peptide 1 (GLP 1) analogs, and sodium-glucose transporter-2 (SGL2) inhibitors have been evaluated in CV safety trials. Results from the first major CV outcome studies in type 2 diabetes, SAVOR-TIMI 53 and EXAMINE, have shown that neither saxagliptin nor alogliptin had increases in major CV events relative to placebo in high-risk patients. Ongoing and future trials will elucidate the CV safety for other DPP-4 inhibitors compared to SUs and the GLP-1 agonists versus placebo.