A review of cardiovascular outcome trials in type 2 diabetes

Type 2 diabetes is a complex metabolic disorder associated with a high risk of cardiovascular complications. In December 2008, due to concerns about the cardiac safety of antihyperglycaemic therapies, the Food and Drug Administration (FDA) published a new guidance on special requirements for the demonstration of cardiovascular safety for these medications. In 2012, similar recommendations were made for antidiabetic drug manufacturers by the European Medicines Agency (EMA). Since then, both FDA and EMA recommendations have been applied in cardiovascular outcome trials (CVOTs) for several new antihyperglycaemic drugs. Unlike conventional trials, CVOTs are usually placebo controlled, non-inferiority trials that examine the cardiovascular safety of a drug compared to standard of care in large cohorts of patients with high cardiovascular risk or established cardiovascular disease. Patients in CVOTs are also monitored for a longer observation period than in typical randomised controlled trials to provide data on long-term cardiovascular risk. To date, nine CVOTs involving patients with type 2 diabetes have been completed, and at least 13 are still ongoing. These studies focus on a variety of antihyper-glycaemic drugs, including incretin-based agents, sodium-glucose cotransporter 2 inhibitor (SGLT-2) inhibitors, and insulin formulations. This article takes a critical look at these CVOTs and summarises the results of the completed trials.