Diabetes Mellitus and Cardiovascular Disease: An Evidence-Based Review of Provincial Formulary Coverage

Cardiovascular mortality is the primary cause of death in patients with type 2 diabetes mellitus (T2DM). Recently, clinical trials of the sodium-glucose transport protein 2 (SGLT-2) inhibitors empagliflozin and canagliflozin and of the glucagon-like peptide-1 (GLP-1) agonists liraglutide and semaglutide demonstrated that the agents reduced cardiovascular events. Furthermore, empagliflozin and liraglutide reduced cardiovascular mortality. However, despite the proven cardiac benefits, many but not all provincial formularies have restrictive rules for payment and access for SGLT-2 inhibitors and GLP-1 agonists. These restrictions impede a practitioner's ability to provide optimal care for patients with T2DM and cardiovascular disease. The 2018 Diabetes Canada Guidelines recommend the use of a glucose-lowering agent with proven cardiovascular benefit (ie, empagliflozin, canagliflozin, liraglutide, or semaglutide) as second-line therapy after metformin, for patients with T2DM and cardiovascular disease who fail to achieve the glycemic target of A1C <7% with metformin. We recognize that provinces must allot resources especially when health care budgets are limited and not able to provide all available treatments. However, today we have glucose-lowering agents that reduce mortality in patients at very high cardiovascular risk. Furthermore, for empagliflozin, the cost effectiveness is highly favourable. Consequently, we urge provincial formularies to re-examine the access requirements for SGLT-2 inhibitors and to consider adding GLP-1 agonists use to reflect current evidence and clinical guideline recommendations.