The role of glucose lowering agents on restenosis after percutaneous coronary intervention in patients with diabetes mellitus

Introduction: The prevalence of diabetes is increasing rapidly, and individuals with diabetes are at high risk for cardiovascular disorders. Subsequently the percentage of patients with diabetes subjected to revascularisation, i.e. either percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) also rises rapidly. The outcome of patients with diabetes after PCI is worse than for patients without diabetes. Restenosis is the main limiting factor of the long-term success of PCI. Although stents and antithrombotics improved outcome after PCI in both diabetics and non-diabetics, diabetics still have a worse prognosis. This leads to the suggestion that the restenosis mechanism in diabetics might be different from that in non-diabetics. Conclusion: Several glucose lowering agents have been shown to influence the restenosis process and thus the outcome after PCI. Current data of especially metformin and thiazolidinediones indicate beneficial results as compared to insulin and sulfonylurea on restenosis. However, no large trials have been undertaken in which the effect of glucose lowering agents on restenosis is associated with improved outcome. The purpose of this review is to summarize the effect of diabetes and glucose lowering agents on restenosis.