Abstract 19610: Role of Hypoglycemic Agents on Ischemic Preconditioning in Diabetic Patients with Stable Multivessel Coronary Artery Disease

Abstract

Background: Ischemic preconditioning (IPC) protects the heart from irreversible injury and some hypoglycemic drugs can abolish IPC, affecting infarct size and contractile function and contributing to a worse prognosis. We aimed to evaluate the effect of 2 hypoglycemic agents on myocardial IPC in patients with type 2 diabetes and symptomatic coronary artery disease. Methods: We evaluated 81 patients, consecutively included, with type 2 diabetes, previous positive exercise test and multivessel coronary disease confirmed by coronary angiography. In phase I, without drug, all patients underwent 2 consecutive treadmill exercise tests (T1 and T2). After that, we started the phase II: 42 patients received repaglinide 6 mg per day (group R) and 38 pacients received Vildagliptin 100 mg per day ( group V), during one week and underwent 2 sequential tests (T3 and T4). The time interval between the exercise tests was 30 minutes. Results: In phase 1, IPC was demonstrated, in all patients, by improvement in the time to 1.0 mm of ST segment depression (T-1.0mm) in second of two sequential tests. All patients developed ischemia in T3; however, 83.3% of patients in group R experienced ischemia earlier in T4, indicating the cessation of IPC ( P <0.0001). In group V, only 28% of patients demonstrated IPC cessation, with 72% still preserving the protective effect ( P <0.0069). Conclusions: Repaglinide eliminated myocardial IPC, probably by its effect on the ATP-K channel. Vildagliptin did not affect this protective mechanism in a relevant way in patients with type 2 diabetes and coronary artery disease, suggesting a good alternative treatment in this population.