Effect of Hypoglycemic Agents on Ischemic Preconditioning in Patients With Type 2 Diabetes and Symptomatic Coronary Artery Disease

OBJECTIVE: To assess the effect of two hypoglycemic drugs on ischemic preconditioning (IPC) patients with type 2 diabetes and coronary artery disease (CAD). RESEARCH DESIGN AND METHODS: We performed a prospective study of 96 consecutive patients allocated into two groups: 42 to group repaglinide (R) and 54 to group vildagliptin (V). All patients underwent two consecutive exercise tests (ET1 and ET2) in phase 1 without drugs. In phase 2, 1 day after ET1 and -2, 2 mg repaglinide three times daily or 50 mg vildagliptin twice daily was given orally to patients in the respective group for 6 days. On the seventh day, 60 min after 6 mg repaglinide or 100 mg vildagliptin, all patients underwent two consecutive exercise tests (ET3 and ET4). RESULTS: In phase 1, IPC was demonstrated by improvement in the time to 1.0 mm ST-segment depression and rate pressure product (RPP). All patients developed ischemia in ET3; however, 83.3% of patients in group R experienced ischemia earlier in ET4, without significant improvement in RPP, indicating the cessation of IPC (P < 0.0001). In group V, only 28% of patients demonstrated IPC cessation, with 72% still having the protective effect (P < 0.0069). CONCLUSIONS: Repaglinide eliminated myocardial IPC, probably by its effect on the K(ATP) channel. Vildagliptin did not damage this protective mechanism in a relevant way in patients with type 2 diabetes and CAD, suggesting a good alternative treatment in this population.