Effects of low dose pioglitazone on restenosis and coronary atherosclerosis in diabetic patients undergoing drug eluting stent implantation.

PURPOSE: Thiazolidinediones are insulin-sensitizing agents that reduce neointimal proliferation and the adverse clinical outcomes associated with percutaneous coronary intervention (PCI) in patients with diabetes mellitus (DM). There is little data on whether or not low dose pioglitazone reduces adverse clinical outcomes. MATERIALS AND METHODS: The study population included 121 DM patients with coronary artery disease and they were randomly assigned to 60 patients taking 15 mg of pioglitazone daily in addition to their diabetic medications and 61 patients with placebo after the index procedure with drug-eluting stents (DESs). The primary end points were rate of in-stent restenosis (ISR) and change in atheroma volume and in-stent neointimal volume. The secondary end points were all-cause death, myocardial infarction (MI), stent thrombosis and re-PCI. RESULTS: There were no statistical differences in the clinical outcomes and the rate of ISR between the two groups [all-cause death; n=0 (0%) in the pioglitazone group vs. n=1 (1.6%) in the control group, p=0.504, MI; n=2 (3.3%) vs. n=1 (1.6%), p=0.465, re-PCI; n=6 (10.0%) vs. n=6 (9.8%), p=0.652, ISR; n=4 (9.3%) vs. n=4 (7.5%), p=1.000, respectively]. There were no differences in changes in neointimal volume, percent neointimal volume, total plaque volume and percent plaque volume between the two groups on intravascular ultrasonography (IVUS) study. CONCLUSION: Our study demonstrated that low dose pioglitazone does not reduce rate of ISR, neointimal volume nor atheroma volume in DM patients who have undergone PCI with DESs, despite the limitations of the study.