Pioglitazone reduces neointimal tissue proliferation after coronary stent implantation in patients with type 2 diabetes mellitus: an intravascular ultrasound scanning study

Background It has been reported that pioglitazone reduces neointimal hyperplasia after balloon-induced vascular injury in an experimental model. Methods To determine whether pioglitazone reduces neointimal tissue proliferation after coronary stent implantation in patients with type 2 diabetes mellitus, we studied 44 stented lesions in 44 patients with diabetes mellitus who underwent successful coronary stent implantation. Study patients were randomized into 2 groups: the pioglitazone group (23 patients with 23 lesions) and the control group (21 patients with 21 lesions). All patients underwent serial quantitative coronary angiography and serial intravascular ultrasound scanning studies. With a motorized pullback system, multiple image slices within the stent were obtained at every 1 mm. The stent area and lumen area were measured, and the neointimal area was calculated. Measurements were averaged over the number of selected image slices. The neointimal index was calculated as the averaged neointimal area divided by the averaged stent area multiplied by 100 (%). Results After 6 months of treatment, angiographic in-stent restenosis (17% vs 43%, respectively, P = .0994) and target lesion revascularization (13% vs 38%, respectively, P = .0835) were less frequent in the pioglitazone group than the control group; however, these differences did not reach significance. The intravascular ultrasound scanning study demonstrated that the neointimal index in the pioglitazone group was significantly smaller than that in the control group (28% ± 9% vs 48% ± 15%, respectively, P <.0001). Conclusion A serial intravascular ultrasound scanning assessment demonstrated that pioglitazone reduces neointimal tissue proliferation after coronary stent implantation in patients with type 2 diabetes mellitus.