Background: Pioglitazone has a preventive effect on cardiovascular disease, but its ability to stabilize coronary plaque is unknown.
Methods and results: A prospective, randomized trial was conducted in 54 patients with type 2 diabetes and stable angina pectoris, randomly assigned to either a pioglitazone group or control group. Non-culprit, angiographically mild-to-moderate obstructive lesions were examined with virtual histology intravascular ultrasound (VH-IVUS) at coronary intervention and 6 months later. In total, 42 lesions of 22 patients in the pioglitazone group and 44 lesions of 24 patients in the control group were analyzed. After 6 months, patients in the pioglitazone group had significantly improved blood sugar, high-sensitivity C-reactive protein, and plasma adiponectin levels. VH-IVUS analysis revealed that, although the total plaque-to-vessel volume was not changed in either group, the necrotic-core area had significantly decreased in the pioglitazone group (-4.6+/-5.9% vs 1.1+/-9.3%, P=0.001). There was a significant inverse correlation between the change in plasma adiponectin levels and the change in necrotic-core area (r=-0.46, P<0.0001).
Conclusions: Pioglitazone may stabilize coronary plaque by reducing the necrotic-core component, in association with enhanced plasma adiponectin levels.