Regression and shift in composition of coronary atherosclerotic plaques by pioglitazone: insight from an intravascular ultrasound analysis.

BACKGROUND: Plaque reduction with the use of pioglitazone and statin combination therapy has been observed in carotid plaque. We sought to investigate the effect of combination therapy with statins and pioglitazone on coronary plaque regression and composition with the use of intravascular ultrasound (IVUS) and intravascular ultrasound-virtual histology (IVUS-VH). METHODS: We analysed 29 plaques in 25 diabetic patients with angiographic evidence of nonsignificant coronary lesions with IVUS-VH. Patients were treated with 80 mg of atorvastatin and 30 mg of pioglitazone daily for 6 months. After 6 months of therapy, IVUS-VH of each lesion was reacquired. RESULTS: Mean elastic external membrane volume was significantly reduced between baseline and follow-up (343.9 vs. 320.5 mm; P < 0.05) as was mean total atheroma volume (179.3 vs. 166.6 mm; P < 0.05). Change in total atheroma volume showed a 6.3% mean reduction. Areas of fibrous tissue, fibrolipidic tissue and calcium decreased over the 6 months of follow-up, although not significantly. On the other hand, the necrotic core increased from 9 to 14% (P < 0.05). CONCLUSION: Our data demonstrated that atorvastatin/pioglitazone association is able to induce significant regression of coronary atherosclerosis, acting on plaque composition. Our findings are preliminary results and will be confirmed in an ongoing randomized placebo-controlled multicenter trial (PIPER; Pioglitazone for Prevention of Restenosis in Diabetics with Complex Lesion; trial registration: clinical trials.gov. Identifier: NCT 00376870).