Impact of type 2 diabetes on serial changes in tissue characteristics of coronary plaques: an integrated backscatter intravascular ultrasound analysis

Abstract

Several studies have demonstrated that type 2 diabetes mellitus (T2DM) is associated with accelerated atherosclerosis, which results in an increased risk of coronary vascular events. However, serial changes in plaque characteristics have not been reported in vivo. We evaluated the progression of coronary atherosclerosis in patients with T2DM using an integrated backscatter intravascular ultrasound (IB-IVUS) examination. Forty-two T2DM and 48 non-diabetic patients who underwent percutaneous coronary intervention were enrolled in the study. Non-culprit 20-mm length coronary lesions with mild-to-moderate stenosis were measured using a 40-MHz (motorized pullback of 0.5 mm/s) IVUS catheter. IVUS examinations were performed on one target lesion in each patient. Six months later, a follow-up IVUS examination was repeated in the same coronary segment imaged at the baseline examination. T2DM patients demonstrated a greater total plaque volume (TPV; 139 ± 53 vs. 114 ± 45 mm(3), P = 0.02) and total lipid volume (TLV; 67 ± 26 vs. 55 ± 30 mm(3), P = 0.039) at the baseline examination. The progression of TPV (8.6 ± 15.4 vs. -2.2 ± 16.0%, P < 0.01) and TLV (10.8 ± 28.8 vs. -2.5 ± 20.0%, P < 0.05) from the baseline was observed in T2DM patients, but not in non-diabetic patients. The increase in TLV was blunted in T2DM patients who achieved HbA1c levels of <6.5%. Accelerated plaque progression with an increase in the lipid-rich component of non-culprit plaques was observed in T2DM, despite the use of standard medical treatment. Better glycaemic control ameliorated the worsening of plaque characteristics in T2DM.