Abstract 3972: Impact of Metabolic Syndrome on Tissue Characteristics of Angiographically Normal Coronary Lesions: Integrated Backscatter Intravascular Ultrasound Study
Background: The metabolic syndrome (MetS) is associated with the increased risk of cardiovascular disease. In this study, we assessed the impact of MetS on tissue characteristics of coronary plaques using integrated backscatter intravascular ultrasound (IB-IVUS).
Methods: Among consecutive 123 patients with stable angina pectoris recruited to undergo percutaneous coronary intervention, we identified MetS by the International Diabetes Federation definition [ethnicity/gender adjusted abdominal obesity measured by waist circumference plus two or more criteria]. Conventional and IB-IVUS parameters were measured in nontarget coronary lesions with moderate stenosis using a 40-MHz (motorized pullback 0.5mm/s) intravascular catheter. A total of 20 IB-IVUS images were captured at an interval of 0.5 mm and the segment with minimum lumen area was evaluated in each plaque. Then % fibrous area (%FA), % lipid area (%LA) and % calcification area were automatically counted using commercially available computer software. Volumetric analysis was also performed using Simpson’s rule.
Results: The prevalence of MetS was 61 patients (49.5%). Vessel area (12.5 vs 10.0 mm2, p=0.007), vessel volume (135.9 vs 103.4 mm3, p=0.001), plaque area (7.9 vs 6.0 mm2, p=0.01) and plaque volume (69.6 vs 50.9 mm3, p=0.005) were significantly increased in MetS, whereas the other conventional IVUS parameters were similar between the two groups. Furthermore, significant decrease in % FA (60.2 vs 66.8 %, p=0.04), and significant increase in % LA (33.2 vs 22.9 %, p=0.02), lipid area (2.94 vs 1.44 mm2, p=0.003), lipid volume (25.3 vs 14.6 mm3, p=0.009) and fibrous volume (40.8 vs 32.2 mm3, p=0.02) were observed in MetS compared with non-MetS. On logistic regression analysis after adjusted for confounding and coronary risk factors, MetS (OR 3.29, CI 1.08–9.46, p=0.036) was an independent predictor of the greater lipid volume (> median).
Conclusions: MetS is associated with plaque vulnerability, suggesting the contribution to the increased risk of cardiovascular events.