Abstract 5599: Relationship between Coronary Arterial Remodeling and Fibrous Cap Thickness in Patients with Acute Coronary Syndrome

Abstract

The aim of this study was to evaluate the relationship between coronary arterial remodeling and the thickness of fibrous cap in patients with acute coronary syndrome (ACS). Thin-capped fibroatheroma is recognized as a precursor lesion for ACS. Positive remodeling (PR) is predominant pattern of arterial remodeling in patients with ACS. However, the relationship between PR and the thickness of fibrous cap has not been elucidated in vivo. We enrolled 41 patients with ACS who underwent both intravascular ultrasound (IVUS) and optical coherence tomography (OCT). The arterial remodeling was assessed by IVUS and the thickness of fibrous cap was measured by OCT. The thin fibrous cap was defined as <70μm in the thinnest part. Remodeling index (RI) was calculated as lesion divided by the reference external elastic membrane cross-sectional area and PR was defined as RI > 1.05 (a PR group). Thin-capped fibroatheroma were observed more frequently in the PR group than in the intermediate and negative remodeling (IR/NR) groups (63% versus 16%, p=0.0057). RI was inversely correlated with the thickness of fibrous cap (r=−0.53, p=0.019). High-sensitive C-reactive protein (hs-CRP) levels were higher in the PR group than in the IR/NR groups (0.50±0.63mg/dL versus 0.20±0.15mg/dL, p<0.05). Also, the hs-CRP levels were higher in patients with thin fibrous cap (0.54±0.71mg/dL versus 0.21±0.14mg/dL, p<0.05). The coronary arterial remodeling, the thickness of fibrous cap and CRP level in patients with ACS were associated with each other. These results suggest that inflammatory process contributes to both plaque growth and plaque instability.