Abstract 13668: Relationship Between Morphologies of Disrupted Cap Assessed by Optical Coherence Tomography and Clinical Presentation of Acute Coronary Syndrome
Backgrounds: Fibrous cap disruption of coronary plaque and subsequent thrombus formation has been reported as a major cause of acute coronary syndrome. Objectives: To determine the relationship between the morphologic characteristics of cap disruption and clinical presentation in vivo by optical coherence tomography (OCT).
Methods: From a total of 456 de novo coronary lesions, 106 lesions with fibrous cap disruption were identified by pre-procedural OCT imaging and investigated in the present study (STEMI 45, NSTEMI/UAP 25, SAP 36). Intravascular ultrasound (IVUS) was also performed before PCI. OCT analyses included thinnest cap thickness (CT), the type of a rupture site, longitudinal length of fibrous cap disruption (LL), aperture length of disrupted cap (AL) and cavity cross-sectional area (c-CSA). Rupture site was defined as center- or shoulder-type by the site of cap disruption. Location of rupture was classified into 3 types of proximal-type, distal-type, and mid-type according to longitudinal position of fibrous cap disruption to minimum lumen area site. Presence of intraluminal thrombus and its location were assessed by OCT. Vessel area, remodeling index (RI), and percent plaque area were determined by IVUS.
Results: Center-type rupture was significantly frequent in STEMI than in NSTEMI/UAP and SAP (75.5%, 44.0%, and 33.3%, respectively, p<0.01). Proximal-type rupture tended to be frequent in STEMI than in NSTEMI/UAP or SAP (STEMI 62.2%, NSTEMI/UAP 48.0%, SAP 41.6%, p=0.10). LL was significantly greater in STEMI than in NSTEMI/UAP (4.6±2.8mm vs 3.3±2.1mm, p=0.04), whereas modest trends were observed in c-CSA and AL between STEMI and NSTEMI/UAP (1.8±1.2mm2 vs 1.3±1.0mm2, p=0.06, and 0.65±0.34mm vs 0.77±0.37mm, p=0.17, respectively). Intraluminal thrombus was significantly frequent in STEMI than the other groups, whereas no significant difference was observed in thrombus location. Of all ruptured plaques, center-type rupture showed significant association with greater RI, thinner CT, greater LL, and the presence of thrombus.
Conclusions: Morphologies of disrupted cap assessed by OCT was associated with clinical presentation and plaque morphology. These findings may help understand the nature of the onset of acute coronary syndrome.
- © 2011 by American Heart Association, Inc.