Abstract 13061: Quantitative Assessment of Tissue Protrusion within Stented Segments on Optical Coherence Tomography after Percutaneous Coronary Intervention
[Background] Tissue protrusion within stented segments are sometimes detected on optical coherence tomography (OCT) after percutaneous coronary intervention (PCI) in patients with coronary artery disease. We sought to conduct a quantitative assessment of tissue protrusion after PCI and evaluated its relation with the underlying plaque morphologies and coronary flow during PCI.
[Methods] We investigated 147 lesions that underwent PCI with pre- and post-intervention OCT. We measured quantitatively the whole volume of tissue protrusion (tissue protruding within the stent struts) throughout the stented segments after PCI. Based on the volume of protrusion, we divided all lesions into tertiles; T1: protrusion >0.44 mm3, T2: 0.44≤ protrusion >1.35 mm3 and T3: protrusion ≥1.35 mm3. Among tertiles, we evaluated the differences of plaque morphologies such as lipid-rich plaque (lipid arc >180 degrees), thin-cap fibroatheroma (TCFA) (lipid arc >180 degrees and fibrous cap thickness >70 µm), plaque rupture and intraluminal thrombi at the culprit sites and the coronary flow during PCI.
[Results] Lipid-rich plaque, TCFA, plaque rupture and thrombi were detected in 52.4%, 29.3%, 12.9% and 36.1% of the lesions, respectively. Slow-flow phenomenon during PCI (deterioration of coronary flow to TIMI flow grade 0-2) was observed in 11 lesions (7.5%). The existence of TCFA and thrombi were related to a larger volume of protrusion; lesions with TCFA: 2.01±2.49 mm3 vs. without TCFA: 1.24±1.69 mm3 (P=0.03) and lesions with thrombi: 2.51±2.63 mm3 vs. without thrombi: 1.31±1.83 mm3 (P=0.01). The upper tertile with the larger volume of protrusion had a higher frequency of lipid-rich plaque (T1: 40.8%, T2: 51.0% and T3: 65.3%, P=0.05), TCFA (T1: 18.4%, T2: 24.5% and T3: 44.9%, P=0.01) and thrombi (T1: 16.3%, T2: 36.7% and T3: 55.1%, P=0.0003). Further, lesions with the greater volume of protrusion showed a higher frequency of slow-flow phenomenon during PCI (T1: 0.0%, T2: 10.2% and T3: 12.2%, P=0.04).
[Conclusion] Tissue protrusion within stented segments on OCT remaining after PCI might be related with the pre-existence of TCFA and intraluminal thrombi and the occurrence of slow-flow phenomenon during PCI, which suggests a significant relation to worse outcomes after PCI.
- © 2012 by American Heart Association, Inc.