AS-16: Does Microchannel Structure Identified by Optical Coherence Tomography Demonstrates Plaque Vulnerability in Patients with Coronary Artery Disease?

AS-16: Does Microchannel Structure Identified by Optical Coherence Tomography Demonstrates Plaque Vulnerability in Patients with Coronary Artery Disease?

Thursday, April 29, 2010 Coronary Imaging Imaging I Ida I Thursday, April 29, 2010 8:30 AM⬃ 9:30 AM (Abstract nos. AS-14, AS-15, AS-17, AS-20, AS-21)...

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Thursday, April 29, 2010

Coronary Imaging Imaging I Ida I Thursday, April 29, 2010 8:30 AM⬃ 9:30 AM (Abstract nos. AS-14, AS-15, AS-17, AS-20, AS-21) Imaging II Ida I Thursday, April 29, 2010 9:30 AM⬃ 10:30 AM (Abstract nos. AS-16, AS-18, AS-19, AS-22, AS-23)

AS-14 Coronary Artery Spasm in Unstable Angina Pectoris: Assessment of Plaque Morphology and Dynamic State of Vasoconstriction by Optical Coherence Tomography. Naoki Maniwa, Masato Mizukoshi, Takashi Kubo, Hironori Kitabata, Takashi Tanimoto, Kenichi Komukai, Kohei Iashibashi, Yasushi Ino, Keizou Kimura, Akio Kuroi, Hideyuki Ikejima, Hiroto Tsujioka, Keishi Okochi, Manabu Kashiwagi, Keisuke Satogami, Aiko Shimokado, Tsuyoshi Nishiguchi, Tomizou Masuno, Ikuko Teraguchi, Toshio Imanishi, Takashi Akasaka. Wakayama Medical University, Wakayama, Japan. Background: Intravascular ultrasound studies have suggested that the plaque morphology of spasm coronary arteries might be related to the pathogenesis of variant angina. However, the influence on unstable angina pectoris (UAP) remains unclear. Optical coherence tomography (OCT) is a high-resolution imaging modality and allows detailed analysis of tissue characteristics. In this study, we assessed the dynamic state of vasoconstriction and plaque morphology at the spasm sites in patients with UAP by OCT. Methods: Fifty patients with UAP were enrolled. Nine patients had coronary spasm. OCT examinations were performed at the spasm sites during coronary spasm and after intracoronary injection of nitroglycerin. Results: OCT findings were as follows: mild intimal thickening (0.130 – 0.180 mm) with erosion, 3 patients (33.3%); lipid-rich plaque with rupture, 1 patient (11.1%); and eccentric fibro-fatty plaque, 5 patients (55.5%). In 5 patients with fibro-fatty plaque, there were more intensity-attenuated areas in the plaques, which correspond to necrotic core or hemorrhage. Furthermore, accumulation of erythrocytes and macrophages was observed in the plaque specimen obtained by direc-

tional coronary atherectomy. OCT examinations revealed a dynamic state of spasm. Circumferential vasoconstriction occurred equally regardless of the plaque burden. The constriction changed the morphology of the intima. The surface of the intima was folded, whereas the media thickened without folding. Conclusion: Tissue characteristics at coronary spasm sites has the potential to lead to progression of plaque vulnerability. Furthermore, the dynamic state of coronary spasm may lead to intimal injury. Coronary spasm may play an important role on the onset or progression of acute coronary syndrome.

AS-15 Plaque Characteristics and Acute Percutaneous Coronary Intervention Outcomes According to the Remodeling Pattern in Diseased Saphenous Vein Graft: Intravascular Ultrasound Analysis. Young Joon Hong1, Myung Ho Jeong1, Youngkeun Ahn1, Gary S. Mintz2, Sang Wook Kim3, Sung Yun Lee4, Seok Yeon Kim5, Augusto D. Pichard6, Ron Waksman6, Neil J. Weissman6, Jung Chaee Kang1. 1Heart Center of Chonnam National University Hospital, Gwangju, Republic of Korea; 2Cardiovascular Research Foundation, New York, USA; 3Chung-Ang University Hospital, Seoul, Republic of Korea; 4Inje University Ilsan Paik Hospital, Ilsan, Republic of Korea; 5Seoul Medical Center, Seoul, Republic of Korea; 6Washington Hospital Center, Washington, DC, USA. Background: Plaque characteristics and post–percutaneous coronary intervention (PCI) outcome according to the remodeling pattern in saphenous vein graft (SVG) lesions have not been fully assessed. We evaluated pre- and post-PCI intravascular ultrasound (IVUS) images of 311 SVG lesions and compared IVUS findings between lesions with positive remodeling (PR, n ⫽ 113) and those with intermediate/negative remodeling (IR/NR, n ⫽ 198). Methods: Remodeling index was the ratio of the lesion site SVG area to the mean of the proximal and distal references (PR: remodeling index [RI] ⬎1.05, IR: 0.95 ⱕ RI ⱕ 1.05, NR: RI ⬍0.95)]. Plaque prolapse (PP) was defined as tissue extrusion through the stent strut post-PCI, and the volume of PP was calculated by subtracting lumen volume from stent volume. Results: The presence of hypoechoic plaque (59% vs 36%, p ⫽ 0.001), plaque rupture (26% vs 16%, p ⫽ 0.042), multiple plaque rupture (12% vs 5%, p ⫽ 0.020), and an intraluminal mass (59% vs 41%, p ⫽ 0.002) were more common in PR than in IR/NR lesions. Plaque cavity area was greater in PR compared with IR/NR lesions (0.83 ⫾ 1.43 mm2 vs 0.42 ⫾ 1.07 mm2, p ⫽ 0.009). Post-PCI no-reflow (19% vs 9%, p ⫽ 0.019) and post-PCI PP (53% vs 27%, p ⬍0.001) were more frequently observed, and PP volume were significantly greater after PCI for PR than for IR/NR lesions (0.86 ⫾ 1.30 mm3 vs 0.34 ⫾ 0.74 mm3, p ⬍0.001). PR was the independent predictor of post-PCI no-reflow (odds ratio [OR] ⫽ 2.58; 95% confidence interval [CI] 1.25–5.64, p ⫽ 0.040] and poststenting PP (OR ⫽ 2.45; 95% CI 1.46 –5.41, p ⫽ 0.045). Conclusion: SVG lesions with PR have vulnerable plaque and are associated with no-reflow and PP after PCI.

AS-16 Does Microchannel Structure Identified by Optical Coherence Tomography Demonstrates Plaque Vulnerability in Patients with Coronary Artery Disease? Hironori Kitabata, Atsushi Tanaka, Takashi Kubo, Shigeho Takarada, Kohei Ishibashi, Kenichi Komukai, Takashi Tanimoto, Yasushi Ino, Kumiko Hirata, Kazushi Takemoto, Keizo Kimura, Masato Mizukoshi, Toshio Imanishi, Takashi Akasaka. Wakayama Medical University, Wakyama, Japan.

The American Journal of Cardiology姞 APRIL 28 –29 2010 ANGIOPLASTY SUMMIT ABSTRACTS/Oral

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Thursday, April 29, 2010

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Background: Increased neovascularization in atherosclerotic plaques is associated with plaque vulnerability. To date, however, an appropriate in vivo imaging modality that identifies this feature is lacking. The high-resolution of optical coherence tomography (OCT) may provide a chance to directly visualize plaque neovascularization. The purpose of this study was to investigate the relationship between microchannels in culprit plaques identified by OCT and plaque vulnerability in patients with coronary artery disease (CAD). Methods: We enrolled 63 patients with CAD and examined lesion morphologies by using both OCT and intravascular ultrasound before interventions. Results: Microchannel was defined as a no-signal capillary-like tubular structure on the cross-sectional OCT image. Microchannels were found in 24 (38%) of 63 patients. According to the presence or absence of microchannel, patients were divided into 2 groups. The frequency of plaque rupture tended to be higher in the microchannel group (50% vs 28%, p ⫽ 0.11). The thickness of fibrous cap (median 60 vs 100 ␮m, p ⫽ 0.001) was significantly thinner in patients with microchannel, and there were significant differences in the frequency of thin-cap fibroatheroma (54% vs 21%, p ⫽ 0.012) and positive remodeling (67% vs 36%, p ⫽ 0.02) between the 2 groups. High-sensitivity C-reactive protein (hs-CRP) levels in the microchannel group was significantly higher than those in the no microchannel group (median 0.27 vs 0.13 mg/dL, p ⫽ 0.015). Moreover, increased microchannel counts were associated with higher hs-CRP levels (p ⫽ 0.01; see Figure).

Conclusion: There was a significant relationship between microchannels in plaques identified by OCT and plaque vulnerability in patients with CAD.

AS-17 Dual-Source Computed Tomography Has a High Negative Predictive Value in the Evaluation of Restenosis after the Left Main Coronary Artery Stenting. Pavla Bradacova1, David Zemanek1, Theodor Adla2, Josef Veselka1. 1University Hospital Motol, Prague, Czech Republic; 2Department of Imaging Methods, Charles University, 2nd Faculty of Medicine, Prague, Czech Republic. Background: Restenosis of the left main coronary artery (LMCA) after previous stenting is potentially associated with the fatal myocardial infarction and sudden cardiac death. Therefore, it has been widely accepted to perform repeat coronary angiography (CAG) after the intervention to rule out a significant LMCA restenosis. The aim of this study was to determine whether CAG and dual-source computed to-

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mography (DSCT) are accurate methods in the evaluation of the LMCA after PCI with stent implantation. Methods: Thirty-two consecutive patients (56% men, aged 68 ⫾ 13 years) were prospectively enrolled for follow-up coronary angiography, intravascular ultrasound (IVUS), and DSCT examinations after LMCA stenting (twice during 9-month follow-up). Twenty-five patients were treated with drug-eluting stents and 7 with bare metal stents. Restenosis was defined by CAG as ⬎50% of luminal diameter and by DSCT and IVUS minimal luminal area (MLA) as ⬍6 mm2. IVUS was considered the gold standard in the evaluation of LMCA. Results: Thirty-nine complete examinations were performed. There were no significant complications during any examination. We found 2, 8, and 1 significant restenoses according to CAG, MSCT, and IVUS, respectively. Positive predictive values according to CAG and DSCT were 50% and 12.5%, in contrast to negative predictive values for both methods, which were 100%. Conclusion: These results suggest that all methods studied are safe. Positive predictive value of CAG and DSCT seem to be limited. However, negative predictive value of CAG and DSCT is close to 100%. Thus, DSCT is a useful, noninvasive method in the evaluation of the post-PCI restenosis of LMCA. However, findings of restenosis of any significance should be reevaluated by IVUS.

AS-18 Predictors and Mechanism of Lesion Progression at the Side Branch Ostium after Main Vessel Stenting: Serial Intravascular Ultrasound Analysis. Joo-Yong Hahn, Young Bin Song, Seung-Hyuk Choi, Jin-Ho Choi, Sang Hoon Lee, Hyeon-Cheol Gwon. Samsung Medical Center, Seoul, Republic of Korea. Background: Today the majority of bifurcation lesions are treated with the 1-stent technique. However, the predictors and mechanism of lesion progression at the side branch (SB) ostium after a 1-stent procedure have not been fully elucidated. Methods: We studied 72 bifurcation lesions with postprocedural and 9-month follow-up intravascular ultrasound (IVUS) images for both main vessel (MV) and SB. All lesions were treated with drugeluting stents by MV stenting with or without kissing balloon. In the left main distal bifurcation lesions, the left circumflex artery was regarded as the SB. IVUS analysis included 4 distinct locations: MV proximal stent, MV middle area, MV distal stent, and SB ostium (⬍5 mm distal to the carina). Lesion progression at the SB ostium was defined as decrease of the minimum lumen area (MLA) at follow-up compared with immediately after procedure. Plaque area was calculated as external elastic membrane (EEM) area minus lumen area. Percent plaque area was calculated 100 ⫻ plaque area/EEM area. Results: True bifurcation was noted in 23 lesions (32%), and left main lesions were observed in 29 lesions (40%). Final kissing ballooning was performed in 57 lesions (79%). At the SB ostium, follow-up MLA significantly correlated with postprocedural MLA (4.0 ⫾ 1.9 and 4.3 ⫾ 2.3 mm2, r ⫽ 0.82, p ⬍0.001), but lesion progression at the SB ostium developed in 37 lesions (51%). Left main lesions were significantly associated with lesion progression at the SB (69% in the left main vs 40% in the non–left main lesions, p ⫽ 0.01). However, true bifurcation, angle between the MV and SB, and final kissing ballooning were not associated with lesion progression at the SB. Among IVUS parameters, change of the EEM area (–1.1 ⫾ 2.2 vs 0.5 ⫾ 0.9 mm2, p ⬍0.001), but not change of the plaque area (0.1 ⫾ 1.6 vs – 0.2 ⫾ 0.9 mm2, p ⫽ 0.40), was associated with lesion progression at the SB ostium. Although postprocedural and follow-up plaque area was significantly larger in the SB with lesion progression than those without lesion progression, percent plaque area was not significantly different between the 2 groups. Conclusion: Left main lesions are associated with SB lesion progression. Serial IVUS analysis suggests that the negative remodeling is associated with the SB lesion progression.

The American Journal of Cardiology姞 APRIL 28 –29 2010 ANGIOPLASTY SUMMIT ABSTRACTS/Oral