Kenzo Fukuhara

In-stent neointimal characteristics and late neointimal response after drug-eluting stent implantation: A preliminary observation

BACKGROUND Progressive neointimal proliferation may lead to late restenosis and/or neoatherosclerosis after drug-eluting stent (DES) implantation. Late neointimal response may be different among different tissue characteristics. The aim of this study was to assess impact of in-stent neointimal characteristics on late neointimal response following DES implantation. METHODS Serial (median 270 days and median 551 days after stent implantation) optical coherence tomography (OCT) examinations were performed in 42 stented lesions from 26 patients. In-stent neointimal tissue was categorized as either homogeneous or heterogeneous neointima based on the OCT appearance at 1st follow-up. Serial changes in neointimal area (NIA) were compared between lesions with homogeneous neointima and those with heterogeneous neointima. RESULTS At first follow-up, homogeneous neointima was observed in 22 (52%) and heterogeneous neointima in 20 (48%) lesions, respectively. During follow-up, NIA in lesions with homogeneous neointima decreased significantly (1.8±0.93 mm(2) to 1.5±0.88 mm(2), p<0.001). On the other hand, NIA in lesions with heterogeneous neointima did not change significantly (2.7±1.8 mm(2) to 2.8±1.6 mm(2), p=0.658). Homogeneous neointima was the only predictor of late neointimal regression (late neointimal regression defined as NIA at first follow-up - NIA at second follow-up <0) by multivariable analysis (odds ratio=7.591, 95% confidence interval: 1.616-35.67, p=0.010). CONCLUSIONS OCT characteristics of neointima after DES implantation may be related to late neointimal progression or regression.

In vivo assessment of vasa vasorum neovascularization using intravascular ultrasound: A comparison between acute coronary syndrome and stable angina pectoris

BACKGROUND Previous studies have suggested that vasa vasorum (VV) neovascularization plays an important role in the progression and vulnerability of coronary atherosclerotic plaque. METHODS A total of 130 patients with coronary artery disease including 75 acute coronary syndrome (ACS) cases and 55 stable angina pectoris (SAP) cases were studied. By using intravascular ultrasound (IVUS), VV was defined as a small (<1mm) tubular or vesicular, low-echoic structure observed exterior to the media. Prevalence and maximal number of VV were compared between patients with ACS versus SAP. RESULTS The prevalence of VV at the culprit lesion was similar between the 2 groups (97% vs. 93%, p=0.216). On the other hand, it was significantly higher in ACS than SAP at both reference sites (proximal: 93% vs. 81%, p=0.047 and distal: 88% vs. 60%, p<0.001, respectively). The maximum number of VV was significantly higher in ACS than in SAP (at the culprit lesion: 2.8±1.3 vs. 1.8±1.0, p<0.001, at the proximal reference: 1.9±1.1 vs. 1.3±0.9, p=0.003 and distal reference: 1.7±1.1 vs. 1.1±1.1, p=0.003, respectively). CONCLUSIONS VV neovascularization of coronary arteries was more enhanced in patients with ACS than in those with SAP, supporting its relation to plaque vulnerability. VV detected by widely used IVUS could be an adequate surrogate marker for plaque vulnerability in vivo.

Acute Coronary Syndrome Demonstrating Plaque Rupture in Calcified Lesions Visualized by Optical Frequency Domain Imaging

A 68-year-old female with acute coronary syndrome was transferred to our hospital. Emergency coronary angiography showed 90% stenosis with severe calcification in the proximal right coronary artery (RCA). Intravascular ultrasound (IVUS) images were obtained and showed circumferential heavy calcification without any evidence of plaque rupture. Optical frequency domain imaging (OFDI) images were obtained in the RCA lesion 3 days after the initial coronary angiography. A cavity of plaque rupture in the calcified plaque by using OFDI was observed in the lesion, which could not be recognized by IVUS. Necrotic tissue was observed frequently in heavy calcified lesions and was usually hidden behind calcification. Judging from the OFDI images in this case, the thin fibrous cap over the necrotic tissue even if surrounded by calcification was disrupted and might have caused the acute coronary syndrome. However, necrotic tissue surrounded by calcification is generally recognized as calcified plaque in OFDI images because discrimination between necrotic tissue and calcification is based on the border characteristics (low intensity with diffuse border: necrotic tissue, low intensity with sharp border: calcification). Superficial residual necrotic tissue not yet replaced completely by calcification might cause plaque rupture and thus, result in acute coronary syndrome. In fact, there is a variety of OFDI and optical coherence tomography (OCT) characteristics in calcified plaque, such as relatively high intensity without attenuation or very low intensity with attenuation. Residual necrotic tissue within calcification could pose a problem in OCT/OFDI plaque evaluation.

Direct relationship of local C-reactive protein production and lipid pool characterized by integrated backscatter intravascular ultrasound: a preliminary observation.

BackgroundLocal production of C-reactive protein (CRP) in human coronary arterial plaque was reported as a possible marker for local inflammation and vulnerable plaque. Integrated backscatter intravascular ultrasound (IB-IVUS) plaque tissue characterization may detect vulnerable plaque with high local plaque inflammation. Thus, the aim of this study was to clarify the relationship between IB-IVUS-based plaque characteristics and local high-sensitivity C-reactive protein (hs-CRP) production in stable and unstable plaque. Methods and resultsEighteen patients (nine unstable angina/non-ST-segment elevation myocardial infarction and nine stable angina) were prospectively enrolled. Using the microcatheter, blood samples from the proximal and distal sites of the culprit lesion were obtained to measure local CRP production. Translesional hs-CRP was defined as distal hs-CRP minus proximal hs-CRP of the culprit lesion. Gray-scale and IB-IVUS analyses were carried out at the target lesion. The translesional hs-CRP level tended to be higher in the unstable angina group than in the stable angina group (0.026±0.033 vs. 0.003±0.007 mg/dl, P=0.050). Gray-scale IVUS-derived indices did not correlate with translesional hs-CRP. However, % lipid pool area by IB-IVUS correlated positively (r=0.54, P=0.02) and % fibrosis area correlated negatively with the translesional hs-CRP level (r=−0.52, P=0.03). ConclusionLipid pool area detected by IB-IVUS is correlated positively with the translesional hs-CRP level.

Coronary bifurcation bench test using multimodality imaging: Impact of stent strut link location on stent deformity and jailed side-branch orifices during re-proximal optimizing technique

The purpose of this study was to compare the stent deformation, obstruction of stent struts at a jailed side branch (SB) ostium, and stent strut malapposition after a repetitive proximal optimizing technique (re‐POT) sequence between bifurcation lesions with and without stent links at SB ostia in ex vivo experimental setting.

High Platelet Reactivity and Intrastent Thrombi Assessed by OCT After DES

High platelet reactivity (HPR) on clopidogrel may be related to stent thrombosis after drug-eluting stent (DES) implantation [(1)][1]. To investigate the relationship between HPR and intrastent thrombi following DES implantation, 202 lesions treated with DES from 109 patients were studied. Coronary

VASA VASORUM NEOVASCULARIZATION PREDICTS PERI-PROCEDURAL MYOCARDIAL INJURY AFTER SUCCESSFUL CORONARY STENTING IN PATIENTS WITH STABLE ANGINA

Previous studies have suggested that vasa vasorum (VV) neovascularization is related to coronary plaque vulnerability. Vulnerable plaque may have higher risk for peri-procedural myocardial injury during coronary stenting. The purpose of this study was to assess impact of VV on peri-procedural

TCT-601 Serial Optical coherence tomography assessment of natural history of silent plaque rupture

Plaque rupture is one of the characteristics of vulnerable plaque responsible for acute coronary syndrome (ACS). Multiple plaque rupture of the non-culprit lesion could be occasionally detected by intravascular ultrasound or optical coherence tomography (OCT). However, the natural course of non-

Prediction of Chronic Vessel Enlargement by a Novel Intravascular Ultrasound Finding

BACKGROUND Coronary arterial segments distal to the severely stenotic lesion sometimes shrink as a result of decreased coronary flow. Pathological studies have shown that vessel shrinkage is accompanied by folding of the internal elastic membrane (IEM). A peri-medial high-echoic band (PHB) by intravascular ultrasound (IVUS) may represent folding of the IEM and therefore detect chronically shrunken coronary segments that have potential to enlarge subsequently. METHODS AND RESULTS: IVUS imaging of the distal reference segments was performed in 27 patients after stenting. PHB was defined as a high-echoic band observed at the luminal side of the media. Serial (baseline and 9 months) changes in minimal lumen diameter (LD) were compared between those with (PHB group) and without PHB (non-PHB group). During follow-up, LD increased significantly in PHB group (1.2±0.3 vs. 1.7±0.5 mm, P=0.001) but not in the non-PHB group (2.0±0.7 vs. 2.1±0.7 mm, P=NS). Late lumen gain (LLG) was observed in 16 of the 27 (59%) lesions. Lesions with LLG showed a trend toward smaller baseline lumen cross-sectional area and significantly higher prevalence of PHB (88% vs. 18%, P=0.007). By multivariable logistic regression analysis, PHB was the only IVUS predictor of LLG. CONCLUSIONS Presence of PHB on IVUS predicts chronic enlargement of the coronary segments distal to the stented lesion.

FREQUENCY AND NATURAL COURSE OF SILENT PLAQUE RUPTURE

Plaque rupture is one of the characteristics of vulnerable plaque responsible for acute coronary syndrome (ACS). Multiple plaque rupture of the non-culprit lesion could be occasionally detected by intravascular ultrasound or optical coherence tomography (OCT). However, the natural course of non-