External Elastic Membrane Cross-sectional Area Research Articles

Reproducibility of Femoropopliteal Artery Intravascular Ultrasound Imaging in Patients With Peripheral Artery Disease

Despite increased use of intravascular ultrasound (IVUS) during peripheral artery interventions, evidence for reproducibility of IVUS measurements and its relation to angiography is lacking. Forty cross-sectional IVUS images of the femoropopliteal artery from 20 randomly selected patients enrolled in the XLPAD (Excellence in Peripheral Artery Disease) registry who underwent peripheral artery interventions and met criteria based on IVUS consensus guidelines were independently assessed by 2 blinded readers. IVUS images from 6 patients (40 images) were selected for angiographic correlation and met criteria for identifiable landmarks (e.g., stent edge and bifurcation). Lumen cross-sectional area (CSA), external elastic membrane (EEM) CSA, luminal diameter, and reference vessel diameter were repeatedly measured. The Lumen CSA and EEM CSA intra-observer agreement by Spearman rank-order correlation (ρ) was >0.993, intraclass correlation coefficient was >0.997, and repeatability coefficient was <1.34. For the interobserver measurement of luminal CSA and EEM CSA, the ρ=0.742 and 0.764; intraclass correlation coefficient=0.888 and 0.885; and repeatability coefficient=7.24 and 11.34, respectively. A Bland-Altman plot for lumen and EEM CSA showed good reproducibility. For angiographic comparison, the ρ for luminal diameter, luminal area, and vessel area were 0.419, 0.414, and 0.649, respectively. Femoropopliteal IVUS measurements showed strong intra-observer and interobserver agreement; IVUS and angiographic measurements did not demonstrate a similar strong agreement.

Association of culprit lesion plaque characteristics with flow restoration post-fibrinolysis in ST-segment elevation myocardial infarction: an intravascular ultrasound-virtual histology study

BackgroundNot every patient achieves normal coronary flow following fibrinolysis in STEMI (ST-segment elevation myocardial infarction). The culprit lesion plaque characteristics play a prominent role in the coronary flow before and during percutaneous coronary intervention. The main purpose was to determine the culprit lesion plaque features by virtual histology-intravascular ultrasound (VH-IVUS) in patients with STEMI following fibrinolysis in relation to baseline coronary angiogram TIMI (thrombolysis in myocardial infarction) flow. Pre-intervention IVUS was undertaken in 61 patients with STEMI after successful fibrinolysis. After the coronary angiogram, they were separated into the TIMI1–2 flow group (n = 31) and TIMI 3 flow group (n = 30). Culprit lesion plaque composition was evaluated by VH-IVUS.ResultsOn gray-scale IVUS, the lesion external elastic membrane cross-sectional area (EEM CSA) was significantly higher in the TIMI 1–2 groups as compared to the TIMI 3 group (15.71 ± 3.73 mm2 vs 13.91 ± 2.94 mm2, p = 0.041) with no significant difference in plaque burden (82.42% vs. 81.65%, p = 0.306) and plaque volume (108.3 mm3 vs. 94.3 mm3, p = 0.194). On VH-IVUS, at the minimal luminal area site (MLS), the fibrous area (5.83 mm2 vs. 4.37 mm2, p = 0.024), necrotic core (NC) area (0.95 mm2 vs. 0.59 mm2, p < 0.001), and NC percentage (11% vs. 7.1%, p = 0.024) were higher in the TIMI 1–2 groups in contrast to the TIMI 3 group. The absolute necrotic core (NC) volume (8.3 mm3 vs. 3.65 mm3, p < 0.001) and NC percentage (9.3% vs. 6.0%, p = 0.007) were significantly higher in the TIMI 1–2 groups as compared to the TIMI 3 group. Absolute dense calcium (DC) volume was higher in TIMI 1–2 groups with a trend towards significance (1.0 mm3 vs.0.75 mm3, p = 0.051). In multivariate analysis, absolute NC volume was the only independent predictor of TIMI 1–2 flow (odds ratio = 1.561; 95% CI 1.202–2.026, p = 0.001). Receiver operating characteristic curves showed absolute NC volume has best diagnostic accuracy (AUC = 0.816, p < 0.001) to predict TIMI 1–2 flow with an optimal cutoff value of 4.5 mm3 with sensitivity and specificity of 79% and 61%, respectively.ConclusionsThis study exemplifies that the necrotic core component of the culprit lesion plaque in STEMI is associated with the coronary flow after fibrinolysis. The absolute necrotic core volume is a key determinant of flow restoration post-fibrinolysis and aids in prognostication of less than TIMI 3 flow.

Impact of plaque burden and composition on coronary slow flow in ST-segment elevation myocardial infarction undergoing percutaneous coronary intervention: intravascular ultrasound and virtual histology analysis

Aim Coronary slow flow (SF) is an important complication of percutaneous coronary intervention (PCI) associated with poor prognosis. The aim was to assess grey-scale intravascular ultrasound (IVUS) and virtual histology (VH-IVUS) characteristics of culprit lesion in ST-elevation myocardial infarction (STEMI). Methods A total of 295 consecutive patients with STEMI underwent coronary angiogram and IVUS. Following PCI, patients divided into two groups; SF (thrombolysis in myocardial infarction [TIMI] flow ≤ 2, n = 74) and normal flow (NF) (TIMI flow >2, n = 221). Coronary plaque burden and its composition in relation to SF were evaluated. Results On grey-scale IVUS, the plaque area (12.3 mm2 vs. 11.5 mm2, p = .01), plaque volume (110.7 mm3 vs. 99.8 mm3, p < .001), lesion external elastic membrane (EEM) cross-sectional area (14.9 mm2 vs. 14.0 mm2, p = .011) and remodelling index (1.3 vs. 1.2, p = .043) were significantly higher in SF group. On VH-IVUS, absolute fibrous volume (48.1 mm3 vs. 41.5 mm3, p ≤ .001), fibrofatty volume (23.8 mm3 vs. 18.6 mm3, p = .015), necrotic core volume (8.3 mm3 vs. 5.5 mm3, p < .001), dense calcium volume (1.2 mm3 vs. 0.6 mm3, p = .003) and thin cap fibroatheroma either single (30.1% vs. 16.1%, p < .001) or multiple (9.6% vs. 1.8%, p < .001) were higher in SF arm. In multivariable analysis, absolute necrotic core volume (odds ratio = 1.159; 95% CI 1.030–1.305, p = .015) was the only independent predictor of SF. Conclusions Higher necrotic core volume as detected by VH-IVUS may be a potential risk factor for the development of coronary SF phenomenon in patients with STEMI after PCI.

Coronary artery size in North Indian population – Intravascular ultrasound-based study

ObjectiveThe coronary artery dimensions have important diagnostic and therapeutic implications in management of coronary artery disease (CAD). There is paucity of data on the coronary artery size in the Indian population as measured by intravascular ultrasound (IVUS). MethodsA total of 303 patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI) with intravascular ultrasound underwent analysis along with quantitative coronary angiography (QCA). Of the 492 proximal coronary segments; 221 relating to left main (LM), 164 to left anterior descending artery (LAD), 45 to left circumflex artery (LCX), and 62 to right coronary artery (RCA) were considered. ResultsPatient's mean age was 53.37 ± 3.5 years; men 80%; hypertension 35% and diabetes 24.8%. On IVUS, mean minimal lumen diameter as compared to QCA in LM (4.60 mm versus 4.50 mm, p < 0.001), LAD (3.71 mm versus 3.45 mm, p < 0.001), LCX (3.55 mm versus 3.16 mm, p < 0.001) and RCA (3.85 mm versus 3.27 mm, p < 0.001) were significantly larger. Lumen and external elastic membrane (EEM) cross-sectional area (CSA) were larger in males as compared to females with statistical significance for lumen CSA in LM (p = 0.04); RCA (p = 0.02) and EEM CSA in LM (p = 0.03); RCA (p = 0.006) but no significance for adjusted body surface area (BSA). In multivariate models, BSA and age were independent predictors of LM and LAD diameters and areas, but age was an independent predictor indexed to BSA. ConclusionThe coronary artery dimensions by IVUS are significantly larger than QCA. No gender difference in coronary artery size. Age was an independent predictor of coronary artery size in left main and LAD. The coronary artery size may not be a risk factor for acute coronary syndrome.

Vessel Stretching Is a Cause of Lumen Enlargement Immediately After Balloon Pulmonary Angioplasty: Intravascular Ultrasound Analysis in Patients With Chronic Thromboembolic Pulmonary Hypertension.

Balloon pulmonary angioplasty (BPA) has become an alternative therapy for patients with chronic thromboembolic pulmonary hypertension who are ineligible for pulmonary endarterectomy. We retrospectively investigated intravascular ultrasound measurements to elucidate how the lumen enlarges immediately after BPA. A total of 326 lesions in 71 patients with chronic thromboembolic pulmonary hypertension were analyzed. The cross-sectional areas (CSAs) of the external elastic membrane and lumen measured by intravascular ultrasound before and after BPA were assessed for each lesion type (type A, ring-like stenosis lesions; type B, web lesions; type C, subtotal occlusion lesions). Comparing the lesion types, the proportion of the area occupied by fibrous tissue was smallest in the type A lesions and largest in the type C lesions. The mean lesion lumen CSA was increased after BPA because of an increase in external elastic membrane CSA (from 23.2±12.9 to 27.2±14.3 mm2; P<0.001) with a slight decrease in fibrous tissue plus media CSA (from 17.7±11.7 to 17.3±11.1 mm2; P<0.001). The change in lumen CSA correlated strongly with the change in external elastic membrane CSA (r2=0.762; P<0.001). Lumen enlargement immediately after BPA was obtained by the overall vessel expansion induced by a stretch of the arterial wall. In addition, the amount of fibrous tissue depended on each lesion type. Thus, it might be beneficial to change the balloon size to correspond with the lesion type.

Assessment of Coronary Plaque Vulnerability in Acute Coronary Syndromes using Optical Coherence Tomography and Intravascular Ultrasound. A Systematic Review

Abstract The aim of this systematic review was to analyze studies characterizing vulnerable coronary plaques using optical coherence tomography (OCT) and intravascular ultrasound (IVUS), in order to identify the most efficient invasive technique permitting plaque characterization in patients with acute myocardial infarction. Method: A total number of 432 studies were identified, 420 through database searching and 12 through manual searching. Eight duplicate studies were removed, leaving a total number of 424 studies to be screened. Twenty-six studies only available in Abstract-only form were excluded, resulting in 398 studies checked for eligibility. Eleven studies fulfilled the eligibility criteria and were included in this systematic analysis. Plaque vulnerability was investigated in plaques with thin cap fibroatheroma (TCFA) versus those with thick cap fibroatheroma, in ruptured coronary plaques versus non-ruptured coronary plaques, in culprit versus non-culprit lesions and in lipid-rich versus non-lipid-rich plaques. Results: A total of 1,568 coronary plaques in 1,225 patients with acute coronary syndromes (ACS) who underwent both IVUS and OCT for analysis of plaque features were included in the final analysis. The review identified the following IVUS-derived features as significantly correlated with plaque vulnerability: plaque burden (p &lt;0.001), remodeling index (p &lt;0.001), external elastic membrane cross-sectional area (p &lt;0.001), and the amount of necrotic core (p &lt;0.001), while OCT-derived features characterizing unstable plaque were TCFA (p &lt;0.001), lipid arch (p &lt;0.001), accumulation of macrophages (p = 0.03), and presence of intracoronary thrombus (p &lt;0.001). Conclusion: Both IVUS and OCT are invasive imaging techniques able to provide relevant information on the vulnerability of coronary atheromatous plaques, identifying, as they do, various plaque features significantly associated with unstable plaques. Information provided by the two techniques is complementary, and both methods can serve as a useful clinical diagnostic tool, especially in cases of ACS patients undergoing a revascularization procedure.

Relation Between Renal Function and Coronary Plaque Morphology (from the Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents Virtual Histology-Intravascular Ultrasound Substudy)

We sought to examine the relation between various degrees of renal function and coronary plaque morphology by grayscale and virtual histology intravascular ultrasound (IVUS). ADAPT-DES was a prospective, multicenter registry of 8,582 consecutive patients treated using coronary drug-eluting stents with a prespecified grayscale and virtual histology-IVUS substudy. A lesion-level analysis of study participants was performed by comparing IVUS parameters of culprit and nonculprit lesions across tertiles of estimated creatinine clearance (CrCl). Preintervention IVUS imaging of 762 patients identified 898 culprit and 752 nonculprit native coronary artery lesions. Patients in the lowest CrCl tertile were older, more often women, and more often presented with stable angina. Compared with the middle and upper tertiles, the lowest tertile was significantly associated with culprit lesion smaller mean external elastic membrane cross-sectional area (12.9 vs 14.2mm3/mm vs 14.9mm3/mm, p<0.0001), smaller mean lumen cross-sectional area (5.5mm3/mm vs 5.8mm3/mm vs 6.1mm3/mm, p= 0.002), and more dense calcium volume (11.5% vs 10.2% vs 9.7%, p=0.02). Similar trends were found in the nonculprit lesions. Plaque rupture was least common in patients in the lowest tertile. On multivariable analysis, independent predictors of greater dense calcium volume were lower CrCl, hyperlipidemia, female gender, and presentation without ST-segment elevation myocardial infarction. In conclusion, in the present large-scale IVUS study diminishing renal function was associated with increased coronary calcification and decreased coronary vessel and lumen sizes, with a graded response according to the reduction in CrCl. In addition, these patients were more likely to present with stable angina versus patients with normal renal function who were more likelyto present with an acute coronary syndrome.

Abstract 12148: Impact of Multiple Plaque Ruptures and Cavity Area on Intraprocedural Stent Thrombosis: Intravascular Ultrasound Analysis

Objectives: We examined characteristics of lesions in cases of intraprocedural stent thrombosis (IPST) using intravascular ultrasound (IVUS). Background: IPST is a rare complication occurring during percutaneous coronary intervention (PCI) that leads to poor outcomes. However, factors that contribute to IPST remain largely unknown. Methods: We retrospectively analyzed 1,504 consecutive stent-implanted lesions in 1,324 patients [326 with ST-segment elevation myocardial infarction (STEMI), 403 with non-ST-segment elevation acute coronary syndrome (NSTE-ACS), and 595 with stable angina]. IVUS characteristics of plaques that led to IPST were compared with those of a matched control (non-IPST) group (n = 15) without evidence of IPST matched by age; gender; lesion location; or STEMI, NSTE-ACS, or stable angina. Positive remodeling was defined as a lesion greater than the mean reference external elastic membrane cross-sectional area. Continuous variables were displayed as median and 1st and 3rd interquartile range. Results: IPST occurred in 5 (0.4%; 3 with STEMI, 2 with NSTE-ACS) of 1,324 patients during PCI. Plaque burden at the minimum lumen area site was significantly greater in the IPST group than in the non-IPST group (93.0% vs. 87.9%, P = 0.0035). All 5 culprit lesions that led to IPST had ruptured plaques with positive remodeling and attenuation. The maximum cavity area was larger in the IPST group than in the non-IPST group (4.6 [4.3, 6.5] mm2 vs. 0 [0, 1.9] mm2, P = 0.0011), whereas plaque rupture was also observed in 40% of subjects in the non-IPST group. Multiple plaque ruptures in the culprit lesion were far more common in the IPST group (80.0% vs. 6.7%, P = 0.0049). Conclusion: Multiple plaque ruptures and a larger cavity area were associated with IPST occurrence. IVUS assessment may help predict the development of IPST during PCI.

Coronary Plaque Characteristics Affect No-Reflow During Primary Percutaneous Coronary Intervention: A Pooled Analysis of 14 Observational Studies Using Intravascular Ultrasound.

The association between coronary plaque composition and no-reflow during percutaneous coronary intervention (PCI) is still debated. We performed a systematic literature search using MEDLINE, Embase, Cochrane, and Ovid databases for intravascular ultrasound (IVUS) studies evaluating the relationship between coronary plaque characteristics and no-reflow after PCI. Fourteen observational trials were included in the meta-analysis, including 1457 patients (237 in the no-reflow group, 1220 in the normal reflow group). Pooled analysis indicated that the no-reflow group had a significantly higher absolute volume of fibrofatty plaque (weighted mean differences [WMD], 4.94 mm(3); 95% confidence interval [CI], 1.83-l8.06; P = .002), external elastic membrane cross-sectional area (EEM-CSA) (WMD, 3.40 mm2; 95% CI, 2.22-4.58; P = .00001), plaque area (WMD, 4.06 mm(2); 95% CI, 2.24-5.89; P = .0001), and artery remodeling index (WMD, 0.09; 95% CI, 0.06-0.13; P = .00001), and a smaller percentage of fibrous plaque (WMD, -5.89 %; 95% CI, -0.66 to -11.12; P = .03) than in the normal reflow group. There were no significant differences in the other plaque components between the two groups. This meta-analysis confirmed that high absolute volume of fibrofatty plaque, EEM-CSA, plaque area, and coronary artery remodeling index, and a decreased percentage of fibrous plaque as detected by IVUS in culprit lesions, are linked with the development of the no-reflow phenomenon after PCI.

Multidetector Computed Tomography for the Evaluation of Coronary Artery Disease; The Diagnostic Accuracy in Calcified Coronary Arteries, Comparing with IVUS Imaging

PurposeContrast enhanced multidetector computed tomography (MDCT) has been used as an alternative to coronary angiography for the assessment of coronary artery disease in the patient of the intermediate risk group. However, coronary calcium is a known limiting factor for MDCT evaluation. We investigated the diagnostic accuracy of 64-channel MDCT with each coronary artery calcium score (CACS) by compared with intravascular ultrasound (IVUS) imaging.Materials and MethodsA total of 54 symptomatic patients with intermediate-risk (10 females, mean age 59.9±6.9 years, Framingham point scores 9-20) with 162 sites who had a culprit lesion on 64-channel MDCT before performing coronary angiography with IVUS were enrolled. Patients were divided into 4 subgroups depending on CACS: 0, 1-99, 100-399, and >400. Lesion length, external elastic membrane (EEM) cross sectional area (CSA), minimal luminal area, and plaque area were measured and compared between IVUS and MDCT.ResultsThe correlation coefficients for the measurements of the EEM CSA, lumen CSA, and plaque area were r=0.514, r=0.837, and r=0.578, respectively. Furthermore, there were close correlation of plaque area between four subgroups of CACS (r=0.671, r=0.623, r=0.562, r=0.571, respectively).ConclusionDespite the increase in CACS, the geometric analysis of coronary arteries using with 64-channel MDCT was comparable with IVUS in symptomatic patient of the intermediate risk group.

Vessel remodeling and plaque distribution in side branch of complex coronary bifurcation lesions: a grayscale intravascular ultrasound study

To investigate vessel remodeling and plaque distribution in side branch (SB) of true coronary bifurcation lesions with SB disease extending from its ostium. A total of 62 patients with single de novo true bifurcation lesions with SB with severe and extensive disease were enrolled. Of that, 45 patients/lesions underwent pre-intervention intravascular ultrasound (IVUS) at the SB. Left anterior descending was the most prevalent target vessel (>85%). All lesions had significant involvement of both branches of the bifurcation, and the majority were classified as type 1,1,1 according to the Medina classification. Considering the subset with IVUS imaging, mean lesion length, reference diameter and % diameter stenosis in the SB were 8.88 ± 4.61 mm, 2.68 ± 0.59, and 70.2 ± 16.0%, respectively. Also, mean proximal (take-off) and distal (carina) angles were 142.3 ± 21.9° and 60.7 ± 22.4°, respectively. At minimum lumena area (MLA) site, mean external elastic membrane and MLA cross-sectional areas were 6.70 ± 2.08 and 1.87 ± 0.93 mm2, respectively; given that the mean distance measured between the SB origin and MLA site was <1 mm. In addition, mean plaque burden was 67.9% and mean remodeling index was 0.78 ± 0.21. Importantly, only 9 cases out of 45 presented remodeling index > 1.0. Also, plaque distribution analysis within the SB ostium demonstrated preferable plaque positioning in the opposite side to the flow divider. In conclusions, significant negative remodeling is a frequent encounter in SB of complex coronary bifurcation lesions presenting with extensive and severe disease; in addition, plaque distribution in the SB ostium appears to be asymmetric in relation to the parent vessel, as plaque burden is mostly found in regions of low wall shear stress including the opposite side to the flow divider within the bifurcation anatomy.

Periprocedural myocardial damage during percutaneous coronary intervention: a point-of-care platelet testing and intravascular ultrasound/virtual histology study

Recent studies have implied that platelet reactivity as well as certain lesion morphology may be linked to myocardial injury during percutaneous coronary intervention (PCI). However, to date the abovementioned features have not been investigated simultaneously in one population. To determine if and how high on-treatment platelet reactivity, different lesion morphology, and plaque components are associated with increased risk of periprocedural myocardial injury in patients referred for elective coronary stenting. Sixty patients pretreated with aspirin and clopidogrel and undergoing elective PCI with stent(s) implantation were included. On-treatment platelet reactivity was measured with VerifyNow Aspirin and P₂Y₁₂ assays (Accumetrics, USA) before PCI. Grey-scale intravascular ultrasound (IVUS) and virtual histology were performed before stent(s) implantation (Volcano, USA). Two levels of myocardial injury were considered: any elevation of troponin I (periprocedural myocardial damage, PMD) and/or > 3 times the upper normal limit (periprocedural myocardial infarction, PMI). By receiver-operating characteristics analysis, the following factors, ranked from strongest to weakest, were able to distinguish between patients with and without PMD: remodelling index (RI), fibrous tissue, fibro-fatty tissue volume (FFT), plaque and media cross-sectional area, and external elastic membrane cross-sectional area (EEM CSA). Only platelet count and RI could differentiate patients with and without PMI. PMD as well as PMI could not be predicted either by VerifyNow Aspirin or P₂Y₁₂ assay. Likewise, there was no association between necrotic core volume and PMD or PMI. In logistic regression analysis, after adjusting for possible clinical and procedural confounding factors, only EEM CSA > 14.6 mm² (OR 23.7, 95% CI 1.9-302, p = 0.015), RI > 1.044 (OR 12.3, 95% CI 1.2-121.9, p = 0.032) and FFT > 11.2 mm³ (OR 13.6, 95% CI 1.1-160.9, p = 0.038) were independent predictors of PMD. Only RI > 1.044 was identified as an independent predictor of PMI (OR 7.5, 95% CI 1.92-29.6, p = 0.004). Greater total vessel area, positive remodelling at the lesion site, and high volume of FFT in the coronary plaque are independently associated with increased risk of myocardial injury. Only positive RI was an independent predictor of PMI. Simple lesion morphology, rather than more complex VH-IVUS analysis or platelet reactivity, seems to predict myocardial injury after elective PCI.

Comparison of quantitative measurements between two different intravascular ultrasound systems: In vitro and in vivo studies

BackgroundAlthough intravascular ultrasound (IVUS) allows for precise measurements of coronary artery dimension, variability in quantitative measurements among currently available different IVUS systems is unknown. The aim of study was to compare two different IVUS catheters and consoles to verify their accuracy and compatibility. Methods(1) In vitro study: IVUS imaging was performed in a concentric cylindrical phantom with 6 sections of known, cross-sectional diameter ranging from 3.0 to 8.0mm. The minimum lumen diameter (MLD) and lumen cross sectional area (CSA) were measured and compared. (2) In vivo study: IVUS imaging was performed in 69 coronary arterial segments from 20 patients. The external elastic membrane cross sectional area (EEM-CSA), lumen CSA, and plaque plus media (P+M) CSA were measured and compared between the two IVUS systems. Results(1) In vitro study: MLD and lumen CSA obtained by the two IVUS systems correlated well with the actual values. (2) In vivo study: EEM-, lumen and P+M CSA obtained by the two IVUS systems showed good correlations (R2=0.973, p<0.0001; R2=0.938, p<0.0001; R2=0.949, p<0.0001, respectively). ConclusionsQuantitative measurements by 2 different, currently available IVUS systems were accurate and comparable. These results suggest that the 2 different IVUS catheters/systems may be alternatively used during clinical studies assessing coronary arterial size.

Culprit lesion remodelling and long-term prognosis in patients with acute coronary syndrome: an intravascular ultrasound study

Positive arterial remodelling is recognized as one of the morphological characteristics of the vulnerable plaque. Limited data are available on a long-term outcome of acute coronary syndrome (ACS) patients with culprit lesion positive arterial remodelling (PR). The aim of this study was to investigate the long-term impact of culprit lesion PR in patients with ACS. In 134 patients with ACS, intravascular ultrasound (IVUS) was performed to assess target lesion remodelling before percutaneous coronary intervention. PR was defined as the ratio of the external elastic membrane cross-sectional area at the target lesion to that of at the proximal reference of >1.05, and intermediate or negative remodelling (IR/NR) was defined as that of ≤1.05. Major adverse cardiac event (MACE) was defined as a composite of death, ACS, and target lesion revascularization. During the follow-up (median 5.8 years), MACE-free survival was significantly lower in the PR group than that in the IR/NR group (log-rank, P = 0.005). Survival and ACS-free survival were also significantly lower in the PR group than that in the IR/NR group (log-rank, both P = 0.04). By multivariable Cox regression analysis, PR (hazard ratio = 2.4, P = 0.02) and diabetes (hazard ratio = 1.9, P = 0.03) were independent predictors of MACE. Culprit lesion PR was associated with a poor long-term prognosis in patients with ACS. PR may be a marker of vulnerable patients.

Abstract 17781: Relationship Between Epicardial Adipose Tissue and Coronary Arterial Remodeling as Assessed by Intravascular Ultrasound in Patients with Coronary Artery Disease

Background: Recently, the interest in epicardial adipose tissue (EAT) is rapidly growing. Several study suggest that EAT induces inflammation of the artery wall by secretion of pro-inflammatory proteins and plays a role in the pathogenesis of coronary artery disease. However, there is no information regarding the impact of EAT on coronary arterial remodeling and plaque vulnerability. Objectives: The aim of this study was to evaluate the relationship between EAT and intravascular ultrasound (IVUS) findings, mainly remodeling, in patients with coronary artery disease. Methods: One hundred and eight consecutive patients with de novo lesions located in native coronary artery were studied. The EAT thickness on the right ventricle was measured using transthoracic echocardiography, and arterial remodeling of culprit lesion was assessed by preinterventional IVUS. The remodeling index (RI) was calculated as lesion divided by the reference external elastic membrane cross-sectional area, Positive remodeling (PR) was defined as RI&gt;1.05, intermediate remodeling (IR) as between 0.95 and 1.05, and negative remodeling (NR) as &lt;0.95. IVUS findings included plaque characteristics-lipid rich, mixed and calcified plaque and plaque eccentricity. Results: There was significant relationship between EAT thickness and RI(r= 0.36, p=0.0001). Higher EAT thickness (≥10mm, n=55) were associated with higher BMI(25.2±3.6 kg/m 2 vs. 23.9±2.8 kg/m 2 , p=0.04), plasma triglyceride level (189.1±103.8 mg/dl vs. 146.1±80.9 mg/dl, p=0.02), and plasma urinary acid level(6.8±1.5mg/dl vs. 5.9±1.5 mg/dl, p=0.02). PR and more lipid rich and mixed plaque were observed in patients with higher EAT thickness than lower EAT thickness (PR ;43.6% vs. 18.9%,p=0.02. lipid rich and mixed plaque; 89% vs.66%,p=0.004). Multivariate analysis showed high EAT thickness was independent factor affecting coronary positive remodeling (OR3.05,p=0.02).There was no significant association EAT thickness and plaque eccentricity. Conclusion; High EAT thickness was significantly correlated with the coronary positive remodeling and non calcified plaque characteristics.

Plaque Characteristics of Thin-Cap Fibroatheroma Evaluated by OCT and IVUS

The purpose of this study was to assess plaque characteristics of optical coherence tomography (OCT)-derived thin-cap fibroatheroma (TCFA) by integrated backscatter intravascular ultrasound (IB-IVUS). Radiofrequency signal-derived IVUS tissue characterization technology has become clinically available and provided objective and quantitative plaque characteristics of the coronary vessel wall. Integrated backscatter IVUS is one of the tissue characterization methods that can possibly provide quantitative plaque characteristics of the OCT-derived TCFA. Eighty-one coronary lesions with plaque burden >40% were selected and analyzed with both IB-IVUS and OCT. The OCT-derived TCFA was defined as a presence of thin fibrous cap (<65 μm) overlying a signal-poor lesion with diffuse border representing a lipid-rich plaque. By conventional gray-scale IVUS, external elastic membrane (EEM) cross-sectional area (CSA), lumen CSA, plaque plus media (P+M) CSA, plaque burden and remodeling index were measured. By IB-IVUS, plaque characteristics were further classified as fibrosis, dense fibrosis, calcification, or lipid pool. Optical coherence tomography identified 40 TCFAs (49%) and 41 non-TCFAs. The EEM CSA, P+M CSA, plaque burden, and remodeling index were significantly larger in OCT-derived TCFA than non-TCFA. By IB-IVUS, percentage lipid pool area (= lipid pool area/P+M CSA × 100) was significantly higher (62.4 ± 12.8% vs. 38.4 ± 13.1%, p<0.0001) and percentage fibrosis area (= fibrosis area/P+M CSA × 100) was significantly lower (34.6 ± 11.4% vs. 50.5 ± 8.7%, p<0.0001) in OCT-derived TCFA than non-TCFA. By receiver-operator characteristic curve analysis, percentage lipid pool area ≥55%, percentage fibrosis area ≤41%, and remodeling index ≥1.0 were predictors of OCT-derived TCFA. The OCT-derived TCFA had larger plaque burden and positive remodeling with predominant lipid component and less fibrous plaque assessed by IB-IVUS.

Relation Between Hyperinsulinemia and Nonculprit Plaque Characteristics in Nondiabetic Patients With Acute Coronary Syndromes

We sought to assess whether hyperinsulinemia is associated with percentage lipid and coronary plaque burden in nondiabetic patients with acute coronary syndromes (ACS). Hyperinsulinemia carries an increased risk of cardiovascular disease even in pre-diabetic patients, but the precise mechanisms of its effects remain unclear. Nonculprit coronary lesions associated with mild-to-moderate stenosis in 82 nondiabetic patients with ACS were examined by integrated backscatter intravascular ultrasound (IB-IVUS), using a 40-MHz intravascular catheter. Conventional IVUS and IB-IVUS measurements from the worst 10-mm segment (1-mm intervals) were calculated. All patients underwent a 75-g oral glucose tolerance test (OGTT) to calculate the area under the insulin concentration-time curve (AUC insulin) from 0 to 120 min. Patients in the high tertile of AUC insulin had a significantly greater percentage lipid area and absolute lipid volume than did patients in the intermediate and low tertiles (tertile 3 vs. tertile 2 vs. tertile 1; 37.6 ± 16.6% vs. 25.8 ± 11.9% vs. 27.5 ± 14.7%, p < 0.01 by analysis of variance [ANOVA], and 29.9 ± 22.6 mm(3) vs. 15.3 ± 12.6 mm(3) vs. 17.7 ± 12.7 mm(3), p < 0.01 by ANOVA, respectively) and a smaller percentage fibrosis area (55.0 ± 11.5% vs. 61.7 ± 9.4% vs. 60.7 ± 9.4%, p = 0.03 by ANOVA). Multiple regression analysis showed that the high tertile of AUC insulin was independently associated with an increased percentage lipid area (p < 0.05). On conventional IVUS analysis, external elastic membrane cross-sectional area was significantly increased with greater plaque volume in patients in the high tertile of AUC insulin (both p < 0.05 by ANOVA). Hyperinsulinemia is associated with an increased lipid content and a greater plaque volume of nonculprit intermediate lesions in nondiabetic patients with ACS, suggesting that plaque vulnerability is increased in this subgroup of patients.

Intravascular Ultrasonic Features of Unstable Atherosclerotic Plaques in Unstable Angina patients

Objective To investigate the characteristics of plaque morphology of the patients with unstable angina(UA)by intravascular ultrasound(IVUS). Methods 24 patients with stable angina pectoris(SA)and 33 patients with unstable angina(UA)were examined by coronary coronary arteriograph(CAG)and intravascular ultrasound(IVUS).The culprit lesions about the characteristic of the plaque were studied,the external elastic membrane cross-sectional area and lumen cross-sectional area were measured,the plaque area,plaque burden,eccentricity index were calculated,and the remodeling index was examined. Results External elastic membrane area,plaque area and vascular remodeling ratio were significantly greater at target lesions in UA patients than in patients with SA(P＜0.05).Positive remodeling and soft plaque were predominantly in UA patients(P＜0.05). Conclusion The morphological features of coronary artery plaques in UA group were significantly different from those in SA group.More soft plaque,plaque rupture,thrombus formation,and positive remodeling were found in UA patients compared with SA patients. Key words: Angina pecloris,Variant; Ultrasonophy,Interventional

Relationship Between Arterial and Fibrous Cap Remodeling

Background— Positive arterial remodeling and thin fibrous cap are characteristics of rupture-prone or vulnerable plaque. The natural course of the fibrous cap thickness and the relationship between serial arterial remodeling and changes in fibrous cap thickness are unknown. Therefore, the purpose of this study was to evaluate the relationship between changes in fibrous cap thickness and arterial remodeling by using optical coherence tomography (OCT) and intravascular ultrasound (IVUS) during 6-month follow-up. Methods and Results— Both IVUS and OCT examinations were performed on 108 vessels from 36 patients with ischemic heart disease who underwent percutaneous coronary intervention. Fifty-eight fibroatheromas were selected from 82 nonsignificant, nonculprit lesions (angiographic diameter stenosis, 25% to 75%; plaque burden, &gt;40% by IVUS). Fibroatheroma was defined by OCT as lipid-rich plaque in &gt;1 quadrant that has lipid. Thickness of the fibrous cap was measured by OCT. IVUS and OCT examinations were repeated at 6-month follow-up. Serial changes and relationships between IVUS indices and fibrous cap thickness were investigated. Overall, fibrous cap thickness (98.1±38.9 to 96.9±44.5 μm) as well as IVUS indices did not change significantly within 6 months. The percent changes in fibrous cap thickness correlated negatively and significantly ( r =−0.54; P &lt;0.0001; generalized estimating equation adjusted, r =−0.42; P =0.001) with the percent changes in external elastic membrane cross-sectional area. Conclusions— Arterial remodeling is related to changes in fibrous cap thickness. Positive arterial remodeling is not only an adaptive process, but also related to thinning of the fibrous cap.

Impact of angiographic and intravascular ultrasound features on clinical outcome after sirolimus-eluting stent implantation for de-novo lesions in nondiabetic and type 2 diabetic patients

This study aimed to evaluate the impact of angiographic and intravascular ultrasound (IVUS) features on clinical outcome in nondiabetic and type 2 diabetic patients after percutaneous coronary intervention (PCI) with sirolimus-eluting stent (SES) implantation. Repeat coronary angiography with IVUS imaging was performed after SES-based PCI for de-novo lesions in 128 diabetic and 327 nondiabetic patients (189 lesions and 504 lesions, respectively). The rate of major adverse cardiac events including cardiac death, non fatal myocardial infarction (MI), and target lesion revascularization during clinical follow-up was recorded. In-stent and in-segment late loss, intimal hyperplasia volume, and percentage volumetric obstruction were similar, but stented external elastic membrane cross-sectional area and reference/stented segment ratio were lower in diabetic than in nondiabetic patients. Incomplete stent apposition (ISA) was less frequent, but occurrence of new coronary lesions was higher in diabetic than in nondiabetic patients. Despite similar target lesion revascularization, cumulative survival rates freedom from composite cardiac death and nonfatal MI or major adverse cardiac events were reduced in diabetic patients. Cox proportional hazards model identified diabetes, left ventricular ejection fraction, minimal stent CSA, maximal ISA area, atherosclerotic progression and lesion length as independent predictors of non fatal MI or mortality at follow-up. In diabetic patients, PCI with SES implantation neutralizes the excess risk of intimal hyperplasia and decreases occurrence of ISA, but could not modify the propensity of increased adverse clinical outcomes at follow-up.