Minimal Lumen Cross-sectional Area Research Articles

Comparison between minimum lumen cross-sectional area and intraluminal ultrasonic intensity analysis using integrated backscatter intravascular ultrasound for prediction of functionally significant coronary artery stenosis.

Intravascular ultrasound (IVUS)-derived minimum lumen cross-sectional area (MLA) is useful to predict myocardial ischemia using fractional flow reserve (FFR). Recent studies reported an increase in the intraluminal ultrasonic integrated backscatter (IB) value using IVUS across the coronary artery stenosis (CAS) was significantly correlated with FFR. However, these details have not been fully understood. We evaluated the utility of intraluminal IB analysis for predicting myocardial ischemia based on FFR measurements by comparing that with conventional IVUS-derived MLA. A total of 65 patients with 75 intermediate lesions underwent both FFR and IB-IVUS simultaneously were analyzed. We measured IVUS-derived MLA and intraluminal IB value at the coronary ostial site, 5mm distal site to the CAS, and far distal site, which is the same as the position of the pressure wire sensor. The increase in IB values was calculated as the distal IB value - the ostial IB value (focal ∆IB) and the far distal IB value - the ostial IB value (total ∆IB). MLA did not show a significant correlation with FFR (p = 0.13); however, focal ∆IB and total ∆IB showed significant correlations with FFR (p = 0.008 and p < 0.001, respectively). The receiver operating characteristic curve analysis shows that the best cut-off value of focal ∆IB and total ∆IB was 8 and 14, respectively. Although the diagnostic abilities to predict FFR ≤ 0.75 among IVUS-derived MLA ≤ 3.0mm2, focal ∆IB ≥ 8, and total ∆IB ≥ 14 were similar, a multivariate analysis showed that total ∆IB was the most useful index (p < 0.001). In conclusion, total ∆IB, which is measured at the same as the position of FFR measurement, might be useful for functional assessment of intermediate CAS.

Features and Outcomes of Patients with Calcified Nodules at Culprit Lesions of Acute Coronary Syndrome: An Optical Coherence Tomography Study

Objectives: We sought to clarify clinical features and outcomes related to calcified nodules (CN) compared with plaque rupture (PR) and plaque erosion (PE) detected by optical coherence tomography (OCT) at the culprit lesions in patients with acute coronary syndrome (ACS). Methods: Based on OCT findings for culprit lesion plaque morphologies, ACS patients with analyzable OCT images (n = 362) were classified as CN, PR, PE, and other. Results: The prevalence of CN, PR, and PE was 6% (n = 21), 45% (n = 163), and 41% (n = 149), respectively. Patients with CN were older (median 71 vs. 65 years, p = 0.03) and more diabetic (71 vs. 35%, p = 0.002) than those without CN. In OCT findings, the distal reference lumen cross-sectional area (median 4.2 vs. 5.2 mm², p = 0.048) and the postintervention minimum lumen cross-sectional area (median 4.5 vs. 5.3 mm², p = 0.04) were smaller in lesions with CN than in those without. Kaplan-Meier estimate survival curves showed that the 500-day survival without target lesion revascularization (TLR) was lower (p = 0.011) for patients with CN (72.9%) than for those with PR (89.3%) or PE (94.8%). Conclusions: ACS patients with CN at the culprit lesion had more TLR compared to those with PR or PE.

Tissue characterization and phenotype classification in patients presenting with acute myocardial infarction: Insights from the iWonder study.

We sought to assess a new modality of radiofrequency intravascular ultrasound (IVUS) called iMAP-IVUS (Boston Scientific, Santa Clara, California) during the evaluation of patients presenting with high-risk acute coronary syndromes. There are limited data on plaque tissue characterization and phenotype classification using iMAP-IVUS. In the iWonder study patients presenting with ST-elevation myocardial infarction (STEMI) or non-STEMI underwent three-vessel grayscale IVUS and iMAP-IVUS tissue characterization prior to percutaneous intervention. In total 385 lesions from 100 patients were divided into culprit (n = 100) and nonculprit (n = 285) lesions. Lesion phenotype was classified as (i) thin-cap fibroatheroma (iMAP-derived TCFA); (ii) thick-cap fibroatheroma; (iii) pathological intimal thickening; (iv) fibrotic plaque; and (v) fibrocalcific plaque. Culprit lesions had smaller minimum lumen cross-sectional area (MLA) with greater plaque burden compared to non-culprit lesions. Volumetric analysis showed that culprit lesions had longer length and larger vessel and plaque volumes compared to non-culprit lesions. iMAP-IVUS revealed that culprit lesions presented more NC and fibrofatty volume, both at lesion level and at the MLA site (all P < 0.001). Any fibroatheroma was more frequently identified in culprit lesions compared with non-culprit lesions (93% vs. 78.9%, P = 0.001), anywhere within the lesion 19.0%, P < 0.001) as well as at the MLA site (18.0% vs. 9.5%, P = 0.07). Three-vessel radiofrequency iMAP-IVUS demonstrated a greater plaque burden and higher prevalence of any fibroatheroma as well as iMAP-derived TCFAs in culprit versus non-culprit lesions in patients presenting with STEMI or non-STEMI undergoing percutaneous coronary intervention. © 2017 Wiley Periodicals, Inc.

Procedural outcomes with use of the flash ostial system in aorto-coronary ostial lesions.

The Flash Ostial system (Ostial Corporation, Sunnyvale, CA) was designed to optimize implantation of aorto-ostial coronary stents by flaring the proximal stent struts against the aortic wall. We retrospectively reviewed the medical record, angiograms, and intravascular ultrasound images of 22 aorto-ostial percutaneous coronary interventions performed at our institution between March and September 2015. The Flash Ostial system was used in 13 cases (59%). Mean age was 67 ± 8 years and all patients were men. The target vessel was the right coronary artery (59%), left main (27%), or a saphenous vein graft (14%); 59% of the lesions had moderate/severe calcification. The mean number of predilation balloons was 1.8 ± 1.6, mean Flash ostial balloon diameter was 3.3 ± 0.5 mm and mean inflation pressure was 13.1 ± 4.0 atmospheres. Intravascular ultrasonography (available for 19 patients) revealed mean ostial minimum lumen cross-sectional area (MLA) of 9.2 ± 3.0 mm2 and reference MLA of 8.5 ± 2.7 mm2 . The percent difference between ostial and reference MLA was higher in cases in which the Flash Ostial system was used versus those where it was not (9.6 ± 5.5% vs. 4.0 ± 2.8%, P = 0.03). All stent struts were well apposed. Technical success was 100%. One patient developed a left groin pseudoaneurysm treated with thrombin injection and one patient had a periprocedural myocardial infarction. Median contrast, fluoroscopy time, and procedure time were 235 mL, 33 min, and 118 min, respectively. The Flash Ostial system can be successfully used in aorto-ostial stenting, resulting in large ostial vessel MLA. © 2016 Wiley Periodicals, Inc.

Intensive plaque modification with rotational atherectomy and cutting balloon before drug-eluting stent implantation for patients with severely calcified coronary lesions: a pilot clinical study.

BackgroundThis study investigated whether, for patients with severely calcified coronary lesions, use of a cutting balloon (CB) during rotational atherectomy (RA) before placing a drug-eluting stent will improve periprocedural outcomes, compared to RA with a conventional plain balloon.MethodsIn a randomized controlled trial, patients with severely calcified lesions of calcium arc ≥180° were apportioned to receive intensive plaque modification with RA and CB (RA + CB; n = 35) or RA with conventional plain balloon (RA; n = 36). Intravascular ultrasound was applied for quantitative or qualitative analyses of percutaneous coronary intervention outcomes. The primary outcome was acute lumen gain after drug-eluting stent.ResultsThe RA + CB and RA groups were similar in baseline mean arcs of superficial calcium, and minimum lumen cross-sectional areas (CSAs). The mean minimum stent CSA after percutaneous coronary intervention (PCI) of the RA + CB group (5.9 ± 1.7 mm2) was significantly larger than that of the RA group (5.0 ± 1.4 mm2; P = 0.021). Patients in the RA + CB group achieved significantly larger acute CSA gain after PCI (4.5 ± 1.5 mm2) relative to the RA group (3.8 ± 1.5 mm2; P = 0.035). The groups were similar in rates of periprocedural complications, but at the 1-year follow-up the RA + CB had a lower rate of revascularization for restenosis of the target vessel and MACE (5.7 %) than did the RA group (22.2 %, P = 0.046).ConclusionAggressive plaque preparation with RA and CB seems to be safe and effective for patients with severely calcified coronary lesions.Trial registrationCurrent Controlled Trials ChiCTR-INR-16008274. Retrospectively registered 12 April 2016.

Serial Intravascular Ultrasound Findings After Treatment of Chronic Total Occlusions Using Drug-Eluting Stents

Morphologic changes after chronic total occlusion (CTO) treatment with drug-eluting stents (DESs) have not been assessed in detail. Our aim was to use both baseline and follow-up intravascular ultrasound studies to evaluate the morphologic changes and, especially, the changes in distal vessel size and the effect of subintimal stenting after treatment of CTOs with DES. We analyzed serial follow-up intravascular ultrasound (baseline and follow-up at 9 ± 2 months) after DES implantation into 40 CTOs. Overall, 33 CTOs were treated by the anterograde approach; and 7 were treated by the retrograde approach. Minimum lumen cross-sectional area (CSA) trended toward a decrease from baseline to follow-up (4.8 ± 1.7 vs 4.5 ± 1.7 mm(2), p = 0.10), although the minimum stent CSA (4.8 ± 1.7 vs 4.9 ± 1.7 mm(2), p = 0.26) did not change. The distal reference, but not the proximal reference lumen CSA, increased significantly at follow-up (3.8 ± 2.0 to 5.1 ± 2.3 mm(2), p = 0.0004). Late-acquired stent malapposition was seen in 17 patients (42.5%). In 8 CTOs (20%), a part of the stent was implanted into a subintimal space; in these 8 patients, maximum percent neointimal hyperplasia and minimum lumen area was similar in the subintimal segment compared with the adjacent intraplaque segment. The frequency of late-acquired stent malapposition was similar. In conclusion, after CTO treatment with DES, distal vessel enlargement was detected. Subintimal stenting after recanalization of CTO was not inferior compared with stenting within the plaque in terms of long-term morphologic impact.

Incidence and Morphological Predictors of Intrastent Coronary Thrombus After Drug-Eluting Stent Implantation (from a Multicenter Registry)

The mechanisms responsible for late and very late stent thrombosis remain incompletely understood. This study aimed to evaluate the incidence and morphologic predictors of intrastent thrombus in patients after drug-eluting stent (DES) implantation using optical coherence tomography (OCT). A total of 208 patients with 262 DES who underwent follow-up OCT examination >6 months after DES implantation were included. The detailed vascular morphology including characteristics of neointima was analyzed. Thrombus was identified in 24 patients (11.5%) 11 months after DES implantation. Minimal lumen cross-sectional area was significantly smaller in the thrombus group than in the nonthrombus group (2.9 ± 1.7 vs 4.6 ± 2.0 mm(2); p <0.001). No difference was found in the frequency of uncovered or malapposed struts between the 2 groups. Thin-cap fibroatheroma (20.6% vs 0.1%; p <0.001) and heterogeneous neointima (22.2% vs 9.0%; p = 0.001) were more frequently detected in the thrombus group compared to the nonthrombus group. Second-generation DES showed lower incidence of thrombus, uncovered struts, and extrastent lumen compared with first-generation DES. In conclusion, the present OCT study revealed that smaller lumen cross-sectional area and neointimal morphology are important factors associated with intrastent thrombus. Second-generation DES demonstrated improved arterial healing and a lower incidence of intrastent thrombus compared with first-generation DES.

Abstract 13930: Culprit Lesion in Patients With ST-elevation Myocardial Infarction is Severely Narrowed With Large Plaque Burden: A Combined Intravascular Ultrasound and Optical Coherence Tomography Study

Background: There have been controversies on the degree of stenosis of the culprit lesion in patients with ST-elevation myocardial infarction (STEMI). In the past it was thought the culprit lesion for STEMI had only mild to moderate stenosis. However, recent studies suggested that in fact the degree of the luminal narrowing might be severe at the culprit site. Aim: The aim of the current study was to investigate the severity and the detailed morphologic characteristics of the culprit lesion in patients with STEMI using intravascular ultrasound (IVUS) and optical coherence tomography (OCT). Methods and Results: A total of 111 STEMI patients (67.8±11.2 years, 89 male) who underwent percutaneous coronary intervention within 12 hours from symptom onset were included. TIMI flow grade 2 or 3 was achieved in 108 (97%) patients after thrombectomy. Both OCT and IVUS were performed. Minimum lumen cross-sectional area (MLA) and plaque burden (PB) were 3.14±1.45 mm 2 and 83.0±7.24% by IVUS. Patients were divided into 2 groups on the basis of MLA by IVUS: Group A (MLA &lt;4 mm 2 , n=104) and Group B (MLA &gt;4 mm 2 , n=7). Group A had a higher incidence of PB &gt;70% compared to Group B (99.0% vs 28.6%, p&lt;0.001). OCT revealed that lipid plaque, microchannel and macrophage were more frequent in Group A than in Group B. The incidence of plaque rupture tended to be higher in Group A than in Group B (Figure). Conclusions: Among STEMI patients, more than 90% of culprit lesions have a small MLA (&lt;4.0 mm 2 ) with large plaque burden. Severely narrowed culprit lesion had more features of vulnerability.

Abstract 11522: Does Neointimal Pattern Predict Instent Thrombus

Introduction: Local determinants of instent thrombus formation after drug-eluting stent (DES) implantation have not been systematically investigated. Hypothesis: Certain neointimal patterns assessed by optical coherence tomography (OCT) may represent local surface thrombogenesity after DES implantation. Methods: A total of 208 patients with 262 DES who underwent follow-up OCT examination 11 months after DES implantation were studied. The detailed OCT findings including characteristics of neointima, lumen size, and stent morphology were compared between the group with and without thrombus. Results: Thrombus was identified in 11.5% (24/208) of the patients. Lipid-laden neointima, thin-cap fibroatheroma, heterogeneous neointima, and extra-stent lumen were more frequently detected in the thrombus group compared to the non-thrombus group (Figure). No difference was found in the % of uncovered (4.9±6.7% vs. 4.2±5.4%; p=0.575) or malapposed struts (1.5±2.5% vs. 0.8±2.1%; p=0.116) between the two groups. Minimal lumen cross sectional area was significantly smaller in the thrombus group compared with the non-thrombus group (2.9±1.7mm 2 vs. 4.6±2.0mm 2 ; p&lt;0.001). Conclusions: Neointimal morphology and smaller lumen cross-section area are important factors associated with instent thrombus.

Limitations of coronary computed tomographic angiography for delineating the lumen and vessel contours of coronary arteries in patients with stable angina.

We sought to evaluate whether coronary computed tomographic angiography (CCTA) could accurately and reproducibly delineate the lumen and vessel contours of coronary arteries. One hundred coronary stenotic lesions representing 91 patients with stable angina who received both CCTA and intravascular ultrasound (IVUS) were analysed. Three segments with minimal lumen cross-sectional area (CSA), proximal reference, and distal reference on IVUS images were selected for each lesion. Five observers measured lumen and vessel CSAs at three matching segments on CCTA images. These CSAs were compared with the IVUS-measured CSAs as a reference standard. All five observers underestimated lumen CSA at the three selected segments by CCTA. The minimal lumen CSA assessed by CCTA exhibited very weak correlations with those obtained by IVUS (r =0.23, 0.24, 0.15, 0.25, and 0.28, respectively). In contrast to the lumen CSA, the vessel CSA at the three segments was overestimated by all observers when assessed by CCTA. At the segment with minimal lumen CSA, the vessel CSA obtained by CCTA showed weak correlations with those assessed by IVUS (r = 0.43, 0.33, 0.44, 0.37, and 0.42, respectively). Moreover, intra-class correlation coefficients ranged from 0.44 to 0.73 among the five observers for lumen or vessel CSA measurements by CCTA at the segment with minimal lumen CSA. CCTA has potential limitations in the accurate delineation of lumen and vessel contours in patients with angina, as there was a high level of discordance with the IVUS-measured lumen and vessel CSAs and high inter-observer variability.

A study in the correlation between vascular factors and plaque imaging morphology of coronary borderline lesions in patients with coronary heart disease

Objective To investigate the correlation between the levels of placenta growth factor (PLGF) , soluble angiopoietin receptor-2 (sTie-2) and critical coronary artery plaque imaging morphology of coronary borderline lesions in patients with coronary heart disease (CHD) . Methods In three consecutive years from April 2007 to September 2009, a cohort of 719 patients with borderline coronary lesions with stenosis in three main vessels with lumen diameter reduction varied all the way from more than 20% to less than 70% and with greater than 2.25 mm of the inner diameter were selected in this study from 4 teaching hospitals of tertiary class A in Beijing. These patients fell into three categories: unstable angina pectoris (UAP, n =292) , stable angina pectoris (SAP, n =219) and coronary arteriosclerosis (AS, n =208) . The vessels involved were analyzed using quantitative coronary angiography (QCA) . Plasma levels of PLGF and sTie-2 were measured by using protein chip. The relationship between plasma levels of vascular factors, sTie-2, PLGF and coronary artery plaque imaging morphology among three groups were analyzed. Results (1) Plasma level of PLGF was 80.33 ng/L in the UAP group, which was significantly higher than 54.29 ng/L in the SAP group and 45.16 ng/L in AS group (both P <0.05) . Plasma level of sTie-2 was 1353.06 ng/L in the UAP group, which was significantly higher than 1308.28 ng/L in the AS group (P =0.008) . (2) There was significantly statistical differences in QCA between the SAP group and the UAP group as well as the AS group (both P <0.05) in terms of the minimal lumen diameter, diameter stenosis rate, minimal lumen cross-sectional area and cross-sectional area of stenosis. The plaque area in the UAP group was larger than that in the AS group (P =0.013) . (3) The relationship between vascular factors and plaque imaging morphology was analyzed. There was significantly statistical difference in the involved lesions among the three groups (P <0.01) . (4) There was a positive correlation between plasma level of PLGF and minimal lumen cross-sectional area (r =0.493, P =0.009). Conclusions The plasma levels of PLGF and sTie-2 reflect the level of neo-vascularization in the plaque, and could be taken as predictive factors for potential pathogenesis of coronary plaque. Key words: Coronary heart disease; PLGF; sTie-2; Quantitative coronary angiography

Comparison of Plaque Characteristics in Narrowings With ST-Elevation Myocardial Infarction (STEMI), Non-STEMI/Unstable Angina Pectoris and Stable Coronary Artery Disease (from the ADAPT-DES IVUS Substudy)

Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents (ADAPT-DES) was a prospective, multicenter registry of 8,582 consecutive stable and unstable patients who underwent percutaneous coronary intervention using a drug-eluting stent. We sought to identify key morphologic features leading to ST-segment elevation myocardial infarction (STEMI) versus non-STEMI (NSTEMI) or unstable angina pectoris (UA) versus stable coronary artery disease (CAD) presentation. In the prespecified grayscale and virtual histology (VH) substudy of ADAPT-DES, preintervention imaging identified 676 patients with a single culprit lesion. The relation between lesion morphology and clinical presentation was compared among patients with (1) STEMI, (2) NSTEMI or UA, and (3) stable CAD. Intravascular ultrasound identified more plaque rupture and VH thin-cap fibroatheroma (TCFA) in STEMI lesions compared with NSTEMI/UA or stable CAD lesions; conversely, fibroatheromas appeared more often calcified with a thick fibrous cap in stable CAD. Minimum lumen cross-sectional area (MLA) was smaller with larger plaque burden and positive remodeling in STEMI lesions. Lesions with plaque rupture versus those without plaque rupture showed higher prevalence of VH-TCFA and larger plaque burden with positive remodeling, especially in patients with STEMI. Multivariate analysis showed that in the lesions with plaque rupture, plaque burden at the MLA site was the only independent predictor for STEMI (cutoff of plaque burden = 85%) and in lesions without plaque rupture, MLA was the only independent predictor for STEMI (cutoff of MLA = 2.3 mm(2)). In conclusion, culprit lesions causing STEMI have smaller lumen areas, greater plaque burden, and more plaque rupture or VH-TCFA compared with NSTEMI/UA or stable CAD; in lesions with plaque rupture, only plaque burden predicted STEMI, and in lesions without plaque rupture, only MLA area predicted STEMI.

Optical coherence tomography-based predictors for creatine kinase-myocardial band elevation after elective percutaneous coronary intervention for in-stent restenosis.

We evaluated whether morphological characteristics of neointimal tissue of in-stent restenosis (ISR) lesions assessed by optical coherence tomography (OCT) affect periprocedural elevation of creatine kinase-myocardial band (CK-MB). The impact of neointimal characteristics of ISR lesions on periprocedural myocardial injury has not been sufficiently investigated. A total of 125 patients with ISR lesions underwent elective percutaneous coronary intervention (PCI) and pre-PCI OCT examination. Measurements of CK-MB were performed upon hospitalization, before PCI, and every 8 hr for 24 hr after PCI. CK-MB elevation was defined as levels above the 99th percentile of the upper reference limit. Neoatherosclerosis was defined as neointima with lipid or calcification. Post-PCI CK-MB elevation was observed in 20 (16.0%) patients. The maximum length of consecutive cross-sections with neoatherosclerosis on the longitudinal axis of the stent was significantly larger in patients with post-PCI CK-MB elevation than in those without [8.8 mm (1.5-10.4) vs. 0.0 mm (0.0-1.0), P < 0.001], and thin-cap fibroatheroma (TCFA) were more frequently observed at the site of minimal lumen cross-sectional area in patients with post-PCI CK-MB elevation (55.0% vs. 1.9%, P < 0.001). Multivariate analysis revealed that the maximum length of segments with neoatherosclerosis [odds ratio (OR), 1.463; 95% confidence interval (CI), 1.090-1.962; P = 0.011] and TCFA (OR, 14.328; 95% CI, 1.118-183.628; P = 0.041) were independent predictors for post-PCI CK-MB elevation. A greater axial length of neoatherosclerosis and the presence of TCFA at the most stenotic site were significantly associated with post-PCI CK-MB elevation in ISR lesions.

Long-Term Outcomes of Neointimal Hyperplasia Without Neoatherosclerosis After Drug-Eluting Stent Implantation

ObjectivesThe aim of this study was to investigate the correlation between in-stent neointimal tissue without features of neoatherosclerosis and long-term clinical outcomes. BackgroundRecent studies have reported differential morphological characteristics of in-stent neointimal tissue assessed by optical coherence tomography (OCT). MethodsThe study population consisted of 336 patients with 368 drug-eluting stent-treated lesions. Patients received a follow-up OCT examination without any intervention. OCT-based neointima was categorized as homogeneous (n = 227 lesions in 208 patients), heterogeneous (n = 79 lesions in 73 patients), or layered (n = 62 lesions in 55 patients). Major adverse cardiac events (MACE) (a composite of cardiac death, nonfatal myocardial infarction, or target lesion revascularization) were assessed according to neointimal patterns during long-term clinical follow-up after OCT examination. ResultsThe time interval between stent implantation and OCT examination was similar among the 3 groups (p = 0.64). On multivariate logistic regression analysis, the significant determinant for the heterogeneous neointima was age (odds ratio [OR]: 1.037, 95% confidence interval [CI]: 1.007 to 1.068, p = 0.015) and an initial clinical presentation of acute coronary syndrome (OR: 1.967, 95% CI: 1.159 to 3.339, p = 0.012). The overall median follow-up duration for all patients after follow-up OCT examination was 31.0 months, and this was statistically different among the heterogeneous group (22.0 months), the homogeneous group (34.0 months), and the layered group (28.0 months, overall p = 0.002). MACE occurred more frequently in patients with heterogeneous neointima over a median 31-month follow-up period after OCT examination (13.7% vs. 2.9% in homogeneous vs. 7.3% in layered, p = 0.001). A propensity score–adjusted Cox regression analysis showed that independent risk factors for MACE were inclusion in the heterogeneous neointima (hazard ratio: 3.925, 95% CI: 1.445 to 10.662, p = 0.007) and minimal lumen cross-sectional area (hazard ratio: 0.368, 95% CI: 0.242 to 0.560, p < 0.001). ConclusionsDetermination of neointimal characteristics is helpful in predicting long-term clinical outcomes. Our data suggest that heterogeneous lesions are linked to poor long-term clinical prognoses.

Cutting-balloon angioplasty before drug-eluting stent implantation for the treatment of severely calcified coronary lesions.

BackgroundSeverely calcified coronary lesions respond poorly to balloon angioplasty, resulting in incomplete and asymmetrical stent expansion. Therefore, adequate plaque modification prior to drug-eluting stent (DES) implantation is the key for calcified lesion treatment. This study was to evaluate the safety and efficacy of cutting balloon angioplasty for severely calcified coronary lesions.MethodsNinety-two consecutive patients with severely calcified lesions (defined as calcium arc ≥ 180° calcium length ratio ≥ 0.5) treated with balloon dilatation before DES implantation were randomly divided into two groups based on the balloon type: 45 patients in the conventional balloon angioplasty (BA) group and 47 patients in the cutting balloon angioplasty (CB) group. Seven cases in BA group did not satisfactorily achieve dilatation and were transferred into the CB group. Intravascular ultrasound (IVUS) was performed before balloon dilatation and after stent implantation to obtain qualitative and quantitative lesion characteristics and evaluate the stent, including minimum lumen cross-sectional area (CSA), calcified arc and length, minimum stent CSA, stent apposition, stent symmetry, stent expansion, vessel dissection, and branch vessel jail. In-hospital, 1-month, and 6-month major adverse cardiac events (MACE) were reported.ResultsThere were no statistical differences in clinical characteristics between the two groups, including calcium arc (222.2° ± 22.2° vs. 235.0° ± 22.1°, P = 0.570), calcium length ratio (0.67 ± 0.06 vs. 0.77 ± 0.05, P = 0.130), and minimum lumen CSA before PCI (2.59 ± 0.08 mm2 vs. 2.52 ± 0.08 mm2, P = 0.550). After stent implantation, the final minimum stent CSA (6.26 ± 0.40 mm2 vs. 5.03 ± 0.33 mm2; P = 0.031) and acute lumen gain (3.74 ± 0.38 mm2 vs. 2.44 ± 0.29 mm2, P = 0.015) were significantly larger in the CB group than that of the BA group. There were not statistically differences in stent expansion, stent symmetry, incomplete stent apposition, vessel dissection and branch vessel jail between two groups. The 30-day and 6-month MACE rates were also not different.ConclusionsCutting balloon angioplasty before DES implantation in severely calcified lesions appears to be more efficacies including significantly larger final stent CSA and larger acute lumen gain, without increasing complications during operations and the MACE rate in 6-month.

Qualitative and Quantitative Assessment of Stent Restenosis by Optical Coherence Tomography

We hypothesized that the tissue components of in-stent restenosis (ISR) might differ between drug-eluting stents (DES) and bare-metal stents (BMS) and that these differences could be distinguished by qualitative and quantitative optical coherence tomography (OCT) analyses. One-hundred and twenty-two initial ISR lesions (sirolimus-eluting stents: n=28; paclitaxel-eluting stents: n=51; BMS: n=43) were evaluated with OCT. Based on their OCT appearance, the lesions were classified as homogeneous, layered or heterogeneous. The optical properties of backscatter, attenuation and signal intensity of the neointimal tissue (NIT) were quantified. To evaluate the vascular response after balloon angioplasty (BA), the rate of reduction of the NIT area (NITA) was calculated (NITA before - after BA/NITA before BA at the minimum lumen cross-sectional area). Among the morphologic OCT patterns, the layered type was predominant with DES, whereas lesions were homogeneous with BMS (P<0.001). Backscatter and signal intensity were significantly higher with BMS (P<0.05 and P<0.001 respectively). The NITA reduction rate was significantly greater in the layered and heterogeneous groups than in the homogeneous group (P<0.01). The morphologic OCT patterns of the NIT in ISR differed significantly between DES and BMS, probably reflecting pathologic differences. Layered and heterogeneous tissues might respond better than homogeneous tissue to simple balloon dilatation, suggesting a possible direction for OCT-based ISR treatment strategies.

Feasibility of a novel radiofrequency signal analysis for in-vivo plaque characterization in humans: Comparison of plaque components between patients with and without acute coronary syndrome

BackgroundThe iMAP™ is a novel intravascular ultrasound (IVUS)-based technology to classify coronary plaque into 4 components. The aim of this study was to evaluate the feasibility of iMAP™ technology by comparing plaque characteristics in patients with and without acute coronary syndrome (ACS and non-ACS). Materials and methodsA total of 93 culprit lesions from 87 patients were analyzed using the iMAP™. Each plaque was classified into 4 components with a newly introduced parameter, confidence level (CL). ResultsiMAP™ analysis of the minimal lumen cross-sectional area (MLA) revealed that ACS lesions had significantly larger lipidic and necrotic areas than non-ACS lesions. Multivariate analysis revealed that the lipidic area at the MLA was an iMAP™ factor independently associated with ACS lesions (odds ratio −1.5, p=0.04). Based on receiver operating characteristic analysis with 4 different CL ranges, the lipidic area at the MLA with 25%–100% CL had the largest area under the curve (0.756), suggesting that 25%–100% is the best CL range for identifying ACS culprit lesions. ConclusionsThe feasibility of the novel iMAP™ IVUS system was shown in discriminating culprit lesions in patients with and without ACS. Analyzing with a CL of 25%–100% may be the best option for discriminating lesions.

In-stent area stenosis on 64-slice multi-detector computed tomography coronary angiography: optimal cutoff value for minimum lumen cross-sectional area of coronary stents compared with intravascular ultrasound

We aimed to prospectively assess the optimal cutoff value for a minimum lumen cross-sectional area (CSA) on a 64-slice multidetector computed tomography (MDCT) compared with an intravascular ultrasound (IVUS). In 39 patients with 43 stents, the minimum lumen diameter, stent diameter, diameter stenosis, minimum lumen CSA, stent CSA, and area stenosis at the narrowest point were measured independently on 64-slice MDCT and IVUS images. For the assessment of diameter and CSA, 64-slice MDCT showed good correlations with IVUS (r = 0.82 for minimum lumen diameter, r = 0.66 for stent diameter, r = 0.79 for minimum lumen CSA, and r = 0.75 for stent CSA, respectively, P < 0.0001). For the assessment of diameter and area stenoses, a 64-slice MDCT showed good correlations with IVUS (r = 0.89 and 0.91, respectively, P < 0.0001). The overall sensitivity, specificity, positive predictive value, and negative predictive value to detect in-stent area restenosis (≥ 50 % area stenosis) of a 64-slice MDCT were 77, 100, 100, and 91 %, respectively. The cutoff value of a 64-slice MDCT, determined by receiver operator characteristic (ROC) analysis, was 5.0 mm(2) with 76.5 % sensitivity and 92.3 % specificity for significant in-stent area restenosis; the area under the ROC curve was 0.902 (P < 0.0001). A good correlation was found between a 64-slice MDCT and the IVUS, regarding the assessment of diameter and area stenoses of coronary stents in selected patients implanted with stents of more than 3 mm in diameter. Optimal cutoff value for the minimum lumen CSA of coronary stents on the 64-slice MDCT is 5 mm(2) to predict a CSA of 4 mm(2) on IVUS.

Optical coherence tomography for guidance of treatment of in-stent restenosis with cutting balloons

The treatment of in-stent restenosis (ISR) remains a challenge with poor immediate results and higher restenosis rate than in de novo lesions. We propose, based on a consecutive series of patients treated with cutting balloon, a strategy of aggressive device selection based on the results of serial FD-OCT assessment. Fourteen consecutive ISR lesions were evaluated both angiographically and with frequency domain optical coherence tomography (FD-OCT) (C7; LightLab Imaging Inc., Westford, MA, USA). Cutting balloon (CB) was used in all cases, sized firstly according to conventional angiographic criteria and then upgraded based on OCT assessment with the aim of creating cuts as close as possible to the struts. OCT data analysis included measurements of lumen and stent area, minimal distance lumen-struts and residual plaque neointimal hyperplasia. With an OCT guided CB strategy, the final minimal lumen cross-sectional area (MLCSA) after the final treatment reached 6.68±1.14 mm², with a reduction from 69% to 25% of neointimal hyperplasia. In the patients with a two-step strategy using a first CB guided by angiography and a second CB guided by OCT, the increase in CB diameter was 0.5 mm, achieving an increase in MLCSA area from 4.9±0.42 to 6.35±0.92 mm² with a reduction from 41% to 27% of neointimal hyperplasia. The OCT measurements of strut-to-strut distance allow safe upsizing of the CB with an acceptable lumen increase before deployment of a new DES. The strategy appears of particular usefulness for a DEB strategy with no intention to implant new stents.

Effect of atorvastatin therapy on borderline vulnerable lesions in patients with acute coronary syndrome

IntroductionIt is still controversial whether borderline lesions with a vulnerable plaque should be stented early or simply treated pharmacologically. No data exist concerning the potential effects of statin therapy on borderline vulnerable lesions in patients with acute coronary syndrome (ACS).Material and methodsFifty patients with ACS whose culprit lesions were classified as “borderline lesions” were enrolled. All patients were treated with atorvastatin (20 mg) for 12 months. Intravascular ultrasound (IVUS) was performed and matrix metalloproteinase-9 (MMP-9), tissue inhibitor of metalloproteinase-1 (TIMP-1), and high-sensitive C-reactive protein (hsCRP) levels were measured at baseline and 12-month follow-up.ResultsAt 12-month follow-up, we found: 1) IVUS revealed that minimal lumen cross-sectional area (CSA) increased but plaque/media (P&M) area and plaque burden decreased. A total of 25 soft plaques (50%) were transformed into fibrous plaques. 2) ApoB, MMP-9 and hsCRP levels decreased, but TIMP-1 level increased. 3) Stepwise multivariate linear regression analysis showed that the independent predictors for changes in P&M area/year were the decrease in MMP-9 and hsCRP levels.ConclusionsAtorvastatin therapy stabilized borderline vulnerable plaques and reversed atherosclerosis progression in patients with ACS. Reversal of this progression was accompanied by a decrease in the levels of plasma MMP-9 and hsCRP. Changes in MMP-9 and hsCRP could predict vulnerable plaque stabilization.