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We evaluated early vascular responses after new-generation drug-eluting stent (DES) implantation. From 2 randomized trials, we identified 471 patients (138 patients with acute myocardial infarction [AMI] vs 333 patients with stable angina or unstable angina [SA/UA]) treated by DESs who underwent serial optical coherence tomography (OCT) from postprocedure to 3 months. At 3-month follow-up OCT, malapposed strut percentage was higher in AMI than in SA/UA (5.3% vs 0.7%, P < .001); it was markedly increased from postprocedure in AMI (2.0%-5.3%, P < .001), whereas it decreased in SA/UA (1.7%-0.7%, P < .001). Patients with AMI showed a higher risk of persistent (59% vs 37%; P < .001) or late-acquired malapposition (15% vs 8%; P = .04). Uncovered strut percentage at 3 months was also higher in AMI than in SA/UA (13.1% vs 6.7%, P < .001). The AMI presentation was the significant risk factor for both significant stent malapposition (SM, ≥200 μm; odds ratio [OR] = 3.45, CI = 1.85-7.14, P < .001) and uncovered stent (% uncovered struts >6.0%; OR = 2.44, CI = 1.35-4.76, P = .004), together with malapposed distance and postprocedural thrombi. Further, AMI presentation was the predictor for the occurrence of early period late-acquired and persistent malapposition. Serial OCT comparison analyses showed that patients with AMI compared with patients with SA/UA showed more delayed strut coverage, more severe degree SM or uncovered stents, and higher incidences of early period persistent or late-acquired SM.

Purpose: Acute coronary occlusion is a rare but fatal complication that may occur during trans-catheter aortic valve implantation (TAVI) and appears more frequently in patients with low coronary heights. We evaluated the feasibility of self-expanding valves in patients with low coronary heights undergoing TAVI., Materials and Methods: TAVI for native aortic valve stenosis was conducted in 276 consecutive patients between 2015 and 2019 at our institute. Using multi-detector computed tomography (MDCT), information on the aortic valve, coronary arteries, and vascular anatomy in 269 patients was analyzed. Patients with low coronary heights were defined as those with coronary heights of 10 mm or less during MDCT analysis., Results: Among the 269 patients, 29 (10.8%) patients had coronary arteries with low heights. The mean coronary height was 8.9±1.2 mm in the left coronary artery. These patients with low coronary heights were treated with self-expandable (n=28) or balloon-expandable (n=1) valves. Prophylactic coronary protection with a guidewire, balloon, or stent prepositioned down at-risk coronary arteries was not pursued in all patients. No acute coronary occlusion occurred in any of these patients during TAVI. Five patients (17.9%) died during follow-up (average of 553.8 days), including four from non-cardiogenic causes and one from a cardiogenic (aggravation of heart failure) cause., Conclusion: A considerable number of patients with low coronary heights were observed among TAVI candidates in this study. Use of a self-expandable valve may be feasible for successful TAVI without acute coronary occlusion in patients with low coronary heights., Competing Interests: The authors have no potential conflicts of interest to disclose., (© Copyright: Yonsei University College of Medicine 2021.)

Background: Research has shown that the prognosis of in-stent restenosis (ISR) lesions after drug-coated balloon (DCB) angioplasty can differ in relation to in-stent neointimal characteristics. However, changes in neointima characteristics after DCB have not been studied. This study sought to investigate changes in neointima characteristics after DCB for ISR., Methods: From the Yonsei Optical Coherence Tomography (OCT) registry, data on DCBs performed in patients with ISR were collected. Neointima characteristics were categorized as homogeneous, heterogeneous, layered neointima, and neoatherosclerosis in each OCT procedure. Homogeneous and layered neointima were classified as a favorable neointima, while heterogeneous neointima and neoatherosclerosis were classified as an unfavorable neointima. The data of 67 ISR patients were analyzed., Results: The median duration between initial and follow-up OCT was 9.6 months. Patients with homogeneous and layered neointima on the initial OCT before DCB mostly appeared as homogeneous (66.7 and 68.2%, respectively) on the follow-up OCT, whereas most of the patients with heterogeneous neointima on the initial OCT remained unaltered (70%). Patients with unfavorable neointima at either the initial (P = 0.023) or the follow-up OCT (P = 0.037) had a worse major adverse cardiovascular event-free survival than the other patients. Patients who showed unfavorable neointima at both the initial and the follow-up OCT had the worst event-free survival (P = 0.038)., Conclusions: The follow-up OCT neointimal characteristics after DCB for ISR was associated with initial OCT characteristics. Sustained unfavorable neointima in serial OCT imaging may reflect poor prognosis in patients with ISR treated with DCB.

Limited data exist on the long-term efficacy of extended dual antiplatelet therapy (DAPT) after left main coronary artery (LMCA) bifurcation stenting. This study investigated the long-term clinical outcomes associated with long-term DAPT after LMCA bifurcation stenting. Using data from the multicenter KOMATE and COBIS registries, we analyzed 1,142 patients who received a drug-eluting stent for a LMCA bifurcation lesion and who experienced no adverse events for 12 months after the index procedure. Patients were divided into 2 groups: DAPT >12 months (n = 769) and DAPT ≤12 months (n = 373). The primary end point was major adverse cardiovascular events (MACEs), as a composite of cardiac death, myocardial infarction, stroke, and stent thrombosis, over 5 years of follow-up. We further performed propensity score adjustment for clinical outcomes. DAPT >12 months afforded a lower MACE rate than DAPT ≤12 months (2.3% vs 5.4%, adjusted hazard ratio [HR] 0.37; 95% confidence interval [CI] 0.19 to 0.71; p = 0.003). The use of DAPT for >12 months was an independent predictor of a reduced likelihood of MACEs (HR 0.34; 95% CI 0.17 to 0.67; p = 0.002). A DAPT score ≥2, chronic kidney disease, and age >75 years were significant independent predictors of MACEs. In subgroup analysis, the use of DAPT for >12 months consistently resulted in better clinical outcomes across all subgroups, especially among patients with ACS, compared with the use of DAPT for ≤12 months. In conclusion, an extended duration of DAPT reduces MACE rates after LMCA bifurcation stenting., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Optical coherence tomography (OCT) was used to assess serial changes in severe acute stent malapposition (ASM) after drug-eluting stent (DES) implantation., Methods: The maximal depth and axial lengths of ASM after DES implantation were serially quantified at percutaneous coronary intervention (PCI), and at 3 and 12-month follow-up, for 100 lesions in 96 patients. Severe ASM was defined as a maximal malapposed depth ≥400 μm or maximal malapposed axial length ≥1 mm., Results: Of the 100 lesions, 23 lesions (23%) had a severe ASM depth at PCI. At 3 months, the maximal depth decreased to <400 μm in 12 of 23 lesions (52%). At 12 months, the maximal depth further decreased to <400 μm in 8 of the remaining 11 lesions (73%). Similarly, of 53 lesions (53%) with a severe ASM length at PCI, the maximal length decreased to 0 mm in 26 (49%) but remained severe in 17 lesions (32%) at 3 months. At 12 months, 9 of the 17 remaining lesions (53%) further decreased to 0 mm. The cut-off values for the maximal malapposed depth and length to predict the absence of stent malapposition at 12 months were 565 μm at PCI and 165 μm at 3 months, and were 2.7 mm at PCI and 0.1 mm at 3 months, respectively., Conclusion: Half of the severe ASM cases resolved within 3 months, and another half resolved during 3-12 months of follow-up. Our findings provide a better understanding of the time-dependent natural course of severe ASM using OCT., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background: We investigated whether optical coherence tomography (OCT) guidance would reduce nonoptimal bioresorbable vascular scaffold (BVS) deployment., Methods: This was a randomized controlled trial. Patients who required percutaneous coronary intervention for ischemic heart disease were recruited from 2 centers in Korea. The enrolled patients were randomly assigned to receive either OCT-guided BVS (Absorb; Abbott Vascular) implantation or angiography-guided BVS implantation using an optimized technique. The primary outcome was nonoptimal deployment, which was a composite outcome of the following parameters assessed by OCT: a minimal scaffold area <5 mm 2 , residual area stenosis >20%, incomplete apposition of the scaffold struts >5%, major edge dissection, or scaffold disruption. The secondary outcome was a procedural complication defined by the occurrence of no reflow, coronary perforation, or flow-limiting dissection., Results: Between September 2016 and January 2018, 88 patients (90 lesions) were assigned to OCT guidance, while 88 patients (89 lesions) were assigned to angiography guidance. The recruitment was prematurely terminated in March 2018 because the manufacturer stopped supplying BVS. Postprocedural OCT data were available for 88 lesions with OCT guidance and for 88 lesions with angiography guidance. There was nonoptimal BVS deployment postprocedurally in 35.2% of patients in the OCT-guidance group and in 38.6% in the angiography-guidance group (absolute difference, -3.7% [95% CI, -19.0% to 11.6%]; P =0.64). There were no procedural complications in either group., Conclusions: OCT-guided BVS implantation did not reduce the incidence of nonoptimal deployment compared to that of angiography-guided BVS implantation (using optimized techniques)., Clinical Trial Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02894697.

Objectives: To evaluate the incidence, predictors, and outcomes of distal vessel expansion on intravascular ultrasound (IVUS) after recanalization of chronic total occlusion (CTO) particularly using new-generation drug-eluting stent (DES)., Background: The luminal changes of narrowed vessels distal to CTO segments after recanalization using new-generation DES have rarely been studied., Methods: This substudy of the CTO-IVUS (Chronic Total Occlusion InterVention with drUg-eluting Stents) trial included a total of 69 new-generation DES-treated CTOs with serial matched IVUS analyses at index percutaneous coronary intervention (PCI) and at 1-year follow-up. The predictors of distal vessel expansion, any increase of lumen area at the distal reference (LA distal ) on 1-year follow-up IVUS, were evaluated by multivariable binary logistic analyses., Results: Distal vessel expansion was identified in 46 (67%). Independent determinants of distal vessel expansion were proximal CTO, a smaller LA distal at the index PCI, a greater minimal stent area-to-LA distal (MSA-to-LA distal ) ratio, and a greater lumen area at the distal stent edge-to-LA distal (LA edge -to-LA distal ) ratio. The cut-off values of a MSA-to-LA distal ratio and a LA edge -to-LA distal ratio predicting the distal vessel expansion by receiver operating characteristic curve analysis were 1.0 and 1.1, respectively. During the median 5.1 years, rates of target vessel revascularization, cardiac death, and stent thrombosis were similar in the distal vessel-expanded and nonexpanded groups., Conclusion: After opening CTO with new-generation DES, two-thirds of patients exhibited distal vessel expansion on 1-year follow-up IVUS. Expansion determinants were a proximal CTO, lower LA distal , and larger stent areas relative to the LA distal (modifiable procedural predictors)., (© 2019 Wiley Periodicals, Inc.)

Background and Aims: The impact of late drug-eluting stent (DES) malapposition detected by optical coherence tomography (OCT) on long-term clinical outcomes has not been clearly established. We evaluated long-term clinical outcomes of late stent malapposition (LSM) detected by OCT in a qualified study population., Methods: A total of 428 patients were selected from previous randomized OCT studies that evaluated the degree of strut coverage of different DESs at a 3-12-month follow-up OCT examination. These patients were assigned to one of two groups based on the presence (n = 136) or absence (n = 292) of LSM on follow-up OCT images (performed at 7.0 ± 3.4 months after DES implantation). The cumulative rates of composite events (cardiac death, target-vessel-related myocardial infarction, target-vessel revascularization, and stent thrombosis) were compared between the two groups., Results: During 73.7 ± 18.3 months of follow-up, cardiac death or (very) late stent thrombosis did not occur in either group. The cumulative rate of composite events was similar among the patients in each group (6.2% in patients with LSM vs. 11.7% in those without LSM) [hazard ratio (HR) = 0.569, 95% confidence interval (CI) = 0.257-1.257, p = 0.163]. Target vessel-related myocardial infarction occurred in 0.7% of patients with LSM vs. 1.5% of those without LSM (HR = 0.521, 95% CI = 0.058-4.670, p = 0.560). Target-vessel revascularization was performed in 5.4% of patients with LSM vs. 10.2% of those without LSM (HR = 0.574, 95% CI = 0.246-1.343, p = 0.201)., Conclusions: Cardiac death or (very) late stent thrombosis did not occur in patients with OCT-detected LSM during long-term follow-up. The presence of OCT-detected LSM was not associated with adverse clinical events., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background The effects of severe acute stent malapposition ( ASM ) after drug-eluting stent implantation on long-term clinical outcomes are not clearly understood. We evaluated long-term clinical outcomes of severe ASM using optical coherence tomography. Methods and Results We pooled patient- and lesion-level data from 6 randomized studies. Five studies investigated follow-up drug-eluting stent strut coverage and one investigated ASM . In this data set, a total of 436 patients with 444 lesions underwent postintervention optical coherence tomography examination and these data were included in the analysis. Severe ASM was defined as lesions with ≥400 μm of maximum malapposed distance or ≥1 mm of maximum malapposed length. Composite events (cardiac death, target lesion-related myocardial infarction, target lesion revascularization, and stent thrombosis) were compared between patients with and without severe ASM . The postintervention optical coherence tomography findings indicated that 62 (14.2%) patients had lesions with ≥400 μm of maximum malapposed distance and 186 (42.7%) patients had lesions with ≥1 mm of maximum malapposed length. The 5-year clinical follow-up was completed in 371 (86.1%) of the eligible 431 patients. The cumulative rate of composite events was similar among the patients in each group during 5-year follow-up: 3.3% in patients with ASM ≥400 μm of maximum malapposed distance versus 3.1% in those with no ASM or ASM <400 μm of maximum malapposed distance ( P=0.89), and 1.2% in patients with ASM ≥1 mm of maximum malapposed length versus 4.6% in those with no ASM or ASM <1 mm of maximum malapposed length ( P=0.06). Conclusions During the 5-year follow-up, ASM severity was not associated with long-term clinical outcomes in patients treated with drug-eluting stents.

Patient preference plays an important role in daily practice; however, its implication has not been well investigated regarding treatment strategy for complex coronary artery disease. We prospectively evaluated a trend of patient-centered decision-making of revascularization strategy in patients with multivessel or unprotected left main coronary artery disease. A standardized protocol that favors coronary artery bypass graft surgery (CABG) as the primary treatment of choice, rather than percutaneous coronary intervention, was adopted. According to the protocol, patients decided whether or not they received CABG. Among the 763 consecutively enrolled patients, 293 patients (38%) consented to receive CABG. Fifty-six percent of patients with a high Synergy between PCI with Taxus and Cardiac Surgery (SYNTAX) score chose CABG. SYNTAX score was independently correlated with consent to receive CABG in each patient SYNTAX score stratum. In-stent restenosis was an independent predictor of choosing CABG in patients with low and intermediate SYNTAX scores. Unprotected left main coronary artery disease was negatively correlated with the decision to choose CABG in patients with intermediate SYNTAX score. Reasons for declining CABG included refusal of open-heart surgery in 318 patients (68%), mild presentation of angina symptoms in 132 patients (28%), low self-confidence to expect long-term survival in 120 patients (26%), and economic factors in 10 patients (2%). Short-term major adverse cardiac and cerebrovascular events occurred in about 1% of patients without significant differences between the 2 groups. In conclusion, despite the preferred use of the CABG protocol, more than half of the patients declined CABG. Patient-centered decision-making as well as heart team approach should be considered in real-world practice situations., (Copyright © 2018. Published by Elsevier Inc.)

Background: Using optical coherence tomography, we evaluated early follow-up findings of significant stent malapposition (SSM) in patients treated with second-generation drug-eluting stent., Methods and Results: From the DETECT-OCT randomized trial (Determination of the Duration of the Dual Antiplatelet Therapy by the Degree of the Coverage of the Struts on Optical Coherence Tomography From the Randomized Comparison Between Everolimus- Versus Biolimus-Eluting Stent), a total of 386 patients (390 lesions) who underwent both postintervention and 3-month follow-up optical coherence tomography examinations were included for the present analysis. SSM was defined as a stent that had a strut with a maximal wall-to-strut distance of ≥200 μm. Postintervention, SSM was detected in 175 lesions (44.9%), including 117 lesions with a maximal wall-to-strut distance of ≥200 to <400 μm and 58 lesions with a maximal wall-to-strut distance of ≥400 μm. As the implanted stent diameter-to-reference vessel diameter ratio grew, the risk of postintervention SSM dropped (odds ratio, 0.587; 95% CI, 0.367-0.941; P=0.0398). The optimal value that best separated SSM from non-SSM postintervention was a stent diameter-to-reference vessel diameter ratio of 1.0. At 3 months follow-up, the frequency of SSM decreased from 44.9% to 33.6% (131 lesions; P=0.0001), mainly driven by the decrease in lesions with a maximal wall-to-strut distance of ≥200 to <400 μm. As the maximal wall-to-strut distance on postintervention optical coherence tomography was larger, the risk of 3-month SSM increased (odds ratio, 1.607; 95% CI, 1.131-2.286; P=0.0284). The optimal value that best separated SSM from non-SSM at 3 months follow-up was a maximal wall-to-strut distance postintervention of 230 μm., Conclusions: A spontaneous decrease in SSM was observed early in this qualified study with a large number of study patients treated with second-generation drug-eluting stent., Clinical Trial Registration: URL: https://www.clinicaltrials.gov . Unique identifier: NCT01752894.

Background: The pathophysiology underlying very late drug-eluting stent (DES) thrombosis is not sufficiently understood. Using optical coherence tomography, we investigated characteristics of very late stent thrombosis (VLST) according to different onset times., Methods and Results: A total of 98 patients from 10 South Korean hospitals who underwent optical coherence tomography for evaluation of very late DES thrombosis were retrospectively included in analyses. VLST occurred at a median of 55.1 months after DES implantation. All patients were divided into 2 equal groups of earlier versus delayed presentation of VLST, according to median onset time. In total, 27 patients were treated with next-generation DES and 71 with first-generation DES. Based on optical coherence tomography findings at thrombotic sites, main VLST mechanisms were as follows, in descending order: neoatherosclerosis (34.7%), stent malapposition (33.7%), and uncovered struts without stent malapposition or evagination (24.5%). Compared with patients with earlier VLST, patients with delayed VLST had lower frequency of uncovered struts without stent malapposition or evagination (34.7% versus 14.3%, respectively; P =0.019). Conversely, the frequency of neoatherosclerosis was higher in patients with delayed versus earlier VLST (44.9% versus 24.5%, respectively; P =0.034). The frequency of stent malapposition was not different between patients with earlier and delayed VLST (34.7% versus 32.7%, respectively; P =0.831). The frequency of stent malapposition, evagination, and uncovered struts was still half of delayed VLST., Conclusions: The pathological mechanisms of very late DES thrombosis changed over time. Delayed neointimal healing remained a substantial substrate for VLST, even long after DES implantation., (© 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.)

Introduction and Objectives: There are limited data on the usefulness of intravascular ultrasound (IVUS) for long coronary lesions treated with second-generation drug-eluting stents. We evaluated IVUS predictors of major adverse cardiovascular events (MACE) 12 months after implantation of everolimus-eluting stents for long coronary lesions., Methods: A total of 804 patients who underwent both postintervention IVUS examination and long everolimus-eluting stent (≥ 28mm in length) implantation were included from 2 randomized trials. MACE was defined as a composite of cardiac death, myocardial infarction, and target-lesion revascularization., Results: MACE occurred in 24 patients (3.0%) over 12 months. On multivariable Cox regression analysis, independent IVUS predictors of MACE included the postintervention minimum lumen area (MLA) at the target lesion (HR = 0.623; 95%CI, 0.433-0.895; P=.010) and the ratio of MLA/distal reference segment lumen area (HR = 0.744; 95%CI, 0.572-0.969; P=.028). The MLA and MLA-to-distal reference segment lumen area ratio that best predicted patients with MACE from those without these events were 5.0 mm 2 and 1.0, respectively. Patients with MLA<5.0 mm 2 or a distal reference segment lumen area had a higher risk of MACE (HR = 6.231; 95%CI, 1.859-20.891; P=.003) than those without MACE., Conclusions: Patients with a postintervention IVUS-measured MLA of<5.0 mm 2 or a distal reference segment lumen area were at risk for MACE after long everolimus-eluting stent implantation., (Copyright © 2016 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.)

Background: There is general agreement that the optimal duration of dual antiplatelet therapy (DAPT) in patients treated with drug-eluting stents should be individualized. We hypothesized that the extent of coronary artery disease may affect the clinical outcomes of DAPT., Methods and Results: We pooled patient-level data from 5 large, randomized trials comparing short-term DAPT with prolonged therapy. From the data, we identified 5476 patients who received newer-generation drug-eluting stents. Net adverse clinical event (NACE) was defined as a composite of all-cause mortality, myocardial infarction, stroke, or major bleeding. At 1 year, NACE had occurred in 171 patients (3.1%). Independent predictors of NACE were older age (>65 years), sex, presence of diabetes mellitus, left ventricular dysfunction (ejection fraction <40%), and angiographic multivessel disease. Multivessel disease and DAPT duration were significantly associated with NACE (P for interaction=0.002); the association was driven by the greater occurrence of myocardial infarction in patients with multivessel disease. In patients with multivessel disease, 6-month DAPT (versus 12-month DAPT) was associated with a higher incidence of myocardial infarction (adjusted hazard ratio=2.748; 95% confidence interval=1.375-5.491; P=0.004), compared with patients with single-vessel disease (P for interaction=0.001)., Conclusions: In patients treated with newer-generation drug-eluting stents, a significant interaction between DAPT strategy and multivessel disease was found regarding the occurrence of NACE at 1 year. Among adverse events, myocardial infarction was more frequent in 6-month DAPT than in 12-month DAPT in patients with multivessel disease., (© 2016 American Heart Association, Inc.)

Background: The assessment of fractional flow reserve (FFR) in coronary lesions determines the strategy of percutaneous coronary intervention. However, the association between FFR and characteristics of the underlying coronary plaque has not been sufficiently investigated., Methods: A total of 110 coronary lesions in 106 patients were evaluated using both FFR and optical coherence tomography (OCT). Coronary plaques were classified into fibrous, fibrocalcific, or fibroatheroma according to OCT evaluation at the site of minimal lumen area. Plaque microstructures such as cap thickness, macrophage accumulation, intimal vasculature, or cholesterol crystals were also evaluated., Results: Lesions with FFR≤0.8 showed a higher frequency of fibroatheroma, macrophage accumulation, and cholesterol crystals when compared to those with FFR>0.8. The angle of lipid was wider in lesions with FFR≤0.8 (145.1±63.0° vs. 120.7±48.9°, p=0.047), and the longitudinal length was longer in those with FFR≤0.8 (4.2±2.8mm vs. 2.5±2.9mm, p=0.007). However, multiple linear regression analysis revealed that the morphological characteristics of plaques assessed by OCT were not independently associated with FFR. Minimal lumen area [coefficient, 0.035; 95% confidence interval (CI), 0.022-0.048; p<0.001] and area stenosis (coefficient, -0.003; 95% CI, -0.005 to -0.001; p=0.001) assessed by OCT significantly correlated with FFR., Conclusion: The morphological characteristics of coronary plaque derived from OCT are not directly related to FFR., (Copyright © 2015 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.)

Background: The severity of angiographic diameter stenosis of the jailed side-branch ostium is usually overestimated over the 3-D optical coherence tomography (OCT)-measured actual stenosis. Using 3-D OCT, morphologic changes in the jailed side-branch ostium were evaluated before and after a single stent crossover at coronary bifurcation lesions., Methods: In 109 patients who received a single stent crossover at coronary bifurcation lesions, the minimal lumen area (MLA) before and after intervention and the eccentricity of the jailed side-branch ostium were measured with 3-D OCT. The eccentricity index was defined as the ratio of maximal diameter/minimal diameter of the jailed side-branch ostium. When the eccentricity index was < 1.5, the shape of the jailed side-branch ostium was defined as circular. The MLA of the jailed side-branch ostium was also calculated from the quantitative coronary angiography (QCA) minimal lumen diameter assuming a circular lumen., Results: The 3-D OCT-measured MLA of the jailed side-branch ostium decreased from 2.91 ± 1.65 mm(2) before intervention to 2.37 ± 1.48 mm(2) after intervention (P < 0.01). The QCA-derived MLA also decreased from 2.35 ± 1.71 mm(2) before intervention to 1.68 ± 1.56 mm(2) after intervention (P < 0.01). However, the 3-D OCT-measured MLA was significantly larger than the QCA-derived MLA (P < 0.01). The shape of the jailed side-branch ostium changed from circular to elliptical after the stent implantation (eccentricity index: 1.40 ± 0.33 before intervention; 1.71 ± 0.60 after intervention; P < 0.01)., Conclusions: Compared with QCA measurements, 3-D OCT analysis could be useful to guide decisions regarding additional intervention after stent implantation across coronary bifurcation lesions., (Copyright © 2016 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.)

Aims: We sought to evaluate whether coronary computed tomographic angiography (CCTA) could accurately and reproducibly delineate the lumen and vessel contours of coronary arteries., Methods and Results: 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., Conclusion: 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., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.)

Objective: The influence of high-dose statin therapy on the serial stent healing process has not been fully investigated. Using optical coherence tomography, the effect of high-dose statin therapy on stent strut coverage was evaluated in drug-eluting stent-treated patients., Approach and Results: Sixty patients were randomly assigned to 2 groups according to the statin dose (atorvastatin 40 mg as high-dose statin therapy [n=29] versus pravastatin 20 mg as low-dose statin therapy [n=31]). Serial optical coherence tomographic evaluation post procedure and at the 3-month and 12-month follow-ups was performed in 50 patients with 54 stents (23 atorvastatin-treated patients versus 27 pravastatin-treated patients). The percentage of uncovered struts was defined as the ratio of uncovered struts/total struts. The primary end point was the percentage of uncovered struts at the 12-month follow-up. The secondary end point was the percentage of uncovered struts at the 3-month follow-up and the comparative percentage change (Δ) of uncovered struts at the 3- and 12-month follow-ups between the different dose statin therapies. The percentage of uncovered struts was 7.4% (range, 4.3%-10.4%) in atorvastatin-treated patients versus 10.6% (range, 5.7%-22.6%) in pravastatin-treated patients at the 3-month follow-up (P=0.13) and 1.3% (0.3%-3.8%) versus 2.5% (0.9%-9.7%), respectively, at the 12-month follow-up (P=0.01). The percentage Δ of uncovered struts from 3 to 12 months of follow-up was -7.9±8.5% in atorvastatin-treated patients versus -9.3±12.5% in pravastatin-treated patients (P=0.67)., Conclusions: This study suggested that high-dose statin therapy might provide a beneficial effect for the vascular healing process after drug-eluting stent implantation., (© 2015 American Heart Association, Inc.)

Purpose: To evaluate the impact of pre-procedural coronary plaque composition assessed by virtual histology intravascular ultrasound (VH-IVUS) on late stent malapposition assessed by optical coherence tomography (OCT) following drug-eluting stent (DES) implantation., Materials and Methods: The study population consisted of 121 patients (121 lesions) who underwent both pre-procedural VH-IVUS and follow-up OCT after DES implantation. The association between pre-procedural plaque composition [necrotic core (NC), dense calcium (DC), fibrotic (FT), and fibro-fatty (FF) volumes] assessed by VH-IVUS and late stent malapposition (percent malapposed struts) or strut coverage (percent uncovered struts) assessed by follow-up OCT was evaluated., Results: Pre-procedural absolute total NC, DC, FT, and FF plaque volumes were 22.9±19.0, 7.9±9.6, 63.8±33.8, and 16.5±12.4 mm³, respectively. At 6.3±3.1 months post-intervention, percent malapposed and uncovered struts were 0.8±2.5% and 15.3±16.7%, respectively. Pre-procedural absolute total NC and DC plaque volumes were positively correlated with percent malapposed struts (r=0.44, p<0.001 and r=0.45, p<0.001, respectively), while pre-procedural absolute total FT plaque volume was weakly associated with percent malapposed struts (r=0.220, p=0.015). Pre-procedural absolute total DC plaque volume was the only independent predictor of late stent malapposition on multivariate analysis (β=1.12, p=0.002). There were no significant correlations between pre-intervention plaque composition and percent uncovered struts., Conclusion: Pre-procedural plaque composition was associated with late stent malapposition but not strut coverage after DES implantation. Larger pre-procedural absolute total DC plaque volumes were associated with greater late stent malapposition.

Background: Compared with bare-metal stents, neoatherosclerosis reportedly develops earlier and more frequently after drug-eluting stent (DES) implantation. This study evaluated the incidence, clinical presentation, and predictors of early neoatherosclerosis after DES implantation., Methods: Neointimal characteristics were evaluated in 449 patients (482 lesions) who underwent follow-up optical coherence tomography ≤12 months after DES implantation (median 9.1 months) and displayed a mean neointimal thickness >100 μm. Neoatherosclerosis was defined as neointima with the presence of lipid or calcification., Results: Early neoatherosclerosis, defined as occurrence of neoatherosclerosis within 12 months after DES implantation, was observed in 31 lesions (6.4%). Compared with patients without early neoatherosclerosis, those with early neoatherosclerosis presented with a higher incidence of clinical symptoms (13% vs 57%, respectively; P < .001) and had undergone a higher frequency of target-lesion revascularization (9% vs 55%, respectively; P < .001) at the time of optical coherence tomography follow-up. Multivariate logistic regression analysis showed that independent predictors of early neoatherosclerosis were hypertension (odds ratio 3.20, 95% CI 1.32-7.78, P = .010) and pre-stent low-density lipoprotein cholesterol ≥130 mg/dL at the time of the index procedure (odds ratio 3.89, 95% CI, 1.62-9.36, P = .002)., Conclusions: Early neoatherosclerosis was detected in 6.4% of DES-treated lesions with neointimal thickness >100 μm at a median of 9.1 months after DES implantation. The occurrence of early neoatherosclerosis was significantly associated with presentation of clinical symptoms. Independent predictors of early neoatherosclerosis were hypertension and high pre-stent low-density lipoprotein cholesterol at the time of the index procedure., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Objectives: The aim of this study was to evaluate the extent of neointimal response after the implantation of a second-generation drug-eluting stent, zotarolimus-eluting stent (ZES-ER, Endeavor Resolute) or everolimus-eluting stent (EES, Xience V), using intravascular ultrasound (IVUS) in diabetic patients., Materials and Methods: In all, 154 diabetic patients with de-novo coronary lesions were randomized to be implanted with a ZES-ER or EES, and the angiographic follow-up at 9 months combined with a complete IVUS study was available for 96 patients with 101 lesions., Results: Baseline demographic and lesion parameters were similar in both groups at index percutaneous coronary intervention. On follow-up angiography, in-stent late lumen loss and minimal lumen diameter were not different between the two groups. On IVUS study, neointimal hyperplasia volume [median (interquartile range): ZES-ER vs. EES; 2.25 mm (0.57-6.25) vs. 1.59 mm (0.45-8.37), P=0.615] and in-stent percentage of volume obstruction [median (interquartile range): ZES-ER vs. EES; 1.16% (0.33-3.61) vs. 0.77% (0.29-4.01), P=0.615] showed similar results between the two groups., Conclusion: In diabetic patients, the second-generation drug-eluting stents, ZES-ER and EES, were comparable in inhibiting neointimal proliferation.

Background: Angiographic stenosis of a jailed side-branch ostium is usually observed after a single-stent crossover at coronary bifurcation lesions. However, the stenosis severity is typically overestimated due to the limited information obtained from two-dimensional morphology by angiography. We evaluated the actual stenosis of jailed side-branch ostium using three-dimensional (3D) optical coherence tomography (OCT)., Methods: Using 3D reconstructions of OCT data, we analyzed minimal lumen area (MLA) and eccentricity of the jailed side-branch ostium in 41 patients who were treated with single stent crossover at coronary bifurcation lesions and subsequently underwent serial OCT follow-up., Results: The MLA of jailed side-branch ostium calculated from quantitative coronary angiography (QCA) assuming a circular lumen markedly decreased after stent implantation (1.73±1.22mm(2) pre-intervention to 0.84±0.91mm(2) post-intervention, p<0.001). However, the MLA of jailed side-branch ostium measured at post-intervention by 3D-OCT (2.67±1.75mm(2)) was significantly larger than that measured by QCA (p<0.001). There were no statistically significant changes in MLA of jailed side-branch ostium based on 3D-OCT measurements during the follow-up (2.35±1.50mm(2) at 3-6 months post-intervention; 2.44±1.27mm(2) at 1-2 years post-intervention, p=0.098). The shapes of the jailed side-branch ostium were nearly elliptical (mean eccentricity index: 2.97±1.27 post-intervention; 2.79±1.17 at 3-6 months post-intervention; 2.59±1.02 at 1-2 years post-intervention)., Conclusions: Compared to 3D-OCT measurements, QCA measurements overestimated the jailed side-branch ostial stenosis after single stent crossover due to eccentric morphology from orthogonal projection in coronary angiography. Significant changes in the MLA of jailed side-branch ostium by 3D-OCT were not observed during the follow-up., (Copyright © 2015 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.)

Objectives: 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)., Background: The impact of neointimal characteristics of ISR lesions on periprocedural myocardial injury has not been sufficiently investigated., Methods: 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., Results: 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., Conclusions: 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., (© 2014 Wiley Periodicals, Inc.)

No randomized data exist regarding optical coherence tomography (OCT) evaluation immediately post-procedure and at the 3-month follow-up for platinum-chromium everolimus-eluting stents (PtCr-EES) versus cobalt-chromium everolimus-eluting stents (CoCr-EES). A total of 100 patients were randomly assigned to undergo PtCr-EES (n = 51) or CoCr-EES (n = 49) implantation. OCT was serially evaluated after stent deployment with nominal pressure and immediately post-procedure, and 3-month follow-up. The primary endpoint was the percentage of malapposed strut after nominal pressure and immediately post-procedure. Compared to the CoCr-EES, the PtCr-EES showed a lower tendency of percent malapposed strut at nominal pressure [median value (interquartile range); 4.1 % (0.5-11.7) vs. 7.6 % (2.9-13.7), p = 0.082] and immediately post-procedure [1.2 % (0-3.4) vs. 2.5 % (0.7-5.3), p = 0.051]. The percentage of cross sections with any malapposed struts was significantly lower with PtCr-EES at nominal pressure [15.0 % (5.6-39.0) vs. 23.8 % (18.2-44.4), p = 0.036] and immediately post-procedure [6.5 % (0-15.3) vs. 10.5 % (7.1-20.0), p = 0.026]. At the 3-month follow-up, both PtCr-EES and CoCr-EES showed comparable percentages of malapposed struts (0 vs. 0 %, respectively, p = 0.332) and uncovered struts (5.3 vs. 4.7 %, respectively, p = 0.829). We found a significant correlation between the immediate post-procedural percentage of malapposed struts versus the percentage of uncovered struts (r = 0.430, p < 0.001) at the 3-month follow-up. Compared to the CoCr-EES, the PtCr-EES shows a lower tendency toward a lower percentage of malapposed struts but no significant difference in strut coverage at the 3-month follow-up. The percentage of malapposed struts immediately post-procedure was correlated with strut coverage at the 3-month follow-up.

Background: Despite the enhanced properties of the second-generation drug-eluting stent (DES), its association with neoatherosclerosis has not been sufficiently evaluated. Therefore, we sought to evaluate and compare neoatherosclerosis in second-generation DESs to first-generation DESs., Methods and Results: A total of 212 DES-treated patients with >50% percent neointimal cross-sectional area stenosis were retrospectively enrolled from the Korean multicenter optical coherence tomography (OCT) registry. Within this population, 111 patients had a second-generation DES (40 zotarolimus, 36 everolimus, and 35 biolimus) and 101 patients had a first-generation (65 sirolimus and 36 paclitaxel) DES. Neoatherosclerosis on OCT was defined as neointima formation with the presence of lipids or calcification. OCT-determined neoatherosclerosis was identified in 27.4% (58/212) of all DES-treated lesions. The frequency of neoatherosclerosis increased with the stent age. Stent age was shorter in the second-generation DES group (12.4 months versus 55.4 months, P<0.001), and neoatherosclerosis was less frequently observed in that group (10.8% versus 45.5%, P<0.001). However, after adjusting for cardiovascular risk factors, chronic kidney disease (odds ratio, 4.113; 95% confidence interval, 1.086-15.575; P=0.037), >70 mg/dL of low-density cholesterol at follow-up OCT (odds ratio, 2.532; 95% confidence interval, 1.054-6.084; P=0.038), and stent age (odds ratio, 1.710; 95% confidence interval, 1.403-2.084; P<0.001) were all independent predictors for neoatherosclerosis, whereas the type of DES (first- versus second-generation) was not. Patients with neoatherosclerosis showed a higher rate of acute coronary syndrome at follow-up OCT (19.0% versus 3.9%, respectively, P=0.001)., Conclusions: The second-generation DES is not more protective against neoatherosclerosis compared with the first-generation DES., (© 2015 American Heart Association, Inc.)

We sought to evaluate the temporal course of neointimal hyperplasia (NIH) after drug-eluting stent (DES) implantation, using serial optical coherence tomography (OCT). We identified 89 DES (82 patients) that had at least three consecutive cross-sections with a mean NIH thickness >100 µm on first follow-up OCT. Qualitative and quantitative changes in NIH were then assessed at a second follow-up OCT. NIH regression and progression were defined as a decrease or increase in mean NIH cross-sectional area >0.2 mm2, respectively, between the two studies. Between the first and second OCT there was a decrease in NIH in 29 lesions (32.6%), and an increase in NIH in 37 lesions (41.6%). Compared to patients with neointimal progression, those with regression showed lower levels of high sensitivity C-reactive protein (hsCRP) (p = 0.036) and higher levels of high-density lipoprotein (p = 0.012). Between the first and the second OCT, there were no significant changes in NIH morphologic patterns in 67 (75.3%) of 89 DES. In lesions with NIH regression, the evolution of heterogeneous to homogeneous neointima was observed, while the evolution of heterogeneous or homogeneous to layered neointima or the evolution of heterogeneous, homogeneous, or layered neointima to neoatherosclerosis was detected in lesions with NIH progression (p < 0.001). The hsCRP level at index procedure was significantly associated with neointimal regression in multivariate model (odds ratio 0.891, 95% confidence interval 0.796-0.999, p = 0.048). During late follow-up, OCT shows both NIH progression and regression that are paralleled by qualitative changes indicating increasing stability (in regression) and increasing instability (in progression).

Objectives: This study sought to evaluate the relationship between post-stent strut apposition and follow-up strut coverage using contour plot optical coherence tomographic analysis., Background: Tracking the fate of interested regions of struts at different time points has not been investigated., Methods: Post-intervention and 6-month follow-up optical coherence tomographic evaluations were performed in 82 patients treated with biolimus- (n = 37) or sirolimus-eluting stents (n = 45). Post-stent apposition was classified as embedded, apposed, or malapposed. For volumetric stent evaluation, the post-intervention strut-artery distance and the neointimal thickness at follow-up were measured as a function of the circumferential arc length and longitudinal stent length. Computer-generated contour plots of the strut-artery distance and neointimal thickness were compared., Results: The percentages of embedded and malapposed struts after intervention were 1.8% (Interquartile range [IQR]: 0.6% to 6.2%) and 2.3% (IQR: 0.5% to 5.2%), respectively. The percentages of uncovered and malapposed struts at 6 months were 16.0% (IQR: 7.4% to 33.3%) and 0% (IQR: 0% to 0.7%), respectively. The percentage of uncovered struts at 6 months varied significantly with post-stent strut apposition (0% [IQR: 0% to 11.4%] in embedded, 16.3% [IQR: 8.1% to 31.3%] in apposed, and 26.8% [IQR: 0% to 56.3%] in malapposed, p < 0.001 for all pairwise comparisons). In lesions without tissue prolapse, embedded struts were all covered (100% covered struts) compared with those with tissue prolapse (76.8% covered, p < 0.001)., Conclusions: The optical coherence tomography-guided optimization of stent strut apposition enhances strut coverage at follow-up. This comprehensive method for evaluating strut apposition may provide more useful information to understanding the serial changes in strut coverage. (Neointimal Coverage After Implantation of Biolimus Eluting Stent With Biodegradable Polymer: Optical Coherence Tomographic Assessment According to the Treatment of Dyslipidemia and Hypertension and the Types of Implanted Drug-Eluting Stents; NCT01502904)., (Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

The use of drug-eluting stent (DES) has been associated with incomplete endothelialization and coronary endothelial dysfunction. However, the relationship between endothelial vasomotor function and strut coverage evaluated by optical coherence tomography (OCT) has not been sufficiently assessed. Therefore, we evaluated the relationship between endothelial vasomotor function and the degree of stent strut coverage after DES implantation. Coronary angiography and OCT were performed in 112 patients at the 6-month follow-up after DES implantation. The patients were divided into tertiles according to the degree of strut coverage as was assessed by OCT. Endothelial vasomotor function was evaluated with intracoronary infusion of incremental doses of acetylcholine (Ach; 10(-8)-10(-6) mol/L). Vascular responses at the proximal and distal segments to the stent margin were evaluated by quantitative coronary angiography analysis before and after Ach infusion. The percentage of uncovered struts in tertiles 1-3 was 4.2 ± 3.3, 17.3 ± 4.2 and 44.5 ± 14.4 %, respectively, (p < 0.001). The percentage of maximal vasoconstriction in tertiles 1-3 was 8.3, 9.1 and 8.1 % at proximal segment to the stent margin (p = 0.95), respectively, and 13.9, 11.1 and 14.2 % at distal segment to the stent margin (p = 0.74), respectively. The percentage of uncovered struts was not correlated with the degree of vasomotor function (r = -0.01, p = 0.92 at the proximal segment; r = -0.07, p = 0.47 at the distal segment). The percentage of strut coverage was not associated with the degree of abnormal vasoconstriction in response to intracoronary infusion of Ach 6 months after DES implantation.

Purposes: The serial changes in neointimal tissues were compared between everolimus-eluting stent (EES) and bare-metal stent (BMS) in the porcine coronary artery using optical coherence tomography (OCT)., Methods: Serial (1, 3, and 6 month follow-up after stent implantation) OCT examinations were performed in 15 swine with 15 BMS- and 15 EES-treated lesions in porcine coronary arteries., Results: In BMS-implanted lesions, neointimal volume decreased from 7.3 mm(3) to 6.9 mm(3) and 6.4 mm(3) at 1, 3, and 6 months follow-up without statistical significance (P = 0.369). At the time points of 1, 3, and 6 months, neointimal tissue appearance was mainly a homogeneous pattern (80.0%, 93.3%, and 100%, resp.), while the other pattern was layered. In contrast, in EES-implanted lesions, neointimal volume significantly increased from 4.8 mm(3) to 9.8 mm(3) between 1 and 3 months but significantly decreased to 8.6 mm(3) between 3 and 6 months (P < 0.001). Between 1 and 3 months, the layered pattern of neointimal tissue increased from 26.7% to 66.7% but decreased to 20.0% between 3 and 6 months., Conclusions: EES had a biphasic pattern of neointimal amounts that correlated with changes in neointimal morphology.

Aims: The aims of this study were to compare strut tissue coverage at six-month follow-up after Nobori biolimus-eluting stent (N-BES) versus sirolimus-eluting stent (SES) implantation., Methods and Results: A total of 120 patients with a single stenotic lesion requiring revascularisation were randomly assigned to either N-BES (n=60) or SES (n=60). Baseline optical coherence tomography (OCT) was performed post stent implantation, and follow-up OCT was scheduled at six months. Post-intervention and follow-up OCT analyses were available in 51 (85.0%) and 52 (86.7%) patients, respectively. The primary endpoint was the percentage of uncovered struts at follow-up OCT in all cross-sections with analysis of 0.2 mm longitudinal intervals. In addition, an OCT contour plot analysis was constructed to investigate the distribution patterns of uncovered struts. The percentage of uncovered struts of N-BES was significantly lower versus SES (15.9±12.2% versus 25.1±18.3%, respectively, p=0.003). N-BES showed a greater NIH thickness than SES (median [interquartile range] 52.4 μm [41.9-74.9] versus 42.1 μm [30.6-56.0], p=0.005). Contour plot analyses showed a lower incidence of a diffuse distribution pattern of uncovered struts (46.8% versus 75.0%, respectively, p=0.022)., Conclusions: This randomised OCT study showed that N-BES had a significantly lower percentage of uncovered struts, and less common diffuse distribution pattern of uncovered struts versus SES.

Aims: To use optical coherence tomography (OCT) to evaluate the time course, risk factors, and clinical implication of in-stent neoatherosclerosis., Methods and Results: The neointimal characteristics of 152 lesions, 128 drug-eluting stents (DESs) and 24 bare metal stents (BMSs), with >50% percent cross-sectional area (CSA) neointimal stenosis were evaluated. Neoatherosclerosis was defined as neointima with presence of lipid or calcification. Neoatherosclerosis was observed in 54 lesions (35.5%, 35 DESs and 19 BMSs). Median time to follow-up was 70.7 months in lesions with neoatherosclerosis (longer than lesions without neoatherosclerosis [13.4 months, p<0.001]): 58.7 months in DES-treated lesions and 129.5 months in BMS-treated lesions (p<0.001). The optimal cut-off time to predict neoatherosclerosis in DES-treated lesions was 30 months with a sensitivity of 91.4% and a specificity of 72.0% (area under curve: 0.839, 95% confidence interval: 0.764-0.898, p<0.001). Independent risk factors for neoatherosclerosis were stent age, use of first-generation DES and hypertension. Patients with neoatherosclerosis (versus without neoatherosclerosis) had a higher rate of target lesion revascularisation (92.6% vs. 77.6%, respectively, p=0.018) and stent thrombosis (14.8% vs. 0%, respectively, p<0.001)., Conclusions: Neoatherosclerosis occurred in one-third of stented lesions with >50% percent CSA stenosis of neointima. Late-phase development of neoatherosclerosis might be associated with clinical deterioration of stented lesions.

Background: No randomized studies have been conducted to investigate serial changes in optical coherence tomography (OCT) analyses following implantation of biolimus-A9-eluting stents (BES) and sirolimus-eluting stents (SES)., Methods: A total of 60 patients fulfilling the study criteria were randomly assigned into BES (n=30) and SES (n=30) implantation groups. Serial OCT evaluation at post-procedure, 3- and 12-month follow-up was performed in 46 patients [BES (n=22) and SES (n=24)]. OCT analyses were compared according to the type of stents and the follow-up time intervals. The percentage of uncovered struts was defined as the ratio of uncovered struts to total struts in all cross-sections. The primary endpoint was the percentage change (Δ) of uncovered struts in the 3- and 12-month follow-up samples., Results: The percentage of uncovered struts at the 3-month time period was not significantly different in the BES and SES groups; the median value (interquartile range) was 14.7% (0.0-23.4) versus 8.6% (0.7-21.5) (p=0.98), respectively. However, OCT at the 12-month follow-up showed a significantly lower percentage of uncovered struts [2.6% (0.8-5.6) versus 6.2% (1.7-14.7), (p=0.028), respectively] without significant difference of neointimal thickness. BES showed a greater reduction of percentage Δ of uncovered struts from 3-12 months than that of SES [-17.2±14.5% versus -7.7±16.3%, respectively (p=0.043)]., Conclusions: Both drug-eluting stents showed a high percentage of incomplete strut coverage at 3 months. However, BES showed a significantly lower percentage of uncovered struts at 12 months compared to that of SES. This was achieved by superior strut coverage from 3 to 12 months., (© 2013.)

Intravascular ultrasound (IVUS) offers tomographic images of the coronary artery, helping physicians to refine drug-eluting stent (DES) implantation in angiographically complex lesions. However, controversy exists regarding whether the routine use of IVUS in short-length lesions leads to improved clinical outcomes after DES implantation. Therefore, we evaluated the usefulness of IVUS in predicting major adverse cardiac events (MACE), including cardiovascular death, myocardial infarction, or target vessel revascularization, at 1 year after DES implantation in short-length lesions. The present study was a subanalysis of the REal Safety and Efficacy of a 3-month dual antiplatelet Therapy following Endeavor zotarolimus-eluting stent implantation (RESET) study with different clinical outcome parameters. The study population consisted of 662 patients with IVUS guidance and 912 patients with angiography guidance who underwent DES implantation (stent length ≤24 mm). In the IVUS-guided group, adjuvant postdilation was more frequently performed (43.0% vs 34.6%, p <0.001), and the postintervention minimal lumen diameters were greater (2.88 ± 0.44 mm vs 2.72 ± 0.43 mm, p <0.001). MACE occurred in 15 IVUS-guided (2.3%) and 19 angiographically guided (2.1%) patients (p = 0.872). In a subset of patients with diabetes mellitus (n = 292), the MACE rate was 3.4% (n = 4) and 1.7% (n = 3) in the IVUS- and angiographically guided patients, respectively (p = 0.384). The MACE rate in the IVUS- and angiographically guided patients with acute coronary syndrome (n = 601) was 1.1% (n = 3) and 2.7% (n = 9), respectively (p = 0.194). The clinical benefits of IVUS-guided DES implantation compared with angiographically guided DES implantation in short-length lesions could not be confirmed even in patients with clinically high-risk presentations (acute coronary syndrome and diabetes mellitus). In conclusion, routine IVUS guidance does not provide clinical benefits when performing short-length DES implantation., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Although the presence of uncovered struts may be associated with occurrence of stent thrombosis, the impact of uncovered struts detected routinely by optical coherence tomography (OCT) on subsequent long-term clinical outcomes remains unclear. The objective of this study was to determine the cut-off value of uncovered struts that predicted adverse clinical outcomes after drug eluting stent (DES) implantation. Major safety events (MSEs, a composite occurrence of cardiovascular death, myocardial infarction, and stent thrombosis) were evaluated in 489 DES-treated patients (535 lesions) during the median 851 days after follow-up OCT. MSEs occurred in six patients (four definite stent thrombosis and two sudden cardiac death). The best cut-off value of percentage of uncovered struts for predicting MSE was 5.9 % using the maximal χ(2) method: area under the receiver-operating characteristic curve = 0.779, 95 % confidence interval (CI) = 0.648-0.910, p = 0.019, a sensitivity of 83.3 % and a specificity of 70.3 %. Independent predictors for MSE were post-intervention minimal lumen diameter (odds ratio 0.019, 95 % CI = 0.001-0.513, p = 0.018) and percentage of uncovered struts ≥5.9 % (odds ratio 19.781, 95 % CI = 2.071-188.968, p = 0.010). A greater percentage of uncovered struts (the cut-off value of ≥5.9 % uncovered struts) might be significantly associated with occurrence of MSE after DES implantation.

This study was designed to compare neointimal hyperplasia and peri-stent arterial remodeling after implantation of everolimus-eluting stent (EES) versus sirolimus-eluting stent (SES) using intravascular ultrasound (IVUS). The study population was a subgroup of 278 patients from the EXCELLENT trial, a randomized study comparing EES to SES in de novo coronary artery lesions (total n = 1,443, 3:1 randomization) who underwent post-PCI and 9-month follow-up IVUS evaluation. There were 209 patients in the EES group and 69 in the SES group. Baseline clinical and angiographic characteristics were similar between the two groups except for age and target lesion locations. At 9 months, percent neointimal volume obstruction did not differ between EES and SES (2.6 ± 4.0 % vs. 2.5 ± 4.8 %, p = 0.814). However, the relative change in the vessel (4.3 ± 13.7 % vs. 8.8 ± 18.6 %, p = 0.030) and plaque volume index (4.2 ± 17.4 % vs. 10.5 ± 22.3 %, p = 0.016) of the stented segment from post-intervention to follow-up was significantly less with EES than with SES. In addition, positive peri-stent vascular remodeling defined as an increase in vessel volume index >10 % (27.8 vs. 42.0 %, p = 0.027) and late acquired stent malapposition (LASM, 1.9 vs. 15.9 %, p < 0.001) were observed less frequently with EES than SES. EES and SES were similarly effective in reducing neointimal hyperplasia. However, positive peri-stent vascular remodeling and LASM occurred less frequently with EES than SES.

Background: The presence of uncovered struts overlying side branch is considered to be a potential risk of stent thrombosis. The accuracy in detection of neointimal strut coverage at branch point by optical coherence tomography (OCT) has not been validated in comparison with histology., Methods: A total of 5 stents (3 drug-eluting stents and 2 bare-metal stents) were implanted in the bifurcation segment of normal coronary arteries in 4 domestic swine (weight, 25-40 kg). The animals underwent follow-up OCT at 30 days after stent implantation and were then sacrificed for histologic evaluation. The neointimal coverage of the non-apposed struts over the side branch was assessed by light microscopy. Every millimeter of the stent was specified by the OCT frame rate, and comparisons between OCT and pathologic findings were performed through precise histological-OCT frame matching., Results: OCT images at the side branch corresponded well with histological cross-sections. The tissues covering struts as assessed by OCT contained smooth muscle cells with proteoglycan-collagen matrix, but platelets are attached above the neointima in one of them on histologic examination, suggesting that most of the struts were well healed, with normal neointimal coverage., Conclusion: This study demonstrated the accuracy of OCT for the detection of neointimal coverage of non-apposed struts over the side branch.

There have been no optical coherence tomographic (OCT) data directly comparing the pattern of strut coverage between the 2 second-generation drug-eluting stents in the early period. The aim of this prospective study was to evaluate early strut coverage using optical coherence tomography 3 months after Resolute zotarolimus-eluting stent (ZES-R) or everolimus-eluting stent (EES) implantation in de novo coronary artery lesions. A total of 40 patients who were suitable for the OCT procedure and consented to the study protocol were randomized 1:1 to receive either ZES-R or EES. Among these patients, 35 stented lesions (18 ZES-R, 17 EES) in 34 patients were evaluated by optical coherence tomography immediately and 3 months after stent implantation. Neointimal hyperplasia thickness, percentage of uncovered struts, and the proportion of malapposed struts were measured at 1-mm intervals. An uncovered strut was defined as having a neointimal hyperplasia thickness of 0 μm. At the 3-month OCT evaluation, mean neointimal hyperplasia thickness (ZES-R vs EES 74 ± 41 vs 75 ± 35 μm, p = 0.89) and mean percentage of uncovered struts (ZES-R vs EES 6.2 ± 6.9 vs 4.7 ± 5.1%, p = 0.62) were not significantly different between the groups. The percentage of malapposed struts was also similar between the groups (0.7 ± 2.2% for ZES-R and 0.7 ± 1.7% for EES, p = 0.64). Thrombi were documented in 3 stents (1 [5.6%] in a ZES-R vs 2 [11.8%] in EES, p = 0.60). In conclusion, early stent strut coverage on the basis of serial OCT evaluation was comparable between ZES-R and EES 3 months after stent implantation., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Minimal data exist regarding the use of optical coherence tomography (OCT) to evaluate malapposed strut coverage following implantation of drug-eluting stents (DESs). Follow-up OCT examination after DES implantation was performed in 368 patients with 406 lesions at our institute. We assessed the status of malapposed strut coverage that was identified via OCT in 92 (23 %) lesions. An absence of uncovered struts among malapposed struts was defined as completely covered (CC) malapposition; the presence of uncovered struts was defined as incompletely covered (IC) malapposition. Among the 92 lesions with malapposed DES struts, CC malapposition was detected in 47 lesions (51 %). Compared to lesions with IC malapposition (n = 45, 49 %), lesions with CC malapposition showed a significantly lower percentage of uncovered struts among all the struts (14.9 ± 14.5 vs. 4.4 ± 8.5 %, respectively, p < 0.001) and among the other well-apposed struts without malapposition (12.7 ± 12.8 vs. 4.5 ± 8.7 %, respectively, p = 0.001). The degree of malapposed strut coverage was significantly different according to the type of DES; new-generation DESs such as everolimus- or zotarolimus-eluting stents showed a higher incidence of CC malapposition, compared to first-generation DESs such as sirolimus- or paclitaxel-eluting stents (82 vs. 34 %, respectively, p < 0.001). This study showed the complete coverage in about 50 % of the lesions with malapposed DES struts on follow-up OCT. The degree of malapposed DES strut coverage was strongly affected by the type of implanted DESs.

Objectives: The study evaluated serial quantitative and qualitative changes in vascular responses to drug-eluting stents (DES) using optical coherence tomography (OCT)., Background: Serial changes in stent strut coverage and neointima characteristics in DES-treated lesions have not been sufficiently investigated using OCT., Methods: Serial OCT was performed in 72 patients with 76 DES-treated lesions at 9 months and 2 years after DES implantation (sirolimus-eluting stent, n = 23; paclitaxel-eluting stent, n = 20; zotarolimus-eluting stent, n = 25; everolimus-eluting stent, n = 8). Serial changes in quantitative parameters (neointimal thickness, stent strut coverage, and apposition at each strut) and qualitative characteristics of the neointima were evaluated., Results: Mean neointimal thickness significantly increased from 164 μm to 214 μm between 9 months and 2 years (p < 0.001), and the percentage of uncovered stent struts significantly decreased (from 4.4% to 2.3%, p < 0.001). Completely covered lesions were more frequently observed at 2 years (44.7% vs. 59.2%, p = 0.07). However, the percentage of malapposed struts (0.6% vs. 0.9%, p = 0.24) and incidence of intracoronary thrombi (10.5% vs. 9.2%, p > 0.99) were similar. On qualitative evaluation of neointimal morphology, lipid-laden neointima (27.6% vs. 14.5%, p = 0.009) and thin-cap neoatheroma (13.2% vs. 3.9%, p = 0.07) were more frequently detected at 2-year follow-up compared with 9 months. In matched cross-sectional evaluation, the change of neointimal morphology from homogeneous to heterogeneous or lipid-laden pattern was observed in 23 (30.3%) of 76 lesions. There was a significant increase in percent neointimal hyperplasia cross-sectional area in those lesions., Conclusions: This OCT study suggested that neointimal coverage improved from 9 months to 2 years without significant changes in the incidence of malapposed struts and intracoronary thrombus. Additionally, in-stent neoatherosclerosis including transformation to lipid-laden neointima might progress during extended follow-up periods after DES implantation., (Copyright © 2012 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: Serial changes in strut coverage of drug-eluting stents (DESs), which are placed across side-branch vessels, remain unclear., Methods: The changes in strut coverage of DESs crossing side-branch vessels (size ≥2.0 mm) were serially evaluated by optical coherence tomography (OCT) in 30 patients at 9 months and 2 years after the index DES implantation. DESs were paclitaxel-eluting stents (PESs), sirolimus-eluting stents (SESs), and zotarolimus-eluting stents (ZESs), each in 10 patients. Measured neointimal hyperplasia (NIH) thickness of 0 μm on OCT was defined as an uncovered strut., Results: The percentage of uncovered side-branch struts significantly decreased from 55.7 ± 39.9% to 36.6 ± 32.0% (P<.0001) on serial follow-up: PES, 93.4 ± 10.5% to 67.6 ± 24.2%, P=.018; SES, 47.5 ± 34.4% to 29.6 ± 24.1%, P=.036; and ZES, 26.2 ± 34.8% to 12.4 ± 19.0%, P=.028. Among covered side-branch struts, the overall percentage of struts with NIH thickness more than 30 μm significantly increased from 36.3 ± 37.4% to 51.0 ± 36.0% (P<.0001). However, compared to other DES types, a significant increase in relatively thin NIH (0 to 30 μm) was observed in PESs (1.6 ± 3.4% to 17.4 ± 16.0%; P=.018)., Conclusion: Serial follow-up OCT examination showed a significant decrease in the percentage of uncovered side-branch struts, and the coverage pattern differed with DES type.

Minimal data have been published on the correlation between angiographic late loss (LL) and incomplete neointimal coverage of struts after drug-eluting stent (DES) implantation. Therefore, we evaluated the relationship between angiographic LL and the percentage of uncovered struts on follow-up optical coherence tomography (OCT) images, in all cross-sections of the lesions. From the OCT registry database, 219 lesions without restenosis after DES implantation were divided into tertiles based on angiographic LL: tertile I (LL ≤ 0.26 mm), tertile II (0.26 < LL < 0.59 mm), and tertile III (≥0.59 mm). Lesions with the percentage of uncovered struts in the highest quartile (≥75th percentile; >6.0%) were defined as highly uncovered; in an independent analysis, lesions without any uncovered strut(s) were defined as completely covered. Higher percentages of uncovered struts were observed in tertile I than in both tertile II and III (10.3 ± 12.8% vs. 4.2 ± 7.4% vs. 2.4 ± 5.1%, respectively; P < 0.001 for I vs. II and I vs. III). Angiographic LL correlated significantly with the percentage of uncovered struts on OCT (r = -0.340, P < 0.001). The best cut-off values of angiographic LL to predict highly uncovered and completely covered lesions were 0.29 mm (area under curves [AUC] = 0.723, P < 0.001) and 0.61 mm (AUC = 0.692, P < 0.001), respectively. Angiographic LL inversely and significantly correlated with the percentage of uncovered struts on OCT after DES implantation.

The Resolute zotarolimus-eluting stent (ZES-R) has a thinner stent strut with biocompatible polymer than first generation drug-eluting stents. However, minimal optical coherence tomography (OCT) data exists about vascular responses after ZES-R implantation. This study investigated OCT findings in ZES-R implantation and compared them to those in sirolimus-eluting stent (SES) implantation. A total of 123 lesions (43 ZES-R and 80 SES) in 111 patients were evaluated with OCT at 9 months after stent implantation. Strut apposition, neointimal hyperplasia (NIH) thickness, and stent coverage on each stent strut were evaluated. Mean NIH thickness was significantly greater in ZES-R-treated lesions than in SES-treated lesions (166 ± 73 μm vs. 96 ± 63 μm, respectively, P < 0.001). The percentage of uncovered strut was significantly lower in ZES-R-treated lesions than in SES-treated lesions (4.4 ± 4.8% vs. 10.3 ± 13.2%, respectively, P = 0.05). The percentage of malapposed struts was also significantly lower in ZES-R-treated than in SES-treated lesions (0.1 ± 0.4% vs. 1.5 ± 4.2%, respectively, P = 0.002). Intracoronary thrombus was less frequently detected in ZES-R-treated lesions (4.7% vs. 30.0%, respectively, P = 0.001). ZES-R showed a lower incidence of uncovered or malapposed stent struts and intracoronary thrombus than SES at 9-month follow-up OCT examination. Compared with SES, ZES-R may elicit more favorable vascular responses at the expense of an increased neointimal proliferation.

Purpose: Accurate evaluation of side branch (SB) ostium could be critical to the treatment of bifurcation lesions. We compared measured and calculated values of side branch ostial length (SBOL) in coronary bifurcation lesions with intravascular ultrasound (IVUS)., Materials and Methods: Pre-intervention and post-intervention IVUS was performed in 113 patients who underwent stent implantation of bifurcation lesions. For the IVUS longitudinal reconstruction of the bifurcation lesions, SBOL, SB diameter, and the angle between the distal portion of the main vessel (MV) and SB were directly measured. In addition, SBOL was calculated as: SB diameter/ sin (angle between distal MV and SB). The relationship between measured and calculated SBOL was then evaluated., Results: The angled between the distal MV and SB were 57.3±12.4° at pre-intervention and 59.4±12.6° at post-intervention. The mean measured and calculated SBOL values were 2.91±0.86 mm and 3.06±0.77 mm at pre-intervention and 2.79±0.82 mm and 2.92±0.69 mm at post-intervention, respectively. Differences between measured and calculated SBOL were 0.15±0.44 mm at pre-intervention and 0.13±0.41 mm at post-intervention. We found that calculated SBOL was correlated with measured SBOL (pre-intervention r=0.863, p<0.001; post-intervention r=0.868, p<0.001)., Conclusion: There was a good correlation between measured and calculated SBOLs of the bifurcation lesions in IVUS longitudinal reconstruction. SBOL in the bifurcation lesions can therefore be estimated using the SB diameter and the angle between distal MV and SB.

Background: Using optical coherence tomography (OCT), we evaluated the relationship between malapposed and uncovered struts following implantation of drug-eluting stents (DESs)., Methods: A total of 271 patients with 306 lesions who underwent DES implantation and follow-up OCT were included in the study. The lesions were grouped based on the presence of malapposition and then by the median value of the percentage of malapposed struts (1.3%) to produce 3 groups: lesions without malapposition (group I, n = 232) and those with percentage of malapposed struts <1.3% (group II, n = 37) or ≥1.3% (group III, n = 37). Percentages of malapposed and uncovered struts were calculated as percent ratio of malapposed or uncovered to total struts in the defined cross-sections, respectively. We compared percentage of uncovered struts in all analyzable struts and in the residual struts without malapposed segments among the 3 groups., Results: Group III showed a significantly larger percentage of uncovered struts among all the struts (group I, 3.7 ± 6.4 vs. II, 5.5 ± 5.6 vs. III, 17.6 ± 15.9%, P < 0.001) and among residual struts without malapposed segments (3.7 ± 6.4 vs. 5.2 ± 5.7 vs. 15.0 ± 14.4%, respectively, P < 0.001). There was a significant correlation between malapposed and uncovered struts in group III (r = 0.393, P = 0.016), but not in group II (r =-0.007, P = 0.965) among residual struts without malapposed segments., Conclusion: The percentage of uncovered DES struts was quite different depending on the presence and extent of malapposed struts., (©2012, Wiley Periodicals, Inc.)

There have been little data regarding major determinants for the uncovered stent struts after drug-eluting stent (DES) implantation on optical coherence tomography (OCT). We investigated the major determinants of incomplete neointimal coverage of DES struts on OCT after implantation in a large cohort of patients. A total of 261 patients with 279 lesions who were treated with various DESs were selected from the OCT registry database. The lesions were divided into two groups based on the ratio of uncovered struts to total struts in all OCT cross-sections; an uncovered group (highest quartile with % uncovered struts ≥5.4%, n = 70), and covered group (the remaining lower quartiles with % uncovered struts <5.4%, n = 209). The uncovered group was more likely to have complex lesions, smaller reference vessel and stent diameter, and longer stent, more use of sirolimus-eluting stents, and less use of zotarolimus-eluting stents compared with the covered group. Of these variables, the most significant determinant of uncovered stent struts was DES type (odds ratio [OR] = 2.75, 95% confidence interval [CI] = 1.94-3.89, P < 0.001). The use of sirolimus-eluting stents (OR = 2.44, 95% CI, 1.15-5.47, P = 0.023) and zotarolimus-eluting stents (OR = 0.02, 95% CI = 0.01-0.25, P = 0.002) were the only significant risk and protective factors for uncovered stent struts, respectively. This study demonstrated that DES type might be associated with the most important determinants of uncovered struts compared to any other clinical or angiographic factor.