Optical coherence tomographic comparison of neointimal coverage between sirolimus- and resolute zotarolimus-eluting stents at 9 months after stent 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?相似文献   

Stent detection with very thick tissue coverage in intravascular OCT

Coronary stenting or percutaneous coronary intervention (PCI) is widely used to treat coronary artery disease. Improper deployment of stents may lead to post-PCI complication, in-stent restenosis, stent fracture and stent thrombosis. Intravascular optical coherence tomography (OCT) with micron-scale resolution provides accurate in vivo assessment of stent apposition/malapposition and neointima coverage. However, manual stent analysis is labor intensive and time consuming. Existing automated methods with intravascular OCT mainly focused on stent struts with thin tissue coverage. We developed a deep learning method to automatically analyze stents with both thin (≤0.3mm) and very thick tissue coverage (>0.3mm), and an algorithm to accurately analyze stent area for vessels with multiple stents. 25203 images from 56 OCT pullbacks and 41 patients were analyzed. Three-fold cross-validation demonstrated that the algorithm achieved a precision of 0.932±0.009 and a sensitivity of 0.939±0.007 for stents with ≤0.3mm tissue coverage, and a precision of 0.856±0.019 and a sensitivity of 0.874±0.011 for stents with >0.3mm tissue coverage. The correlation between the automatically computed and manually measured stent area is 0.954 (p<0.0001) for vessels with a single stent, and is 0.918 (p<0.0001) for vessels implanted with multiple stents. The proposed method can accurately detect stent struts with very thick tissue coverage and analyze stent area in vessels implanted with multiple stents, and can effectively facilitate the evaluation of stent implantation and post-stent tissue coverage.     

Very early tissue coverage after drug-eluting stent implantation: an optical coherence tomography study

The aim of this study was to evaluate neointimal coverage in the very early phase after second-generation drug-eluting stent (DES) implantation using optical coherence tomography (OCT). Patients who underwent staged percutaneous coronary intervention within 30 days after DES implantation were enrolled. OCT was performed to observe DES previously implanted. The median time interval from implantation to OCT examination was 21.5 days. A total of 10,625 struts of 54 stents (52 everolimus-eluting stents and 2 zotarolimus-eluting stents) in 42 lesions were analyzed. Strut tissue coverage was observed in 71.1?±?19.2?% of the struts, malapposed struts in 2.56?±?3.37?%, strut tissue coverage at the side branch orifice in 10.6?±?17.2?%, and struts with protrusion in 0.95?±?3.46?%. Mean tissue thickness on the covered struts was 39.8?±?14.2 µm. The percentage of stent coverage was significantly lower in the overlapping segments than in the non-overlapping segments (48.4?±?17.5?% vs. 74.4?±?20.2?%, P?<?0.05). Most of the stent struts were covered by tissue within 30 days after second-generation DES implantation. However, the percentage of strut coverage was lower in the overlapping segments than in the non-overlapping segments, suggesting that very early interruption of dual antiplatelet therapy might result in increased risk of stent thrombosis, even in second-generation DES.     

How Do OCT and IVUS Compare to Histology in Coronary Atherosclerosis and Stenting?

Recent advances in intra-coronary imaging modalities have enabled us to evaluate precise plaque morphologies and vascular response to coronary stents in vivo. Superior resolution of optical coherence tomography (OCT) allows the measurement of fibrous cap thickness and detection of macrophage accumulation, both of which are critical to identify vulnerable plaques. Poor penetration of OCT however limits the assessment of plaque volume and vessel remodeling, while intravascular ultrasound (IVUS) is capable of evaluating these parameters. Caution must be exercised when interpreting IVUS-based tissue characterization because this technology lacks sufficient resolution to evaluate plaque composition. In stented arteries, OCT has the ability to detect uncovered struts and abnormal neointimal tissues including fibrin deposition, inflammation (hypersensitivity), and neoatherosclerosis, especially following drug-eluting stent placement. These findings suggest a potential clinical benefit of OCT to assess the risk of future adverse cardiac events; at the same time understanding the limitation of this technology is also important.     

Optical Coherence Tomography: Potential Clinical Applications

Optical coherence tomography (OCT) is a novel intravascular imaging modality using near-infrared light. By OCT it is possible to obtain high-resolution cross-sectional images of the vascular wall structure and assess the acute and long-term effects of percutaneous coronary intervention. For the time being OCT has been mainly used in research providing new insights into the pathophysiology of the atheromatic plaque and of the vascular response to stenting, however, it seems that there is potential for clinical application of OCT in various fields, such as pre-interventional evaluation of coronary arteries, procedural guidance in coronary interventions, and follow-up assessment of vascular healing after stent implantation. This review will focus on the potential and advantages of OCT in the clinical practice of a catheterization laboratory.     

In vivo volumetric analysis of coronary stent using optical coherence tomography with a novel balloon occlusion-flushing catheter: a comparison with intravascular ultrasound

Optical coherence tomography (OCT) is limited as an intravascular imaging tool because of interference with blood. This study tested a new balloon occlusion-flushing catheter for OCT scanning of stented coronary arteries and compared stent measurements between OCT and intravascular ultrasound (IVUS). Motorized pullback with OCT and IVUS was examined in coronary stents deployed in swine. Quantitative measurements were obtained and compared between both groups. In addition, stent strut thickness was compared among OCT, IVUS and actual measurement. The occlusion catheter successfully provided motorized pullback OCT images in the stented coronary arteries without any complications. There were no differences in calculated lumen volume. However, stent volumes were significantly smaller with OCT than with IVUS (p < 0.05). OCT significantly underestimated the stent strut thickness compared with the actual measurement. Although OCT underestimates the stent strut thickness, motorized pullback OCT imaging with the occlusion catheter can provide appropriate in-stent images in the porcine coronary arteries.     

Ultrasound and light: friend or foe? On the role of intravascular ultrasound in the era of optical coherence tomography

More than 20 years after its introduction, intravascular ultrasound (IVUS) has outlived many other intracoronary techniques. IVUS was useful to solve many interventional problems and assisted us in understanding the dynamics of atherosclerosis. It serves as an established imaging endpoint in large progression-regression trial and as an important workhorse in many catheterization laboratories. Nowadays, increasingly complex lesions are treated with drug-eluting stents. The application of IVUS during such interventions can be very useful. Recently, optical coherence tomography (OCT), a light-based imaging technique, has entered the clinical arena. The “omnipresence” of OCT during scientific sessions and live courses with PCI may raise in many the question: Does IVUS have a future in the “era of OCT”? Three review articles, highlighted by this editorial, demonstrate the broad spectrum of current IVUS applications and underline the significant role of IVUS during the last two decades. OCT, the much younger technique, still has to prove its value. Yet OCT is likely to take over some of the current indications of IVUS as a research tool. In addition, OCT is currently gaining clinical significance for stent optimization during complex interventional procedures. Nevertheless, there is little doubt that IVUS still has a major role in studies on coronary atherosclerosis and for guidance of coronary stenting. Thus, ultrasound and light—are they friend or foe? In fact, both methods are good in their own rights. They are complementary rather than competitive. Moreover, in combination, at least for certain indications, they could be even better.     

Optical coherence tomography

Optical coherence tomography (OCT) with micron-scale resolution has become a key intracoronary imaging modality in vivo, providing insights not only into mechanisms of atherosclerotic coronary artery disease, but also into the understanding of vascular response following stent implantation. Although the time-domain OCT system has some technical limitations to acquire images, the recently developed frequency-domain OCT with faster pullback speeds has simplified the procedural requirements with elimination of an occlusion balloon. This article outlines the current and future developments in OCT technology for clinical use and research.     

Favorable neointimal coverage in everolimus-eluting stent at 9 months after stent implantation: comparison with sirolimus-eluting stent using optical coherence tomography

Recent studies reported favorable angiographic and clinical outcomes after everolimus-eluting stent (EES) implantation. However, there were no studies to assess vascular responses after EES implantation using optical coherence tomography (OCT). Therefore, the OCT findings in EES were investigated and compared with those in sirolimus-eluting stent (SES). Follow-up OCT studies were performed in 110 lesions (40 EES and 70 SES) of 104 patients at 9 months after stent implantation. The strut apposition, neointimal hyperplasia (NIH) thickness and stent coverage on each stent struts were evaluated. The mean NIH thickness was significantly greater in EES-treated lesions than in SES-treated lesions (115 ± 52 μm vs. 89 ± 58 μm, P = 0.001, respectively). The percentage of uncovered strut was significantly smaller in EES-treated lesions than in SES-treated lesions (4.4 ± 4.7% vs. 10.5 ± 12.7%, P = 0.016, respectively). There was no significant difference in the percentage of malapposed strut between the two groups (0.4 ± 0.8% in EES vs. 1.7 ±  4.5% in SES, P = 0.344). The incidence of intracoronary thrombus was significantly lower in EES-treated lesions than in SES-treated lesions (5.0% vs. 34.3%, P < 0.001, respectively). EES showed a significantly lower incidence of uncovered stent struts and intracoronary thrombus than SES in 9-month follow-up OCT examination. Compared to SES, EES might have more favorable vascular responses after stent implantation.     

光学相干断层成像对冠状动脉支架植入后高压球囊后扩张的指导作用

目的 评价光学相干断层成像(OCT)在冠状动脉支架植入后高压球囊后扩张的作用.方法 回顾性分析2007年7月至2009年7月连续在本研究所住院并行冠状动脉介入治疗的冠心痛患者29例,年龄40～77岁,平均(59.2±4.5)岁.按标准方法行冠状动脉造影术及支架植入术,分别在支架命名压扩张和高压球囊后扩张后行OCT检查,分析支架小梁贴壁情况和内膜脱垂及微小夹层的发生情况.结果 29例患者均顺利完成OCT检查,围手术期内无心绞痛和心衰并发症的发生.高压球囊后扩张后支架小梁与血管壁的距离(94.00±22.42)μm明显短于支架命名压扩张后的距离(137.38±26.80)μm,差异有统计学意义(P<0.01).高压后扩张后内膜脱垂和微小夹层的发生(分别为14处和0处)明显少于支架命名压扩张后内膜脱垂和微小夹层的发生(分别为32处和5处),两者差异均有统计学意义(P<0.05).结论 OCT时支架植入术后行高压球囊后扩张有一定的指导作用.     

Disruption of bioresorbable vascular scaffold struts due to loss of radial integrity: insights from optical coherence tomography

Strut disruption of bioresorbable vascular scaffold is a known potential concern, although uncommon when adequate lesion preparation is achieved and nominal size of the scaffold is respected. It is usually difficult to detect with angiography and/or intravascular ultrasound. Three-dimensional reconstructions of optical coherence tomography facilitates understanding of complex luminal anatomy and configuration of stent struts, providing evaluation of stent integrity immediately after deployment and therefore optimization of the complex revascularization procedure. The present article reports a case where this image modality enabled successful use of a drug-eluting stent inside a bioresorbable vascular scaffold to restore the luminal integrity, jeopardized by struts disruption. This case highlights the need to better characterize coronary atherosclerotic disease complexity before considering bioresorbable vascular scaffold implantation. Optical coherence tomography imaging could be a useful tool for accurate selection of the most suitable lesions for bioresorbable stents and to guide the revascularization process, so that in the event of stent fracture it may be detected and managed in a timely fashion.     

Major determinants for the uncovered stent struts on optical coherence tomography after drug-eluting stent implantation

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.     

Assessment of drug-eluting stents and bioresorbable stents by grayscale IVUS and IVUS-based imaging modalities

Grayscale IVUS and IVUS-based imaging modalities during the last years have become useful in the assessment not only of drug eluting stent, but also of new bioresorbable vascular scaffolds. Although IVUS resolution is not sufficient for determining stent coverage (optical coherence tomography is the gold standard), serial IVUS can measure intimal hyperplasia, assess acute and late incomplete stent apposition, detect the presence and persistence of edge dissections, study edge effects and look for causes of restenosis and thrombosis. In addition other IVUS-based imaging modalities, such as IVUS-VH, iMAP or palpography, can be used to study the serial compositional and mechanical changes of the plaque behind stent struts and also to follow the bioresorption of the new bioresorbable scaffolds, analyzing the backscattering signal coming from the polymeric struts. This review details and evaluates grayscale IVUS and IVUS-based techniques findings in clinical trials, highlighting the usefulness of these imaging modalities in the study of drug eluting stents and bioresorbable vascular scaffold.     

Serial changes of minimal stent malapposition not detected by intravascular ultrasound: follow-up optical coherence tomography study

Morphologic changes of small-sized post-stent malapposition have not been sufficiently evaluated. We investigated serial changes of minimal post-stent malapposition with a follow-up optical coherence tomography (OCT) study. Post-stent OCT and intravascular ultrasound (IVUS) and follow-up OCT were performed in 26 patients with minimal post-stent malapposition. Serial changes of number and percent of malapposition struts, and mean extra-stent malapposition area were measured in OCT analysis. Zotarolimus-eluting stent (ZES), sirolimus-eluting stent (SES), and paclitaxel-eluting stent (PES) were deployed in 17, 7 and 2 patients, respectively. Mean durations of the follow-up OCT study were 5.7 ± 3.0 months. The minimal post-stent malapposition cannot be detected by the IVUS, but be visualized with an OCT examination. According to different drug-eluting stents, malapposed stent struts were defined as the struts with detachment from the vessel wall ≥160 μm for SES, ≥130 μm for PES, and ≥110 μm for ZES. The percent of malapposition struts significantly decreased from 12.2 ± 11.0% post-stent to 1.0 ± 2.2% follow-up (P < 0.001). There was a significant decrease in the mean extra-stent malapposition area from 0.35 ± 0.16 mm² post-stent to 0.04 ± 0.11 mm² follow-up (P < 0.001). Complete disappearance of stent malapposition was also observed in 22 (85%) patients. In conclusion, minimal stent malapposition which is not detectable by IVUS may disappear or decrease in follow-up OCT evaluation.     

IVUS与CAG在指导冠心病冠状动脉支架置入术中的应用效果比较

目的比较血管内超声(IVUS)与冠状动脉造影(CAG)在指导冠心病冠状动脉支架置入术中的应用效果。方法选取2016年5月至2018年5月我院收治的90例冠心病患者为研究对象,所有患者均行冠状动脉支架置入术治疗,根据随机数字表法将受试者分为对照组和研究组,每组45例。对照组与研究组患者分别在CAG与冠脉IVUS指导下行冠状动脉支架置入术,比较两组的治疗效果。结果手术前,两组患者的MID、PB及DS比较,差异没有统计学意义(P>0.05);手术后,两组患者的MID、PB及DS均明显改善,且研究组显著优于对照组,差异具有统计学意义(P<0.05)。研究组患者支架置入率、达标率以及扩张率均显著高于对照组,差异具有统计学意义(P<0.05)。研究组患者不良心血管事件总发生率及冠状动脉再狭窄发生率均低于对照组,差异具有统计学意义(P<0.05)。结论IVUS指导下冠状动脉支架置入术可有效改善冠脉血流,提高支架置入效果,且不良心血管事件发生率较低,效果安全可靠,在冠状动脉支架置入术中具有较高的应用价值。     

血管内超声波法指导及评价冠状动脉支架置入的研究

目的:探讨血管内超声波法(IVUS)在指导及评价高压球囊扩张支架置入术中的作用。方法:对2002年1月~2002年12月收治的50例58处冠状动脉(冠脉)病变行支架置入术时进行冠脉造影(CAG)及IVUS检查,IVUS指导选择支架的适应证及支架的大小,当达到CAG理想的支架置入标准时,置入支架并应用IVUS进行评价,观察支架是否充分扩张,血管扩张未达到IVUS的理想标准者再次行高压球囊扩张。结果:支架置入后仅35处(60.3%)符合IVUS理想支架置入标准,23处(39.7%)支架未达到IVUS理想置入标准,再次经高压球囊扩张后全血管面积(VA)及最小血管内膜腔面积(MLA)明显增加,斑块面积(PA)减小,病变均达到CAG理想的支架置入标准。结论:采用高压球囊扩张支架置入术,并不能使支架完全达到理想的扩张状态,IVUS指导下的高压球囊扩张可进一步改善支架置入效果,是目前指导及评价支架置入效果的最佳手段。     

Intracoronary Optical Frequency Domain Imaging for Identifying Stent-Related Complications

Percutaneous coronary intervention is the most common treatment of coronary artery disease with the majority of cases undergoing stent implantation. Furthermore, adequate stent deployment is of primary importance to avoid late stent thrombosis and achieve a favorable clinical outcome. Optical coherence tomography (OCT) is a new imaging modality that utilizes advanced photonics and fiberoptics to obtain intravascular images on a microscopic scale. Today, many new drug-eluting stents (DES) are now undergoing clinical trials. Moreover, the intricacies of stent design, local pharmacology, tissue biology, and rheology preclude an intuitive understanding of usability of DES. After stent implantation, assessment should include both the acute and chronic stent/vessel-related changes which include stent malapposition, tissue prolapse, edge dissections, and thrombus formation. OCT plays an indispensable part in determining mechanistic information on the relevance of these phenomena among each DES that cannot be covered by several other modalities.     

Rationale and design: Impact of intravascular ultrasound guidance on long-term clinical outcomes of everolimus-eluting stents in long coronary lesions

BackgroundAlthough the use of drug-eluting stents (DESs) in patients with coronary artery disease has contributed to a significant reduction in in-stent restenosis and repeat revascularization, treating diffuse long lesions using DESs remains challenging due to the high rates of in-stent restenosis and stent thrombosis. Intravascular ultrasound (IVUS) provides tomographic images of coronary vascular structure and is useful for evaluating lesion morphology and stent optimization during percutaneous coronary intervention. However, it remains controversial whether IVUS guidance in DES implantation for long coronary lesions could reduce adverse clinical outcomes.HypothesisWe hypothesize that the long-term clinical outcomes of IVUS-guided DES implantation would be superior to those of angiography-guided DES implantation in a subset of patients with long coronary lesions.Study designThis study is a randomized, prospective, multi-center trial comparing the long-term clinical outcomes of IVUS-guided and angiography-guided everolimus-eluting stent implantation in patients with long coronary lesions (implanted stent ≥ 28 mm in length). The primary end point is a composite of major adverse cardiac events, including cardiac death, target lesion-related myocardial infarction, or target lesion revascularization at 1 year following intervention. A total of 1,400 patients will be required to be enrolled according to sample size calculations.ConclusionThis study will test the hypothesis that IVUS guidance improves long-term clinical outcomes in patients treated with everolimus-eluting stents for long coronary lesions compared with angiographic guidance.