Evaluation neointimal coverage in patients with coronary artery aneurysm formation after drug-eluting stent implantation by optical coherence tomography

The neointimal coverage in patients with coronary artery aneurysms (CAA) formation after drug eluting stent (DES) implantation is not clear. Total of 175 patients who had been implanted DES were identified. Patients were divided into the CAA group (n = 31) and non-CAA group (n = 144) based on the results of the coronary angiography. The cardiac events including angina and acute myocardial infarction were noted, in addition, the neointimal thickness and the frequence of strut malapposition and strut uncoverage were noted. A greater proportion of incomplete neointimal coverage (17.17 vs. 1.9 %, P < 0.001) and malapposition struts (18.2 vs. 1.38%, P < 0.001) were observed in the CAA group. 8 patients in CAA group underwent OCT examination twice in the period of follow-up. The proportion of incomplete neointimal coverage increased significantly as compared the second OCT results with the first examination (18.45 vs. 2.66 %, P < 0.001). Hyperplasia neointimal desquamated from struts and acquired struts incomplete neointimal coverage were detected. Patients with CAA had a higher frequency of cardiac events including angina pectoris (25.81 vs. 6.25 %, P = 0.001) and acute myocardial infarction (9.68 vs. 0.13 %, P = 0.002) and thrombosis (16.13 vs. 0.69 %, P < 0.001). The longitudinal length of CAA in cardiac event group was significantly longer than no cardiac event group (20.0 ± 9.07 vs. 12.05 ± 5.38 mm, P = 0.005). CAA formation after DES implantation frequently associated with cardiac events as a result of stent malapposition and incomplete neointimal coverage. Acquired incomplete neointimal coverage associated with CAA formation.     

Relationship between endothelial vasomotor function and strut coverage after implantation of drug-eluting stent assessed by optical coherence tomography

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.     

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.     

Optical coherence tomography findings of very late stent thrombosis after drug-eluting stent implantation

Previous optical coherence tomography (OCT) studies in patients with drug-eluting stents (DESs)-related very late stent thrombosis (VLST) were scarce. Therefore, we investigated OCT findings of VLST after implantation of DESs. Using OCT, we analyzed the status of stent struts and neointimal characteristics in 18?patients who developed VLST after DES implantation. These results were compared to those in 57?patients with neointimal hyperplasia causing?>40% diameter stenosis. Lipid-laden neointima was defined as a region with marked signal attenuation and a diffuse border. Four (22.2%) of 18 patients with VLST had ruptured and lipid-laden neointima inside DESs without uncovered or malapposed stent struts. In the remaining 14 patients who developed VLST without neointimal rupture, uncovered and malapposed struts were observed in nine and seven patients, respectively, and lipid-laden neointima in four patients. Lipid-laden neointima was more frequently observed in four patients with neointimal rupture than in 14 patients without neointimal rupture (100% vs. 28.6%, respectively, P?=?0.023). Of 57 patients with neointimal hyperplasia, eight (14.0%) had lipid-laden neointima. Time to OCT study after DES implantation was significantly longer in the eight patients with lipid-laden neointima than in 49 patients without lipid-laden neointima (45.5?±?17.7?months vs. 11.7?±?7.2?months, respectively, P?<?0.001). Lipid-laden neointima was detected in some patients with neointimal hyperplasia?>?1?year after DES implantation. In addition to uncovered or malapposed struts, rupture of lipid-laden neointima inside DESs was identified in some patients with DES-related VLST.     

Correlation of angiographic late loss with neointimal coverage of drug-eluting stent struts on follow-up optical coherence tomography

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?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?相似文献   

Differences between first-generation and second-generation drug-eluting stent regarding in-stent neoatherosclerosis characteristics: an optical coherence tomography analysis

We compared first-generation and second-generation drug-eluting stent (DES) with respect to neoatherosclerosis using optical coherence tomography or optical frequency domain imaging. In-stent restenoses in 102 first-generation and 114 second-generation DES were retrospectively assessed. Neoatherosclerosis, which was defined as the presence of lipid-laden neointima or calcification inside a stent, was observed in 33 (27.2%) and 31 (32.4%) lesions in the first-generation and second-generation DES respectively. In the first-generation DES group, the lipid length was significantly longer (5.5?±?3.8 vs. 3.1?±?2.1 mm, P?=?0.0007), the lipid arc was significantly larger (324?±?70° vs. 250?±?94°, P?=?0.002), the prevalence of a 360° lipid arc was significantly greater (58 vs. 31%, P?=?0.03), and the fibrous cap was significantly thinner (153?±?85 vs. 211?±?95 µm, P?=?0.02) compared with those in the second-generation DES group. These differences remained significant after adjusting for the age of the stent (lipid length: P?<?0.001; lipid arc: P?=?0.019; and fibrous cap thickness: P?<?0.001). The proliferation course and stability of neoatherosclerosis over time might be superior in second-generation DES.     

Comparison of in-stent neoatherosclerosis and tissue characteristics between early and late in-stent restenosis in second-generation drug-eluting stents: an optical coherence tomography study

Optical frequency domain imaging (OFDI) was utilized to compare the prevalence of neoatherosclerosis (NA) and morphological characteristics of the neointimal tissue in second generation drug eluting stent (G2-DES)-treated lesions between early (<1 year, E-ISR) and late (>1 year, L-ISR) in-stent restenotic phases. Data comparing NA and in vivo tissue characteristics between early and late in-stent restenosis (ISR) after implantation of G2-DES is limited. An OFDI analysis was performed in 50 G2-DESs {35 everolimus-eluting stent [22 cobalt-chromium (CoCr), 13 platinum-chromium (PtCr)], and 15 biolimus-eluting stent [BES]} ISR lesions (46 consecutive patients) undergoing target lesion revascularization, classified as E-ISR (n?=?22 lesion) and L-ISR (n?=?28 lesion). NA, defined as a neointima formation containing lipids or calcification was observed in fewer than half (24/50) of all ISR lesions with no significant difference between E-ISR and L-ISR lesions (50 vs. 46.4%, p?=?0.8). There were also no significant differences in the morphological appearance and tissue characteristics between E-ISR and L-ISR lesions. ISR was more likely to occur earlier [median 8.6 (8.3–8.9) months] after PtCr-EES implantations (12 lesions vs. 1, p < 0.001), while 3/4 of the BES ISR lesions and more than 2/3 of the CoCr-EES ISR lesions were observed after 1 year of implantation [median 21.3 (20.7–27.5) months, p < 0.001]. Acknowledging some limitations, our observations may suggest that the prevalence of neoatherosclerosis and the morphological appearance, and tissue characteristics of G2-DESs restenotic lesions are similar between the early and late restenotic phases. Certain platforms (PtCr-EESs) may have preferentially presented with early ISR.     

Very early neointimal coverage of new biodegradable polymer drug-eluting stent compared with durable polymer everolimus-eluting stent evaluated by optical frequency domain imaging

Polymeric component is associated with the increased risk of delayed vessel healing and stent endothelialization. We aimed to clarify neointimal coverage within 1 month after implantation of the new-generation abluminal biodegradable polymer (BP) drug-eluting stent (DES) compared with the second-generation durable polymer (DP) everolimus-eluting stent (EES). Between November 2015 and October 2016, 32 BP-DES and 25 DP-EES were evaluated by optical frequency domain imaging (OFDI) within 1 month after the procedure. The average interval to follow-up OFDI was not significantly different between the groups (16.3?±?7.7 days in BP-DES vs. 15.4?±?7.4 days in DP-EES, P?=?0.75). Neointimal coverage was significantly superior in BP-DES in both apposed and malapposed strut (apposed: 53.9% in BP-DES vs. 28.0% in DP-EES, P?<?0.001; malapposed: 22.9% in BP-DES vs. 7.5% in DP-EES, P?=?0.001). When the follow-up period was divided into <?2 and >?2 weeks, neointimal coverage was also significantly superior in BP-DES (<?2 weeks: 47.7% in BP-DES vs. 19.2% in DP-EES, P?<?0.001; > 2 weeks: 60.1% in BP-DES vs. 37.4% in DP-EES, P?=?0.001). The new-generation BP-DES showed excellent early neointimal coverage compared with the second-generation DP-EES in both apposed and malapposed struts.     

Reproducibility of qualitative assessment of stent struts coverage by optical coherence tomography

Assessment of stent strut coverage by optical coherence tomography (OCT) is not standardized. The methodology most commonly used is based on a visual binary qualitative assessment (strut covered or not). However, the influence of magnification (zoom setting) to the inter- and intra-observer agreements has not yet been evaluated. Aim of our study was therefore to evaluate the agreements of this approach, taking into account various zoom settings. 126 struts from 10 selected frames were independently evaluated by four observers using a stepwise approach increasing the zoom setting as following: (1) full view of the lumen (FV), (2) half view of the lumen (HV) and (3) a quarter view of the lumen (QV). Intra- and inter-observer agreements (κ) were assessed. The rate of uncoverage was determined for each strut as the number of times it was defined as uncovered divided by the total number of observations (maximum 12 = 3 zoom settings × 4 analysts) and expressed as percentage. The inter-observer κ values (mean [range]) were 0.32 [0.07–0.63], 0.40 [0.18–0.69] and 0.33 [0.09–0.6], within FV, HV and QV respectively. The intra-observer κ values were 0.60 [0.50–0.70], 0.75 [0.75–0.76] and 0.60 [0.50–0.70], within FV, HV and QV respectively. By increasing zoom setting the κ value of intra-observer agreement was 0.74 [0.58–0.83] (from FV to HV), 0.70 [0.56–0.83] (from HV to QV) and 0.70 [0.37–0.86] (from FV to QV). Overall, the rate of uncoverage was 15.5% [8.3–100%]. The OCT qualitative evaluation of strut coverage has wide inter and intra-observer agreements and is dependent of the zoom setting used during the analysis. A more reproducible approach would be needed to eventually increase the probability to link uncovered struts with clinical events.     

New insight to estimate under-expansion after stent implantation on bifurcation lesions using optical coherence tomography

Optical coherence tomography (OCT) allows full volumetric segmentation of the lumen. However, for the estimation of stent under-expansion we still rely on the conventional method (CM) of single cross-sectional narrowing compared with reference vessel, likely masking true lesion significance, especially for bifurcations and tapered vessels. We, therefore, suggest a novel concept of volumetric metrics that take into account vessel tapering and major side branches and is capable of obtaining ideal lumen area for every frame of the stent by OCT. Forty-four patients with bifurcation lesions were enrolled. In volumetric metrics, expansion index was calculated as [(actual lumen area/ideal lumen area)?×?100] in all frames. While minimum expansion index (MEI) was often located in the proximal segment to the major side branch, minimum stent area (MSA) by CM was frequently located in the distal segment (p?<?0.001). Furthermore, the frequency of the under-expansion was significantly greater in newly metrics compared with CM [21 (47.7%) and 11 (25.0%), p?=?0.045]. New metrics changed the presence of the under-expansion in 40.9% (18/44) of patients and the locations of MEI and MSA were different in 72.7% (32/44) of cases. Volumetric assessment enables to more accurately assess stent under-expansion.     

Comparison of vascular responses after different types of second-generation drug-eluting stents implantation detected by optical coherence tomography

Few studies have directly compared vascular responses to second-generation drug-eluting stents (DESs). We performed optical coherence tomography examinations in 56 consecutive patients with implanted single stent [19 cobalt-chromium everolimus-eluting stents (CoCr-EES), 22 platinum-chromium EES (PtCr-EES), and 15 resolute zotarolimus-eluting stents (R-ZES)] for de novo lesions, and who did not have restenosis at their 9-month follow-up. Neointimal thickness (NIT), stent apposition, and neointimal coverage were assessed in every strut. A neointimal unevenness score [(NUS), maximum NIT/average NIT in the same cross-section] was determined for every 1-mm cross-section (CS). A total of 8350 struts and 1159 CSs were analyzed. The CoCr- and PtCr-EES had significantly fewer malapposed struts compared to the R-ZES (CoCr-EES: 0.19?% vs. PtCr-EES: 0.19?% vs. R-ZES: 0.61?%, p?=?0.007). Furthermore, the PtCr-EES had a lower frequency of uncovered struts compared to the others (CoCr-EES: 2.0?% vs. PtCr-EES: 1.4?% vs. R-ZES: 2.3?%, p?=?0.047). The NUS correlated with the frequency of uncovered struts (p?<?0.001, r?=?0.54). The EESs demonstrated more homogenous neointimal growth, as shown in the NUS, compared to the R-ZES [CoCr-EES: 1.66 (1.38–1.97) vs. PtCr-EES: 1.67 (1.41–2.00) vs. R-ZES: 1.94 (1.56–2.28), p?<?0.001]. Our results demonstrate that unevenness neointimal growth may relate with strut coverage after second-generation DES implantation. The PtCr-EES had a high frequency of strut coverage with a homogeneous neointima, suggesting fewer risks for stent thrombosis.     

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.     

药物洗脱支架置入术后非急性血栓预防的临床研究

目的 探讨药物洗脱支架(DES)置入术后非急性血栓的防治,以减少DES置入术后急性心肌梗死(AMI)等事件的发生.方法 选择2005年1月到2008年9月在本院置入DES的手术患者,按入院顺序随机将患者分为两组进行不同方案的抗血栓治疗.对照组患者术后应用阿司匹林联合氯吡格雷抗血小板治疗(双抗治疗);试验组患者术后在双抗治疗基础上应用替罗非班和华法林,华法林疗程为6个月,将国际标准化比值(INR)维持在1.5 ～ 2.0.两组患者术后1～3个月随访1次,至2012年10月为止.按照美国学术联合会对支架血栓的定义判定支架血栓形成,主要终点指标为主要不良心脑血管事件(MACCE),次要终点指标为出血及不良反应.结果 共入选505例患者,试验组245例,对照组260例.试验组术后1 ～ 48个月MACCE均显著低于对照组(1个月:0.41％比3.08％,2～6个月:0比2.31％,7～12个月:0.82％比4.23％,13～24个月:1.22％比8.85％,25 ～ 48个月:2.04％比12.31％,均P＜0.05),其中试验组心源性死亡(13 ～24个月:0.41％比3.08％,25～48个月:0.82％比4.23％)、与靶血管无关的非致死性AMI(25 ～ 48个月:0.41％比3.08％)、靶血管的血运重建(13 ～ 24个月:0.41％比3.08％,25～48个月:0.82％比4.23％)均较对照组明显减少(均P＜0.05).试验组术后亚急性支架血栓形成、晚期支架血栓形成、极晚期支架血栓形成的发生率显著低于对照组(0比2.31％,0.82％比4.23％,1.63％比8.46％,均P＜0.05).试验组轻微出血发生率略高于对照组(3.27％比1.54％,P=0.167),无严重出血发生.全部患者也无其他严重不良反应发生.结论 DES置入术后在应用阿司匹林和氯吡格雷双抗治疗基础上,联合替罗非班及华法林,可预防支架血栓形成,降低MACCE和严重出血的发生率.     

Very long-term follow-up of strut apposition and tissue coverage with Biolimus A9 stents analyzed by optical coherence tomography

First generation drug-eluting stents (DES) are associated with reduced in-stent restenosis but significant increased risk of very late stent thrombosis (VLST). The absence of polymer in DES systems may reduce the occurrence of VLST. Optic coherence tomography (OCT) has been used for stent analysis as a surrogate safety endpoint. This study aimed to assess the long-term follow up of strut apposition and tissue coverage of BioMatrix? DES by OCT. 20 patients undergoing BioMatrix? DES (n = 15) or S-Stent? BMS (n = 5) implantation were followed for at least 5 years and evaluated by quantitative coronary angiography, intravascular ultrasound, and OCT. The difference between the stent types was evaluated by nonparametric Mann–Whitney U test while categorical variables were evaluated by Fisher exact test. Rates of in-stent late loss were similar between groups [0.40 (0.21;0.77) vs. 0.68 (0.66; 0.82) mm, p = 0.205, for BioMatrix? and S-Stent?, respectively]. The vessel, stent and lumen volumes did not differ between groups. Patients treated with BioMatrix? had significantly less stent obstruction [5.6 (4.4;9.7) vs. 28.6 (24.7;29.0) %, p = 0.001]. OCT analysis of 12 stents (Biomatrix? = 9 and S-Stent? = 3) demonstrated 126 (8.7 %) uncovered struts in the BioMatrix? group compared to 23 (4.0 %) in the S-Stent? group (p = 0.297), being the majority of them well apposed (117/126 and 21/23, respectively, p = 0.292). Only 9 (0.6 %) struts in the DES and 2 (0.4 %) struts in the BMS groups were simultaneously uncovered and malapposed (p = 0.924). BioMatrix? DES was associated with lower rates of in-stent obstruction, and similar percentage of neointimal coverage on struts and of complete strut apposition.     

冠状动脉药物涂层支架与置入后的血管再狭窄

背景：近年来随着药物涂层支架研究的增多及临床应用不断扩大,使冠状动脉内支架置入后再狭窄率显著降低,且在预防再狭窄中较裸支架具有独特应用价值。目的：阐述药物涂层支架的临床应用进展,并探讨支架的涂层材料、类型与置入后再狭窄的关系及与宿主的相容性。方法：作者以＂冠脉支架,金属支架,药物涂层支架,再狭窄＂为检索词,在中国期刊全文数据库及Medline数据库中,采用电子检索的方式进行文献检索。排除Meta分析及重复性研究,共检索到27篇文献。结果与结论：药物涂层支架的确是介入心脏病学的一项重要突破,使介入心脏病学进入了一个新的时代,但其远期效果仍需进一步观察。各种药物涂层支架所含药物或含量不同,其作用机制不同,而且药物释放的速率也不同,所以药物涂层支架临床应用后的效用和安全性需要由严谨和大量的临床研究来证实。现今药物支架的载体材料经过长时间的人体腐蚀,材料本身会老化、脱落,在血管组织内形成小块,从而可能引起晚期的不良反应。如果采用生物可降解的材料作为药物载体材料,那么就有可能减少晚期不良反应的出现。因此,开发一种理想的支架系统,目前主要的研究方向是可降解的低致炎性聚合物材料以及高效的药物控释体系。     

冠状动脉药物涂层支架与置入后的血管再狭窄

背景:近年来随着药物涂层支架研究的增多及临床应用不断扩大,使冠状动脉内支架置入后再狭窄率显著降低,且在预防再狭窄中较裸支架具有独特应用价值.目的:阐述药物涂层支架的临床应用进展,并探讨支架的涂层材料、类型与置入后再狭窄的关系及与宿主的相容性.方法:作者以"冠脉支架,金属支架,药物涂层支架,再狭窄"为检索词,在中国期刊全文数据库及Medline 数据库中,采用电子检索的方式进行文献检索.排除Meta分析及重复性研究,共检索到27篇文献.结果与结论:药物涂层支架的确是介入心脏病学的一项重要突破,使介入心脏病学进入了一个新的时代,但其远期效果仍需进一步观察.各种药物涂层支架所含药物或含量不同,其作用机制不同,而且药物释放的速率也不同,所以药物涂层支架临床应用后的效用和安全性需要由严谨和大量的临床研究来证实.现今药物支架的载体材料经过长时间的人体腐蚀,材料本身会老化、脱落,在血管组织内形成小块,从而可能引起晚期的不良反应.如果采用生物可降解的材料作为药物载体材料,那么就有可能减少晚期不良反应的出现.因此,开发一种理想的支架系统,目前主要的研究方向是可降解的低致炎性聚合物材料以及高效的药物控释体系.     

Diagnostic accuracy of optical coherence tomography for the identification of in-stent fibroatheroma following stent implantation: an ex vivo histological validation study

The International Journal of Cardiovascular Imaging - The accurate identification of in-stent fibroatheroma by in vivo imaging is clinically important to preventing the late catch-up phenomenon...