First-in-Man Evaluation of a Sirolimus-Eluting Stent With Abluminal Fluoropolymeric/Triflusal Coating With Ultrathin Struts by OCT at 9 Months' Follow-Up: The PROMETHEUS Study

ObjectivesWe sought to investigate stent healing and neointimal hyperplasia with ihtDEStiny drug-eluting stent (DES) by optical coherence tomography (OCT) examination conducted 9 months after implantation.BackgroundThe currently used DES present certain features that have been linked separately to their better performance in terms of efficacy and safety.MethodsFirst-in-man, prospective and multicenter study including patients treated with ihtDEStiny stent undergoing OCT examination at 9 months follow up. The ihtDEStiny stent is a sirolimus eluting stent with an oval shape ultrathin struts (68 μm) and an abluminal coating of a fluoropolymer containing the antiplatelet agent triflusal. Primary endpoint was the percentage of obstruction of the in-stent volume by the neointima.ResultsIn 58 patients (63 lesions) in-stent late lumen loss was 0.11 ± 0.23 mm (95% CI 0.05–0.16) with only in 6% of stents being > 0.5 mm and in-segment binary stenosis was 1.6%. In OCT mean neointima volume obstruction was 10.5 ± 6.9% with a mean neointima thickness of 110.9 ± 89.8 μm. The proportion of uncovered struts was 2.5%, malapposed struts 1.1% and malapposed/uncovered struts 0.7% and no subclinical thrombi detected. Mean incomplete stent apposition area was 0.1 ± 0.1 mm². At 12 months target lesion revascularization rate was 3% and no stent thrombosis was reported.ConclusionsIn this study the ihtDEStiny stent has shown a very low degree of neointimal proliferation associated with a low rate of uncovered/malapposed struts and total absence of subclinical thrombi at 9 months follow up.     

Optical coherence tomography analysis of the stent strut and prediction of resolved strut malapposition at 3 months after 2nd-generation drug-eluting stent implantation

Our objective was to clarify whether thrombogenic problems with stent struts are resolved at 3 months after 2nd-generation drug-eluting stent implantation. Twenty-one patients with stable angina pectoris having 28 (22 zotarolimus-eluting, 6 everolimus-eluting) stents with optical coherence tomography (OCT)-guided percutaneous coronary intervention (PCI) were evaluated. Stent strut coverage and malapposition were evaluated by OCT immediately after PCI and at 3-month follow-up. Acute strut malapposition was observed in 26 out of 28 analyzed stents (92.9 %). At 3-month follow-up, 7 (26.9 %) of those 26 stents with strut malapposition were completely resolved, and the mean percentages of uncovered struts and malapposed struts were 8.3 and 2.0 % when analyzed by each individual stent. When analyzing a total of 30,060 struts, 807 struts (2.7 %) demonstrated acute strut malapposition. Among these, 219 struts (27.1 %) demonstrated persistent strut malapposition. On the basis of receiver-operating characteristic curve analysis, a strut-to-vessel (S-V) distance ≤160 µm on post-stenting OCT images was the corresponding cutoff point for resolved malapposed struts (sensitivity 78.1 %, specificity 62.8 %, area under the curve 0.758). The S-V distance of persistent malapposed struts on post-stenting OCT images was longer than that of resolved malapposed struts (235 ± 112 vs. 176 ± 93 µm, p < 0.01). At 3 months after PCI, the prevalence rates of uncovered and malapposed struts were relatively low in 2nd-generation drug-eluting stent. Our results suggest that OCT-guide PCI with an S-V distance ≤160 µm may be recommended especially in patients with planed short-term DAPT.     

Stent malapposition,as a potential mechanism of very late stent thrombosis after bare-metal stent implantation: A case report

A 90-year-old man was admitted to our hospital with acute ST-segment elevation myocardial infarction. He had a history of post-infarction angina pectoris 79 months ago and had a bare-metal stent (BMS) implanted in the proximal left anterior descending artery at our hospital. Emergent coronary angiography demonstrated thrombotic occlusion in the previously stented segment. After catheter thrombectomy, antegrade flow was restored, but 90% stenosis with haziness persisted in the proximal and distal portions of the previously stented segment. Intravascular ultrasound imaging showed interstrut cavities or stent malapposition at the proximal and distal sites of stented segment. In close proximity to the sites, residual thrombi were also observed. Optical coherence tomography (OCT) demonstrated neither lipid-laden neointimal tissue nor rupture but clearly demonstrated residual thrombus adjacent to the malapposed region in addition to the stent malapposition. PCI with balloon was successfully performed and stent apposition was confirmed by OCT. Stent malapposition is an unusual mechanism of very late stent thrombosis after BMS implantation. OCT can clearly reveal the etiology of stent thrombosis.     

Neointimal coverage of zotarolimus-eluting stent at 1, 2, and 3 months’ follow-up: an optical coherence tomography study

Incomplete neointimal coverage and malapposed struts after stenting are associated with increased risk of stent thrombosis. We aimed to evaluate neointimal coverage early after Resolute zotarolimus-eluting stent (R-ZES) implantation using optical coherence tomography (OCT). A total of 20 patients with de novo native coronary lesions with R-ZES were enrolled. Among these patients, 20 stented lesions in 19 patients were evaluated at 1, 2, and 3 months after R-ZES implantation. The strut apposition and neointimal coverage were evaluated by OCT. Neointimal hyperplasia (NIH) thickness and percentage of covered struts and the proportion of incompletely apposed struts were measured at 1-mm intervals. The mean percentages of covered stent struts were over 85 % within 3 months (88.4 ± 6.3 % at 1 month, 95.5 ± 5.5 % at 2 months, 93.6 ± 3.5 % at 3 months). The percentages of incompletely apposed struts were not significantly different among the groups (4.4 ± 4.2 % at 1 month, 1.9 ± 1.9 % at 2 months, 3.1 ± 2.2 % at 3 months, p = 0.51). Mean NIH thickness (38.9 ± 8.1 μm at 1 month, 70.6 ± 18.8 μm at 2 months, 54.1 ± 5.9 at 3 months, p = 0.0016) was thickest in the 2 months group. Most of all OCT findings within 2 months demonstrated neointimal coverage with low signal intensity. The neointimal coverage of ZES-R was over 85 % within 3 months. These data may support shorter requirement of dual antiplatelet therapy duration with R-ZES.     

Neointimal coverage of sirolimus-eluting stents at 6-month follow-up: evaluated by optical coherence tomography.

AIMS: Since the intravascular ultrasound (IVUS) cannot detect neointimal layers in the majority of sirolimus-eluting stents (SES) at the chronic phase, it is still controversial to what extent SES remain uncovered. However, optical coherence tomography (OCT) with excellent resolution may be able to detect thinner neointima. METHODS AND RESULTS: A total of 34 patients (57 SES) underwent OCT and IVUS evaluations at 6-month follow-up. The thickness of neointima on each SES strut cross-section and strut apposition to the vessel wall was evaluated. By OCT evaluation, the median (25th, 75th percentiles) neointima thickness was 52.5 microm (28.0 microm, 147.6 microm) and the prevalence of struts covered by thin neointima undetectable by IVUS was 64%. The average rate of neointima-covered struts in an individual SES was 89%. Nine SES (16%) showed full coverage by neointima, whereas the remaining stents had partially uncovered strut lesions. Among the 6840 struts visualized by OCT in all of the SES, 79 struts showed malapposition without neointimal coverage, and were frequently observed in the areas of SES overlap. CONCLUSION: At 6 months, most of the SES were covered with thin neointima, but few showed full coverage.     

Impact of drug-eluting balloon (pre- or post-) dilation on neointima formation in de novo lesions treated by bare-metal stent: the IN-PACT CORO trial

The efficacy of DEB in modifying the high restenosis risk associated with BMS implantation is doubtful. Optical coherence tomography (OCT) may allow precise assessment of neointimal formation after stent implantation. We performed a single-center, prospective, 1:2 randomized trial comparing BMS implantation alone (BMS group) vs. additional DEB (DEB group). DEB patients were further randomized 1:1 to DEB before stenting (pre-DEB group), or after stenting (post-DEB group). Primary endpoint was OCT-assessed neointimal hyperplasia (expressed both as mean in-stent neointimal area and as percentage obstruction of the mean stent area) at 6 months. Secondary endpoints were the percentage of uncovered and malapposed stent struts. Thirty patients were enrolled and randomized to BMS (n = 10), pre-DEB (n = 10), post-DEB (n = 10). At 6-month OCT follow-up, DEB significantly reduced neointimal area compared with BMS: mean neointimal area 2.01 ± 0.89 vs. 3.03 ± 1.07 mm² (p = 0.02), percentage area obstruction 24.56 ± 12.50 vs. 37.51 ± 12.26 % (p = 0.02). The percentage of uncovered and malapposed stent struts did not differ significantly between BMS and DEB. In the comparison between pre-DEB and post-DEB, no significant difference was observed for both primary and secondary endpoints. In de novo coronary lesions treated with BMS, DEB use could be associated with a mild reduction in neointimal hyperplasia at 6 months; this effect could be unrelated to the timing of DEB dilation (pre- or post-stenting).Clinical Trial Registration Information: http://www.clinicaltrials.gov. Identifier: NCT01057563.     

Neointimal coverage and stent strut apposition six months after implantation of a paclitaxel eluting stent in acute coronary syndromes: An optical coherence tomography study

Objectives

Prospective optical coherence tomography (OCT) study of strut apposition and neointimal hyperplasia thickness (NIH) of a paclitaxel eluting stent (PES), (Infinium, Sahajanand Medical Technologies Pvt Ltd.).

Background

Few data exist concerning neointimal coverage of PES. Uncovered and malapposed struts are more common following stenting in acute coronary syndromes (ACS) than in non-ACS lesions.

Methods

All consecutive patients with ACS, treated with the above PES for single native coronary lesions between August 2008 and January 2009, who consented to invasive follow-up with OCT at six months (N = 13), were included.

Results

At 6 months no patient demonstrated angiographic restenosis. 3180 struts from 20 stents were analyzed, and 91.3% were covered with neointima (NIH 204.8 ± 159.5 μm). Standard statistics and least squares estimates (LSE) derived from a hierarchical ANCOVA model to take into account clustering effects are presented. Rate of uncovered struts was 8.6%, LSE 7.39 (95% CI 3.05-11.73), malapposed struts 2.2%, LSE 1.76 (95% CI 0.05-3.58), and protruding struts 2.9%, LSE 2.8 (95% CI 1.35-4.65). The proportion of uncovered malapposed struts was significantly higher compared to uncovered embedded struts (55.7% vs. 6.8%, p < 0.01). In total, 5 (25%) PES were fully covered by neointima. No intracoronary thrombus or clinical events were detected.

Conclusions

Six months after implantation of a specific PES in patients with ACS, most of the stents were only partially covered with neointima, especially at sites of strut malapposition or protrusion. These findings emphasize the need for optimal stent apposition during implantation and for prolonged dual antiplatelet therapy.     

光学相干断层成像在冠心病介入治疗中的应用价值

目的应用光学相干断层成像（OCT）技术评价冠状动脉内粥样硬化斑块、血管对置入支架后即刻和中远期的反应。方法20例冠心病患者,有22支血管在完成冠状动脉造影或介入治疗后进行OCT成像。同时获取23个支架OCT成像,在23个支架中有15个为支架术后4～35个月随访,其中7个为雷帕霉素药物洗脱支架,8个为金属裸支架,另外8个为支架置放后即刻成像。结果入选的20例患者均成功进行OCT检查,并获取22支血管和23个支架满意的图像。通过OCT成像清晰地显示8处纤维斑块、3处钙化斑块、9处富含脂质斑块、2处血栓形成、斑块破裂3处及血管壁上夹层、粥样硬化斑块微小裂口和夹层等。7个置入雷帕霉素药物洗脱支架后OCT随访,均未发现有明显再狭窄,支架表面有少量内膜覆盖,部分支架表面没有内膜覆盖,其中1个支架血管出现瘤样扩张、支架与血管壁分离、支架表面没有内膜覆盖,有1个支架没有充分扩张。8个金属裸支架后用OCT随访发现,所有置入金属裸支架后支架表面内膜增殖明显,其中有3个支架因为内膜过度增殖而出现再狭窄,并再次接受介入治疗。8个支架术后即刻OCT检查显示,与血管贴壁均良好、支架扩张充分有3个支架,4个支架充分扩张,但可见到斑块裂片通过支架网眼突入管腔,1个支架支撑杆分布不均,可见支架与血管壁分离,在8个支架中有2个为支架内套叠支架。结论OCT成像技术可清晰显示各种冠状动脉粥样斑块情况,并可用于评价冠状动脉介入治疗的效果。     

Comparison of neointimal coverage by optical coherence tomography of a sirolimus-eluting stent versus a bare-metal stent three months after implantation

No detailed data regarding neointimal coverage of bare-metal stents (BMSs) at 3 months after implantation was reported to date. This investigation was designed to evaluate the neointimal coverage of BMSs compared with sirolimus-eluting stents (SESs) using optical coherence tomography. A prospective optical coherence tomographic follow-up examination was performed 3 months after stent implantation for patients who underwent BMS (n = 16) or SES implantation (n = 24). Neointimal hyperplasia (NIH) thickness on each stent strut and percentage of NIH area in each cross section were measured. Malapposition of stent struts to the vessel wall and the existence of in-stent thrombi were also evaluated. There were 5,076 struts of SESs and 2,875 struts of BMSs identified. NIH thickness and percentage of NIH area in the BMS group were higher than in the SES group (351 +/- 248 vs 31 +/- 39 mum; p <0.0001; 45.0 +/- 14% vs 10.0 +/- 4%; p <0.0001, respectively). The frequency of uncovered struts was higher in the SES group than the BMS group (15% vs 0.1%; p <0.0001). Malapposed struts were observed more frequently in the SES group than the BMS group (15% vs 1.1%; p <0.0001). In conclusion, there was no difference in incidence of in-stent thrombus between the 2 groups (14% vs 0%; p = 0.23). The present study showed almost all BMS struts to be well covered at a 3-month follow-up, suggesting that patients receiving BMS stents may not require dual-antiplatelet therapy >3 months after implantation.     

Possible role of damaged neoendothelial cells in the genesis of coronary stent thrombus in chronic phase. A dye staining angioscopic study

The mechanism(s) underlying formation of coronary stent thrombus (ST) in chronic phase is yet unclear. Endothelial cells are highly antithrombotic, therefore, it is conceivable that neoendothelial cells (NECs) covering stent struts are damaged and cause ST. This study was performed to examine the role of damaged NECs covering coronary stent struts in the genesis of occlusive or nonocclusive ST in chronic phase.(1) Forty-four patients with acute coronary syndrome (17 females and 27 males) underwent dye-staining coronary angioscopy, using Evans blue which selectively stains damaged endothelial cells, 6 months after bare-metal stent (BMS) deployment. Neointimal coverage was classified into not covered (grade 0), covered by a thin layer (grade 1), and buried under neointima (grade 2) groups. (2) In 7 beagles, the relationships between neointimal thickness and ST were examined 6 months after BMS deployment. (3) The NECs on the struts were stained blue in 4 of 25 patients with grade 2 and in 11 of 20 patients with grade 0/1 (P < 0.05). ST was observed in none of the former and in 5 of the latter (P < 0.05). (4) In beagles, neointimal coverage was grade 0/1 when neointimal thickness was 80.2 ± 40.0 μm, whereas grade 2 when thickness was 184 ± 59.4 μm. ST was observed in 9 of 15 struts with neointimal thickness within 100 μm and in one of 17 struts with thickness over 100 μm (P < 0.05). ST arose from damaged NECs covering the stent struts. NECs may have been damaged due to friction between them and struts due to thin interposed neointima which might have acted as a cushion, resulting in ST.     

The wound healing response after implantation of a drug-eluting stent is impaired persistently in the long term

A 70-year-old man underwent stent implantation for right coronary artery (RCA) lesions with a bare metal stent (BMS) and two sirolimus-eluting stents (SES). However, as both the BMS and SES stented sites developed restenosis after 13 months, he underwent target lesion revascularization using directional coronary atherectomy (DCA). On histopathology, the restenosis lesion at the SES-deployed site showed greater inflammation and less re-endothelialization than that at the BMS-deployed site. Three months later, the SES-deployed site developed a second restenosis, in which paclitaxel-eluting stents (PES) were implanted (PES-in-SES), while the BMS-deployed site was restenosis free. Five years later, restenosis was absent in these RCA lesions. However, by optical coherence tomography and/or coronary angioscopy, the PES-in-SES site in the RCA showed poor neointimal coverage over the stent struts and yellowish neointima, suggesting lipid-rich neoatheroma formation, whereas at the BMS site appropriate white neointima formation was observed. Drug-eluting stents still have problems of persistent inflammation, inappropriate neointima formation, and neoatherosclerosis. Although we are now in the era of second generation DESs in which better stent performance would be promising, we should remember that we are obliged to continue to follow-up all patients in whom first generation DESs such as SES or PES have been placed.     

抗CD34抗体优化雷帕霉素洗脱支架疗效的实验研究

目的 评价抗CD34抗体对雷帕霉素洗脱支架早期再内皮化以及远期抗再狭窄的影响.方法 将裸金属支架(BMS)、雷帕霉素洗脱支架(SES)和抗CD34抗体与雷帕霉素洗脱联合支架(ASES)随机置入到22头中华小型猪的冠状动脉内(共置入15枚BMS、17枚SES和16枚ASES).10头中华小型猪在置入支架(共置入6枚BMS、7枚SES和7枚ASES)后2周,另外12头中华小型猪在置入支架(共置入9枚BMS、10枚SES和9枚ASES)后3个月,进行冠状动脉造影及冠状动脉内光学相干断层成像( OCT)检查,并在处死动物后对支架段冠状动脉进行病理组织学检查及扫描电镜观察.结果 (1)支架术后2周,冠状动脉造影、OCT图像及支架段冠状动脉的病理组织学的观察均未发现支架内血栓及小的附壁血栓.对OCT图像的分析显示,ASES新生内膜覆盖率显著高于SES[ (55.56±35.27)％比(41.82±23.28)％,P＜0.05];ASES平均内膜覆盖厚度不但显著高于SES[(89.0±5.0)μm比(32.0±4.9) μm,P＜0.01],而且显著高于BMS[( 89.0±5.0) μ,m比(44.0±7.2)μm,P＜0.01].病理组织学观察及扫描电镜观察显示,ASES和BMS新生内膜覆盖水平及质量均优于SES.(2)支架术后3个月,定量冠状动脉造影显示ASES晚期支架内管腔丢失显著低于BMS [(0.18±0.06)mm比(0.35±0.06)mm,P＜0.05];对OCT图像的分析显示,ASES和SES新生内膜增生百分比均显著低于BMS[ (34.75±2.64)％和(35.63±2.07)％比(48.28±3.25)％,均P＜0.01];组织病理学分析显示,ASES和SES面积再狭窄百分比均显著低于BMS组[(28.65±5.64)％和(29.33±6.07)％比(46.18±8.25)％,均P＜0.05].结论 将抗CD34抗体联合应用到雷帕霉素洗脱支架上能够显著抵消后者在支架术后2周对再内皮化的抑制作用,同时没有削弱雷帕霉素洗脱支架术后3个月的抗再狭窄效能.     

Incomplete neointimal coverage of sirolimus-eluting stents: angioscopic findings.

OBJECTIVES: The goal of this study was to use angioscopy to investigate the amount of neointimal coverage after sirolimus-eluting stent (SES) implantation. BACKGROUND: Sirolimus-eluting stents reduce intimal hyperplasia. METHODS: We used angioscopy to evaluate 37 consecutive stented coronary artery lesions (15 SES and 22 bare-metal stents [BMS]) in 25 patients (18 men, 7 women) at 3 to 6 months after stent implantation. Angioscopic evaluation focused on: 1) neointimal coverage of stent struts, and 2) the existence of thrombi. The degree of neointimal coverage was classified as grade 0 when there was no neointimal coverage (similar to immediately after the implantation); grade 1 when stent struts bulged into the lumen, but were covered and still translucently visible; grade 2 when stent struts were visible but not clearly seen (not translucent); and grade 3 when stent struts were not visible because they were embedded in the neointima. RESULTS: Thrombi were identified in eight stented segments, tended to be more common with SES (p = 0.14), but were not seen on angiography. Three of the 15 SES (20%) had grade 0 neointimal coverage, and only 2 SES (13.3%) had complete coverage (grades 2/3). In contrast, all 22 BMS showed complete intimal coverage (grades 2/3). Thrombi were more common in stents with incomplete neointimal coverage (p = 0.09). CONCLUSIONS: The SES had incomplete neointimal coverage three to six months after implantation, and this was associated with subclinical thrombus formation.     

Comparisons of detailed arterial healing response at seven months following implantation of an everolimus- or sirolimus-eluting stent in patients with ST-segment elevation myocardial infarction

Background

The difference of arterial healing response following everolimus-eluting stent (EES) or sirolimus-eluting stent (SES) implantation in patients with ST-segment elevated myocardial infarction (STEMI) has not been compared in detail.

Methods

Thirty-five patients with STEMI were randomly implanted with an EES or SES (23 EES, 12 SES). At seven months, neointimal thickness (NIT) and strut malapposition were evaluated by optical coherence tomography (OCT) and the grade and heterogeneity of neointimal coverage (NIC) and development of intra-stent thrombi were evaluated by angioscopy.

Results

No significant differences were noted in clinical events experienced by the two groups, although one patient with an EES died following a papillary muscle rupture and one patient with a SES experienced sub-acute stent thrombosis. On OCT, although the EES implants showed a greater NIT than the SES implants (94.8 ± 88.8 μm vs 65.6 ± 63.3 μm, P < 0.0001), both the EES and SES showed an excellent suppression of neointimal proliferation in the culprit lesion of STEMI. The frequency of uncovered and malapposed struts of EES was significantly lower than that of SES (2.7% vs. 15.7%, P < 0.0001, 0.7% vs. 2.3%, P < 0.0001, respectively). The ratio of stents fully covered with neointima of EES group was significantly higher than that of SES group (P = 0.04). Angioscopic analysis also showed greater dominant NIC grade with homogenous NIC in EES than in SES (P = 0.03, P = 0.0002, respectively). The incidence of massive intra-stent thrombus of EES was lower than that of SES (P = 0.05).

Conclusion

For patients with STEMI, EES may promote better arterial healing response than SES.     

Comparison of the performance of zotarolimus- and everolimus-eluting stents by optical coherence tomography and coronary angioscopy

Overall stent performance should be characterized by geometric luminal gain acquisition, neointimal coverage of the stent struts, and stabilization of the underlying inflammatory neoatheroma. The aim of this study was to compare the performance of zotarolimus-eluting stent (ZES), everolimus-eluting stent (EES) and bare metal stent (BMS) using optical coherence tomography (OCT) and coronary angioscopy. For 36 stented coronary lesions (BMS, 12 lesions; ZES, 11 lesions; EES, 13 lesions) in 27 patients, we calculated neointimal area and uncovered stent strut rate based on OCT findings at 10 months after stent placement. The grades of neointimal coverage and yellow color, both of which were classified from 0 to 3, were also assessed by coronary angioscopy. The plaque area of the ZES lesions was larger than that of the EES lesions (P < 0.05) but smaller than that of the BMS lesions (P < 0.05). The OCT-based uncovered rate of the ZES lesions was less than that of the EES lesions (P < 0.01), but similar to that of the BMS lesions. The stent coverage grade by angioscopy was higher in the ZES lesions than in the EES lesions (P < 0.05), but similar to the BMS lesions. The yellow grade was less in the ZES lesions than in the EES lesions (P < 0.01), but similar to the BMS lesions. ZES might be better than BMS in terms of neointimal thickening, and better than EES in terms of neointimal coverage as well as prevention of neoatheroma formation. ZES may have superior performance compared with EES.     

Preliminary observations using optical coherence tomography to assess neointimal coverage of a metal stent in a porcine model

BackgroundConcerns surrounding late stent thrombosis have prompted the development of novel imaging techniques to assess neointimal coverage. Recent clinical studies have evaluated optical coherence tomography (OCT) to evaluate neointimal coverage, but pathologic correlation in an animal model is lacking. We assessed the hypothesis that OCT could accurately assess early neointimal coverage in a porcine model.MethodsOCT imaging of bare metal stents in each coronary artery was performed at implantation (n=6), Day 4 (n=3), and Day 20 (n=3), and images were evaluated at three cross-sections per stented segment. Neointimal strut coverage was categorized by OCT as covered or uncovered, and neointimal thickness was determined (Day 20). Pathological correlation was obtained using scanning electron microscopy (SEM) to assess strut coverage (Day 4) and histomorphometry to quantify neointimal thickness (Day 20).ResultsAt Day 4, OCT imaging detected 28 (26%) of 109 uncovered struts, and the ratio of uncovered/total strut area by SEM was 31%. All imaging modalities showed complete coverage at Day 20. Mean (±SE) neointimal thickness at Day 20 was 109±6 μm by OCT (n=116 struts) and 93±5 μm by pathology (n=68). Mean neointimal thickness on a segment-by-segment basis determined by OCT correlated with mean histomorphometric analysis (Reviewer 1: r=.74, P=.092 and Reviewer 2: r=0.60, P=.212).ConclusionsDay 4 represents an important time point for the assessment of early neointimal coverage in the porcine model. OCT imaging accurately assesses the extent and thickness of early neointimal coverage with good pathologic correlation. OCT represents a promising imaging modality for the in vivo assessment of neointimal coverage.     

Comparison of neointimal coverage and extra-stent lumen between sirolimus and everolimus-eluting stent using optical coherence tomography

The external lumen of a stent [defined as extra-stent lumen (ESL)] assessed by optical coherence tomography (OCT) may be related to the risk of thrombus formation after sirolimus-eluting stent (SES) implantation. An everolimus-eluting stent (EES) might provide relatively minimal inflammatory reaction and appropriate neointimal coverage. The purpose of this study was to compare the neointimal thickness and ESL between SES and EES. Patients who underwent OCT examination more than 7 months after either SES or EES implantation were enrolled. Stent area (SA), lumen area (LA), neointimal area (NIA) and neointimal thickness (NIT) of each strut were measured at 1-mm intervals between stented segments. The area, angle (summation per cross-section) and depth (maximum distance from adjacent vessel surface to the outline of stent) of ESL were analyzed. A total of 49 lesions were included (SES n = 20, EES n = 29). Mean follow-up period was 11 months. A total of 998 cross-sections and 9874 struts were analyzed. There were no differences in stent area, lumen area and neointimal area (SA: 6.01 ± 1.60 vs. 6.02 ± 1.40 mm², p = 0.572, LA: 5.37 ± 1.52 vs. 5.29 ± 1.34 mm², p = 0.692, NIA: 0.64 ± 0.49 vs. 0.72 ± 0.37 mm², p = 0.493). Mean NIT of SES and EES were 0.11 ± 0.05 and 0.10 ± 0.05 mm, respectively (p = 0.367). Conversely, area, angle and depth of ESL in SES group were significantly greater than those in EES group (0.20 ± 0.39 vs. 0.03 ± 0.09 mm², p < 0.001, 56.2 ± 59.1° vs. 20.1 ± 41.9°, p < 0.001, 0.10 ± 0.09 vs. 0.03 ± 0.03 mm, p < 0.001). OCT showed that the efficacy of neointimal growth suppression is similar between SES and EES, whereas the adverse vascular response after EES implantation is smaller than that after SES implantation.     

采用光学相干断层成像技术评价国产雷帕霉素洗脱支架术内膜覆盖情况

Objective:Confirming complete neointimal coverage after implantation of drug-eluting stent(DES)is clinically important because incomplete stent coverage is maybe responsible for late thrombosis and sudden cardiac death.Optical coherence tomography(OCT)is a high-resolution(≈10 μm)imaging technique capable of detecting a thin layer of neointimal hyperplasia(NIH)inside DES.Helios stent system(KinheIy Bio-tech Co(Shenzhen).Ltd)is a new generation of sirolimus eluting stents.Methods:Motorized optical coherence t...     

光学相干断层显像评价药物洗脱支架置入后内膜增殖和血栓形成

目的 应用光学干涉断层显像(OCT)技术评价雷帕霉素洗脱支架(SES)置入后3个月和2年后内膜增殖和支架内血栓形成情况.方法 对3个月组进行SES置入后3个月的OCT随访观察,对2年组进行SES置入后2年的随访观察.测量每一个支架支撑杆表面的新生内膜厚度,并评估无内膜覆盖支架支撑杆及支架内血栓形成情况.结果 2年组的内膜厚度显著大于3个月组[(71±93)μm比(29±41)μm,P＜0.01],而2年组中的无内膜覆盖支架支撑杆的比例明显低于3个月组(5%比15%,P＜0.01).2年组与3个月组无内膜覆盖支撑杆患者的比例差异无统计学意义(81%比95%,P＞0.05).两组中均有14%的患者出现无临床症状的支架内血栓形成.结论 SES置入后3个月到2年新生内膜的增生在不断进展,无内膜覆盖支撑杆数明显减少.但是直到支架置入后2年,多数患者体内仍然存在部分无内膜覆盖的支架支撑杆.