经皮腔内β-射线放射疗法联合切割球囊成形术治疗冠状动脉支架内再狭窄

目的旨在研究经皮冠状动脉(冠脉)内β-射线放射疗法(β-放疗,Novoste)与切割球囊成形术(CBA)联合治疗支架内再狭窄(ISR)的疗效及其安全性.方法冠脉内支架植入术后ISR＞70%的病人295例(男性188例,女性90例,年龄59.76±10.83岁),其中112例均行CBA联合β-放疗为β-放疗组(n=112),183例单独采用CBA(89例)或普通球囊扩张成形术(94例)为对照组(n=183).弥漫性长病变ISR者β-放疗先照射病变远段,再回撤导管照射病变近段.所有病例术前、术后即刻及术后随访期行定量冠脉造影(QCA),分析病变长度,最小管腔直径(MLD),参照管腔直径(RLD)和管腔直径狭窄百分比(DS).防访靶血管再次成形率(TVR)和主要不良心血管事件(MACE)发生率.结果术前及术后即刻两组病人的QCA结果无显著性差异,P＜0.05.随访期(6.3±1.6月)β-放疗组的MLD大于对照组,Ds小于对照组,P＜0.015.β-放疗组与对照组的心绞痛、心肌梗死及死亡率相似(心绞痛为10%对17%,心肌梗死为1%对2%,死亡率为0%对2%,P=NS),但β-放疗组的TVR和MACE明显低于对照组(TVR为5%对16%,MACE为10%对25%,P＜0.05).β-放疗组28例(26%)弥漫性长病变ISR,回撤β-放疗导管分段照射后,随访TVR和MACE无增加.结论冠脉内β-放疗和CBA相结合治疗ISR安全、有效,TVR和MACE明显降低.采用回撤β-放疗导管技术可以有效地治疗弥漫性长病变ISR.     

切割球囊成形术与经皮腔内β-射线放射疗法联合治疗冠状动脉支架内再狭窄

目的观察切割球囊成形术(CBA)与经皮冠状动脉(冠脉)内β-射线放射疗法(β-放疗)联合治疗支架内再狭窄(ISR)的疗效及其安全性.方法冠脉内支架置入术后ISR>70%的患者295例,男性205例,女性90例,平均年龄(59.76±10.83)岁,其中112例均行CBA联合β-放疗作为β-放疗组(n=112),183例单独采用CBA(89例)或普通球囊扩张成形术(94例)为对照组(n=183).弥漫性长病变ISR者回撤β-放疗导管分段照射.所有患者术前、术后即刻及术后随访期行冠脉造影,随访靶血管血运重建(TVR)和主要不良心血管事件(MACE)发生率.结果两组患者的术前及术后即刻冠脉造影结果差异无显著性.随访期(6.3±1.6) 月β-放疗组的最小管腔直径大于对照组,管腔直径狭窄百分比小于对照组,P<0.05.β-放疗组与对照组的心绞痛、心肌梗死及病死率相似(心绞痛为10%比17%,心肌梗死为1%比2%,病死率为0%比2%), 但β-放疗组的TVR和MACE明显低于对照组(TVR为5%比16%,MACE为11%比21%,P<0.05).β-放疗组28例(25%)弥漫性长病变ISR,分段照射后随访TVR和MACE无增加.结论冠脉内β-放疗和CBA相结合治疗ISR安全、有效,TVR和MACE明显降低.采用回撤β-放疗导管技术可以有效地治疗弥漫性长病变ISR.     

冠状动脉支架内再狭窄介入术后即刻结果对长期疗效的影响

目的　旨在评价冠状动脉支架内的再狭窄 (ISR)介入治疗术后即刻的结果以及有或无联合冠状动脉内放射治疗是否影响其长期的结果。方法　研究来源于 3个γ射线治疗试验 (WRIST试验、Gamma 1试验和ARTISTIC试验 )。 1 80例ISR患者均有系列 (介入治疗术后即刻和随访 )的血管内超声 (IVUS)资料 ,分为1 92 Ir放疗组 (1 0 6例 )和安慰剂组 (74例 )。定量分析根据美国心脏病协会临床专家委员会的报告 :关于IVUS图像的获得、测量和报告标准。采用自动回撤技术 ,每隔 1mm在支架内获得一幅图像 ,测量支架长度、支架面积和管腔面积。结果　介入治疗术后即刻的最小管腔面积 (MLA)、最小支架面积 (MSA)、和放疗是随访时的MLA的独立预测因子。安慰剂组丢失术后即刻MLA的 4 5 %,而放疗组仅丢失 1 3%。术后即刻的增生内膜百分比 (IH %)和放疗是随访时的IH %和净增加的内膜量的独立预测因子。安慰剂组随访时的增生内膜中 5 3%是新生内膜积累 ,而放疗组仅有 2 3%。结论　系列IVUS分析显示随访时的MLA和IH %与ISR病变治疗即刻的结果相关。     

冠状动脉内超声评价支架再狭窄

目的探讨冠状动脉内支架再狭窄的机制.方法50例确诊冠心病患者接受65个支架置入术,10个月后复查冠状动脉造影和血管内超声成像检查.根据冠状动脉造影结果将患者分为支架再狭窄组(26个支架)和无支架再狭窄组(39个支架),分别对其冠状动脉造影和血管内超声进行定量测量分析.同时观察支架内再狭窄的方式.结果血管内超声定量测量发现支架再狭窄组最小血管内膜腔面积和支架最小截面积[分别为(2.5±1.2)mm2和(4.2±1.8)mm2]明显小于无支架再狭窄组[分别为(5.2±1.4)mm2和(6.8±1.7)mm2](P分别＜0.001和＜0.01),但两组新生内膜截面积比较差异无显著性[分别为(1.7±1.0)mm2和(1.5±0.9)mm2,P＞O.05].支架内再狭窄以局灶性狭窄为多见(69.2%).结论支架扩张程度是决定支架内再狭窄的重要因素,而支架内内膜增生并不明显.支架内再狭窄以局灶性狭窄为多见.     

介入治疗后有或无冠脉内放射治疗对老年支架内再狭窄的作用和疗效:血管内超声分析

目的　采用血管内超声 (IVUS)评价常规介入治疗术 (CIT)有或无联合冠脉内放射治疗 (IRT)对支架内再狭窄 (ISR)复发的作用及随访观察 1年的临床疗效。方法　 99例ISR的患者经常规介入治疗后随机分为CIT IRT组和CIT组 ,在放疗后即刻和 6个月行IVUS检查 ,分别测量支架、管腔及增生内膜 (IH)面积 ,经计算得到支架、管腔内和IH体积并临床随访 1年。结果　两组基线指标无显著性差异 ,具有可比性。术后 6个月 ,CIT IRT组和CIT组的最小管腔面积 (MLA)各为 (4.30± 2 .0 0 )mm2 与 (2 .81± 2 .56)mm2 (P =0 .0 0 6) ,随访 6个月与放射治疗后即刻MLA差值各为 (- 0 .55± 1 .35)mm2 与 (- 1 .93± 1 .66)mm2 (P <0 .0 0 1 )。CIT IRT组和CIT组的IH体积各为 (69.2 3± 58.57)mm3 与 (1 1 6 .91± 1 2 1 .83)mm3 (P =0 .0 2 1 ) ,随访 6个月与放射治疗后即刻IH体积差值各为 (1 9.50± 35 .90 )mm3 与 (51 .36± 58.80 )mm3 (P =0 .0 1 7)。CIT IRT组 ,随访 6个月 ,MLA≥ 4mm2 的比例明显高于CIT组 (52 .7%与 2 4 .0 % )。术后 6个月 ,冠脉造影显示 ,CIT IRT组和CIT组ISR的复发率分别为 2 4 .53 %与 78.6 % (P =0 .0 2 7)。临床随访 1年 ,CIT IRT与CIT组的主要不利心脏事件 (MACE)、靶血管再次成形术 (TVR)及靶     

Mytrolimus药物洗脱支架预防支架内再狭窄的实验研究

目的评价新型聚烯烃类高分子化合物涂层携载雷帕霉素衍生物-Mytrolimus(CCI-779)洗脱支架在小型猪冠状动脉模型预防再狭窄的疗效。方法小型猪冠状动脉分别置入裸支架、单纯聚烯烃类高分子化合物涂层支架和Mytrolimus洗脱支架(160μg/18mm)。术后4周重复冠状动脉造影后处死动物,测定3组支架血管段的损伤指数、冠状动脉横截面积、管腔面积、支架上平均内膜厚度、支架间平均内膜厚度、新生内膜面积、面积再狭窄百分比,并作比较。结果裸支架组(置入支架数n=10)、单纯聚烯烃类高分子化合物涂层支架组(n=10)和Mytrolimus洗脱支架组(n=8)3组冠状动脉大小和血管损伤程度基本相同,术后4周,单纯聚烯烃类高分子化合物涂层组与裸支架比较多项参数差异均无统计学意义。Mytrolimus药物洗脱支架组和裸支架组的支架上内膜厚度分别为(0.18±0.08)mm和(0.33±0.25)mm(P<0.05);支架间内膜厚度分别为(0.14±0.05)mm和(0.28±0.23)mm(P<0.05);新生内膜面积分别为(1.09±0.24)mm2和(2.44±1.59)mm2(P<0.05)。上述多项参数在Mytroliums洗脱支架组均显著少于裸支架组。Mytrolimus组新生内膜面积比裸支架组少了55.33%,且Mytrolimus组无一例再狭窄。结论Mytrolimus洗脱支架在置入小型猪冠状动脉4周时可有效抑制内膜增生、预防冠状动脉实验性支架内再狭窄。     

雷帕霉素洗脱支架治疗支架内再狭窄的临床及冠状动脉造影随访观察

目的评价雷帕霉素洗脱支架(商品名Cypher支架,强生公司产品)治疗支架内再狭窄的疗效及安全性。方法27例支架内再狭窄且有临床缺血症状的患者接受了Cypher支架治疗,其中23例患者的支架内再狭窄为弥漫、复杂病变,有5例同时置入了2个Cypher支架。术后对所有患者进行临床随访及冠状动脉造影复查。结果所有支架均成功置入,无残余狭窄或残余狭窄<10%,未见任何并发症。平均随访时间8.9±2.1(5～14)年,临床随访率96.3%,造影随访率92.6%。随访期间,无一例患者死亡。有1例支架近端边缘节段血管发生了再狭窄导致临床心绞痛复发,2例支架近端边缘节段有轻微的新生内膜增殖,但狭窄程度<25%,其余24例均无明显的晚期管腔丢失。本组支架内平均晚期管腔丢失(0.09±0.02)mm、支架远端边缘节段(0.10±0.03)mm、支架近端边缘节段(0.20±0.06)mm。靶血管血运重建率3.8%。结论Cypher支架治疗支架内再狭窄安全、可行,它能有效防止这类病变的新生内膜增殖和再次再狭窄。     

巨细胞病毒感染与冠状动脉支架内新生内膜组织量的关系

目的　探讨巨细胞病毒 (CMV)感染对冠状动脉支架内内膜增生的影响。方法　 180例冠心病患者 ,于冠状动脉内支架置入术后 6个月复查冠状动脉造影和血管内超声检查。定量冠状动脉造影测定随访时的腔径减小 ,血管内超声测定支架内的平均新生内膜组织面积及其与支架横截面积之比。酶联免疫吸附法测定抗人CMVIgG抗体。 结果　CMV感染率达 5 1%。平均血管参考直径为 (2 94± 0 4 8)mm ,支架置入使平均最小腔内直径由 (0 99± 0 35 )mm上升至 (2 4 5± 0 4 2 )mm。 6个月随访时平均腔径减小 (0 74± 0 5 0 )mm ;平均新生内膜组织面积为 (3 8± 1 7)mm2 ,其与平均支架横截面积之比为 (4 5± 18) %。逐步多变量回归分析显示上述再狭窄指标与CMV感染无关联。结论　既往CMV感染与冠状动脉支架内新生内膜组织量无关。     

冠状动脉支架内再狭窄的相关因素分析

目的　探讨可能引起支架内再狭窄的临床及支架相关因素。方法　选择随访的冠状动脉造影资料较全的 137例支架术后患者。依冠状动脉造影结果将其分为支架内再狭窄组和非再狭窄组 ,然后对可能引起支架内再狭窄的临床和支架相关因素在两组中进行对比分析。结果　两组年龄、吸烟、饮酒等情况相似 ,高血压病及糖尿病的发生率差异无显著性。再狭窄组术前靶血管狭窄程度较非再狭窄组重 ,分别为 91%± 7%和 88%± 14% (P =0 0 33)。再狭窄组所选支架的平均直径较非再狭窄组的小 ,分别为 (3 19± 3 90 )mm和 (3 6 3± 0 30 )mm(P =0 0 0 5 ) ;支架长度却较非再狭窄组的长 ,分别为 (2 1 91± 8 98)mm和 (18 2 0± 6 0 7)mm(P =0 0 11)。再狭窄组的支架扩张总时间明显短于非再狭窄组 ,分别为 (2 2 74± 19 5 6 )s和 (2 9 12± 2 5 72 )s(P =0 0 2 6 )。两组的支架扩张次数和扩张压力差异无显著性。结论　本文资料提示年龄、吸烟、饮酒、高血压病、糖尿病、支架扩张次数及压力的大小等因素对支架内再狭窄无明显影响 ,但术前靶血管狭窄程度和支架长度与支架内再狭窄呈正相关 ,而支架直径和支架扩张总时间则呈负相关。     

切割球囊对冠状动脉支架内再狭窄的近期及远期疗效

目的　比较切割球囊成形术 (CBA)与普通球囊成形术 (POBA) ,对支架内再狭窄病变的近、远期血管造影结果 ,评价CBA对支架内再狭窄病变的有效性。方法　 16 6例支架内再狭窄PTCA病人 ,按所用球囊不同 ,分为CBA组 (98例 ) ,POBA组 (6 8例 ) ,分别比较术后即刻及远期定量冠脉造影最小血管径 (MLD)、狭窄度及再狭窄率。结果　术后即刻MLD及狭窄度两组差别无显著性 ,CBA组最大扩张压明显为低 [(8 3± 0 9)atm比 (14 7± 4 6 )atm ,P <0 0 5 ]。追踪造影结果 ,CBA组MLD明显大于POBA组 [(1 7± 0 5 )mm比 (1 4± 0 5 )mm ,P <0 0 5 ]、狭窄度明显小于POBA组 [(36± 13) %比(46± 15 ) %,P <0 0 1],再狭窄率低于POBA组 (2 6 1%比 4 0 3%,P <0 0 5 )。结论　CBA的低压扩张效果在支架内再狭窄病变亦是有效的 ,并且获得了较POBA低的再狭窄率 ,值得进一步探讨总结。     

Relationship between neointimal regrowth and mechanism of acute lumen gain during the treatment of in-stent restenosis with or without supplementary intravascular radiation.

We investigated whether neointimal regrowth is related to the mechanism of acute lumen gain during the treatment of in-stent restenosis (ISR) lesions both with and without adjunct intravascular brachytherapy. From the WRIST (Washington Radiation for In-Stent Restenosis Trial) cohort, 54 ISR patients ((192)Ir, 29; placebo, 25) were treated with nonrepeat stenting percutaneous interventions (excimer laser, rotational atherectomy, and/or balloon angioplasty) prior to (192)Ir or placebo therapy. Using Simpson's method, serial volumetric intravascular ultrasound (IVUS) analyses (pre- and posttreatment and 6-month follow-up) were analyzed to obtain stent, lumen, and intimal hyperplasia (IH) volumes that were then adjusted for stent length to create stent, lumen, and IH volume indexes. In the placebo group, the acute reduction of neointima (1.6 +/- 1.4 mm(3)/mm) was counteracted by intimal regrowth (2.1 +/- 1.7 mm(3)/mm). The amount of intimal regrowth correlated directly with the intimal reduction due to the intervention (r = 0.76; P < 0.001), but not with the amount of additional stent expansion. In the (192)Ir-treated group, intimal regrowth was significantly less than in the placebo group (-0.3 +/- 0.1 vs. 2.1 +/- 1.7 mm(3)/mm; P < 0.001) despite a similar initial intimal reduction (1.3 +/- 0.9 vs. 1.6 +/- 1.4 mm(3)/mm; P = NS). No correlation was found between intimal reduction at the time of the procedure and intimal regrowth in the (192)Ir group. In this study, neointimal regrowth following treatment of ISR lesions correlates directly with the extent of acute intimal volume reduction, but not with the extent of additional stent expansion. This relation is not seen in ISR segments treated with radiation, where intimal regrowth is substantially inhibited.     

Late vascular response to repeat stenting for in-stent restenosis with and without radiation: an intravascular ultrasound volumetric analysis

BACKGROUND: Re-stenting of in-stent restenosis (ISR) improves acute angiographic results. Methods and Results- Volumetric intravascular ultrasound analysis was performed in 70 ISR lesions that received either placebo (n=36) or (192)Ir radiation (n=34). ISR lesions treated by re-stenting were divided into 3 groups: old stent not re-stented (A), old/new stent overlap (B), and new stent only (C). ISR lesions treated without re-stenting were categorized as D. In placebo patients, postintervention lumen volume index (LVI) was significantly greater in re-stented segments B and C than in non-re-stented segment A (P<0.05).At follow-up, however, LVI was similar in all 4 segments secondary to the increased intimal hyperplasia (IH) reaccumulation within the re-stented segments. In patients treated with (192)Ir radiation, LVI was maintained from baseline to follow-up only in non-re-stented segments A and D. Conversely, there was a significant decrease in LVI in re-stented segments B and C (P<0.05). Qualitatively, 79% of patients in the irradiated group had stent struts with undetectable neointimal versus only 27% in the placebo group (P<0.001). Coefficient of variation of IH reaccumulation was greater in re-stented segments of (192)Ir patients (B=57.3% and C=58.9%) than in re-stented segments in placebo patients (B=27.3% and C 26.8%) and non-re-stented segments in irradiated patients. CONCLUSIONS: Additional lumen gain from re-stenting ISR lesions is counteracted by exaggerated neointimal proliferation in placebo patients. Maximum effectiveness and safety of radiation can be achieved for ISR lesions when treated without re-stenting. Thus, regardless of supplementary intravascular brachytherapy, repeat stenting strategies provided little long-term advantage.     

Late intravascular ultrasound findings of patients treated with brachytherapy for diffuse in-stent restenosis.

This study aimed at evaluating long-term (24-month) effects of beta-irradiation (188Re-MAG3-filled balloon) using intravascular ultrasound (IVUS) in patients with in-stent restenosis (ISR). Long-term effects of beta-irradiation on intimal hyperplasia (IH) within the stented segment and vessel and lumen dimensions of nonstented adjacent segments in patients with ISR have not been sufficiently evaluated. Two-year follow-up IVUS was performed in 30 patients with patent ISR segments at 6-month follow-up angiography. Serial IVUS images were acquired at five equidistant intrastent sites and at three different reference segment sites. IH burden (%) was defined as 100 x (IH/stent area). Mean intrastent IH area and IH burden significantly increased between 6 and 24 months, from 2.1 +/- 1.1 to 2.6 +/- 1.4 mm2 (P < 0.001) and from 26% +/- 10% to 33% +/- 14% (P < 0.001), respectively. There was a significant decrease of mean external elastic membrane (from 10.1 +/- 3.9 to 9.7 +/- 3.9 mm2; P = 0.015) and lumen area (from 5.6 +/- 2.3 to 5.1 +/- 2.3 mm2; P = 0.021) within distal reference segments between 6 and 24 months. Target lesion revascularization (TLR) was performed in six patients (20%) between 6 and 24 months after beta-irradiation therapy. There were no significant differences between TLR and non-TLR groups except for a smaller minimum lumen area at 24 months in the TLR group. Because of a small amount of late loss between 6 and 24 months, most irradiated ISR vessel segments remained stable for up to 2 years. However, quantitative evidence of late catch-up was evident in most patients and was significantly associated with 24-month TLR in some patients.     

Impact of the acute results on the long-term outcome after the treatment of in-stent restenosis: a serial intravascular ultrasound study.

The current study used serial (postintervention and follow-up) intravascular ultrasound (IVUS) to assess the impact of acute results on long-term follow-up of patients with in-stent restenosis (ISR). All patients (n = 180) with serial IVUS studies of ISR lesions from the following gamma-irradiation brachytherapy trials were included: Washington Radiation for In-Stent Restenosis Trial (WRIST), Gamma-1, and Angiorad Radiation Technology for In-Stent Restenosis Trial in Native Coronaries (ARTISTIC). There were 106 irradiated and 74 placebo patients. Quantitative analysis was performed according to the American College of Cardiology Clinical Expert Consensus Document on Standards for Acquisition, Measurement and Reporting of IVUS. Images were acquired using motorized transducer pullback, cross-sectional analysis was performed every 1 mm, and volumetric and mean planar dimensions were calculated. The independent predictors for the absolute follow-up minimum lumen area (MLA) were the postintervention MLA, the postintervention minimum stent area, and the use of brachytherapy. Placebo patients lost 45% of the postintervention MLA while irradiated patients lost only 17% of the MLA. The independent predictors of the follow-up percent intimal hyperplasia (intimal hyperplasia volume divided by stent volume) and the independent predictors of the absolute increase in intimal hyperplasia were the postintervention percent intimal hyperplasia and the use of brachytherapy. Serial IVUS analysis shows that the follow-up MLA and percent intimal hyperplasia are dependent on the results obtained during the treatment of ISR lesions.     

Edge stenosis and geographical miss following intracoronary gamma radiation therapy for in-stent restenosis

OBJECTIVES: We sought to determine the relationship between geographical miss (GM) and edge restenosis (ERS) following intracoronary radiation therapy. BACKGROUND: Edge restenosis may be a limitation of intracoronary irradiation to prevent in-stent restenosis (ISR). Inadequate radiation source coverage of the injured segment (GM) has been proposed as a cause of ERS. We studied the relationship between GM and ERS following 192Ir treatment of ISR. METHODS: There were 100 patients with native vessel ISR in WRIST (Washington Radiation for In-Stent Restenosis Trial), in which patients with ISR were first treated with conventional techniques and then randomized to gamma irradiation (192Ir) or placebo. Geographical miss was defined as segments proximal or distal to the treated lesion that were subjected to injury during primary intervention but were not covered by the radiation source. RESULTS: Geographical miss was documented in 56 of 164 edges (34%). Edge restenosis was noted at eight of 80 radiated edges and in four of 84 placebo edges. In the irradiated group, ERS was observed in 21% of edges with GM and in 40% of edges without GM (p = 0.035). In contrast, in the placebo group, ERS was observed in only 7% of edges with GM and in 4% of edges without GM (p = NS). The late edge lumen loss was higher in the irradiated group with GM as compared to placebo with GM (0.74 +/- 0.57 vs. 0.41 +/- 0.50 mm, p = 0.016). CONCLUSIONS: Edge restenosis following gamma irradiation treatment of ISR is related to GM: a mismatch between the segment of artery injured during the primary catheter-based intervention and the length of the radiation source.     

Serial intravascular ultrasound analysis of the impact of lesion length on the efficacy of intracoronary gamma-irradiation for preventing recurrent in-stent restenosis

BACKGROUND: The relation between lesion length and effectiveness of brachytherapy is not well studied. METHODS AND RESULTS: We compared serial (postintervention and follow-up) intravascular ultrasound findings in 66 patients with native coronary artery in-stent restenosis (ISR) who were treated with (192)Ir (15 Gy delivered 2 mm away from the radiation source). Patients were enrolled in the Washington Radiation for In-Stent Restenosis Trial (WRIST; ISR length, 10 to 47 mm; n=36) or Long WRIST (ISR length, 36 to 80 mm; n=30). External elastic membrane, stent, lumen, and intimal hyperplasia (IH; stent minus lumen) areas and source-to-target (intravascular ultrasound catheter to external elastic membrane) distances were measured. Postintervention stent areas were larger in WRIST and smaller in Long WRIST patients (P:<0.0001). At follow-up, maximum IH area significantly increased in both WRIST and Long WRIST patients (P:<0.0001 for both), but this increase was greater in Long WRIST patients (P:=0.0006). Similarly, minimum lumen cross-sectional area significantly decreased in both WRIST and Long WRIST patients (P:<0.05 and P:<0.0001, respectively), but this decrease was more pronounced in Long WRIST patients (P:=0.0567). The maximum source-to-target distance was longer in Long WRIST than in WRIST, and it correlated directly with ISR length (r=0.547, P:<0.0001). Overall, the change in minimum lumen area and the change in maximum IH area correlated with the maximum source-to-target distance (r=0.352, P:=0.0038 and r=0.523, P:<0.0001 for WRIST and Long WRIST, respectively). The variability (maximum/minimum) in IH area at follow-up also correlated with the maximum source-to-target distance (r=0.378, P:<0.0001). CONCLUSIONS: Brachytherapy may be less effective in longer ISR lesions because of the greater variability and longer source-to-target distances in diffuse ISR.     

Serial Intravascular Ultrasound Analysis of the Impact of Myocardial Bridge on Neointimal Proliferation After Coronary Stenting in Patients with Acute Myocardial Infarction

Background: Mechanisms underlying the association between myocardial bridge (MB)‐stenting and in‐stent restenosis (ISR) are still unclear. Objective: To assess the impact of MB on ISR using intravascular ultrasound (IVUS). Methods: In the Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction (HORIZONS‐AMI) trial, 100 left anterior descending artery (LAD) culprit lesions (79 treated with paclitaxel‐eluting stents [PES] and 21 treated with bare metal stents) were imaged with serial IVUS immediately postprocedure and at 13 months. Results: At baseline the LAD stent extended into the MB segment beyond the culprit lesion in seven patients (MB‐stent group). In the remaining 93 patients the LAD stent was implanted only in the culprit lesion without extending into the MB segment (non‐MB‐stent group). In PES‐treated lesions intimal hyperplasia (IH) was greater in MB‐stent group than in non‐MB‐stent group (1.0 [0.9, 1.3] mm² vs. 0.4 [0.2, 0.7] mm², P = 0.007). When comparing the MB‐stent segment with the non‐MB‐stent segment in the MB‐stent group treated with PES, a significant reduction in lumen area was observed in only the MB‐stent segment, owing to an augmented IH within the MB‐stent segment (1.56 [1.40, 1.91] mm² vs. 0.77 [0.55, 1.23] mm² for non‐MB‐stent segment, P = 0.08), not significant stent recoil (Δstent area). At follow‐up, the minimum lumen area was smaller in the MB‐stent group than in the non‐MB‐stent group (2.9 [2.5, 4.2] mm² vs. 5.2 [4.1, 6.7] mm², P = 0.02). Conclusions: Increased incidence of ISR associated with MB‐stenting may be attributable to enhanced IH, specific to stented MB segment, not to chronic stent recoil. (J Interven Cardiol 2010;23:114‐122)     

The effect of intracoronary radiation for the treatment of recurrent in-stent restenosis in patients with diabetes mellitus

OBJECTIVES: The purpose of this study was to examine the effect of intracoronary radiation therapy (IRT) in diabetic patients with in-stent restenosis (ISR). BACKGROUND: Diabetic patients are at an increased risk for restenosis, repeat revascularization procedures and late mortality after percutaneous coronary interventions and stenting. Intracoronary radiation therapy, utilizing both gamma and beta-emitters, has been shown to reduce the rate of ISR. METHODS: The study group consisted of 749 consecutive patients with ISR who were treated with either IRT or placebo in randomized trials and registries at our center. Diabetic patients (252 radiation and 51 placebo) were compared with nondiabetic patients (371 radiation and 75 placebo). RESULTS: In-hospital outcomes were similar between diabetic and nondiabetic patients treated with and without radiation. At six-month clinical and angiographic follow-up, there was a significant reduction in the binary restenosis (63.8% vs. 15.7%, p < 0.0001), target lesion revascularization (66.7% vs. 17.6%, p < 0.0001) and target vessel revascularization (TVR) (70.6% vs. 22.9%, p < 0.0001) rates in diabetic patients treated with radiation compared to placebo. Comparisons between the placebo arms detected a trend towards higher restenosis (63.8% vs. 48.4% p = 0.13) and TVR (70.6% vs. 56.0%, p = 0.14) in diabetic versus nondiabetic patients. In contrast, diabetic and nondiabetic patients treated with IRT experienced similar restenosis (15.6% vs. 10.7% p = 0.33) and TVR (22.9% vs. 28.2% p = 0.41) rates. CONCLUSIONS: In diabetic patients with ISR, intracoronary radiation significantly reduced the recurrence of ISR compared to placebo. Additionally, similar rates of restenosis and revascularization procedures were achieved in irradiated diabetic and nondiabetic patients. In view of these results, IRT should be considered as a valuable therapeutic alternative in all diabetic patients with ISR.     

Serial intravascular ultrasound comparison of the extent and distribution of intimal hyperplasia six months after stent implantation for de novo versus in-stent restenosis lesions

The aim of this study was to compare intimal hyperplasia (IH) growth at 6 months in patients with de novo lesions treated with stents versus IH regrowth in patients with treated in-stent restenosis. Intravascular ultrasound was performed after intervention and at the 6-month follow-up visit as part of a standardized protocol across several clinical trials. At 6 months, the lumen was larger in the de novo group (mean lumen cross-sectional area [CSA] 6.31 +/- 2.2 vs 4.48 +/- 1.9 mm(2), p = 0.0001; minimum lumen CSA 4.2 +/- 1.8 vs 2.59 +/- 1.5 mm(2), p = 0.0001). However, the total increase in the mean IH CSA volume was the similar in the de novo and ISR groups (2.89 +/- 1.6 vs 2.64 +/- 1.94 mm(2), respectively; p = 0.11). We found that IH regrowth in restented in-stent restenosis lesions was similar to that in de novo stent implantation and that the final lumen CSA was an important component of in-stent restenosis recurrence.