Revisiting late loss and neointimal volumetric measurements in a drug-eluting stent trial: analysis from the SPIRIT FIRST trial.

This study was conducted to reevaluate the significance of angiographic late loss and to assess the agreement between new proposed neointimal volumetric measurements derived from quantitative coronary angiography (QCA) and standard intravascular ultrasound (IVUS)-based parameters. Neointimal volumetric measurements may better estimate the magnitude of neointimal growth after stenting than late loss. In 56 in-stent segments (27, everolimus; 29, bare metal) in the SPIRIT FIRST study, we compared QCA measures with the corresponding IVUS parameters. Two IVUS-late loss models were derived from minimal luminal diameter (MLD) using either a circular model or a so-called projected MLD. QCA-neointimal volume was calculated as follows: stent volume (mean area of the stented segment x stent length) at post procedure - lumen volume (mean area of the stented segment x stent length) at follow-up (the stent length either from nominal stent length or the length measured by QCA). Videodensitometric neointimal volume was also evaluated. Each of the three neointimal volume and percentage volume obstruction by QCA showed significant correlation with the corresponding IVUS parameters (r = 0.557-0.594, P < 0.0001), albeit with a broad range of limits of agreement. Late loss and volumetric measurements by QCA had a broader range of standard deviation than those by IVUS. QCA-volumetric measurements successfully confirmed the efficacy of everolimus-eluting stents over bare metal stents (P < 0.05). Our proposed QCA volumetric measurements may be a practical surrogate for IVUS measurements and a discriminant methodological approach for assessment of treatment effects of drug-eluting stents.     

Intravascular Ultrasound Predictors of Angiographic Restenosis in Lesions Treated With Palmaz-Schatz Stents

Objectives. This study sought to evaluate the clinical, procedural, preinterventional and postinterventional quantitative coronary angiographic (QCA) and intravascular ultrasound (IVUS) predictors of restenosis after Palmaz-Schatz stent placement.Background. Although Palmaz-Schatz stent placement reduces restenosis compared with balloon angioplasty, in-stent restenosis remains a major clinical problem.Methods. QCA and IVUS studies were performed before and after intervention (after stent placement and high pressure adjunct balloon angioplasty) in 382 lesions in 291 patients treated with 476 Palmaz-Schatz stents for whom follow-up QCA data were available 5.5 ± 4.8 months (mean ± SD) later. Univariate and multivariate predictors of QCA restenosis (≥50% diameter stenosis at follow-up, follow-up percent diameter stenosis [DS] and follow-up minimal lumen diameter [MLD]) were determined.Results. Three variables were the most consistent predictors of the follow-up angiographic findings: ostial lesion location, IVUS preinterventional lesion site plaque burden (plaque/total arterial area) and IVUS assessment of final lumen dimensions (whether final lumen area or final MLD). All three variables predicted both the primary (binary restenosis) and secondary (follow-up MLD and follow-up DS) end points. In addition, a number of variables predicted one or more but not all the end points: 1) restenosis (IVUS preinterventional lumen and arterial area); 2) follow-up DS (QCA lesion length); and 3) follow-up MLD (QCA lesion length and preinterventional MLD and DS and IVUS preinterventional lumen and arterial area).Conclusions. Ostial lesion location and IVUS preinterventional plaque burden and postinterventional lumen dimensions were the most consistent predictors of angiographic in-stent restenosis.     

Meta-analysis of angiographic versus intravascular ultrasound parameters of drug-eluting stent efficacy (from TAXUS IV, V, and VI)

Both quantitative coronary angiography (QCA) and intravascular ultrasound (IVUS) are currently used to assess in-stent restenosis. This study aimed to use standardized imaging and clinical follow-up to compare QCA parameters with several IVUS parameters to evaluate their strengths and weaknesses for detecting in-stent restenosis in a drug-eluting stent population. A subset of patients from the TAXUS IV, V, and VI studies was evaluated. The subset, which included 216 TAXUS-treated patients and 191 bare-metal stent-treated patients, had complete IVUS and QCA performed at baseline and follow-up. As expected, all QCA and IVUS parameters were consistent with less intimal hyperplasia in TAXUS patients than controls. The overall incidence of QCA binary restenosis was 14.0%, which was 9.3% in TAXUS-treated patients and 19% in bare-metal stent-treated patients (p = 0.0008). Regression analysis showed that QCA late lumen loss and percentage of diameter stenosis correlated only moderately with the various IVUS measures of neointimal hyperplasia for the combined group of patients (TAXUS + bare-metal stent), as well as for the TAXUS-treated and bare-metal stent-treated patients separately. However, in general, correlations within the control (bare-metal stent) group tended to be stronger than within the TAXUS group. The strongest correlation was between QCA percentage of diameter stenosis and IVUS percentage of intimal hyperplasia in the overall group and the control group. The strongest IVUS predictor of QCA binary restenosis at 9 months was maximum percentage of intimal hyperplasia, with an overall C = 0.91 and p <0.001. In conclusion, the QCA and IVUS parameters used to evaluate drug-eluting stent efficacy showed a moderate correlation with IVUS percentage of intimal hyperplasia, reliably predicting QCA binary in-stent restenosis.     

国产与进口西罗莫司洗脱支架置入后血管内超声随访的对比

目的 利用血管内超声对比观察国产与进口西罗莫司洗脱支架对冠心病患者支架术后新生内膜增生的抑制作用.方法 2003年5月至2007年3月,对215例冠心病患者(317处病变)置入西罗莫司洗脱支架,并在术后1年行冠状动脉造影和血管内超声(IVUS)检查.其中Firebird组108例患者(147处病变)置入国产西罗莫司洗脱支架(Firebird支架),Cypher组107例患者(138处病变)置入进121西罗莫司洗脱支架(Cypher支架).结果 两组患者一般临床情况差异无统计学意义.两组靶病变部位、病变长度、狭窄程度及病变类型差异均无统计学意义,但Firebird组术后最小管腔直径大于Cypher组[(2.88±0.43)mm比(2.78±0.33)mm,P＜0.05].随访定量冠状动脉造影分析显示,Firebird组与Cypher组支架内晚期管腔丢失[(0.17±0.29)mm比(0.16±0.27)mm,P＞0.05]和节段内晚期管腔丢失[(0.18±0.36)mm比(0.20±0.32)mm,P＞0.05]差异均无统计学意义.IVUS分析显示,与Cypher组比较,尽管Firebird组支架面积[(6.99±2.25)mm~2比(6.46±1.71)mm~2,P＜0.05]、管腔面积[(6.89±2.30)nm~2比(6.36±1.73)mm~2,P＜0.05]、支架体积[(162.5±68.9)mm~3比(140.8±57.9)mm~3,P＜0.01]、管腔体积[(160.4±69.5)mm~3比(138.6±57.6)mm~3,P＜0.01]及最小支架面积[(5.40±1.85)mm~2比(4.92±1.43)mm~2,P＜0.05]均较大,但两组的内膜增生容积[(2.09±5.46)mm~3比(2.23±6.50)mm~3,P＞0.05]和内膜增生容积百分数[(1.68±5.84)%比(1.59±4.10)%,P＞0.05]差异均无统计学意义.结论 Firebird支架置人后再狭窄的发生率较低,抑制内膜增生作用与Cypher支架相似.     

Angiographic and intravascular ultrasound predictors of in-stent restenosis

Objectives. This study was performed to determine predictors of in-stent restenosis from a high volume, single-center practice.Background. Intracoronary stents have been shown to reduce the restenosis rate as compared with balloon angioplasty, but in-stent restenosis continues to be an important clinical problem.Methods. Between April 1993 and March 1997, 1,706 patients with 2,343 lesions were treated with a variety of intracoronary stents. The majority of stents were placed with high pressure balloon inflations and intravascular ultrasound (IVUS) guidance. Angiographic follow-up was obtained in 1,173 patients with 1,633 lesions (70%). Clinical, angiographic and IVUS variables were prospectively recorded and analyzed by univariate and multivariate models for the ability to predict the occurrence of in-stent restenosis defined as a diameter stenosis ≥50%.Results. In-stent restenosis was angiographically documented in 282 patients with 409 lesions (25%). The restenosis group had a significantly longer total stent length, smaller reference lumen diameter, smaller final minimal lumen diameter (MLD) by angiography and smaller stent lumen cross-sectional area (CSA) by IVUS. In lesions where IVUS guidance was used, the restenosis rate was 24% as compared with 29% if IVUS was not used (p < 0.05). By multivariate logistic regression analysis, longer total stent length, smaller reference lumen diameter and smaller final MLD were strong predictors of in-stent restenosis. In lesions with IVUS guidance, IVUS stent lumen CSA was a better independent predictor than the angiographic measurements.Conclusions. Achieving an optimal stent lumen CSA by using IVUS guidance during the procedure and minimizing the total stent length may reduce in-stent restenosis.     

Two-year serial coronary angiographic and intravascular ultrasound analysis of in-stent angiographic late lumen loss and ultrasonic neointimal volume from the TAXUS II trial

Late loss has been used as a reliable surrogate end point for evaluation and differentiation of short-term performance of drug-eluting stents. This study investigated the consistency between angiographic and intravascular ultrasound (IVUS) outcomes of late lumen loss (late loss) and neointimal growth to measure restenotic plaque load in TAXUS and bare metal stents. The randomized TAXUS II trial evaluates the polymer-based paclitaxel-eluting TAXUS stent in slow- and moderate-release formulations. Serial angiographic and IVUS analyses were available in 155 event-free patients (bare metal stent, 74; TAXUS stent, 81) after the procedure, at 6 months, and at 2 years. For this subanalysis, quantitative coronary angiographic (QCA) and IVUS measurements were used to derive late loss and neointimal volume. From after the procedure to 6 months, quantitative coronary angiography and IVUS showed matching results for the 2 groups with significant decreases in late loss and neointimal volume in the TAXUS versus the control group. From 6 months to 2 years, QCA and IVUS measurements also showed results similar to those in the control group, demonstrating neointimal compaction over time. However, in the TAXUS group, QCA late loss showed a nonsignificant decrease from 6 months to 2 years, whereas IVUS neointimal volume increased. In conclusion, although QCA and IVUS results were similar over the first 6 months, long-term assessment of changes in restenotic plaque load showed discrepant findings for the TAXUS. These findings suggest the need for critical reevaluation of current end points and the use of more precise techniques to detect lumen and stent boundaries.     

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.     

Relation of stent design and stent surface material to subsequent in-stent intimal hyperplasia in coronary arteries determined by intravascular ultrasound

A variety of different stent designs and coatings have become available. This study sought to determine the impact of stent design and gold-coating of stents on intimal hyperplasia (IH) in human atherosclerotic coronary arteries in relation to known predictors of restenosis. Angiographic and intravascular ultrasound (IVUS) studies were performed at 6-month follow-up on 311 native coronary lesions of 311 patients treated with 99 Multi-Link stents, 74 InFlow steel stents, 73 InFlow gold-coated stents, 41 Palmaz-Schatz stents, 12 NIR steel stents, and 12 gold-coated NIR Royal stents. Lumen and stent cross-sectional area (CSA) were measured at 1-mm axial increments. Mean IH CSA (stent CSA − lumen CSA) and mean IH thickness were calculated and averaged over the total stent length. IVUS demonstrated different levels of IH for the 6 stents. Mean IH thickness ranged from 0.20 ± 0.13 mm for Multi-Link stents to 0.43 ± 0.14 mm for InFlow goal-coated stents (p <0.001). Multivariate analysis proved non–Multi-Link stent design (odds ratio 3.45, 95% confidence intervals 1.13 to 11.11, p <0.034) and gold coating (odds ratio 3.78, 95% confidence intervals 1.88 to 7.54, p <0.001) to be the only independent predictors of IH thickness >0.3 mm. In conclusion, stent design and surface material have an important impact on the IH response to stents implanted in human coronary arteries. However, the differences in IH thickness between the analyzed stents were relatively small compared with the absolute lumen dimensions.     

国产西罗莫司洗脱支架与紫杉醇洗脱支架抑制血管内膜增生的血管内超声比较研究

目的利用血管内超声（IVUS）方法比较国产西罗莫司洗脱支架（Firebird^TM）与紫杉醇洗脱支架（Taxus^TM）对冠心病患者新生内膜增生的抑制作用。方法自2003年5月至2007年6月,203例冠心病患者（283处病变）行药物洗脱支架术并在术后1年行冠状动脉造影和血管内超声（IVUS）检查。其中136例患者（185处病变）置入Firebird^TM支架（Firebird组）,67例患者（98处病变）置入TaxusTM支架（Taxus组）。结果203例患者（283处病变）中168例患者（236处病变）接受了一年随访造影和血管内超声检查,其中Firebird组108例患者（147处病变）,Taxus组60例患者（89处病变）。两组患者基础临床情况及造影特征相似。Firebird组支架内晚期管腔丢失（0.17±0.29mm比0.43±0.51mm,P〈0.0001）和节段内晚期管腔丢失（0.18±0.36mm比0.38±0.33mm,P=0.003）明显小于Taxus组,而两组近端参考血管晚期管腔丢失（0.11±0.27mm比0.15±0.32mm,P=0.321）和远端参考血管晚期管腔丢失（0.08±0.10mm比0.09±0.16mm,P=0.483）差异并无统计学意义。IVUS分析显示,两组间平均支架面积、平均管腔面积、最小支架面积、平均支架体积、平均管腔体积比较,差异均无统计学意义。但Firebird组平均内膜增生面积（0.35±0.58mm^2比1.29±1.26mm^2,P〈0.0001）、平均内膜增生面积百分数（5.45%±9.26%比17.38%±13.75%,P〈0.0001）、内膜增生最大面积百分数（9.41%±14.15%比31.56%±20.99%,P〈0.0001）、平均内膜增生容积（2.09±5.46mm^3比13.43±18.59mm^3,P〈0.0001）和平均内膜增生容积百分数（1.68%±5.84%比8.62%±9.90%,P〈0.0001）较Taxus组均明显减少。结论国产西罗莫司洗脱支架（Firebird^TM）置入术后再狭窄发生率较低,与TaxusTM支架相比,抑制内膜增生作用更显著。     

Mechanisms and predictors of carotid artery stent restenosis: a serial intravascular ultrasound study.

OBJECTIVES: The aim of this study was to determine the mechanisms and predictors of carotid artery restenosis after carotid artery stenting (CAS) using serial intravascular ultrasound (IVUS) imaging. BACKGROUND: Carotid artery stenting is increasingly used to treat high-grade obstructive carotid disease, but our knowledge of carotid in-stent restenosis and remodeling remains limited. METHODS: Post-procedural and 6-month (median 6 months) follow-up quantitative carotid angiography and IVUS were performed after self-expanding stent deployment in 50 internal carotid arteries (ICA). The IVUS measurements at multiple designated sites included minimal luminal diameter, lumen area, stent area (SA), and neointimal hyperplasia area (NIH). RESULTS: Late stent enlargement at follow-up was found at all segments, and the percentage increase was greatest at the ICA lesion site (mean +/- SD, 48.9 +/- 35.3%). The NIH, expressed as a percentage of SA, was seen within all segments of the stent and was greatest at the ICA lesion site (37.3 +/- 23.3%). There was a strong positive correlation between the amount of NIH and late stent enlargement (r = 0.64; p < 0.001). Immediate post-procedural minimum ICA SA (r = -0.37; p < 0.01) and stent expansion (r = -0.44; p = 0.001) correlated negatively with the percentage restenotic area at follow-up. CONCLUSIONS: Although self-expanding carotid stents generate considerable neointimal hyperplasia, the process is balanced by marked late stent enlargement. Small stent dimensions immediately post-procedure were associated with a higher risk of restenosis.     

Intravascular ultrasound evaluation after sirolimus eluting stent implantation for de novo and in-stent restenosis lesions.

AIMS: The aim of this study is to compare the efficacy of sirolimus-eluting stents (SES) on neointimal growth and vessel remodelling for in-stent restenosis versus de novo coronary artery lesions using serial intravascular ultrasound (IVUS). METHODS AND RESULTS: The study population consisted of 86 patients with in-stent restenosis (ISR) (n=41) or de novo lesions (n=45) treated with SES and evaluated by IVUS post-procedure and at follow-up. One 18-mm SES was used for de novo lesions while 16 patients with ISR received >1SES (total stented length 17.9 mm vs 22.0 mm respectively; P=0.004). At follow-up, no differences were observed between the ISR and de novo groups with respect to changes in the mean external elastic membrane (1.7% vs 1.3%; P=0.53), plaque behind the stent (1.2% vs 3.4%; P=0.49), and lumen areas (0.7% vs 1.9%; P=0.58). No positive remodelling or edge effect was observed. A gap between stents was observed in two patients with ISR, where more prominent, though non-obstructive, neointimal proliferation was noted. CONCLUSION: Sirolimus-eluting stenting is equally effective at inhibiting neointimal proliferation in de novo and ISR lesions without inducing edge restenosis or positive vascular remodelling.     

Angiographic, intravascular ultrasound, and fractional flow reserve evaluation of direct stenting vs. conventional stenting using BeStent2 in a multicentre randomized trial.

AIMS: Direct stenting (DS) may not be as safe and effective as conventional stenting. The objective was to demonstrate equivalence of post-procedural mean luminal diameter (MLD) by angiography after BeStent2 placement between DS and pre-dilatation (PD) strategy. METHODS AND RESULTS: Two hundred and two patients with a single de novo lesion (diameter >/=3.0 mm and length 相似文献   

Usefulness of intravascular ultrasound-guided histological measurements after stenting in porcine coronary artery

BACKGROUND: We evaluated the usefulness of intravascular ultrasound (IVUS) in the non-uniform distribution of in-stent neointimal hyperplasia, comparing macroscopic measurements with IVUS-guided histomorphometry. METHODS: Coronary stenting was performed in 45 left coronaries of 39 pigs, using 18 Tenax (Biotronik Gmbh and Co., Berlin, Germany), 11 bare Genius (Eurocor, Bonn, Germany), 10 polymer-coated Genius (Eurocor) and six Biodivysio Matrix LO (Biodivysio Ltd, Farnham, Surrey, UK) stents. After 4 weeks, coronary angiography and IVUS with automatic pullback were performed. IVUS images were analysed using three-dimensional analysis (EchoPlaque 2; INDEC Systems Inc., Mountain View, California, USA). The stented segments were formalin fixed, embedded in Technovit 9100 and cut to 4-8 microm thick slides. The most diseased in-stent segment was 4.49 +/- 4.54 mm away from the distal stent edge assessed by IVUS. Sections of these segments were stained for histomorphometry. RESULTS: A significant correlation was found between IVUS-guided histomorphometry and three-dimensional IVUS measurements of maximal intimal thickness (r = 0.6985, P < 0.005) and area (r = 0.7736, P < 0.001). Macroscopic measurements resulted in comparable maximal intimal thickness (0.83 +/- 0.43 mm compared with 0.81 +/- 0.46 mm) and area (4.44 +/- 1.73 mm2 compared with 3.45 +/- 1.55 mm2) by IVUS and histomorphometry, respectively. Although stent length, diameter, nominal inflation pressure and time and injury score did not differ between the stents, bare Genius stents resulted in significant smaller neointimal volume compared to Tenax, polymer-coated Genius and Biodivysio stents: 24.46 +/- 4.98 mm3 compared with 59.18 +/- 26.41, 60.46 +/- 10.03 and 61.41 +/- 16.27 mm3, respectively (P < 0.05). CONCLUSION: The significant correlation between IVUS-guided histomorphometry and IVUS measurements confirms the usefulness of IVUS in evaluation of experimental in-stent restenosis. Implantation of bare Genius stents resulted in significant lower neointimal hyperplasia compared to Tenax, polymer-coated Genius or phosphorylcholine-coated Biodivysio stents.     

Mechanisms of acute lumen gain and recurrent restenosis after rotational atherectomy of diffuse in-stent restenosis: a quantitative angiographic and intravascular ultrasound study.

OBJECTIVES: This quantitative angiographic and intravascular ultrasound study determined the mechanisms of acute lumen enlargement and recurrent restenosis after rotational atherectomy (RA) with adjunct percutaneous transluminal coronary angioplasty in the treatment of diffuse in-stent restenosis (ISR). BACKGROUND: In-stent restenosis remains a significant clinical problem for which optimal treatment is under debate. Rotational atherectomy has become an alternative therapeutic approach for the treatment of diffuse ISR based on the concept of "tissue-debulking." METHODS: Rotational atherectomy with adjunct angioplasty of ISR was used in 45 patients with diffuse lesions. Quantitative coronary angiographic (QCA) analysis and sequential intravascular ultrasound (IVUS) measurements were performed in all patients. Forty patients (89%) underwent angiographic six-month follow-up. RESULTS: Rotational atherectomy lead to a decrease in maximal area of stenosis from 80+/-32% before intervention to 54+/-21% after RA (p < 0.0001) as a result of a significant decrease in intimal hyperplasia cross-sectional area (CSA). The minimal lumen diameter after RA remained 15+/-4% smaller than the burr diameter used, indicating acute neointimal recoil. Additional angioplasty led to a further decrease in area of stenosis to 38+/-12% due to a significant increase in stent CSA. At six-month angiographic follow-up, recurrent restenosis rate was 45%. Lesion and stent length, preinterventional diameter stenosis and amount of acute neointimal recoil were associated with a higher rate of recurrent restenosis. CONCLUSIONS: Rotational atherectomy of ISR leads to acute lumen gain by effective plaque removal. Adjunct angioplasty results in additional lumen gain by further stent expansion and tissue extrusion. Stent and lesion length, severity of ISR and acute neointimal recoil are predictors of recurrent restenosis.     

First human experience with angiopeptin-eluting stent: a quantitative coronary angiography and three-dimensional intravascular ultrasound study.

Angiopeptin has been shown to reduce in-stent restenosis in various animal models. Meanwhile, BiodivYsio DD phosphorylcholine (PC)-coated stent provides a platform for local delivery of antiproliferative agents to the coronary artery. We studied the feasibility, safety, and impact on tissue growth of angiopeptin-eluting BiodivYsio DD PC-coated stents in human native de novo coronary lesions. We enrolled 14 patients (16 lesions) who underwent intravascular ultrasound (IVUS)-guided angiopeptin-eluting stent implantation in native coronary arteries between 3.0 and 4.0 mm in diameter with lesion length相似文献   

"Head-to-head comparison between sirolimus-eluting and paclitaxel-eluting stents in patients with complex coronary artery disease: an intravascular ultrasound study".

BACKGROUND: The aim of this study was to assess neointimal hyperplasia following sirolimus-eluting (SES) and paclitaxel-eluting stents (PES) implantation in a patients with complex coronary disease. METHOD: Between January to December 2004, 70 patients were enrolled in this study (SES = 37; PES = 33. The primary objective was to assess the efficacy of SES and PES on neointimal proliferation inhibition in patients with complex coronary lesions by volumetric 3D intravascular ultrasound (IVUS) assessment at six-month follow-up. RESULTS: Baseline clinical, demographic or angiographic characteristics were well balanced in both groups. All procedures as well as hospitalisation were uneventful. The percentage of B2/C lesions in our study was > 90% in both groups. The IVUS-assessed in-stent mean neointimal hyperplasia volume was significantly lower in lesions treated with SES compared to PES (4.1 +/- 11 mm3 vs. 17.4 +/- 23 mm3, p < 0.002) at 6 month follow-up. No difference in both MACE (3.0 versus 6.0%, p = NS) and restenosis (5.4 versus 9.1%, p = NS) were found. The in-segment late loss at six month was 0.26 mm in the SES and 0.48 mm in the PES group (p = NS). CONCLUSIONS: The present study showed reduced neointimal proliferation after sirolimuseluting as compared to paclitaxel-eluting stents in patients with complex coronary artery disease. Both SES and PES were associated with low rate of angiographic restenosis or major adverse cardiovascular events.     

The effect of paclitaxel-eluting stents on restenosis]

OBJECTIVE: In our study we aimed to investigate the effects of paclitaxel-eluting stent on restenosis. METHODS: Sixteen porcine were randomly assigned to two groups (n=8 per group): control group animals received conventional stent implantation and study group animals -paclitaxel-eluting stent implantation. Both groups were treated with 300 mg acetylsalicylic acid and 75 mg clopidogrel daily. The degree of neointimal proliferation and effect of drug-eluting stent on restenosis were evaluated 6 weeks after by angiography and intravascular ultrasound (IVUS). RESULTS: Angiographic in-stent restenosis was lower in paclitaxel-eluting stent group (12.50 +/- 7.07% versus 41.25 +/- 28.50%, p=0.001). The IVUS data demonstrated that paclitaxel group animals had larger minimal lumen area (8.76 +/- 1.09 mm2 versus 6.23 +/- 3.10 mm2, p=0.028), smaller mean neointimal proliferation area (1.03 +/- 0.75 mm2 versus 3.55 +/- 2.86 mm2, p=0.01) and mean percent stenosis (10.71 +/- 8.10% versus 36.85 +/- 30.93%, p=0.01). CONCLUSION: This study suggests that drug-eluting stents may also have a preventive effect for the in-stent restenosis.     

Meta-analysis of the effects of paclitaxel-eluting stents versus bare metal stents on volumetric intravascular ultrasound in patients with versus without diabetes mellitus

Diabetes mellitus is a strong predictor of in-stent restenosis after bare-metal stent placement because of exaggerated intimal hyperplasia (IH). In this study, serial intravascular ultrasound was used to evaluate the effects of polymer-based, paclitaxel-eluting stents (PES) on in-stent neointima formation in patients with and without diabetes. A volumetric IVUS meta-analysis of 956 patients randomized to PES or bare-metal stents in the TAXUS IV (n=268), TAXUS V (n=509), and TAXUS VI (n=179) trials was performed. Diabetes was present in 273 of the 956 patients (28.6%). Stent, luminal, and IH areas were measured every millimeter within the stent, and volumes, percentage IH (%IH), and neointima-free stent length were calculated. Patients with diabetes treated with bare-metal stents had greater IH volumes (78.9 vs 61.2 mm3, p=0.0095) and %IH (34.9% vs 30.1%, p=0.0186) compared with those without diabetes. However, patients with diabetes treated with PES had similar median IH volume (22.8 vs 16.3 mm3, p=0.35) and median %IH (9.1% vs 9.2%, p=0.27) compared with those without diabetes and significantly less IH volume and %IH than after bare-metal stent implantation (p<0.0001 for the 2 comparisons). In conclusion, serial volumetric IVUS analysis showed that treatment with PES neutralizes the propensity of patients with diabetes to develop greater IH, such that patients with and without diabetes treated with PES have similar vascular responses and restenosis rates.     

A new intracoronary measurement catheter, MetriCath, compared to intravascular ultrasound and quantitative coronary angiography in a stented porcine coronary model.

The purpose of this study was to compare measurements by MetriCath to intravascular ultrasound (IVUS) and quantitative coronary angiography (QCA). The MetriCath system consists of a low-pressure (200 mm Hg) balloon catheter connected to a pressure transducer and infusion pump linked to a computer that records pressure-volume curves. Cross-sectional area of blood vessels is obtained directly from the unrestrained and in-stent pressure-volume measurements. We compared stent cross-sectional area measurements by MetriCath, IVUS, and QCA in a porcine stented coronary artery model. Comparison of area measurements in 14 stents showed no significant differences between the three methods (P = 0.66). On average, values differed 0.37 +/- 0.60 mm(2) between MetriCath and QCA, 0.13 +/- 0.55 mm(2) between MetriCath and IVUS, and 0.22 +/- 0.80 mm(2) between IVUS and QCA. This corresponds to 6.2% +/- 10%, 3.0% +/- 9.0%, and 3.1% +/- 12.9% relative difference from the average of two corresponding measurements. Linear regression analysis showed excellent correlation between measurements (r = 0.99 for all comparisons). The differences in in-stent area measurements between MetriCath and both QCA and IVUS were small. Considering the ease and rapidity of obtaining MetriCath results, this technique may form an alternative to the others in evaluating stent expansion. Based on these findings, clinical evaluation seems warranted.     

Intravascular ultrasound analysis of beta radiation therapy for diffuse in-stent restenosis to inhibit intimal hyperplasia.

We evaluated the efficacy of beta-radiation therapy ((188)Re-MAG(3)) to inhibit intimal hyperplasia (IH) in diffuse in-stent restenosis by intravascular ultrasound (IVUS) analysis in 50 patients. Nine patients who did not agree with radiation therapy, and therefore underwent rotational atherectomy and balloon angioplasty for diffuse in-stent restenosis in the same study period, were selected for control groups. Serial IVUS comparisons were available in 44 of 50 patients with radiation therapy and 7 of 9 control patients. At 6-month follow-up, there was less significant increase of IH area in patients with radiation therapy than in control patients (Delta IH area = 0.1 +/- 0.8 mm(2) vs. 2.6 +/- 1.8 mm(2), P > 0.001 in mean values, and 0.6 +/- 1.4 mm(2) vs. 2.9 +/- 2.1 mm(2), P = 0.026 in values of follow-up lesion site, respectively). In conclusion, beta-radiation therapy might be an effective treatment modality to inhibit intimal hyperplasia in patients with diffuse in-stent restenosis.