冠状动脉介入治疗中StentBoost技术的应用及其与血管内超声的比较

目的:探讨StentBoost技术增强冠状动脉支架显影及检测支架扩张不充分的可行性并与血管内超声(IVUS)进行比较。方法:2009-03至2009-06间我院17例同时行IVUS和StentBoost检查的患者资料,平均年龄(55.76±12.63)岁,32～79岁,其中男性13例(76.47%),女性4例(23.53%),分别对冠状动脉造影定量分析(QCA)、IVUS和StentBoost检测数据进行相关性分析。结果:最小支架直径IVUS与StentBoost的相关性(r=0.9733,P0.0001)优于QCA与StentBoost的相关性(r=0.9708,P0.0001),以及优于QCA与IVUS的相关性(r=0.9589,P0.0001),而支架偏心指数QCA与StentBoost的相关性最好(r=0.5527;P=0.021)。结论:与QCA相比,StentBoost和IVUS具有更好的相关性。     

支架影像增强显影技术及其对球囊后扩张的指导作用

目的:探讨支架影像增强显影技术(StentBoost,SB)增强冠状动脉(冠脉)支架显影以及对球囊后扩张的指导作用。方法:收集2009-03至2010-07经皮冠脉介入治疗(PCI)术后在SB指导下给予球囊后扩张的184例患者资料,平均年龄(64.5±10.9)岁(42～83岁),对其后扩张前后SB测量数据进行比较。其中52例(28.26%)患者给予血管内超声(IVUS)检查,并分别对冠脉狭窄程度定量分析(QCA)、IVUS和SB检测数据进行相关性分析。结果:后扩张后较后扩张前支架内最小直径[(2.72±0.35)mm vs.(2.42±0.39)mm]、支架内最大直径[(3.26±0.37)mm vs.(3.09±0.38)mm]及支架内平均直径[(2.99±0.36)mm vs.(2.76±0.43)mm]均明显增大,支架偏心指数(0.17±0.04 vs.0.22±0.06)明显减小,差异均有统计学意义(P<0.001)。支架内最小直径IVUS与SB的相关性r=0.979,P<0.0001;冠脉狭窄程度定量分析与SB的相关性r=0.973,P<0.0001;QCA与IVUS的相关性r=0.964,P<0.0001。结论:SB与IVUS具有良好的相关性,且在评价支架置入效果以及指导高压球囊后扩张方面具有临床实用价值。     

支架影像增强显影技术在冠脉支架植入术中的应用效果观察

目的：评价支架增强显影（ SB）技术在冠脉支架植入术中的应用效果。方法将204例行冠状动脉支架植入术的患者随机分为观察组和对照组,各102例。两组均采用常规冠状动脉造影方法行冠状动脉造影,并在其指导下进行冠状动脉支架植入术。对照组支架植入后采用QCA自动分析系统测量支架直径的相关参数（包括支架直径的最小值、最大值、均值）并计算支架偏心指数。同时进行支架可视性和球囊内扩张必要性评分。观察组在支架植入后行SB,测量上述指标并进行上述评分。观察组26例支架植入后行血管内超声（ IVUS）检查,测量上述指标并进行上述评分。结果对照组支架植入后支架可视性得分低于观察组, P＜0．05。对照组发现30处、观察组发现48处有球囊内扩张必要性而行支架球囊内扩张术。两组QCA、SB、IVUS测得植入支架最小直径、最大直径、直径均值和支架偏心指数差异无统计学意义。 Pearson相关性分析显示QCA与SB、QCA与IVUS、SB与IVUS测得支架最小直径均有良好的相关性,r分别为0．772、0．775、0．782,P均＜0．05。结论 SB可明显提高支架的可视性,有效指导支架的球囊内扩张,在测量支架直径方面甚至可以替代冠脉内超声。     

不同支架植入方式对小血管支架内再狭窄的影响

目的:观察不同支架植入方式对小血管（血管直径≤2.75 mm）支架内再狭窄的影响。方法: 对69（男51,女18）例患者共111处病变进行治疗,实验组（n=38）直接植入支架64枚（雷帕霉素药物洗脱支架53枚,紫杉醇药物洗脱支架11枚）,对照组（n=31）预扩张后植入支架47枚（雷帕霉素药物洗脱支架41枚,紫杉醇药物洗脱支架6枚）,两组患者术后即刻行冠脉血管内超声(IVUS)检测最小支架直径及横截面积。术后有胸闷胸痛症状患者即刻行冠脉造影术及IVUS,无症状患者6个月后复查。通过IVUS检测,对两组管腔丢失及支架内再狭窄率进行比较。结果: 两组支架植入术后即刻最小支架直径实验组为（2.38±0.26）mm,对照组为（2.34±0.24）mm（P＞0.05）;支架横截面积实验组为（4.5±1.0）mm2,对照组为（4.3±0.9）mm2（P＞0.05）;6个月随访后复查两组管腔丢失,实验组为（1.44±0.30）mm,对照组为（0.98±0.24）mm（P=0.01）;支架内再狭窄发生率实验组为15 %;对照组为30%（P＜0.05）。结论: 对冠状动脉小血管病变患者直接药物洗脱支架植入组支架内再狭窄发生率低于预扩张后支架植入组。     

新型支架增强显影技术诊断支架断裂的临床价值

目的探讨新型支架增强显影技术(StentBoost)诊断支架断裂的临床应用价值。方法回顾性分析我院冠状动脉介入治疗术后并行冠状动脉造影复查的患者资料,对可疑支架断裂患者分别行血管内超声(IVUS)及StentBoost来明确诊断。结果 7例患者出现支架断裂,5例(71.43%)发生在左前降支,其中Cypher支架占71.43%,支架平均直径(3.00±0.47)mm,平均长度(27.00±6.90)mm。发生断裂部位为双支架重叠处3例(42.86%),弯曲病变处3例(42.86%)。支架断裂导致支架内再狭窄5例(71.43%),支架内血栓形成3例(42.86%),瘤样扩张2例(28.57%)。7例患者均进行临床随访,平均随访时间2.8年,均未再发心绞痛,无主要心脏不良事件发生。结论StentBoost能清晰显示支架的骨架结构,可协助冠状动脉造影对支架断裂做出明确诊断并指导治疗。     

支架影像增强显影技术在老年冠脉介入治疗患者中的应用

目的评价支架增强显影技术(SB)在老年冠脉介入患者中的应用价值。方法 2011年10月至2013年3月行冠脉介入治疗(PCI)老年患者102例为观察组,在冠状动脉造影定量分析(QCA)基础上,应用SB进行支架可视性评价和支架后扩张必要性评价;同期进行冠脉介入的老年患者102例作为对照组,单纯应用QCA冠状动脉造影定量分析进行支架可视性评价和支架后扩张必要性评价。通过标准的QCA和SB对支架可视性进行评价并分为1~4级(1级=差,2级=可,3级=良,4级=优)。经QCA定量分析、SB对球囊后扩张的必要性进行评价(球囊后扩张必要性:0=支架贴壁良好不需要后扩张;1=支架贴壁可,不需要后扩张;2=支架贴壁不良,需要后扩张)。结果 QCA显示支架可视性为(2.03±0.84)级(其中1级40个,2级71个,3级32个,4级8个),SB显示支架可视性为(2.79±0.84)级(其中1级14个,2级32个,3级82个,4级28个),两者相比,差异有统计学意义(P0.05)。根据QCA定量分析结果行球囊后扩张30次,根据SB评价结果行球囊后扩张48次,两者相比,差异有统计学意义(P0.001)。结论 SB可明显提高支架的可视性,有效指导支架的后扩张,在不增加手术时间和费用的基础上可能降低支架血栓形成的风险。     

血管内超声指导CYPHERTM支架球囊后扩张的临床应用

目的:在血管内超声(IVUS)指导下,评价雷帕霉素药物洗脱支架(CYPHERTM)置入后球囊后扩张的临床价值。方法:选取72例CYPHERTM置入患者,在IVUS指导下选择支架大小,置入支架后,根据IVUS结果是否满足MUSIC标准分为不需球囊后扩张的支架组(NPB组)和需要球囊后扩张的支架组(PB组),对PB组患者继续用比支架大0.5mm的后扩张球囊1418.2~2026kPa扩张1~4次,反复IVUS检查,直到符合标准。术后6个月内随访观察主要临床心血管事件,满6个月时复查冠状动脉造影和IVUS。结果:球囊后扩张前,PB组支架贴壁状况、支架对称系数、支架最小截面积不满意,和NBP组比较,差异有统计学意义(P<0.01),球囊后扩张后IVUS参数达到标准,2组比较差异无统计学意义(P>0.05),并且球囊后扩张后支架近远端夹层没有明显增加。6个月复查时,2组支架最小截面积、增生内膜面积、面积狭窄率、主要临床心血管事件也差异无统计学意义(P>0.05),但是PB组的面积狭窄率和临床心血管事件有减低趋势。结论:CYPHERTM置入后,在IVUS指导下进行球囊后扩张安全可行,对那些支架扩张不充分的患者能减低再狭窄率和心血管不良事件。     

定量冠状动脉造影对糖尿病患者靶病变及参考血管的评价

目的 对比血管内超声(IVUS)与定量冠状动脉造影(QCA)对于冠心病合并糖尿病患者靶病变和参考血管定量测量结果,评价QCA的准确性,以指导临床的干预治疗.方法 2型糖尿病患者52例,男35例,女27例,年龄(62.3±7.1)岁.接受QCA和IVUS检查.以IVUS测量最小面积处斑块负荷结果作为因变量,以QCA定量测量的病变血管狭窄程度作为自变量,进行相关和回归分析,得到相关系数,建立回归方程.并对比近、远端参考血管直径两类方法测量值.结果 QCA冠状动脉狭窄程度测量结果同IVUS最小面积处斑块负荷结果的回归方程(斜率:0.8286,P=0.001)显示二种方法的测量结果有明确的同步变化趋势和相关性(r=0.691,P＜0.001).但QCA测量结果(57.9%±15.5%)较ivus(53.5%±12.9%)高估了病变的严重程度(差值为4.6%±1.2%).本组患者为血管负性重构,重构指数(RI)为0.87±0.23.相对于近、远端参考血管的管腔直径测量误差[(0.24±0.06)mm和(0.07±0.01)mm]而言,QCA对近、远端参考血管的血管直径的测量误差[(0.81±0.24)mm和(0.64±0.17)mm]更为明显.结论由于糖尿病患者广泛的血管重构(尤其是负性重构),使QCA易高估罪犯血管严重程度.同时,QCA因无法准确显示斑块负荷,而导致造影显示为"正常"血管段,从而低估近远端参考血管直径.     

川芎嗪药物涂层支架预防猪冠状动脉再狭窄的实验研究

目的 探讨川芎嗪药物涂层支架(TES)预防冠状动脉再狭窄的作用机制及其有效性.方法 TES为金属管状支架经喷涂川芎嗪单体制成(含川芎嗪200μg).采用随机、双盲实验在14只小型猪的冠状动脉左前降支分别置入TES及金属裸支架(BMS)(实验组7只,对照组7只).支架置入前后均行定量冠状动脉造影(QCA)及血管内超声(IVUS)检查.术后第28天随访行QCA及ⅣUS观察支架内膜增殖及血栓形成情况.实验终点处死动物,获取支架置入段血管及支架前后5 cm处组织行病理学及免疫组化检查.结果 14只动物均成功置入支架,4只动物因手术意外死亡未列入统计.5只动物于左前降支置入TES,5只动物置入BMs.术后第28天随访,QCA检查支架段血管直径狭窄百分比两组分别为实验组(10.0±2.1)%和对照组(60.2±23.5)%(P=0.01).IVUS检查显示,两组支架内面积相似,均未见血栓形成.对照组内弹力膜面积较实验组明显减小(P=0.021),而新生内膜面积明显增大(P=0.004).术后处死动物组织形态学检查显示两组血管损伤评分和支架内面积相近(P>0.05),均无明显的炎症反应,但实验组管腔面积[(4.34±0.93)mm2]较对照组[(1.29±1.02)mm2]明显增加(P=0.011),新生内膜面积[(1.51±0.45)mm2]较对照组[(4.60±1.39)mm2]明显减少(P=0.004).组织病理学检查提示所有支架置入节段均完全内皮化,实验组增殖细胞核抗原染色阳性细胞核明显减少,凋亡细胞较对照组增多.结论 川芎嗪药物涂层支架能有效抑制血管内膜增殖及血栓形成,减少支架内再狭窄.     

经冠脉内超声指导下的直接冠脉内支架置入术

目的观察冠脉内超声(IVUS)指导下进行直接冠脉内支架置入术的可行性及临床效果.方法 12例冠心病患者常规冠脉造影术后,对拟行直接支架置入术的血管行IVUS术,观察病变特性,记录病变处血管壁直径,病变狭窄处最小腔径及病变长度.根据IVUS测得的病变血管壁直径及病变长度选择置入支架.支架置入后再行IVUS检查,观察支架贴壁性,两端有无夹层,测量管腔内支架最小径/最大径比值,决定是否进一步处理.近期随访有无急性或亚急性血栓形成和主要心脏事件(心脏性死亡、与靶血管相关的心绞痛、心肌梗死及再次血管重建).结果经IVUS指导下,12例冠心病患者直接支架置入术全部成功.冠脉造影显示无残余狭窄,TIMI血流3级.2例患者支架置入后IVUS检查贴壁不满意,管腔最小径/最大径比值＜0.7,经进一步高压扩张达标.最终IVUS显示全部支架贴壁及展开满意,管腔最小径/最大径比值≥0.7,病变处最小径由术前平均1.2±0.87 mm增至术后3.4±2.8 mm.1～4个月随访无血栓形成及主要心脏事件.结论 IVUS指导下直接冠脉内支架置入术成功率高,并发症少,临床应用安全有效.     

Determination of adequate coronary stent expansion using StentBoost, a novel fluoroscopic image processing technique.

OBJECTIVE: We tested the hypothesis that the use of motion-corrected fluoroscopic images results in enhanced coronary stent visualization and improved detection of inadequate stent expansion. BACKGROUND: Intravascular ultrasound (IVUS) more accurately detects inadequate stent expansion when compared with coronary angiography. Stent under-expansion is associated with stent restenosis and thrombosis. Developing a technique to improve fluoroscopic-based assessment of stent expansion is desirable. METHODS: We analyzed measurements of 48 coronary stents implanted in 30 patients using quantitative coronary angiography (QCA), IVUS, and StentBoost (SB), a novel fluoroscopic image processing technique. Correlations of stent diameter between the modalities were determined. Using established IVUS criteria for adequate stent deployment, we assessed the diagnostic test characteristics of SB to detect inadequate stent expansion. RESULTS: Correlations of minimum stent diameter were highest between IVUS and SB (r=0.75; P<0.0001) when compared with QCA and IVUS (r=0.65; P<0.0001), and QCA and SB (r=0.49; P=0.0004). IVUS and SB demonstrated a small difference in minimum stent diameter, 0.043 mm (95% CI: 0.146-0.061 mm). The correlation between IVUS and SB was lower for vessels with intimal calcification (r=0.57; P=0.002) when compared with vessels with deeper calcification (r=0.84; P<0.0001). A SB minimum diameter of <2.5 mm predicted inadequate stent expansion by IVUS with 88% sensitivity, 70% specificity, and a positive likelihood ratio of 2.9. CONCLUSIONS: SB had superior correlations for stent expansion measured by IVUS when compared with QCA. A minimum stent diameter by SB measurement<2.5 mm is associated with inadequate stent expansion using IVUS criteria.     

Safety and utility of intravascular ultrasound-guided carotid artery stenting.

Intravascular ultrasound (IVUS) is useful in evaluating coronary stent deployment. The aim of this study was to assess the safety and utility of IVUS in carotid artery stenting (CAS). Ninety-eight consecutive high-risk patients (107 arteries) underwent CAS. IVUS was performed prior to predilatation in 87 of the 107 vessels and in all 107 following stent deployment when an optimal angiographic appearance was obtained. Quantitative carotid angiography (QCA) and IVUS analysis were performed offline. Procedural success was 97%. Combined stroke or death at 30 days was 5.6%. IVUS measurements of the minimum lumen diameter (MLD) of the distal internal carotid artery (ICA) reference segment were similar to QCA (4.60 +/- 0.74 vs. 4.74 +/- 0.71 mm; P = 0.21). The ICA stent MLD was significantly smaller by IVUS compared to QCA (3.65 +/- 0.68 vs. 4.31 +/- 0.76 mm; P < 0.001). IVUS detected stent malapposition in 11%. IVUS findings, after an optimal angiographic result, necessitated additional treatment in 9% of procedures. Calcium was detected in more arteries with IVUS than angiography (61% vs. 46%; P < 0.05). Arteries with superficial lesion calcification subtending three or four quadrants by IVUS had a 31% incidence of stroke compared with a 1% incidence in arteries without severe superficial calcium (P < 0.001). We found IVUS imaging in CAS to be safe even prior to plaque dilatation. IVUS provides a more accurate assessment of stent dimensions, expansion, and apposition than angiography. Severe calcification by IVUS was associated with a higher risk of stroke.     

Stent boost enhancement compared to intravascular ultrasound in the evaluation of stent expansion in elective percutaneous coronary interventions

Background

Stent underexpansion is a major risk factor for in-stent restenosis and acute in-stent thrombosis¹Intravascular ultrasound (IVUS) is one of the standards for detection of stent underexpansion (de Feyter et al. 1999; Mintz et al., 2001). StentBoost (SB) enhancement allows an improved angiographic visualization of the stent (Koolen et al., 2005).

Assessment of coronary stent deployment using computer enhanced x‐ray images‐validation against intravascular ultrasound and best practice recommendations

Objective : To investigate the accuracy of stent measurements using coronary x‐ray angiograms with a computer based stent enhancement algorithm applied (StentBoost, SB). To derive recommendations for best practice when using such systems. Background : Computer enhancement algorithms allow better visualization of intracoronary stents to assist in ensuring adequate stent deployment. Factors that affect the accuracy of measurements taken on such systems are yet to be fully understood. Methods : We analysed stent deployment of 43 stents in 33 patients measuring minimum stent diameter and cross sectional area (CSA) using intravascular ultrasound (IVUS), SB enhanced x‐ray images, and quantitative coronary angiography (QCA). We investigated if the use of two projections and method of calibration influenced correlation between IVUS and SB measurements. Results : Using two views and performing calibration via the guide catheter improved agreement between SB and IVUS measurements. For example, minimum stent diameter assessed with SB using one view and balloon markers for calibration produced a correlation coefficient, r, of 0.21, whereas using two views and the guide catheter for calibration increased agreement to r = 0.62. Relative measures of stent deployment, such as the ratio of minimum to maximum CSA, produced good correlation between IVUS and SB (r = 0.74). Conclusions : When using the SB system, two projection angles should be used to image the stent. For absolute measurements, the guide catheter should be used for calibration purposes. Relative measures of stent size, which are probably sufficient for assessment of deployment, also give good agreement with similar measures on IVUS, and require no calibration. © 2012 Wiley Periodicals, Inc.     

中重度冠状动脉钙化对介入治疗即刻疗效的影响

目的观察中重度冠状动脉钙化对冠状动脉介入治疗即刻疗效的影响。方法连续收集84例冠心病患者(84处靶病变),在冠状动脉支架置入术前后,通过血管内超声分析冠状动脉斑块特征、评估支架置入情况,并收集临床资料及介入操作相关信息,根据结果分为无钙化组36例和中重度钙化组48例,所有钙化病变均给予充分预扩张,并在血管内超声指导下视情况给予后扩张处理,对比2组PCI前后临床及影像学特征。结果 PCI后中重度钙化组置入支架直径、术后最小支架直径、最小支架横截面积、即刻管腔获得及相对管腔获得均小于无钙化组(P<0.05),PCI前中重度钙化组单支病变、靶病变B1型、斑块偏心指数、远端参考外弹力膜面积及管腔面积小于无钙化组(P<0.05,P<0.01)。而2组支架对称性、膨胀指数、手术并发症、院内主要不良心血管事件发生率比较,差异无统计学意义(P>0.05);2组术前最小管腔截面积、斑块负荷、管腔面积狭窄率、重构指数、病变长度差异无统计学意义(P>0.05)。结论血管内超声指导下给予充分预扩张及非顺应性高压球囊后扩张处理后,中重度钙化仍然影响PCI术后即刻管腔获得,但最终管腔面积基本理想。     

血管内超声与定量冠脉造影应用于冠脉临界病变诊治的比较

目的 研究血管内超声（intravascular ultrasound,IVUS）在优化民航飞行员冠脉临界病变诊断和治疗中的应用。 方法 通过定量冠脉造影（quantitative coronary angiography,QCA）和IVUS对120例飞行员患者165处冠脉临界病的最小管腔直径（minimal lumen diameter,MLD）、直径狭窄率（diamter stenosis,DS）与最小管腔面积（minimal lumen area,MLA）、面积狭窄率（area stenosis,AS）等参数进行对比分析;对IVUS提示管腔MLA<4 mm2飞行员患者的冠脉临界病变行支架植入术。 结果 ①同一临界病变处QCA显示的MLD,DS及MLA,AS值均小于IVUS相应的测量值,且差异有统计学意义（P<0.01）,表明IVUS对冠脉病变狭窄定量测量方面准确性更高;②IVUS提高血栓病变（15.0% vs. 2.5%,P<0.05）和心肌桥（42.5% vs. 2.5%,P<0.01）的诊断率;③与QCA相比,IVUS直接显示介入治疗中支架的贴壁情况,指导支架扩张完全。 结论 IVUS较QCA能更准确地检测冠脉临界病变范围,更灵敏地诊断血栓和心肌桥,利于全面优化临界病变的诊疗。     

High-speed rotational atherectomy and coronary stenting: QCA and QCU analysis.

To evaluate the acute effect of pretreatment with high-speed rotational atherectomy (HSRA) on stent deployment (rotastenting), we studied 33 patients with rotastenting of 40 segments, 34 patients with 40 coronary segments treated with Palmaz-Schatz stenting alone, and 34 patients with 40 segments treated with HSRA. The HSRA- and stent-alone patient groups were selected retrospectively by matching the quantitative coronary angiography (QCA) reference diameter (D ref). QCA revealed similar baseline percent of stenosis (85.3% +/- 12.4%), minimal luminal diameter (MLD), and D ref. The percent area expansion was calculated as a ratio between the minimal intrastent area and the reference area measured by intracoronary ultrasound. The rotastent group was characterized by more frequent calcification compared to HSRA and stent groups (67.5% vs. 20% and 12.5%; P < 0.01). Lesion length determined by QCA was longer both in the HSRA and the rotastent groups vs. the stent-alone group (21.1 +/- 12.3 and 20.9 +/- 4.3 vs. 17.0 +/- 7.7 mm; P < 0.05). In this small study, there was no difference demonstrated between final MLD in the rotastent and stent-alone groups. However, a smaller MLD was achieved in the HSRA group (3.0 +/- 0.7 vs. 3.1 +/- 0.5 vs. 2.5 +/- 0.7 mm, respectively; P < 0.01). The degree of stent expansion was higher in the rotastent group compared to the stent-alone group (91.9% +/- 4.4% vs. 79.7% +/- 3.4%; P < 0.03) and the % residual area of plaque was less for the rotastent group than for the stent-alone group (12.1% +/- 13.2% vs. 21.1% +/- 17.5%; P = 0.03). These data suggest that antecedent HSRA atheroma debulking using HSRA results in improved intravascular stent expansion and reduction in residual plaque, facilitating optimal stent deployment.     

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.