血管内超声指导单支架术式处理左主干分叉病变1年随访结果分析

目的评估血管内超声(IVUS)指导单支架术式处理左主干分叉病变的安全性及有效性。方法入选2015年1月至2017年12月西安交通大学第一附属医院54例经冠状动脉造影检查证实为左主干末端真性分叉病变患者,经IVUS评估后左回旋支开口管腔面积≥3.7 mm~2或斑块负荷≤56.0%时,采用单支架术式处理,观察术后即刻边支血流及1年时主要不良心血管事件发生率。若患者不满足上述条件,则采用双支架技术或者冠状动脉旁路移植术进行血运重建。结果冠状动脉造影定量分析(QCA)显示,54例患者平均左主干直径狭窄(58.2±15.1)%,左前降支开口直径狭窄(79.0±11.1)%,回旋支开口直径狭窄(47.2±11.2)%。IVUS检查提示,术前回旋支开口负性重构指数为(0.9±0.2),有45例(83.3%)发生负性重构。术后左主干最小管腔直径[(3.7±1.1)mm比(2.8±1.1)mm,P=0.032]、管腔面积[(10.1±1.6)mm~2比(5.0±1.1)mm~2,P=0.011],术后前降支开口最小管腔直径[(3.1±1.2)mm比(2.5±1.9)mm,P=0.041]、管腔面积[(7.9±1.4)mm~2比(3.2±1.3)mm~2,P=0.026],左回旋支开口斑块负荷[(50.7±10.6)%比(45.6±10.0)%,P=0.043]、外弹力膜偏心指数[(1.47±0.06)%比(1.24±0.08)%,P=0.018]均显著大于术前数值,而左回旋支开口管腔面积[(3.5±1.1)mm2比(4.0±1.1)mm~2,P=0.026]小于术前数值,差异均有统计学意义。54例患者均完成左前降支到左主干单支架术式治疗,术后即刻边支血流减慢4例(7.4%),其中1例(1.9%)出现分支闭塞。随访1年时因再发心绞痛再住院5例,其中2例由于左前降支支架内再狭窄而行血运重建,1例因左回旋支中段原有病变加重行血运重建。结论 IVUS指导下对特定的左主干末端真性分叉病变行单支架处理可能是安全、可行的。     

冠状动脉粥样硬化性心脏病单支病变和多支病变的血管壁结构的对比研究

目的:冠状动脉造影显示的单支病变和多支病变,只是粗略地反映了血管腔狭窄的程度和范围,无法反映血管壁病变的具体情况。本试验利用血管内超声检测左主干来阐述上述两类患者冠状动脉粥样硬化病变的特点。方法:129例冠心病患者被入选,分为单支病变组49例,多支病变组80例。所有患者在进行左冠状动脉系统的介入检查和治疗时,给予左主干的血管内超声检查,然后在每间隔1 mm的超声断面上测量血管外腔面积、内腔面积、斑块面积以及钙化角度,再将所有检测断面的相应数值相加,从而得到整个左主干的外腔容积、内腔容积、斑块体积和总的钙化负荷,最后比较在最小内腔面积的血管断面上以及整个左主干,各检测数据在两组间的差别。结果:左主干血管内、外腔和粥样斑块的定量血管内超声方面:无论在最小内腔面积(MLA)部位还是在整个左主干(除斑块面积、血管外腔外),单支病变组的血管外腔面积、血管内腔面积均显著大于多支病变组,斑块负荷均显著低于多支病变组,均有显著性差异(P＜0.05～0.001)。在MLA横断面上,单支病变组的斑块偏心指数显著高于多支病变组(0.46±0.18对0.33±0.22,P=0.001),即前者斑块的偏心程度显著低于后者。在粥样斑块的钙化方面:单支病变组钙化阳性率显著低于多支病变组,均有极显著性差异(P＜0.001)。其次,对钙化角度的定量分析显示,单支病变组患者MLA部位的钙化度数、左主干总钙化度数、最大钙化度数以及平均钙化度数均显著低于多支病变组,均有极显著性差异(P＜0.001)。结论:冠状动脉造影显示的单支和多支病变存在粥样硬化斑块病理结构的显著差异,表现为多支病变的患者斑块负荷更重,钙化几率和钙化程度更高。     

血管内超声评估冠状动脉管腔狭窄伴外弹力膜扩张性血管重构的临床研究

目的:应用血管内超声评估冠状动脉(冠脉)管腔狭窄伴外弹力膜扩张性血管重构的临床研究.方法:103例急性冠状动脉综合症(ACS)患者,男68例,女35例,年龄平均(60±11)岁;常规冠脉造影,血管内超声检测103处靶病变和参考血管处动脉粥样斑块形态学参数.将重构指数＞1为正重构组(n=67),重构指数≤1为负重构组(n=36);计算靶病变处管腔面积与平均参考段的管腔面积的比值(称为管腔狭窄比值).比较分析重构分组之间的斑块形态学特点,比较两组在病变处与参考段之间的差异;并进行管腔狭窄、外弹力膜扩张与斑块负荷的相关性分析.结果:103例患者中有5例ACS患者靶病变的管腔面积与平均参考血管的管腔面积相同,1例患者未见参考血管段的病变.102例存在参考血管段病变患者的资料统计显示,靶病变处与近端和远端参考段比较,斑块负荷的明显增加[依次为(71.76±9.17)%,(39.76±12.54)%,(32.38±13.97)%];管腔面积缩小[依次为(3.81±1.09)mm2,(8.91±2.43)mm2,(9.03±2.16)mm2];靶病变处与远端参考段比较,病变处外弹力膜(EEM)面积缩小[(14.71±2.89)mm2 vs(28.37±4.48)mm2],差异有统计学意义(P均＜0.001).管腔狭窄比值与斑块负荷呈负相关性(r=-0.84,P＜0.001)而与管腔面积呈正相关性(r=0.70,P=0.007);重构指数与其他参数未见相关性.结论:ACS患者冠状动脉存在着管腔狭窄伴外弹力膜扩张的双向重构,管腔狭窄比值可能是评估重构的重要指标.     

糖尿病患者冠状动脉粥样硬化病变的虚拟组织学血管内超声研究

目的 使用虚拟组织学血管内超声(virtual histology intravascular ultrasound,VH-IVUS)评价2型糖尿病患者冠状动脉粥样硬化斑块的组织成分和形态特征.方法 在2008年9月至2009年3月,前瞻性连续收集冠状动脉造影提示的、三支主要血管中直径狭窄≥50%的原位粥样斑块病变,进行灰阶血管内超声以及二维和体积法VH-IVUS分析.根据患者临床资料分为糖尿病(DM)组22例(39个病变)和非DM组46例(69个病变).结果 在最小管腔面积处,DM组斑块的坏死核心(19.4%±1.2%比15.1%±1.1%,P=0.015)和钙化成分(15.2%±1.6%比10.7%±1.1%,P=0.016)较非DM组更多,而纤维组织(56.7%±2.3%比64.8%±1.8%,P=0.007)更少;同样,体积法VH-IVUS发现DM组的坏死核心体积(21.3%±1.3%比16.5%±1.1%,P=0.008)和钙化组织体积(16.6%±1.4%比11.3%±1.1%,P=0.003)更大,而纤维组织体积(55.1%±2.1%比63.9%±1.8%,P=0.003)更小.此外,DM组薄帽纤维粥样硬化斑块的发生率(69.2%)较非DM组(42.O%)更高(P=0.009).然而,斑块重构系数和正性重构发生率在两组差异均无统计学意义.结论 相对于非DM患者,DM患者冠状动脉狭窄性粥样斑块的坏死和钙化组织含量更多,易损斑块也更多见.     

血管内超声分析斑块组成与冠状动脉重构之间的关系

目的 本研究的目的旨在应用血管内超声显像(IVUS)技术探讨斑块组成与冠状动脉重构之间的关系.方法 对77例冠心病患者(男性53例,平均年龄58±10岁)的罪犯血管采用ClearView或Galaxy2 (美国波士顿科学公司)血管内超声显像仪进行IVUS检查,其中31例为稳定性心绞痛,46例为急性冠状动脉综合征.对病变进行定性和定量测定.根据斑块组成回声的不同,分为软斑块、纤维斑块、钙化斑块和混合斑块,后三者统称为硬斑块.重构指数(RI)=病变处血管横截面积/平均参考血管面积.若RI＞1.0为正性重构;RI＜1.0为负性重构.比较不同重构形式病变的特性.结果 77处病变中,45处(58%)发生正性重构,32处(42%)发生负性重构.比较两组患者的临床表现,正性重构的患者更多的表现为急性冠状动脉综合征(74%比43%, P=0.006).与负性重构相比,正性重构病变部位的斑块面积和血管面积较大,斑块组成更多为软斑块(71%比34%, P＝0.001),发生钙化的较少(21%比54%, P＝0.003),钙化范围也较小[(18±37)°比(40±50)°, P＝0.027].进行多因素回归分析后,斑块组成和临床表现在两组患者中的差别仍具有统计学意义.结论冠状动脉重构与临床表现及斑块组成有关,正性重构病变软斑块较多见且钙化较少.     

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.     

血管内超声对急性心肌梗死相关病变的分析

目的 应用血管内超声(IVUS)研究急性心肌梗死(AMI)患者梗死相关动脉罪犯斑块与非梗死相关动脉斑块的不同.方法 用IVUS检查了20例AMI患者梗死相关动脉罪犯斑块20个与非梗死相关动脉斑块38个,IVUS分析包括对病变部位及近端参考部位的外弹力膜面积、管腔、斑块面积定量测量,血管重构指数(RI)定义为病变外弹力膜(EEM)截面积(CSA)/参考部位EEM CSA,正性重构(PR)定义为RR＞1.05、负性重构(NR)定义为RR＜0.95.梗死相关动脉及病变部位由心电图、左室壁运动异常(心室造影及超声心动结果)、冠脉造影病变形态联合鉴定.结果 罪犯斑块主要为低回声斑块(60% vs 28.9%)(P＜0.05),病变更长[(17.2±8.7) vs (10.6±5.7) mm;P＜0.05]、具有更大EEM面积[(15.8±6.0) vs (11.9±5.6) mm2;P＜0.05]及斑块面积[(13.1±6.0) vs (9.2±4.3) mm2;P＜0.05],大的斑块负荷[(82.9±6.2)% vs (77.3±7.2)%;P＜0.05],更多的正性重构(75% vs 47.4%;P＜0.05).结论 罪犯斑块具有更多的不稳定指标(正性重构、低回声斑块、大的斑块容积).     

急性冠状动脉综合征患者冠状动脉病变的血管内超声评价

目的采用血管内超声显像(IVUS)技术评价急性冠状动脉综合征(ACS)患者的冠状动脉病变特点.方法对45例ACS患者和28例稳定型心绞痛(SAP)患者的罪犯血管行IVUS检查,对病变部位IVUS图像进行定量和定性分析.定量测定指标包括病变部位和参照节段的血管面积(EEMcsa)、管腔面积(Lcsa,)和斑块面积(EEMcsa-Lcsa),斑块负荷=(EEMcsa-Lcsa)/EEMcsa×100%.血管重构指数(RI)定义为病变部位EEMcsa与参照节段平均EEMcsa的比值,RI＞1.0者为正性重构,RI＜1.0者为负性重构.结果与SAP患者相比,ACS组病变部位的EEMcsa[(15.4±4.6)mm2比(11.8±3.7)mm2,P=0.001],斑块面积[(11.9±4.1)mm2比(8.0±3.0)mm2,P＜0.001]和斑块负荷[(77.1±10.8)%比(65.0±12.0)%,P＜0.001]均显著高于前者,正性重构较SAP患者更常见(68%比38%,P=0.02),其RI(1.05±0.11)也高于SAP(0.98±0.14),P=0.025.ACS组病变以软斑块为主,占73%,明显高于SAP患者的28%(P=0.001),更多斑块破裂(38%比11%,P=0.012)和血栓形成(24%比0%,P=0.005).与负性重构病变比较,正性重构病变中软斑块占的比例较高(70%比34%,P=0.004),钙化较少[(18±37)°比(45±52)°,P=0.017].结论ACS患者冠状动脉病变的常见形态特征为软斑块,斑块破裂,血栓形成和正性重构.冠状动脉的重构形式与病变的组成有关.     

血管内超声及虚拟组织学评估冠状动脉血管重构与斑块成分的关系

目的应用血管内超声及虚拟组织学技术检测冠心病患者的冠状动脉重构与斑块成分之间的关系。方法对41例冠心病患者行血管内超声及虚拟组织学检查,根据其重构指数分为正性重构组(n=19)及负性重构组(n=22),检测并比较两组的斑块负荷、血管面积、管腔面积以及斑块成分等。结果与负性重构组比较,正性重构组最小管腔处血管面积(17.95±4.25 mm~2比11.44±2.13 mm~2)、管腔面积(6.02±1.85 mm~2比4.98±1.06 mm~2)、斑块负荷(63.83%±7.89%比63.83%±7.89%)均显著增大(P0.05)。虚拟组织学显示正性重构组比负性重构组坏死成分比例增加(30.38%±9.33%比17.19%±11.31%,P=0.001)、纤维成分比例减少(44.61%±14.93%比61.08%±14.81%,P=0.002),钙化和纤维脂质比例无明显差异(P0.05)。重构指数与坏死成分比例呈正相关(r=0.373,P=0.023)。结论冠状动脉的正性重构伴随着坏死核心增加,正性重构可能是冠状动脉斑块不稳定的表现。     

冠状动脉CT血管成像定量参数与老年冠心病患者病情严重程度的相关性

目的探讨冠状动脉CT血管成像定量参数与老年冠心病患者病情严重程度的相关性。方法回顾性分析在我院治疗的老年冠心病患者150例为观察组,同时收集健康志愿者150例为对照组,行冠状动脉CT血管成像检查,获取斑块及血管体积、斑块负荷、血管狭窄、血管重建等定量参数,分析定量参数与冠心病患者病情严重程度的相关性。结果与对照组比较,观察组斑块数[(2.43±0.53)个vs(0.82±0.32)个,P=0.000]、非钙化斑块体积[(321.84±124.92)mm^3 vs(125.83±43.28)mm^3,P=0.000]、钙化斑块体积[(43.28±12.84)mm^3 vs(12.74±4.39)mm^3,P=0.000]、总斑块体积[(365.12±109.85)mm^3 vs(138.57±40.92)mm^3,P=0.000]和重建指数(1.89±0.43 vs 1.12±0.24,P=0.000)等均显著增高。Pearson线性相关分析显示,斑块数、非钙化斑块体积、钙化斑块体积、总斑块体积、非钙化斑块负荷、钙化斑块负荷、总斑块负荷、血管狭窄程度与LVEF呈负相关(P<0.01),与平均室壁应力、左心室质量指数、左心室收缩末期容积、左心室舒张末期容积呈正相关(P<0.05,P<0.01)。结论冠状动脉CT血管成像定量参数与老年冠心病患者病情严重程度相关,可用于评估患者预后。     

Remodeling index compared to actual vascular remodeling in atherosclerotic left main coronary arteries as assessed with long-term (> or =12 months) serial intravascular ultrasound.

OBJECTIVES: We present the remodeling index (RI) versus serial intravascular ultrasound (IVUS) data. BACKGROUND: The RI, derived by comparing lesion external elastic membrane (EEM) cross-sectional area versus the reference at one time point, is used in various IVUS studies as a substitute of true remodeling (change in EEM over time), assuming that it represents true remodeling. METHODS: We studied 46 non-stenotic left main arteries using serial IVUS (follow-up 18 +/- 8 months). Plaques were divided into subgroups according to the follow-up RI: follow-up RI >1 (n = 27) versus follow-up RI < or =1 (n = 19). RESULTS: Lesions with a follow-up RI >1 had an increase in lumen despite an increase in plaque because of an increase in EEM. Conversely, lesions with a follow-up RI < or =1 had a reduction in lumen as a result of both a plaque increase and EEM decrease. Overall, the follow-up RI correlated directly with changes in lesion site EEM (baseline-to-follow-up). Although there was no correlation between the follow-up RI and changes in reference EEM area, changes in reference EEM area did correlate directly with changes in lesion EEM area. In nearly 90% of lesions with a follow-up RI >1, there was a previously documented increase in EEM area. Using multivariate linear regression analysis, the follow-up RI was dependent on the baseline RI, the increase in lesion EEM area, and the decrease in reference EEM area. The follow-up RI was not dependent on changes in lesion plaque area. CONCLUSIONS: The vast majority of left main lesions with a remodeling index >1 had evidence of a previous increase in lesion-site EEM area.     

Intravascular ultrasound assessment of remodelling and reference segment plaque burden in type-2 diabetic patients.

AIMS: Intravascular ultrasound (IVUS) assesses arterial remodelling by comparing the lesion external elastic membrane (EEM) with the reference segments; however, reference segments are rarely disease-free. The aim was to assess lesion and reference segment remodelling and plaque burden in patients with type-2 diabetes mellitus. METHODS AND RESULTS: We used pre-intervention IVUS to study 62 de novo lesions in 43 patients with type-2 diabetes mellitus. The lesion site was the image slice with the smallest lumen cross-sectional area (CSA). The proximal and distal reference segments were the most normal-looking segments within 5 mm proximal and distal to the lesion. Plaque burden was measured as plaque CSA/EEM CSA. The remodelling index was defined as lesion EEM CSA/mean reference EEM CSA. Reference segment plaque burden measured 0.54 +/- 0.09. The majority of lesions (83.9%) had negative remodelling (lesion EEM < reference). Similarly, the slope of the regression line relating EEM to plaque CSA within the lesion was less than the reference substantiating negative remodelling. The reference segment plaque burden correlated inversely with the difference between IVUS lumen and quantitative coronary angiographic artery size [slope = -0.12 (95% CI -0.17 to -0.07); P < 0.001] in all patients with type-2 diabetes mellitus. CONCLUSION: Lesions in type-2 diabetic patients are different from previous reports in non-diabetics. Lesions in type-2 diabetics are characterized by a large reference segment plaque burden and negative lesion site remodelling. These IVUS findings may explain the angiographic appearance of small arteries in diabetic patients.     

Correlation of coronary arterial remodeling determined by intravascular ultrasound with angiographic diameter reduction of 20% to 60%

Negative remodeling is commonly observed in stenotic coronary lesions. It is unknown whether negative remodeling is an early or late event. This study was designed to elucidate when negative remodeling occurs in the development of coronary stenosis. Remodeling was assessed by preintervention intravascular ultrasound in 104 native coronary lesions with intermediate stenosis (20% to 60% of diameter stenosis measured by quantitative coronary angiography). Positive remodeling was defined as lesion external elastic membrane (EEM) cross-sectional area (CSA) greater than the proximal reference, intermediate remodeling as lesion EEM CSA between those of the proximal and distal references, and negative remodeling as lesion EEM CSA less than the distal reference. Positive, intermediate, and negative remodeling were observed in 18%, 32%, and 50%, respectively, of lesions with intermediate stenosis. Lesions with negative and intermediate remodeling had more hard plaque compared with those with positive remodeling (79% vs 70% vs 42%, p = 0.02). Calcium was more frequent in lesions with negative and intermediate remodeling than in those with positive remodeling (52% vs 55% vs 16%, p = 0.01). Lesions with negative remodeling had smaller EEM CSA (11.5 +/- 5.2 vs. 13.7 +/- 3.4 vs 14.5 +/- 5.6 mm(2), p = 0.03) and less plaque (7.9 +/- 4.6 vs 10.8 +/- 3.4 vs 10.8 +/- 4.9 mm(2), p = 0.004) compared with positive and intermediate remodeling lesions, although lumen CSA (3.7 +/- 1.7 vs 2.8 +/- 0.8 vs 3.6 +/- 1.3 mm(2), p = 0.1) and area stenosis (57 +/- 15% vs 59 +/- 14% vs 56 +/- 10%, p = 0.7) were similar. Negative remodeling is frequently observed in lesions with intermediate stenosis. This suggests that negative remodeling occurs early in lesion formation.     

Intravascular Ultrasound Assessment of the Mechanisms and Predictors of Restenosis Following Coronary Angioplasty

Restenosis occurs after 30% to 50% of transcatheter coronary procedures; its mechanisms remain incompletely understood. Intravascular ultrasound (IVUS) studies were analyzed in 360 nonstented native coronary artery lesions in which follow-up quantitative angiographic and/or IVUS data was available. Pre-intervention, post-intervention, and follow-up, the external elastic membrane (EEM) and lumen cross-sectional areas (CSA) were measured; plaque+media (P+M=EEM D lumen CSA), and cross-sectional narrowing (CSN=P+M/EEM CSA) were calculated. The anatomic slice selected for serial analysis had an axial location within the lesion at the smallest follow-up lumen CSA. At follow-up, 73% of the decrease in lumen CSA was due to a decrease in EEM CSA; 27% was due to an increase in P+M CSA. The change in lumen CSA correlated more strongly with the change in EEM CSA than with the change in P+M CSA. The change in EEM CSA was bidirectional; 47 lesions (22%) showed an increase in EEM CSA. Despite a greater increase in P+M CSA, lesions exhibiting an increase in EEM CSA had (1) no change in lumen CSA, (2) decreased restenosis, and (3) a 49% frequency of late lumen gain. The independent clinical, angiographic, and IVUS predictors of angiographic restenosis (3 50% diameter stenosis at follow-up) were the IVUS reference lumen CSA, angiographic pre-intervention diameter stenosis, and post-intervention IVUS CSN. Restenosis appeared to be determined primarily by the direction and magnitude of the change in EEM CSA. An increase in EEM CSA was adaptive while a decrease in EEM CSA contributed to restenosis. The most powerful predictor of restenosis was the IVUS post-procedural CSN. The importance of the post-procedural CSN was related to the change in EEM CSA as a mechanism of restenosis.     

Intravascular Ultrasound Assessment of the Mechanisms and Predictors of Restenosis Following Coronary Angioplasty

Restenosis occurs after 30% to 50% of transcatheter coronary procedures; its mechanisms remain incompletely understood. Intravascular ultrasound (IVUS) studies were analyzed in 360 non-stented native coronary artery lesions in which follow-up quantitative angiographic and/or IVUS data was available. Pre-intervention, post-intervention, and follow-up, the external elastic membrane (EEM) and lumen cross-sectional areas (CSA) were measured; plaque + media (P + M = EEM - lumen CSA), and cross-sectional narrowing (CSN = P + M/EEM CSA) were calculated. The anatomic slice selected for serial analysis had an axial location within the lesion at the smallest follow-up lumen CSA. At follow-up, 73% of the decrease in lumen CSA was due to a decrease in EEM CSA; 27% was due to an increase in P+M CSA. The change in lumen CSA correlated more strongly with the change in EEM CSA than with the change in P + M CSA. The change in EEM CSA was bidirectional; 47 lesions (22%) showed an increase in EEM CSA. Despite a greater increase in P + M CSA, lesions exhibiting an increase in EEM CSA had (1) no change in lumen CSA, (2) decreased restenosis, and (3) a 49% frequency of late lumen gain. The independent clinical, angiographic, and IVUS predictors of angiographic restenosis (3 50% diameter stenosis at follow-up) were the IVUS reference lumen CSA, angiographic pre-intervention diameter stenosis, and post-intervention IVUS CSN. Restenosis appeared to be determined primarily by the direction and magnitude of the change in EEM CSA. An increase in EEM CSA was adaptive while a decrease in EEM CSA contributed to restenosis. The most powerful predictor of restenosis was the IVUS post-procedural CSN. The importance of the post-procedural CSN was related to the change in EEM CSA as a mechanism of restenosis.     

Comparison of intravascular ultrasound and angiographic assessment of coronary reference segment size in patients with type 2 diabetes mellitus

During percutaneous coronary intervention, the reference segment is assessed angiographically. This report described the discrepancy between angiographic and intravascular ultrasound (IVUS) assessment of reference segment size in patients with type 2 diabetes mellitus. Preintervention IVUS was used to study 62 de novo lesions in 41 patients with type 2 diabetes mellitus. The lesion site was the image slice with the smallest lumen cross-sectional area (CSA). The proximal and distal reference segments were the most normal-looking segments within 5 mm proximal and distal to the lesion. Plaque burden was measured as plaque CSA/external elastic membrane (EEM) CSA. Using IVUS, the reference lumen diameter was 2.80 +/- 0.42 mm and the reference EEM diameter was 4.17 +/- 0.56 mm. The angiographic reference diameter was 2.63 +/- 0.36 mm. Mean difference between the IVUS EEM diameter and angiographic reference diameter was 1.56 +/- 0.55 mm. The mean difference between the IVUS reference lumen diameter and angiographic reference lumen diameter was 0.18 +/- 0.44 mm. Plaque burden in the reference segment correlated inversely with the difference between IVUS and quantitative coronary angiographic reference lumen diameter (slope = -0.12, 95% confidence interval -0.17 to -0.07, p <0.001), but it was not related to the absolute angiographic reference lumen diameter. Thus, reference segment diameters in type 2 diabetic patients were larger using IVUS than angiography, especially in the setting of larger plaque burden. In conclusion, these findings combined with inadequate remodeling may explain the angiographic appearance of small arteries in diabetic patients.     

Impact of preinterventional arterial remodeling on in-stent neointimal hyperplasia and in-stent restenosis after coronary stent implantation.

BACKGROUND: Patterns of arterial remodeling during the course of plaque development have been shown to play an important role in both the progression of de novo atherosclerosis and in the restenotic process following coronary intervention. The aim of the present prospective study was to evaluate the effect of pre-interventional arterial remodeling on in-stent neointimal hyperplasia (NIH) and in-stent restenosis (ISR) after stenting. METHODS AND RESULTS: Pre-interventional arterial remodeling was assessed in 85 native coronary lesions by using intravascular ultrasound (IVUS). The remodeling index (RI) was 1.09+/-0.20 in the positive remodeling (PR)/intermediate remodeling (IR) group and 0.84+/-0.12 in the negative remodeling (NR) group. The plaque plus media cross sectional area (P&M CSA) at pre-intervention and NIH CSA at follow-up in the minimal lumen CSA were significantly larger in the PR/IR group (9.2+/-2.9 mm2 vs 6.2+/-1.8 mm2, 3.3+/-1.2 mm2 vs 1.5+/-0.9 mm2; p = 0.001, p = 0.001, respectively). On 3-dimensional analysis of IVUS images at follow-up, the lumen volume was significantly smaller in the PR/IR group than that in the NR group (62+/-15 mm3 vs 75 +/-20 mm3; p = 0.001), and neointima hyperplasia volume was significantly larger in the PR/IR group than that in the NR group (46+/-15 mm3 vs 26+/-10 mm3; p = 0.001). A significant positive correlation was found between pre-interventional RI and follow-up NIH CSA (r = 0.25, p = 0.022). The incidence of ISR and repeat intervention was significantly higher in the PR/IR group (30.8% vs 18.2%, 28.8% vs 15.2%; p = 0.032, 0.035, respectively). CONCLUSION: Measuring pre-interventional arterial remodeling patterns by IVUS may be helpful to stratify lesions at high-risk of ISR.     

Impact of different definitions on the interpretation of coronary remodeling determined by intravascular ultrasound.

The objective of this study was to compare the categorizations and determinants related to remodeling by the three definitions commonly used. Several morphological and intravascular ultrasound (IVUS) studies have demonstrated the fundamental importance of arterial remodeling in atherosclerosis. However, lack of consensus on how to define remodeling has led to conflicting analyses of factors that influence this process. Analysis of pre-interventional IVUS images of 514 lesions in native coronary arteries was performed. Arterial remodeling was defined as outward by definition 1, when [cross-sectional area (CSA) of the external elastic membrane (EEM) at the lesion site (EEM(lesion))]/[EEM CSA either at the proximal (EEM(prox ref)) or distal (EEM(distal ref)) reference site with the least amount of plaque] was > 1.05, intermediate when this ratio was between 0.95 and 1.05, and inward when < 0.95. Remodeling was defined as outward by definition 2 when EEM(lesion) > both EEM(prox ref) and EEM(distal ref), inward when EEM(lesion) < both EEM(prox ref) and EEM(distal ref), and intermediate when EEM(lesion) was intermediate between EEM(prox ref) and EEM(distal ref). By definition 3, vessel remodeling was defined as outward when EEM(lesion) > (EEM(prox ref) + EEM(distal ref))/2 and intermediate/inward when EEM(lesion) < or = (EEM(prox ref) + EEM(distal ref))/2. The frequency of outward remodeling was significantly higher by definitions 1 and 3 than by definition 2, whereas a higher frequency of inward remodeling was observed in definition 1, resulting in significantly different remodeling distributions between the three definitions (P < 0.0001). By multivariate logistic analysis, the only clinical determinants related to outward remodeling was younger age, and only by definition 3. IVUS determinants varied significantly between the three definitions. The only consistent determinants among the three definitions were smaller lumen CSA at the reference site and larger plaque + media CSA at the lesion site. This study demonstrates the significant impact of different remodeling definitions on the incidence and determinants of remodeling patterns. The marked variability in categorization of remodeling underscores the importance of developing a standard methodology.     

Coronary risk factors influence plaque morphology in patients with unstable angina.

BACKGROUND: The risk of plaque disruption and subsequent thrombosis in patients with unstable angina depends on the plaque type and size. DESIGN: Intravascular ultrasound (IVUS) was employed to illustrate the correlation between risk factors and plaque morphology in patients with unstable angina. METHODS: In a prospective study of 60 of 95 patients consecutively admitted with unstable angina [41 men, aged 61.2 +/- 8.1 years (mean +/- SD)], qualitative (soft and hard plaque, thrombus, calcification, eccentricity, adaptive and constrictive remodeling) and quantitative [lumen, external elastic membrane (EEM) and plaque cross-sectional area (CSA) and plaque burden] IVUS data relating to the target lesion, and proximal and distal reference segments were analyzed and correlated with risk factors. Univariate and multivariate nominal logistic regression analyses and analyses of variance were used to determine the independent predictors for IVUS morphology. RESULTS: For plaque composition univariate analysis showed a younger age (< 60 years) to be a predictor for adaptive remodeling (P = 0.019), and an older age to be a predictor for constrictive remodeling (P = 0.021). Hypercholesterolemia, smoking and sex were associated with a higher frequency of thrombus (P = 0.044, 0.038 and 0.043, respectively). Multivariate analyses revealed that only younger and older ages were independent predictors for adaptive and constrictive remodeling (P = 0.039 and P = 0.045). For plaque size, univariate and multivariate analyses demonstrated that diabetes mellitus and hypercholesterolemia were independent predictors for greater plaque (13.5 +/- 5.72 versus 10.17 +/- 4.6 mm2, P = 0.015, for diabetic versus non-diabetic patients; 12.0 +/- 5.35 versus 9.03 +/- 3.76 mm2, P = 0.010, for hypercholesterolemic versus normocholesterolemic patients) and EEM CSA (17.16 +/- 5.81 versus 14.3 +/- 5.1 mm2, P = 0.033, for diabetic versus non-diabetic patients; 16.57 +/- 5.49 versus 12.25 +/- 3.8 mm2, P = 0.001, for hypercholesterolemic versus normocholesterolemic patients) at the target lesion. Hypercholesterolemia was associated with significantly greater plaque and EEM CSA in both proximal and distal reference segments. CONCLUSIONS: Multivariate analyses indicated that age, diabetes and hypercholesterolemia are independent predictors for plaque morphology in patients with unstable angina.     

Intravascular ultrasound findings after excimer laser coronary angioplasty

Intravascular ultrasound (IVUS) was used to study 104 lesions in 98 patients after excimer laser coronary angioplasty (ELCA). Lesion site external elastic membrane (EEM) and lumen cross-sectional areas (CSA) were measured; plaque + media (P + M = EEM − lumen) CSA and percentage of cross-sectional narrowing (CSN = P + M CSA/EEM CSA) were calculated; and the results were compared to a reference site. The lumen CSA (2.6 ± 1.0 mm²) averaged 24% larger than the cross-sectional area of the largest laser catheter used, and 64 lesions (62%) fit the definition of arterial expansion (lesion EEM CSA > reference site EEM CSA). The residual percentage of cross-sectional narrowing averaged 83.8 ± 8.8%. Dissections were present in 44% of lesions, and were more common in lesions with superficial calcium (59%) than in lesions with only deep calcium (31%) or no calcium (20%, P = 0.0102). Dissections of superficial calcified plaque had an unusual “shattered” or “fragmented” appearance. These findings suggest that excimer laser angioplasty causes forced vessel expansion with dissection, but limited atheroablation. © 1996 Wiley-Liss, Inc.