Mechanisms of acute gain and late lumen loss after atherectomy in different preintervention arterial remodeling patterns

The main mechanism of restenosis after directional coronary atherectomy (DCA) remains obscure. We investigated mechanisms of restenosis after DCA in different coronary artery remodeling patterns. DCA was performed in 51 de novo lesions. The lesions were evaluated by intravascular ultrasound (IVUS) before, immediately after, and 6 months after the procedure. According to the IVUS findings before DCA, we classified the lesions into the following 3 groups: (1) positive (n = 10), (2) intermediate (n = 25), and (3) negative (n = 16) remodeling. We measured lumen area, vessel area, and plaque area using IVUS before DCA, immediately after DCA, and at follow-up. Lumen area increase after DCA was mainly due to plaque area reduction in the positive and intermediate remodeling groups (90 plus minus 15% and 80 plus minus 25% increase in lumen area, respectively), whereas that in the negative remodeling group was due to both plaque area reduction (57 plus minus 22% increase in lumen area) and vessel area enlargement (43 plus minus 33% increase in lumen area). The plaque area increase correlated strongly with late lumen area loss in the positive and intermediate remodeling groups (r = 0.884, p <0.001; r = 0.626, p <0.001, respectively), but the decrease in vessel area was not correlated with lumen area loss. In contrast, both an increase in plaque area and a decrease in vessel area were correlated with late lumen area loss (r = 0.632, p = 0.009; r = 0.515, p = 0.041) in the negative remodeling group. Coronary artery restenosis after atherectomy was primarily due to an increase in plaque in the positive and/or intermediate remodeling groups. However, in the negative remodeling group, late lumen loss might have been caused by both an increase in plaque and vessel shrinkage.     

Intravascular ultrasound for evaluation of initial vessel patency and early outcome following directional coronary atherectomy

Elastic recoil and thrombus formation may potentially occur following directional coronary atherectomy (DCA) confounding the assessment of late vascular remodeling. Since intravascular ultrasound (IVUS) data on early outcome of DCA is not available, we used IVUS to investigate whether elastic recoil or thrombus formation can affect early (4 hr) outcome. Quantitative coronary angiography (QCA) and IVUS were performed in high-grade coronary lesions in 32 consecutive patients before, immediately after, and 4 hr after DCA. Late clinical follow-up was obtained after a maximum interval of 2 years. Significant acute elastic recoil was observed by both IVUS (19% ± 14%) and QCA (19% ± 12%), but there was no further recoil after 4 hr. DCA reduced plaque area by 51% ± 13%, an effect that was stable after 4 hr, indicating the absence of relevant thrombus formation. Residual area stenosis by IVUS was not related to the occurrence of late clinical events (n = 8). Mechanical recoil or thrombus formation do not hamper initial lumen gain achieved by DCA. Although QCA significantly underestimated residual plaque burden after DCA when compared to IVUS, the degree of residual area stenosis did not identify patients suffering from cardiac events on follow-up.Cathet. Cardiovasc. Intervent. 47:14–22, 1999. © 1999 Wiley-Liss, Inc.     

Comparison of dilatation mechanism and long-term vessel remodeling between directional coronary atherectomy and balloon angioplasty assessed by volumetric intravascular ultrasound

Although acute and late outcomes of coronary interventions have been determined by coronary angiography, this method cannot determine changes in vessel and plaque volume. Volumetric intravascular analysis has the potential to evaluate the morphology and redistribution of plaque after coronary intervention as well as longitudinal vessel remodeling. We used 3-dimensional intravascular ultrasound (3-D IVUS) to delineate the mechanism of coronary dilatation and long-term (> 1 year) remodeling in 25 patients. Ten patients underwent directional coronary atherectomy (DCA), and 15 underwent balloon angioplasty (POBA). No patients exhibited restenosis at 6-month angiographic follow-up. Validated Netra 3-D IVUS was performed pre- and post-intervention, at 6-months and at > 1-year. There were some differences in mechanism of dilatation and time course of change in vessel size between DCA and POBA patients. The principal mechanism was vessel stretching and longitudinal plaque redistribution in the POBA group and plaque debulking in the DCA group. In the POBA group, vessel volume increased just after the procedure; this increase was maintained at 6 months and at > 1-year. However, in the DCA group, vessel volume increased initially 6 months after the procedure. 3-D IVUS revealed a difference in mechanism of dilatation between POBA and DCA; this difference might affect late-term vessel remodeling even in patients without restenosis.     

Plaque morphology at coronary sites with focal spasm in variant angina: study using intravascular ultrasound.

In the present study, the intravascular ultrasound (IVUS) morphologic appearance of coronary atherosclerotic plaque associated with focal spasm was prospectively studied in 45 patients with or without focal coronary spasm provoked by ergonovine or acetylcholine. The percent plaque area and plaque arc were determined from the IVUS images at the sites of spasm. Calcified lesion was defined as the presence of high-intensity echo with acoustic shadowing. Twenty-three patients had focal coronary spasm defined as angiographic narrowing >75% and IVUS demonstrated atherosclerotic plaque in these 23 sites. In the 22 patients without focal spasm, IVUS demonstrated 18 atherosclerotic lesions in 17 patients and the remaining 5 patients did not have significant lesions. There was no difference in the percent plaque area and plaque arc between plaque lesions with (47+/-10%, 298+/-71 degrees ) and without (39+/-15%, 249+/-83 degrees ) coronary spasm. Interestingly, calcified lesion was less frequently present at the sites with than at those without spasm (p<0.05). These results indicate that the presence of plaque without calcification is likely to be related to the occurrence of focal vasospasm, although the severity and distribution of the disease did not differ between each patient group.     

Quantitative angiographic and intravascular ultrasound study >5 years after directional coronary atherectomy

Aggressive and optimal directional coronary atherectomy (DCA) using intravascular ultrasound (IVUS) guidance provides favorable outcomes within 1 year. However, no previous data are available on the changes that occur in target lesions for the long term after stand-alone DCA. This study's aim evaluates, using quantitative angiography and intravascular ultrasonography, the natural history of changes that occur in target lesions between short- (about 6 months) and long-term (>5 years) follow-up angiography after stand-alone DCA. Of 186 patients (221 lesions) with successful stand-alone DCA, 48 patients (53 lesions) underwent revascularization within 6 months, and 14 patients subsequently died, leaving a study population of 124 patients (154 lesions). Complete quantitative coronary angiography (QCA) was obtained in 91 patients (101 lesions) and complete serial IVUS assessment was obtained for 38 lesions before and after intervention and during follow-up. From short- to long-term follow-up angiography, the minimal luminal diameter significantly increased (from 2.12 to 2.56 mm; p <0.0001); lesion subgroups with >30% diameter stenosis at short-term follow-up angiography showed significant late regression as assessed by QCA. Serial IVUS assessment revealed that the vessel cross-sectional area did not change (from 17.3 to 17.4 mm(2); p = NS); however the lumen cross-sectional area significantly increased (from 7.3 to 9.5 mm(2); p <0.0001) due to the reduction of plaque plus media cross-sectional area (from 10.0 to 7.9 mm(2); p <0.0001). The change in lumen cross-sectional area correlated with the change in plaque plus media cross-sectional area (r = -0.686, p <0.0001). Target lesions show late regression due to plaque reduction at >5 years after stand-alone DCA.     

Effects of adjunctive balloon angioplasty after intravascular ultrasound-guided optimal directional coronary atherectomy: the result of Adjunctive Balloon Angioplasty After Coronary Atherectomy Study (ABACAS).

OBJECTIVES: This study was conducted to evaluate: 1) the effect of adjunctive percutaneous transluminal coronary angioplasty (PTCA) after directional coronary atherectomy (DCA) compared with stand-alone DCA, and 2) the outcome of intravascular ultrasound (IVUS)-guided aggressive DCA. BACKGROUND: It has been shown that optimal angiographic results after coronary interventions are associated with a lower incidence ofrestenosis. Adjunctive PTCA after DCA improves the acute angiographic outcome; however, long-term benefits of adjunctive PTCA have not been established. METHODS: Out of 225 patients who underwent IVUS-guided DCA, angiographically optimal debulking was achieved in 214 patients, then theywere randomized to either no further treatment or to added PTCA. RESULTS: Postprocedural quantitative angiographic analysis demonstrated an improved minimum luminal diameter (2.88 +/- 0.48 vs. 2.6 +/- 0.51 mm; p = 0.006) and a less residual stenosis (10.8% vs.15%; p = 0.009) in the adjunctive PTCA group. Quantitative ultrasound analysis showed a larger minimum luminal diameter (3.26 +/- 0.48 vs. 3.04 +/- 0.5 mm; p < 0.001) and lower residual plaque mass in the adjunctive PTCA group (42.6% vs. 45.6%; p < 0.001). Despite the improved acute findings in the adjunctive PTCA group, six-month angiographic and clinical results were not different. The restenosis rate (adjunctive PTCA 23.6%, DCA alone 19.6%; p = ns) and target lesion revascularization rate (20.6% vs. 15.2%; p = ns) did not differ between the groups. CONCLUSIONS: With IVUS guidance, aggressive DCA can safely achieve optimal angiographic results with low residual plaque mass, and this was associated with a low restenosis rate. Although adjunctive PTCA after optimal DCA improved the acute quantitative coronary angiography and quantitative coronary ultrasonography outcomes, its benefit was not maintained at six months.     

不稳定型心绞痛患者的血管内超声分析

目的:应用血管内超声(IVUS)探讨不稳定型心绞痛(UAP)患者的斑块形态学特点。方法:经冠状动脉造影和IVUS检查的冠心病患者57例,其中稳定型心绞痛(SAP)21例,UAP 36例,根据斑块回声的强度,将斑块分为软斑块、纤维斑块、钙化斑块、混合斑块和斑块破裂等,分析比较UAP和SAP患者的斑块的形态学特点。结果:IVUS发现软斑块的比例在SAP和UAP患者中分别为47.6%和75.0%,纤维斑块的比例分别为52.4%和25.0%,斑块破裂分别为0和30.6%,钙化斑块分别为52.4%和19.4%(均P<0.05)。结论:IVUS显示UAP的斑块形态学特点主要表现为软斑块和斑块破裂。     

Stenting after directional coronary atherectomy compared with directional coronary atherectomy alone and stenting alone: a serial intravascular ultrasound study.

BACKGROUND: Directional coronary atherectomy prior to stent implantation (DCA-stent) is expected to be an effective approach to reduce restenosis. The purpose of this study was to determine whether DCA-stent has advantages over DCA alone or stenting alone using serial intravascular ultrasound (IVUS). METHODS AND RESULTS: Serial (pre-, post- and follow-up) IVUS was performed in 187 native coronary lesions treated with each of the 3 strategies. External elastic membrane cross-sectional area (CSA), lumen CSA and plaque CSA were measured. Baseline characteristics were similar. Postprocedural lumen CSA was largest after DCA-stent (11.2+/-2.7 mm2) and DCA (10.8+/-2.5 mm2) than stenting alone (9.0+/-2.9 mm2) (p<0.0005). Follow-up lumen loss was similar. As a result, follow-up lumen CSA was largest after DCA-stent (DCA-stent: 9.1+/-3.4 mm2, DCA: 7.8+/-4.2 mm2, stent: 6.3+/-2.6 mm2, p<0.0005). There was a trend toward a lower rate of restenosis with DCA-stent (DCA-stent, 12.5%; DCA, 18.3%; stent, 18.8%; p=0.57). CONCLUSIONS: DCA-stent is superior to both DCA alone and stent alone in terms of the ability to gain a larger lumen as assessed by IVUS.     

Impact of intravascular ultrasound guidance on directional coronary atherectomy

In contrast to the luminogram of coronary angiography, intravascular ultrasound (IVUS) has proven to accurately assess both coronary lumen and vessel morphology due to its 360 degrees imaging capacity. Directional coronary atherectomy (DCA) improves the coronary lumen by removing plaque mass rather than stretching the vessel and compressing the plaque as with conventional percutaneous transluminal coronary angioplasty. In an attempt to optimize the procedural result of DCA we prospectively investigated the impact of IVUS guidance in a head to head comparison to on-line quantitative coronary angiography (QCA) on the result of DCA. In 16 consecutive patients IVUS demonstrated significant residual plaque mass after DCA irrespective of a satisfactory angiographic result. After a mean of 9 +/- 2 cuts luminal improvement was obtained with an area stenosis by angiography of 39 +/- 17% and by IVUS of 50 +/- 10% (p < 0.05), a diameter stenosis by angiography of 23 +/- 10% and IVUS of 35 +/- 14% (p < 0.05) and finally a minimal lumen diameter (MLD) by angiography of 2.9 +/- 0.5 mm and by IVUS of 2.3 +/- 0.5 mm (p < 0.005). After both on-line QCA and IVUS measurements a second series of 7 +/- 2 cuts were initiated to debulk more atheroma and improve stenosis dimensions. After additional cuts IVUS revealed further luminal improvement with an area stenosis by angiography of 25 +/- 16% and IVUS of 21 +/- 18% (n.s.), a diameter stenosis by angiography of 16 +/- 11% and by IVUS of 13 +/- 19% (n.s.) and finally a MLD by angiography of 3.1 +/- 0.5 mm and by IVUS of 2.8 +/- 0.3 mm (p < 0.05). Intraprocedural use of IVUS is superior to on-line QCA to assess the immediate result of DCA. IVUS-guided DCA results in more effective atheroma debulking than luminographic evaluation. Results of larger follow-up studies are needed to substantiate the intraprocedural advantage of IVUS with DCA.     

Effect of preintervention remodeling type on subsequent coronary artery behavior after directional atherectomy

To evaluate the influence of preintervention remodeling on subsequent vessel behavior after directional coronary atherectomy (DCA) under intravascular ultrasound (IVUS) guidance, serial (before and after DCA and at 6-month follow-up) IVUS data were analyzed for 246 lesions that were classified into 2 categories: positive remodeling (PR) in 77 lesions versus intermediate or negative remodeling in 169 lesions. Although the 2 groups had similar baseline characteristics, IVUS data showed that the PR group had a greater acute lumen area (LA) gain without an increased late LA loss, resulting in a greater net (acute plus late) LA gain and follow-up LA. This suggests that IVUS-guided DCA may neutralize the negative impact of preintervention PR on late vessel patency.     

Intravascular ultrasound classification of atherosclerotic lesions according to American Heart Association recommendation

BACKGROUND: Intravascular ultrasound (IVUS) offers a new modality by which to image the vessel wall in high resolution. The aim of the study was to classify atherosclerotic lesions using IVUS according to American Heart Association (AHA) recommendation. METHODS: IVUS was performed using a 20 or 30 MHz mechanically rotated catheter in 190 patients (aged from 35 to 75 years, mean 59 +/- 9 years) who presented with suspicion of coronary artery disease based on clinical examination. RESULTS: Of the 190 patients, 49 (26%) (group A) were found to have normal or nearly normal coronary arteries, whereas the other 141 (74%) (group B) had significant angiographic stenosis (> 50% luminal narrowing). IVUS image interpretation was based on the recommendation of the Committee on Vascular Lesions of the Council on Atherosclerosis (AHA). In group A, a total of 822 segments were evaluated with IVUS; 444 (54%) were found to have plaque formation. Among these 444 segments, type II lesions were found in 145 (33%), type III lesions in 110 segments (25%), type IV and Va lesions in 169 segments (38%), and type Vb in 18 segments (4%). The severity of plaque area stenosis increased from type II to IV. In group B, only the most stenotic segments (n = 141) on angiography were selected for analysis. No significant differences were found among different lesion types with respect to the severity of plaque area stenosis. Type Vb and Vc lesions presented mainly, but not exclusively, as stable angina, whereas type VI lesions presented mainly as unstable angina. Some patients (12%) with stable angina had complicated lesions (type VIa-VIc). CONCLUSIONS: It is now possible to use intravascular ultrasound to classify atherosclerotic lesions according to the AHA recommendations that were based on histological examination. Standardized reports of IVUS can now be based on these recommendations. Even in angiographically normal coronary arteries, advanced atherosclerotic lesions are found, explaining the potential risk of acute coronary syndromes in this group of patients. In patients with angiographically severe coronary disease, clinical symptoms correlate mainly with plaque characteristics, rather than with the severity of stenosis.     

Ultrasound attenuated coronary plaque as a risk factor for slow flow or no-reflow during percutaneous coronary intervention: a case report

Slow flow or no-reflow is a serious complication during percutaneous coronary intervention (PCI), but little is known about the risk factors. A 64-year-old man underwent coronary angiography and PCI for stable angina. Pre-interventional intravascular ultrasound demonstrated an ultrasound attenuated coronary plaque, as a long eccentric bulky plaque with a marked decrease of the back echo without calcification. Since the lesion was highly eccentric in the large left anterior descending artery, directional coronary atherectomy (DCA) and subsequent stent implantation were planned. Serious no-reflow occurred after DCA. The DCA specimen suggested that the lipid-laden atheromatous gruel could attenuate the ultrasound reflection and cause distal embolization, resulting in no-reflow during PCI. The presence of ultrasound attenuated coronary plaque is a predictor of slow flow or no-reflow in PCI, indicating that distal protection devices may be required during the procedure.     

Involvement of C-reactive protein obtained by directional coronary atherectomy in plaque instability and developing restenosis in patients with stable or unstable angina pectoris

We investigated whether positive immunohistochemical staining of C-reactive protein (CRP) in initial culprit lesions is related to coronary plaque instability and whether it could affect the outcome of directional coronary atherectomy (DCA). The plasma level of CRP is a reliable marker of the risk of coronary events and restenosis after percutaneous coronary intervention. However, the influence of tissue CRP in atheromatous plaque on plaque vulnerability and restenosis remains unknown. Samples of DCA obtained from 12 patients with stable angina pectoris and 15 patients with unstable angina pectoris were immunohistochemically stained with a monoclonal antibody against CRP. We performed follow-up coronary angiography on 22 of 27 patients to evaluate the presence of restenosis after DCA. Immunoreactivity to CRP was localized to macrophages, smooth muscle cells, and necrotic areas. The ratio of CRP positive cells to total cells was significantly higher in DCA samples from patients with unstable (17.9 +/- 2.0%) than with stable angina (11.0 +/- 2.5%) (p <0.05). Follow-up coronary angiography showed that 12 of 22 patients developed restenosis after DCA. The ratio was also significantly higher in DCA specimens from patients with restenosis (19.3 +/- 2.8%) compared with those without restenosis (11.0 +/- 2.0%) (p <0.05). In addition, the ratio significantly correlated with late luminal loss (r = 0.428, p <0.05) and loss index (r = 0.636, p = 0.0011) after DCA. Immunoreactivity to CRP in coronary atheromatous plaque increases in culprit lesions of unstable angina, and it affects restenosis after DCA. These findings suggest that CRP in atheromatous plaque plays an important role in the pathogenesis of unstable angina and restenosis after coronary intervention.     

Intravascular ultrasound assessment of patterns of arterial remodeling in the absence of significant reference segment plaque burden in patients with coronary artery disease

OBJECTIVES: We evaluated the impact of reference vessel segment plaque burden on lesion remodeling.Intravascular ultrasound (IVUS) assessment of lesion remodeling compares lesions to reference segments. However, reference segments are rarely disease-free and, therefore, have also undergone remodeling changes. METHODS: Pre-intervention IVUS was obtained in 274 patients with right coronary artery lesions selected because the right coronary artery has less tapering and fewer side branches than the left anterior descending or left circumflex artery. Standard IVUS definitions were used. Patients were divided according to reference vessel segment plaque burden: group A (minimal reference disease, n = 91), both proximal and distal reference plaque burden <20%; group B (n = 91), either proximal or distal reference plaque burden 20% to 40% but both < or =40%; and group C (n = 92), either proximal or distal reference plaque burden >40%. RESULTS: The remodeling index measured 0.98 +/- 0.16 in group A (range, 0.68 to 1.47), 1.04 +/- 0.18 in group B (range, 0.67 to 1.91), and 1.04 +/- 0.15 in group C (range, 0.74 to 1.70), analysis of variance p = 0.0208 (p = 0.0234 group A vs. group B and p = 0.0012 group A vs. group C, but p = 0.8 group B vs. group C). Positive, intermediate, and negative remodeling were observed in 24 (26%), 24 (26%), and 43 lesions (48%) in group A; 36 (40%), 28 (30%), and 27 lesions (30%) in group B; and 34 (37%), 39 (42%), and 19 lesions (21%) in group C, respectively (p = 0.0022). CONCLUSIONS: Negative remodeling occurs commonly in coronary lesions with minimal reference segment disease. Negative remodeling is not just an "artifact" introduced by comparing lesions to diseased reference segments.     

Predictors of vessel remodeling following directional coronary atherectomy.

The purpose of this study was to clarify predictors of vessel remodeling following directional coronary atherectomy (DCA). Negative remodeling after DCA leads to restenosis. However, little is known about the predictors of the vessel remodeling. Serial IVUS was performed in 43 lesions. The vessel remodeling was defined as adaptive if vessel area at follow-up minus postprocedure vessel area was > 0 mm2, or as constrictive if < 0 mm2. Adaptive remodeling occurred in 21 (49%) lesions. Postprocedure percent plaque area was smaller in the adaptive group (32.9% +/- 5.7% vs. 45.5% +/- 8.8%; P < 0.005). At follow-up, vessel area was larger in the adaptive group. However, plaque area was similar between the two groups. As a result, lumen area was larger in the adaptive group. Multivariate analyses showed that postprocedure percent plaque area < 40% was the only predictor of adaptive remodeling (odds ratio, 6.68; P < 0.05).     

Relation between baseline plaque burden and subsequent remodelling of atherosclerotic left main coronary arteries: a serial intravascular ultrasound study with long-term (> or =12 months) follow-up.

AIMS: Glagov's histopathological observation and non-serial intravascular ultrasound studies (IVUS) concluded that compensatory coronary remodelling diminishes as 40% atherosclerotic plaque burden is reached. We tested this hypothesis with serial IVUS. METHODS AND RESULTS: Serial IVUS examinations of 46 atherosclerotic non-stenotic left main stems (18+/-8 months apart) were analysed to assess the relation between baseline plaque burden (=plaque+media area/vessel area) vs. serial remodelling (=vessel area at baseline - at follow-up). There were 25 plaques with baseline plaque burden <40% (30.1+/-6.6%, group A) and 21 plaques with baseline plaque burden > or =40% (46.1+/-5.8%, group B). There was no relation between baseline plaque burden vs. subsequent changes in vessel area overall (r=0.07, P=0.7), for group A (r=0.03, P=0.6), and group B (r=0.01, P=0.8). The frequency of positive serial remodelling (vessel area increase) vs. negative or intermediate serial remodelling (no change or decrease) were similar in group A [17 (68%) vs. 8 (32%)] and group B lesions [18 (86%) vs. 3 (14%)] (P=0.2). CONCLUSION: IVUS demonstrates that serial coronary remodelling is not related to baseline plaque burden. Lesions with baseline plaque burden <40% may subsequently show a lack of compensation or frank arterial shrinkage, whereas lesions with baseline plaque burden >40% may continue to develop compensatory enlargement.     

Densitometric quantitative analysis of intracoronary ultrasound images: anatomopathologic correlation

To establish if the video densitometric analysis (VDA) of the intracoronary ultrasound images (IVUS) can predict the qualitative and quantitative composition of the atherosclerotic coronary plaques, thirty-one patients with anatomopathologic study of directional coronary atherectomy (DCA) samples and pre and post intervention IVUS image were analyzed. The video IVUS images were digitized in a 512 x 512 matrix and analyzed for densitometric differences with an Automatic Image Analysis System (AIAS) (Vidas 2000, Zeiss Kontron). The components of the plaque were arbitrarily divided into three densitometric categories using a 256 gray scale: high density (HD) 121–255, medium (MD) 81–120 and low (LD) 30–80. The relative percentage of each component was automatically recorded. The DCA samples were microscopically examined and input in the AIAS. The components were divided into: collagenous tissue (CT); lipid-necrotic debris (LND); proliferative tissue (PT). The area of each component was expressed as a percentage of the total. Linear correlation analysis was applied. Comparison between the IVUS and the histological composition of the plaque showed that: HD corresponded to CT; MD to PT; LD to LND. The correlation between the percentage distribution of the densitometric categories and the anatomopathologic components showed a correlation coefficient r%equals;0.91 between HD and CT; r%equals;0.87 between MD and PT; r%equals;0.88 between LD and LND. The VDA of the IVUS can distinguish three basic components of the atherosclerotic plaque: fibrous, lipid-necrotic and proliferative tissue, allowing absolute and relative quantitative analysis. This capability may be of interest for device selection and histopathologic correlation.     

Accuracy of nonstenotic coronary atherosclerosis assessment by multi-detector computed tomography.

BACKGROUND: The ability to evaluate coronary stenosis using multi-detector computed tomography (MDCT) has been well discussed. In contrast, several studies demonstrated that the plaque burden measured by intravascular ultrasound (IVUS) has a relationship to the risk of cardiovascular events. the accuracy of MDCT was studied to determine plaque and vessel size compared with IVUS. METHODS AND RESULTS: Fifty-six proximal lesions (American College of Cardiology/American Heart Association classification: segment 1, 5, 6) from 33 patients were assessed using MDCT and IVUS. The plaque and vessel area were measured from the cross-sectional image using both MDCT and IVUS. Eight coronary artery lesions with motion artifacts and heavily calcified plaques were excluded from the analysis. The vessel and lumen size evaluated using MDCT were closely correlated with those evaluated by IVUS (R(2)=0.614, 0.750 respectively). Furthermore, there was a strong correlation between percentage plaque area assessed by MDCT and IVUS (R(2)=0.824). CONCLUSION: MDCT can noninvasively quantify coronary atherosclerotic plaque with good correlation compared with IVUS in patients with atherosclerosis.     

稳定型心绞痛冠状动脉斑块结构与重构关系的研究

目的:探讨血管内超声对稳定型心绞痛(SAP)患者冠状动脉(冠脉)病变斑块结构与血管重构关系的评估价值。方法:在冠脉介入治疗前应用血管内超声对SAP患者的冠脉病变进行研究。根据测定的重构指数(RI)将患者分为A组(负重构,RI<1.0)和B组(正重构,RI≥1.0),根据管腔面积狭窄率分为管腔面积狭窄率<70%组(轻中度狭窄组)和管腔面积狭窄率≥70%组(重度狭窄组)。结果:①与A组比较,B组近端参考段斑块负荷小,病变处的管腔面积和外弹力膜面积大、斑块负荷小,硬斑块所占比例少,病变处最大钙化弧度和长度小;②与轻中度狭窄组比较,重度狭窄组负重构多,软斑块少,病变处管腔面积小,病变处斑块面积和斑块负荷大,RI偏小,病变最大钙化弧度大。结论:不同程度管腔狭窄的SAP患者中,斑块钙化在负重构和严重管腔狭窄中占优势,负重构更常见于严重狭窄病变。     

Randomized comparison of debulking followed by stenting versus stenting alone for ostial left anterior descending artery stenosis: intravascular ultrasound guidance

Background

Although directional coronary atherectomy (DCA) before stenting has the advantage of combining substantial removal of atheromatous plaque and prevention of elastic recoil, there has been no randomized study to investigate its efficacy in ostial left anterior descending artery (LAD) lesions. This study was aimed to evaluate the effect of DCA followed by stenting on ostial LAD stenosis under the guidance of intravascular ultrasound (IVUS).

Methods

Eighty-six patients with ostial LAD stenoses were randomly assigned to DCA followed by stenting (group I) or stenting alone (group II). Aggressive DCA or optimal stenting was performed in both groups under the guidance of IVUS. The primary end point was angiographic restenosis at 6 months.

Results

Baseline clinical and angiographic characteristics were similar between the 2 groups. The postprocedural minimal lumen diameter was larger in group I than group II (4.0 ± 0.4 mm vs. 3.5 ± 0.5 mm, P < .001). However, the angiographic restenosis rates were not significantly different between the 2 groups (9/32 [28.1%] in group I vs. 11/30 [36.7%] in group II, P = .472). The postprocedural IVUS stent area was the only independent determinant of restenosis by multivariate analysis (odds ratio .61, 95% CI 0.41-0.92, P = .018).

Conclusions

DCA followed by stenting achieved greater lumen gain than stenting alone for ostial LAD stenosis. However, DCA did not improve angiographic restenosis.