Evaluation of vascular injury following percutaneous transluminal coronary angioplasty: a comparison of the accuracy of two- and three-dimensional intracoronary ultrasound imaging

BACKGROUND: Following percutaneous transluminal coronary angioplasty (PTCA), the extent of vascular injury is underestimated by angiographic assessment. Conventional intracoronary ultrasound (ICUS) imaging provides additional information with regard to the extent of dissections but requires mental reconstruction of consecutive images. Three-dimensional ICUS reconstruction overcomes this limitation and may provide more accurate assessment of the extent of vascular injury. This study compares conventional two-dimensional ICUS imaging to combined two- and three-dimensional ICUS information in the assessment of vascular injury following PTCA. METHODS: Atherosclerotic, human coronary arteries (n=24) were studied in a specially constructed flow system. Balloon dilatation of significant stenoses was performed followed by assessment using two- and three-dimensional ICUS imaging methods. Treated arteries were submitted for histological assessment after pressure fixation. Dissection depth and length measurements were made from obtained images and compared to histomorphometric assessments. RESULTS: Of the 20 arterial segments confirmed histologically to contain dissection, 11 (55%) and 18 (90%) were identified by two-dimensional ICUS and combined two- and three-dimensional ICUS respectively. The kappa values for correlation of dissection type were 0.29 (0.23-0.35) and 0.64 (0.57-0.71) respectively indicating better agreement using combined two- and three-dimensional ICUS. Two-dimensional ICUS consistently underestimated dissection length (3.52+/-1.75 mm compared with 6.54+/-2.42 mm, P<0.001) and depth (0.61+/-0.24 mm compared with 0.92+/-0.32 mm, P=0.001). Combined two- and three-dimensional ICUS produced accurate dissection length (6.13+/-2.29 mm compared with 6.54+/-2.42 mm, P=0.09) and depth (0.86+/-0.32 mm compared with 0.92+/-0.32 mm, P=0.28) estimations. CONCLUSION: Computerized three-dimensional reconstruction of ICUS images provides improved accuracy compared to conventional ICUS imaging in the detection and quantitation of arterial dissection. This technique would be a useful adjunct to angiography for the precise assessment of vascular injury following PTCA.     

Comparison of immediate and in-hospital results of conventional balloon and perfusion balloon angioplasty using intracoronary ultrasound

Angiographic studies have demonstrated that perfusion balloon percutaneous transluminal coronary angioplasty (PTCA) may result in modestly improved luminal gains and fewer major dissections than conventional balloon PTCA. However, intracoronary ultrasound (ICUS), which is more sensitive than angiography in evaluating the incidence, extent, and severity of dissection, was not used. We randomized 48 patients with 54 coronary stenoses to conventional or perfusion balloon PTCA. Four 2-minute inflations were permitted with conventional balloon PTCA. Two 10-minute inflations were allowed with perfusion balloon PTCA. Quantitative coronary angiography and ICUS were performed before and after treatment. In-hospital clinical events were recorded. Conventional and perfusion balloon PTCA achieved similar improvements in lumen diameter (1.25+/-0.51 vs 1.28+/-0.51 mm) and reductions in percent stenosis (-45+/-21% vs -44+/-15%) by quantitative coronary angiography. Comparable gains in lumen diameter (0.62+/-0.39 vs 0.50+/-0.38 mm) and lumen area (2.70+/-1.96 vs 2.05+/-1.52 mm2) were observed on ICUS. Angiography demonstrated similar rates of any dissection (36% vs 21%) and major dissection (12% vs 7%). ICUS identified a similar incidence of any dissection (60% vs 76%) and type II dissection (52% vs 62%). The relative dissection area was also similar (9.2+/-5.6% vs 7.8+/-5.8%). One conventional balloon patient experienced postprocedural chest pain. No patient in either group died, or had myocardial infarction, abrupt closure, or urgent revascularization.     

冠状动脉内超声显像与造影对冠状动脉病变检出的比较

目的研究冠状动脉造影（ＣＡＧ）正常者的冠状动脉内超声显像（ＩＣＵＳ）检查结果，结合临床表现及辅助检查，藉以提出ＩＣＵＳ检查的适应证。方法对连续４００例临床待诊或确诊为冠心病的患者行ＣＡＧ同时行ＩＣＵＳ检查。结果４００例患者中，１３５例ＣＡＧ正常者，而ＩＣＵＳ检查示：２８例正常，３８例冠状动脉内膜增厚，６９例有不同性质的斑块。分组分析，斑块组与非斑块组之间的冠心病高危因素比较，差异有显著性（Ｐ＜００５）。结论表明ＩＣＵＳ对冠状动脉病变的检出较ＣＡＧ敏感，认为ＣＡＧ检查结果正常者，若临床上心绞痛症状典型、年龄较大、血脂较高、吸烟及心电图有异常改变者，尤其是男性患者宜进一步行ＩＣＵＳ检查。     

Ultrasound Appearances of Coronary Stents as Obtained by Three-Dimensional Intracoronary Ultrasound Imaging In Vitro

Intracoronary ultrasound (ICUS) is an imaging technique which can provide a cross-sectional image of coronary arteries and implanted stents. Different stents may have individual ICUS imaging characteristics. To investigate the imaging characteristics and three-dimensional (3-D) reconstruction of different coronary stent designs, we examined 26 different stents using ICUS in vitro. All stents could be well visualized with planar ICUS. In 18 stents, 3-D imaging succeeded in reconstructing the spatial stent architecture. This was not possible in the other 8 stents, most probably because of predominantly transversally-orientated strut architecture, the small size of the strut wire width, the limited ICUS lateral catheter resolution, and the smoothing and interpolation algorithms applied for 3-D reconstruction. ICUS in vitro provides a means of identifying coronary stent structures which may be applicable in vivo. Three-D reconstruction of the entire stent architecture in vitro can be achieved in stents with mesh or slotted tube design, while stents with coil design and thin strut wires can only be partially reconstructed.     

Safety of intracoronary ultrasound: Data from a multicenter European registry

The clinical use of intracoronary ultrasound imaging is growing, serving as a useful adjuvant to contrast angiography, and providing additional information to assist with catheter-based interventions. Despite the increasing use of this technique, it remains an invasive procedure, the safety of which has not been definitively established. Data from multiple European centers performing intracoronary ultrasound (ICUS) examinations were collected under the auspices of the Subgroup on Intravascular Ultrasound of the Working Group on Echocardiography of the European Society of Cardiology. Information was obtained about the number of examinations performed, complications related to ICUS imaging, and any adverse clinical consequences related to ICUS imaging. Twelve centers submitted information about their experience with ICUS. Eight (1.1%) complications were reported (spasm, vessel dissection, or guide wire entrapment) in a total of 718 examinations. All complications occurred in patients with atherosclerotic coronary disease with a diagnosis of unstable or stable angina who underwent percutaneous transluminal coronary angioplasty. No permanent adverse clinical consequences due to ICUS imaging were reported. There was no difference in frequency of complications between centers, as assessed by chi-square analysis (P = 0.232). These data suggest that ICUS examinations can be performed safely with a very low rate of complications. © 1996 Wiley-Liss, Inc.     

Incidence and time course of intimal plaque formation in the right coronary artery after radiofrequency current application detected by intracoronary ultrasound

BACKGROUND: Despite the current clinical use of radiofrequency (RF) catheter ablation in infants and children, the late effects of RF current application at immature myocardium remain unclear. The purpose of this study was to investigate incidence and time course of coronary lesions after RF current application at developing myocardium in an animal model. RESULTS: In 10 pigs, 6 weeks of age (13+/-2 kg), RF current (500 kHz) was delivered by temperature guidance (75 degrees C) using a steerable electrode catheter (4 mm tip electrode) over 30-second periods. RF lesions were created at the lateral right atrial wall at the tricuspid valve annulus and the lateral left atrial and ventricular wall at the mitral valve annulus. Subsequent coronary angiography and intracoronary ultrasound (ICUS) of the right coronary artery (RCA) and the left circumflex artery (CX) were performed 3, 6, 9 and 12 months after RF current application. Quantitative coronary angiography did not exhibit any significant stenosis of the vessels during the study period. Intimal lesions of the RCA were documented for the first time at the 6-month study in 3 animals by ICUS (mean plaque area 2.2+/-0.2 mm(2), mean area stenosis 30.4+/-4.0%). There was no significant change in lesion length, area stenosis and plaque area at the 9- and 12-month studies. All 3 coronary artery lesions were confirmed in close proximity to myocardial RF lesions by histological examination 12 months after RF delivery. No intimal plaque formation of the CX was observed. CONCLUSIONS: Affection of the RCA as a late sequel after RF current application at the lateral right atrial wall occurred in 3 out of 8 long-term surviving pigs. Three to six months seem to be the time frame for the development of intimal lesions after RF delivery. In this experimental setting, angiography failed to detect these intimal changes. The potential risk of coronary affection may be important for catheter ablation procedures at the right atrial myocardium in infants and small children.     

Noninvasive detection of coronary lesions by multislice computed tomography: results of the New Age pilot trial.

The reliable noninvasive assessment of coronary artery disease would constitute an important step forward in clinical cardiology. The aim of the New Age pilot trial was to evaluate the diagnostic accuracy of multislice computed tomography (MSCT) in determining coronary lesions. As a gold standard for in vivo plaque detection, intracoronary ultrasound (ICUS) was used. Forty plaques were detected by ICUS in 15 target vessels (LAD, n = 8; RCA, n = 7) in patients assigned for ICUS-guided PTCA. Preinterventional MSCT was performed in all patients and the results were compared to ICUS with regard to lesion detection and quantification. According to ICUS results, the 40 plaques were divided into three groups: group I, mild lesions < 50% (n = 14; 44.36% +/- 5.77%); group II, intermediate lesions 50%-75% (n = 12; 59.18% +/- 9.39%); and group III, severe lesions > 75% (n = 14; 91.47% +/- 3.68%). All MSCT scans showed sufficient image quality for analysis. Thirty of 40 (75%) plaques were detected by MSCT in a first blinded session. After unblinding the ICUS results, the remaining 10 (25%) plaques could be identified. Lesion severity was classified correctly in 34 of 40 (85%) plaques. Plaque calcifications were diagnosed correctly in 16 of 19 (84.2%) plaques. Quantification of vessel size revealed a good correlation to the ICUS results (r(2) 0.68; P = 0.004). Noninvasive MSCT angiography showed good diagnostic accuracy with regard to lesion detection and quantification of vessel size. The overall good image quality, makes this new technology a promising modality, which might become an alternative diagnostic approach in patients with known or suspected coronary artery disease. Cathet Cardiovasc Intervent 2001;53:352-358.     

Evaluation of contrast agents for delineation of vessel wall boundary by intracoronary ultrasound after coronary angioplasty in human

We evaluated the potential for improving visualization at intervention sites using contrast-enhanced intracoronary ultrasound (ICUS) and the suitable contrast agents for this procedure in humans. In 37 patients, ICUS (30 MHz) was performed with intracoronary bolus injection (3 mL) of seven different contrast preparations and without the contrast agents (control) after coronary intervention. The contrast agents used were as follows: saline solution, standard iomeprol, standard ioxaglate, sonicated iomeprol, sonicated ioxaglate, 50% Albunex, and 100% Albunex. Homogeneous and complete opacification of the vessel lumen and false lumen was observed with sonicated ioxaglate, 50% and 100% Albunex. Shadowing was not observed at all with sonicated ioxaglate and was uncommon with 50% Albunex, whereas 100% Albunex caused shadowing in all cases. The coronary delineation rate with the other contrast agents was only 60%–70%, and the homogeneity and peak intensity were relatively low. Thus, sonicated ioxaglate and 50% Albunex both achieved good visualization, but the latter is more expensive, more difficult to handle, and takes longer to prepare. Of the agents we studied, sonicated ioxaglate appears to be best suited for contrast-enhanced ICUS. ICUS using suitable contrast agents could only visualize the large dissections and the strategy was changed according to the contrast-enhanced ICUS results in five cases. Thus, suitable contrast agents, e.g., sonicated ioxaglate, should be used during ICUS after intracoronary intervention.Cathet. Cardiovasc. Intervent. 47:6–13, 1999. © 1999 Wiley-Liss, Inc.     

Retrospective image-based gating of intracoronary ultrasound images for improved quantitative analysis: the intelligate method.

Quantitative analysis of intracoronary ultrasound (ICUS) studies is performed on a series of tomographic cross-sectional ICUS images acquired during a motorized 0.5 mm/sec catheter pullback. Catheter displacement in the vascular lumen during the cardiac cycle causes an anatomically shuffled ICUS study, which results in a sawtooth-shaped appearance of the coronary segment in longitudinal reconstructed views in quantitative coronary ultrasound software packages. This hampers contour detection and leads to a laborious time-consuming semiquantitative analysis process that may produce inaccurate results. To solve these problems, in the past, online ECG-gated acquisition hardware has been applied. This article describes a novel image-based gating method called Intelligate, which features automatic retrospective selection of end-diastolic frames from videotaped or digitally stored ICUS studies. Our evaluation shows that there are no quantitative differences between analysis results of hardware ECG-gated and Intelligated ICUS studies.     

Noninvasive detection and evaluation of atherosclerotic coronary plaques with multislice computed tomography

OBJECTIVES: The aim of the present study was to evaluate the accuracy in determining coronary lesion configuration by multislice computed tomography (MSCT). The results were compared with the findings of intracoronary ultrasound (ICUS). BACKGROUND: The risk of acute coronary syndromes caused by plaque disruption and thrombosis depends on plaque composition rather than stenosis severity. Thus, the reliable noninvasive assessment of plaque configuration would constitute an important step forward for risk stratification in patients with known or suspected coronary artery disease. Just recently, MSCT scanners became available for general purpose scanning. Due to improved spatial and temporal resolution, this new technology holds promise to allow for differentiation of coronary lesion configuration. METHODS: The ICUS and MSCT scans (Somatom Volume Zoom, Siemens, Forchheim, Germany) were performed in 15 patients. Plaque composition was analyzed according to ICUS (plaque echogenity: soft, intermediate, calcified) and MSCT criteria (plaque density expressed by Hounsfield units [HU]). RESULTS: Thirty-four plaques were analyzed. With ICUS, the plaques were classified as soft (n = 12), intermediate (n = 5) and calcified (n = 17). Using MSCT, soft plaques had a density of 14 +/- 26 HU (range -42 to +47 HU), intermediate plaques of 91 +/- 21 HU (61 to 112 HU) and calcified plaques of 419 +/- 194 HU (126 to 736 HU). Nonparametric Kruskal-Wallis test revealed a significant difference of plaque density among the three groups (p < 0.0001). CONCLUSIONS: Our results indicate that coronary lesion configuration might be correctly differentiated by MSCT. Since also rupture-prone soft plaques can be detected by MSCT, this noninvasive method might become an important diagnostic tool for risk stratification in the near future.     

The experience of the use of intracardiac echocardiography during puncture of atrial septum

We analyzed results of 175 intracardiac ultrasound studies (ICUS) in 113 men (mean age 54,6 +/- 11,0 years) and 62 women (mean age 49,7 +/- 8,9 years) with atrial fibrillation (n=146) and WPW syndrome (n=29). ICUS was used for guidance of catheters or electrodes from right to left atrium through ratrial septum in 160 procedures of radiofrequency ablations for atrial fibrillation (n=146) or WPW syndrome (n=14). Complications of transseptal puncture developed in 4 patients (2,7%) with atrial fibrillation. There were no procedure related deaths. In all cases ICUS allowed to visualize interatrial septum and its thinnest part. Thus ICUS facilitates transseptal approach to the left atrium, provides lowering of risk of dangerous complications, and allows real time monitoring of possible intraprocedural complications.     

Dissection iatrogène de la coronaire droite et de l’aorte ascendante au cours d’une procédure d’angioplastie

Iatrogenic acute dissection of the ascending aorta following coronary angiography and percutaneous intervention is rare. The options for treatment are dictated by patient stability, nature of dissection of the coronary vessel, ability to restore the coronary circulation and extent of aortic dissection. Usually localized aortic dissections have been managed conservatively or treated by sealing the entry with a coronary stent. Extensive dissections may require a surgical intervention. We report the case of a 52-year-old man with iatrogenic dissection of the right coronary artery ostium and extension of the dissection to the ascending aorta during intraluminal angioplasty of an obstructive lesion in the first portion of the right coronary artery. The patient was managed conservatively without stenting (failure stenting of the right coronary artery) and without surgery. Aortic dissection was monitored by means of transesophageal echocardiography. Serial computed tomography scans demonstrated spontaneous resolution of the dissection. The evolution of the patient was satisfactory. Causes, frequency and treatment procedures of this iatrogeny are discussed.     

Is intravascular ultrasound after coronary stenting a safe procedure? Three cases of stent damage attributable to ICUS in a tantalum coil stent

The use of coronary stents decreases the morbidity associated with acute closure and restenosis after balloon angioplasty. Intracoronary ultrasound (ICUS) guidance of stent implantation has been advocated to improve stent deployment and thereby to further improve the clinical outcome after stenting, over and above balloon angioplasty. Whereas the merits of intracoronary ultrasound in this respect still remain to be proven, the present paper illustrates that ICUS itself may also entail complications. This paper repoorts on three cases of stent damage induced or aggravated by the ICUS procedure. Cathet. Cardiovasc. Diagn. 40:265–270, 1997. © 1997 Wiley-Liss, Inc.     

Coronary artery dissection after blunt chest trauma: subacute and chronic phase assessment by intravascular ultrasonography: a case report

A 35-year-old man sustained a steering wheel injury in a motor vehicle accident. Initial electrocardiography showed ST-segment elevation. Coronary angiography revealed a dissection of the right coronary artery and perfusion delay in the left anterior descending artery. Coronary stents were inserted into the left anterior descending artery. One month later, coronary angiography and intravascular ultrasonography showed that the dissection of the right coronary artery was still present. Coronary stents were inserted from the aorto-ostial lesion to the mid portion of the right coronary artery. Six months later, coronary angiography and intravascular ultrasonography revealed diffuse neointimal hyperplasia inside all of the stents, and the aorto-ostial stent had severe stenosis with perfusion delay. Severe neointimal hyperplasia was found inside the stents used for repair of the coronary artery dissection.     

Combined dissection of the right coronary artery and right coronary cusp during coronary angiography

Dissection of coronary arteries during diagnostic coronary angiography is infrequent; dissection of the coronary cusp is extremely rare. The combination of coronary artery and coronary cusp dissection has not been reported previously. A case of right coronary artery dissection and right coronary cusp dissection during diagnostic coronary angiography is described. © 1995 Wiley-Liss, Inc.     

Acute occlusion of the left main coronary artery following intracoronary ultrasound examination

Intracoronary ultrasound (ICUS) is generally considered as safe procedure, with a low complication rate. We describe a nearly fatal complication of a diagnostic ICUS study that was treated succesfully with stent implantation in the left main coronary artery and discuss the indications and remaining risks of this procedure. Cathet. Cardiovasc. Intervent. 47:181–184, 1999. © 1999 Wiley-Liss, Inc.     

Regression of an atherosclerotic coronary artery plaque demonstrated by multislice spiral computed tomography in a patient with stable angina pectoris

Multislice spiral computed tomography (MSCT) permits direct visualization of not only coronary artery stenosis but also atherosclerotic plaques in patients with coronary artery disease. In this report, we describe a patient with stable angina in whom the regression of the plaque was documented by serial MSCT examinations. In the patient, a 46-year-old man with stable angina, MSCT revealed a stenotic lesion at the proximal portion of the left anterior descending artery. Axial, curved multiplanar reconstruction and cross-sectional images consistently depicted a protruding computed tomography low-signal mass suggesting an atherosclerotic plaque. Intracoronary ultrasound (ICUS) also documented an eccentric soft plaque with an echo-lucent mass suggesting a lipid core. Lipid-lowering therapy with pravastatin was started. Follow-up MSCT performed 7 months later documented an increase in the luminal area while the external vessel area remained unchanged. The regression of the plaque was also confirmed by a follow-up ICUS study. MSCT was thought to be feasible for serial evaluation of the plaque size and texture.     

Acute inferior myocardial infarction in a young female patient with polyarteritis nodosa

Coronary involvement of polyarteritis nodosa (PAN) has been mostly identified in postmortem studies. We report a case with inferior myocardial infarction (MI) because of coronary dissection and thrombosis in PAN. A 23-year-old woman with chest pain was admitted to the emergency department. The admission ECG was suggestive of inferior MI with no right ventricular infarction. Coronary angiography revealed an occluded right coronary artery because of coronary dissection and concomitant thrombosis. Coronary angioplasty and stent implantation were performed successfully without complications. This report emphasizes the importance of PAN in spontaneous coronary dissection and thrombosis even in young patients.     

Variability in the measurement of intracoronary ultrasound images: implicatioNs for the identification of atherosclerotic plaque regression

Background and hypothesis: Serial coronary angiography cannot reliably detect the small changes in arterial dimensions. Measurement of arterial dimensions by intracoronary ultrasound (ICUS) may be a superior method to determine the extent of atherosclerotic burden since it directly images the diseased portion of the vessel. Methods: To quantify inter- and intraobserver variability of ICUS measurements, 27 images of atherosclerotic coronary lesions were measured by two study physicians and repeated 14 days later. Results: Interobserver correlation coefficients for external elastic lamina, lumen, and effective plaque area were 0.96, 0.99, and 0.91, respectively. Intraobserver correlation coefficients for external elastic lamina, lumen, and effective plaque area were 0.99, 0.99, and 0.97, respectively. To determine progression or regression in effective plaque area, a minimal difference of 2.77 mm² (which represents a 23% change in plaque area) is needed. Conclusions: Direct visualization of the extent of atherosclerosis by ICUS can be accomplished with a low degree of inter- and intraobserver variability. ICUS may be a preferable alternative to angiography in atherosclerosis regression trials.