Limited usefulness of non-invasive coronary angiography with 16-detector multislice computer tomography at a community hospital

OBJECTIVES: To evaluate the usefulness of coronary angiography by 16-detector multislice spiral computed tomography (MSCT) in community hospital outpatients. DESIGN: MSCT was performed at the community hospital in 157 of 218 consecutive outpatients with suspected significant coronary disease, before referral for invasive coronary angiography. RESULTS: 101 patients had interpretable MSCT angiograms (64 men, age 62+/-10 years, calcium score 373+/-678, heart rate 56+/-7 beats/min, beta-blocker used by 91%). Coronary stenoses >50% were identified by invasive angiography in 49 patients. Only 79% of all segments could be assessed by MSCT due to heavy coronary calcification (12%) and blurred images (9%) in the remaining. By interpreting non-assessable segments as negative results 79 patients were correctly classified by MSCT. Sensitivity, specificity, positive and negative predictive values at patient level was 82%, 75%, 75% and 81%. By interpreting non-assessable segments as positive findings, the corresponding values were 100%, 29%, 57% and 100%, with correct diagnoses in 63% of patients. CONCLUSIONS: Limited diagnostic accuracy, non-interpretable scans and radiation exposure restrict the usefulness of coronary MSCT in a community hospital setting.     

多层螺旋CT评价冠状动脉支架通畅的可行性

目的验证多层螺旋CT(MSCT)评价冠状动脉支架通畅的可行性。方法使用MSCT对17例患者的23个支架进行评价,并以常规冠状动脉造影作为金标准进行对照。结果使用MSCT平均只有45%的支架内腔能被显示,另有3个支架内腔不能用于狭窄评价。MSCT显示16个支架通畅,与常规冠状动脉造影相符合的有14个;MSCT显示4个支架闭塞,均得到常规冠状动脉造影证实。结论虽然16层螺旋CT只能显示部分支架内腔,但在评价支架通畅性方面CT能提供有用的信息。     

Intravascular ultrasound in equivocal coronary angiography.

Intravascular ultrasound (IVUS) is a well-established diagnostic tool that supplements coronary angiography in the evaluation of angiographical intermediate lesions as well as guiding Percutaneous transluminal coronary angioplasty. In this case report we describe the benefit of IVUS in diagnosing pseudostenosis as opposed to angiographically suspected guidewire induced dissection, and suggest the use of IVUS in all cases where angiography is equivocal. We also report a case of preoperative IVUS where the IVUS finding resulted in further coronary artery bypass grafting and suggest IVUS as a feasible alternative to probing of coronary arteries suspected of stenosis during coronary artery bypass grafting.     

Intravascular Ultrasound in Equivocal Coronary Angiography

Intravascular ultrasound (IVUS) is a well-established diagnostic tool that supplements coronary angiography in the evaluation of angiographical intermediate lesions as well as guiding Percutaneous transluminal coronary angioplasty. In this case report we describe the benefit of IVUS in diagnosing pseudostenosis as opposed to angiographically suspected guidewire induced dissection, and suggest the use of IVUS in all cases where angiography is equivocal. We also report a case of preoperative IVUS where the IVUS finding resulted in further coronary artery bypass grafting and suggest IVUS as a feasible alternative to probing of coronary arteries suspected of stenosis during coronary artery bypass grafting.     

Limited usefulness of non-invasive coronary angiography with 16-detector multislice computer tomography at a community hospital

Objectives. To evaluate the usefulness of coronary angiography by 16-detector multislice spiral computed tomography (MSCT) in community hospital outpatients. Design. MSCT was performed at the community hospital in 157 of 218 consecutive outpatients with suspected significant coronary disease, before referral for invasive coronary angiography. Results. 101 patients had interpretable MSCT angiograms (64 men, age 62±10 years, calcium score 373±678, heart rate 56±7 beats/min, beta-blocker used by 91%). Coronary stenoses >50% were identified by invasive angiography in 49 patients. Only 79% of all segments could be assessed by MSCT due to heavy coronary calcification (12%) and blurred images (9%) in the remaining. By interpreting non-assessable segments as negative results 79 patients were correctly classified by MSCT. Sensitivity, specificity, positive and negative predictive values at patient level was 82%, 75%, 75% and 81%. By interpreting non-assessable segments as positive findings, the corresponding values were 100%, 29%, 57% and 100%, with correct diagnoses in 63% of patients. Conclusions. Limited diagnostic accuracy, non-interpretable scans and radiation exposure restrict the usefulness of coronary MSCT in a community hospital setting.     

Isotropic half-millimeter angiography of coronary artery bypass grafts with 16-slice computed tomography

BACKGROUND: Computed tomography (CT) with four detector rows and magnetic resonance imaging (MRI) are still of limited value for the assessment of coronary artery bypass grafts (CABG). We investigated the abilities of 16-slice CT in these patients. METHODS: A retrospective analysis of all noninvasive coronary angiographies with multislice computed tomography (MSCT; Aquilion, Toshiba) on patients with CABG referred to our institution between October 2002 and April 2003 was conducted. MSCT angiography was performed using a standard protocol (0.5-seconds rotation time, 16 x 0.5 mm detector collimation, 120 kV, 250 to 300 mA, and 0.25 pitch). None of the patients received beta-blockers to reduce the heart rate. Seventy-five CABGs (20 arterial grafts and 55 venous grafts) in 27 patients were evaluated for patency and adequate diagnostic quality by two radiologists in consensus. RESULTS: All arterial and venous grafts were depicted with adequate diagnostic quality and were eligible for evaluation. Fifteen occlusions and five significant stenoses (at least 50%) could be identified. All of the proximal and 99% of the distal anastomoses were eligible. One distal anastomosis of an arterial graft was not assessable due to surgical clip artifacts. The length of the acquisition window was 174 +/- 46 ms (range 71 to 234 ms). The majority of the patients (70%) had a heart rate above 65 beats/min. However, due to the improved temporal and spatial resolution none of the examinations had an insufficient image quality. CONCLUSIONS: MSCT angiography with 16 detector rows and an isotropic high resolution reliably depicts CABG with adequate diagnostic quality.     

多排螺旋CT冠脉成像与冠脉造影对冠心病诊断的对比研究

目的:初步评价MSCT在冠状动脉成像中的临床应用价值。方法:18例疑诊冠状动脉狭窄患者行MSCT扫描,利用影像曲面重建,3D重建,了解冠状动脉病变情况,并与冠状动脉造影对比。结果:18例76支血管同时经MSCT和CAG成像。冠状动脉造影发现狭窄27支,其中左前降支(LAD)病变11支,回旋支(LCA)病变3支,左主干(LMA)2支,右冠(RCA)病变9支,桥支病变2支。MSCT发现狭窄23支,其中左前降支病变11支,回旋支病变3支,左主干病变1支,右冠病变9支,桥支病变2支。MSCT成像的敏感性为81．5％(22／27),特异性100％,阳性推测值91．7％,阴性推测值94．2％。结论:在控制心率的情况下,MSCT可作为冠状动脉狭窄的一种无创筛选检查方法。     

Coronary graft patency after perioperative myocardial infarction: a study with multislice computed tomography

A total of 55 consecutive patients who experienced perioperative myocardial infarction (MI) after coronary artery bypass grafting were studied using multislice computed tomography (MSCT) angiography to evaluate for graft patency. The MSCT detected acute graft occlusion in 23% grafts. Of the 55 patients, 40% patients had occluded grafts and perioperative MI in the area of the grafted vessels; remaining 60% had patent grafts with infarction in the area of the grafted vessels. Compared with the patients with patent grafts, those with occluded grafts had a higher blood sugar level. In addition, graft occlusion was higher in grafts with severe distal disease. Among the patients with patent grafts, luminal stenosis of the native vessels supplying the infarcted myocardium was higher than that in the native vessels supplying the non-infarcted myocardium. In conclusion, MSCT is feasible for the assessment of graft patency in the setting of perioperative MI. Graft occlusion is detected in less than half of the cases and usually occurs in the grafts with severe distal involvement and the patients with uncontrolled hyperglycemia. In patients with patent grafts, the severity of luminal stenosis of the native grafted vessel is the main predisposing factor for perioperative MI.     

无创性冠状动脉成像技术的新进展

无创性冠状动脉成像技术一直是影像学研究的热点之一。本文综述电子束CT（EBCT）、双源CT（DSCT）、多层螺旋CT（MSCT）和磁共振成像（MRI）在冠状动脉无创性成像方面的研究进展。     

Impact of proximal radiopaque coronary bypass graft markers on postbypass surgery coronary angiography

Background

Implantation of radiopaque bypass graft markers during coronary artery bypass surgery (CABG) has the potential of facilitating subsequent coronary angiography. This study sought to investigate the impact of proximal coronary bypass graft markers on angiographic outcomes during subsequent coronary angiography in a large cohort.

螺旋CT冠脉成像筛选冠状动脉疾病

目的探讨16层螺旋CT冠状动脉造影（MSCTCA）的临床应用价值。方法以回顾性心电门控技术对95例临床高度怀疑冠状动脉硬化性心脏病患者行16层螺旋CT扫描并进行后处理，选择其中阳性27例行冠状动脉造影（CAG）并与MSCTCA对比分析。结果95例MSCTCA显示380支血管，其中346支（91．05％）可用于影像学评价，34支（8．95％）不能评价。27例MSCTA阳性者接受数字减影冠脉造影检查，MSCTCA与CAG诊断符合24例，符合率为88．89％。结论在严格控制心率的情况下，规范检查技术，16层螺旋CT可作为冠脉病变检查的筛查方法，具有较高的临床价值。     

Comparison of multislice computerized tomography angiography and digital subtraction angiography in the postoperative evaluation of patients with clipped aneurysms

OBJECT: In this study the accuracy of multislice computerized tomography (MSCT) angiography in the postoperative examination of clip-occluded intracranial aneurysms was compared with that of intraarterial digital subtraction (DS) angiography METHODS: Forty-nine consecutive patients with 60 clipped aneurysms (41 of which had ruptured) were studied with the aid of postoperative MSCT and DS angiography. Both types of radiological studies were reviewed independently by two observers to assess the quality of the images, the artifacts left by the clips, the completeness of aneurysm occlusion, the patency of the parent vessel, and the duration and cost of the examination. The quality of MSCT angiography was good in 42 patients (86%). Poor-quality MSCT angiograms (14%) were a result of the late acquisition of images in three patients and the presence of clip or motion artifacts in four. Occlusion of the aneurysm on good-quality MSCT angiograms was confirmed in all but two patients in whom a small (2-mm) remnant was confirmed on DS angiograms. In one patient, occlusion of a parent vessel was seen on DS angiograms but missed on MSCT angiograms. The sensitivity and specificity for detecting neck remnants on MSCT angiography were both 100%, and the sensitivity and specificity for evaluating vessel patency were 80 and 100%, respectively (95% confidence interval 29.2-100%). Interobserver agreements were 0.765 and 0.86, respectively. The mean duration of the examination was 13 minutes for MSCT angiography and 75 minutes for DS angiography (p < 0.05). Multislice CT angiography was highly cost effective (p < 0.01). CONCLUSIONS: Current-generation MSCT angiography is an accurate noninvasive tool used for assessment of clipped aneurysms in the anterior circulation. Its high sensitivity and low cost warrant its use for postoperative routine control examinations following clip placement on an aneurysm. Digital subtraction angiography must be performed if the interpretation of MSCT angiograms is doubtful or if the aneurysm is located in the posterior circulation.     

Intraoperative Angiography in Minimally Invasive Direct Coronary Artery Bypass Grafting

Intraoperative angiography in minimally invasive direct coronary artery bypass grafting without cardiopulmonary bypass and in hybrid procedures is reported. Twelve procedures were performed in a specially designed surgical-radiologic suite with a cross-disciplinary organization. In 2 patients the anastomosis was successfully revised on the basis of angiographic findings. In 4 of the 12 patients anastomosis of the left internal mammary artery to the left anterior descending coronary artery performed as a minimally invasive direct coronary artery bypass grafting procedure was combined with percutaneous transluminal coronary angioplasty of lesions in other coronary vessels in the same session. Intraoperative angiography allows a reliable diagnosis of an anastomosis or graft failure and prompt and reliable correction, and it allows the combination of minimally invasive direct coronary artery bypass grafting and angioplasty in one session.     

Advantage of vein grafts for anomalous origin of a right coronary artery

A 66-year-old man with anomalous origin of the right coronary artery suffered from chest pain. The results of coronary angiography and multidetector computer tomography indicated that the proximal right coronary artery was intermittently compressed, causing the ischemia. Coronary artery bypass grafting was regarded as a reliable treatment compared with percutaneous coronary intervention or other surgeries. Because of plentiful flow of the right coronary artery, we decided to use a vein graft to avoid competitive flow. Postoperative coronary angiography revealed intact flow in both the native coronary artery and the vein graft 1 year after the surgery. The myocardial ischemia seen on scintigraphy and the chest pain had disappeared.     

Coronary artery bypass grafting with bilateral internal thoracic arteries for Bland-White-Garland syndrome in an adult

A 46-year-old man with anomalous origin of the left coronary artery from the pulmonary artery (Bland-White-Garland syndrome) is reported. We successfully performed coronary artery bypass grafting with the use of bilateral internal thoracic arteries and ligation of the anomalous left coronary artery. The patient was discharged from the hospital after an uneventful postoperative course and postoperative coronary angiography, which revealed patent internal thoracic arteries and no leakage of blood flow from the anomalous left coronary artery to the pulmonary artery. This surgical procedure is technically simple and useful for adult patients with Bland-White-Garland syndrome. To our knowledge, this is one of only a few reports on coronary artery bypass grafting with bilateral internal thoracic arteries as a treatment of Bland-White-Garland syndrome.     

Internal mammary artery bypass graft for impaired coronary perfusion after neonatal arterial switch operation.

Myocardial ischaemia caused by perfusion impairment of translocated coronary arteries is the major cause of perioperative mortality after neonatal arterial switch operation for transposition of the great arteries. We report the successful use of the right internal mammary artery as a bypass graft to a dominant right coronary artery to treat insufficient perfusion of this artery in a newborn. Eight months later, coronary angiography showed a full blood supply of the right coronary artery across the internal mammary anastomosis. After a follow-up period of more than 30 months, somatic development, electrocardiogram and echocardiographically determined contractility of both ventricles are practically normal indicating regular function of the bypass graft.     

Off-pump combined coronary artery bypass grafting and left upper lobectomy through left posterolateral thoracotomy

A 61-year-old man with angina had a lesion in the left upper lobe of his lung on chest roentgenogram. Coronary angiography revealed a dominant circumflex lesion. Combined coronary artery bypass grafting (CABG) and left upper lobectomy was performed through left posterolateral thoracotomy without the use of cardiopulmonary bypass. Off-pump CABG abolishes the complications of cardiopulmonary bypass, while posterolateral thoracotomy provides a direct access to the circumflex vessels and is ideal for lung resection.     

Electron beam coronary angiography to assess patency in the off-pump coronary bypass graft

BACKGROUND: Off-pump coronary artery bypass is widely practiced today, with critics questioning patency rates. This study was conducted to determine the feasibility of using electron beam coronary angiography to determine patency in this group of patients. METHODS: A total of 27 patients from a series of 653 off-pump coronary artery bypass patients were selected at random and, after informed consent, underwent electron beam coronary angiography with an Imatron C150 single slide mode using loversol as contrast material injected in an antecubital vein. RESULTS: A total of 88 bypasses were studied with an average of 3.2 +/- 0.7125 grafts per patient, with a mean follow-up of 20.3 months. Four bypasses were occluded. CONCLUSIONS: Electron beam coronary angiography appears to be a safe, suitable test to demonstrate patency in the off-pump coronary artery bypass graft patient, allowing study of a large group of patients without the risk or discomfort of cardiac catheterization.     

Coronary artery and graft spasm after off-pump coronary artery bypass grafting

We report a case of a 52-year-old man with severe coronary artery and graft spasm after triple-vessel off-pump coronary artery bypass grafting. Emergent coronary angiography was performed to identify the location and severity of the spasm. Intracoronary injections of several vasodilators failed to relieve the spasm. Observational treatments including intra-aortic balloon pump and inotropic drugs to increase coronary flow were performed until the spasm resolved. The patient recovered and was discharged. A follow-up coronary angiography revealed patent native coronary artery and bypass grafts without evidence of residual spasm.     

Minimally invasive single-vessel coronary artery bypass with the internal thoracic artery and early postoperative angiography: midterm results of a prospective study in 120 consecutive patients

BACKGROUND: This prospective study was undertaken to determine the role of the minimally invasive direct coronary artery bypass with early postoperative angiography and midterm follow-up in 120 consecutive patients with single-vessel coronary artery disease. METHODS: Minimal access (6 to 10 cm), without complete sternotomy and no cardiopulmonary bypass, was used. The lesions were located at the proximal left anterior descending coronary artery in 95% of the patients. Routine coronary angiography was performed before discharge. RESULTS: Postoperative angiography was performed in 104 (90.4%) of those 115 patients who had coronary revascularization concluded by the mini-access method. The internal thoracic artery patency rate was 98.1% (95.2% grade A). Two (1.7%) patients presented with perioperative myocardial infarction, which led to the single in-hospital death (0.8%). Of the remaining 119 patients, 113 (95.0%) were asymptomatic. The event-free probability was 94.9% and the actuarial survival was 98.3% with 42 months of follow-up. CONCLUSIONS: For selected patients with single-vessel coronary artery disease and no major myocardial dysfunction, minimally invasive direct coronary artery bypass is a safe operation and a less invasive alternative to conventional coronary artery bypass grafting.