Noninvasive evaluation of the coronary arteries with multislice computed tomography in hypertensive patients

Because patients with hypertension are at increased risk for coronary artery disease, early and noninvasive identification of the disease in patients with hypertension is important. Recently, multislice computed tomography (MSCT) has been demonstrated to allow both noninvasive coronary angiography and assessment of left ventricular function. The purpose of the present study therefore was to demonstrate the feasibility of this approach in patients with hypertension with known or suspected coronary artery disease and to compare the results to invasive coronary angiography and 2-dimensional echocardiography, respectively. MSCT was performed in 31 patients with confirmed hypertension. From the MSCT images, the presence of significant coronary stenoses (>or=50% luminal narrowing) and regional wall motion abnormalities were evaluated and compared with invasive coronary angiography and 2-dimensional echocardiography. In addition, left ventricular ejection fraction was calculated from the MSCT images. A total of 243 (88%) coronary artery segments could be evaluated with MSCT. Sensitivity and specificity for the detection of significant coronary artery stenoses were 93% and 96%. On a per-patient basis, MSCT was accurate in 28 (90%) patients. Mean left ventricular ejection fraction was 46+/-14% (range, 16% to 64%). The agreement for assessing regional wall motion was 91% (kappa statistic, 0.81). In conclusion, simultaneous, noninvasive evaluation of coronary artery stenoses and left ventricular function with MSCT is accurate in patients with hypertension. This noninvasive approach may allow triage of patient treatment in terms of conservative versus invasive management.     

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

目的初步评价多排螺旋CT（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（CAG）对比。结果18例76支血管同时经MSCT和CAG成像。CAG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24支,其中LAD病变11支,LCA病变3支,LMA病变1支,RCA病变7支,桥支病变2支。MSCT与CAG结果相符的病变血管22支,MSCT成像的敏感性为82%（22/27）,特异性96%（47/49）。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。     

Noninvasive coronary artery imaging by multislice spiral computed tomography.

Although the excellent spatial resolution of multislice spiral computed tomography (MSCT) enables the coronary arteries to be visualized, its limited temporal resolution results in poor image reproducibility because of cardiac motion artifact (CMA) and hence limits its widespread clinical use. A novel retrospectively ECG-gated reconstruction method has been developed to minimize CMA. In 88 consecutive patients, the scan data were reconstructed using 2 retrospectively ECG-gated reconstruction methods. Method 1: the end of the reconstruction window (250 ms) was positioned at the peak of the P wave on ECG, which corresponded to the end of the slow filling phase during diastole immediately before atrial contraction. Method 2 (conventional method): relative retrospective gating with 50% referred to the R-R interval was performed so that the beginning of the reconstruction window (250 ms) was positioned at the halfway point between the R-R intervals of the heart cycle. The quality of the coronary artery images was evaluated according to the presence or absence of CMA. The assessment was applied to the left main coronary artery (LMCA), the left anterior descending artery (LAD, segments #6, #7 and #8), the left circumflex artery (LCx, segments #11 and #13) and the right coronary artery (RCA, segments #1, #2 and #3). The first diagonal artery (#9-1), the obtuse marginal artery (#12-1), the posterior descending artery (#4-PD), the atrioventricular node branch (#4-AV) and the first right ventricular branch (RV) were also evaluated. Of the 88 patients, 85 were eligible for image evaluation. Method 1 allowed visualization of the major coronary arteries without CMA in the majority of patients. The LCA system (segments #5-7, #11 and #13) and the proximal portion of the RCA were visualized in more than 94% of patients. Artifact-free visualization of the distal portion of the LAD (segment #8) and RCA (#4PD and #4AV), and side branches (#9-1, #12-1 and RV) was also achieved in more than 80% of patients. On the other hand, CMA occurred frequently on images obtained by Method 2. The LCx and RCA systems were the most affected by CMA, revealing only 41% artifact-free visualization of the segment #13, 39% of #1, 15% of #2 and 32% of #3. Thus, Method 1, which avoids the ventricular motion occurring during the rapid filling and atrial contraction phases, gives superior image quality over the conventional ECG-gated reconstruction method.     

Advantages of multislice spiral computed tomography for evaluation of serious coronary complications after Kawasaki disease

OBJECTIVES: Novel multislice spiral computed tomography (MSCT) findings were identified in patients after Kawasaki disease that could not be detected by coronary angiography (CAG). METHODS: Eighteen patients had suffered from serious coronary arterial lesions after Kawasaki disease (mean age 21.7 years, range 13-34 years). Seventeen patients had stenotic lesions, and all of them had coronary aneurysms. MSCT was performed using a Siemens SOMATOM Volume Zoom (4-detector row) or a Toshiba Aquillion 16 (16-detector row). Findings of coronary calcification, stenotic lesion, and intimal hypertrophy in all coronary arteries were compared to those of CAG. RESULTS: Eleven of the 18 patients (61%) had novel findings detected by MSCT. Coronary calcifications were found in 11 of the 18 patients (61%). Five patients had concentric calcified aneurysms, four had eccentric calcified aneurysms, and two had mixed calcified aneurysms. Coronary stenotic lesions were present in 6 of the 18 patients (33%) with calcified aneurysms. Two patients had intimal hypertrophy (11%). One patient had intimal hypertrophy along the left main trunk with a giant calcified aneurysm along the left anterior descending artery. Two patients had severe stenoses just distal to giant calcified aneurysms that were regarded as false positive findings, and were identified as mild stenoses by CAG. CONCLUSIONS: MSCT offers advantages over CAG in the evaluation of calcified aneurysms and intimal hypertrophy, and is a potential diagnostic modality for coronary intervention in patients after Kawasaki disease.     

Assessment of coronary artery by four-detector multislice computed tomography: diagnostic accuracy and limitations for coronary artery lesions

OBJECTIVES: The applicability of four-detector multislice computed tomography (MSCT) was investigated for evaluating coronary arteries. METHODS: MSCT (Somatom Volume Zoom, Siemens) was used to evaluate the coronary arteries in 94 patients. The reconstructed images were analyzed using retrospective electrocardiographic gating to determine the image quality of the coronary arteries. In addition, the ability of MSCT to detect coronary artery lesions of > or = 70% (> or = 50% in the left main trunk) diameter stenoses documented by standard coronary angiography was assessed in 67 patients who underwent coronary angiography within the same period. RESULTS: Good image quality was displayed in 488 (58%) and fair in 184 (22%) of a total of 846 coronary segments, but non-assessable in 174 (21%) due to degraded image quality. MDCT detected 33 stenotic lesions correctly in 494 assessable segments, comparable to coronary angiography. The sensitivity and specificity of MSCT were 0.79 and 0.95, respectively. However, an additional 15 lesions were detected by coronary angiography among the non-assessable segments. In total, 24 lesions were missed by MSCT. Accordingly, coronary segments were completely assessable and correctly detected by MSCT in only 20 patients (30%), or 35 (52%) if the distal coronary segments were excluded from analysis. CONCLUSIONS: Four-detector MSCT for detection of coronary artery lesions was applicable to assessable segments. However, clinical use may presently be limited because of the insufficient overall accuracy. Further technical improvement is expected in the near future.     

Myocardial perfusion imaging using adenosine triphosphate stress multi-slice spiral computed tomography: alternative to stress myocardial perfusion scintigraphy.

BACKGROUND: The present study was designed to: (i) detect myocardial ischemia in contrast enhanced multi-slice spiral computed tomography (CE-MSCT) using adenosine triphosphate (ATP) pharmacological stress test; and (ii) evaluate the potential of ATP stress CE-MSCT in a clinical setting. METHODS AND RESULTS: Twelve patients underwent ATP stress CE-MSCT and stress thallium-201 myocardial perfusion scintigraphy (MPS) and 9 of the patients received conventional coronary angiography (CAG). Dual CE-MSCT scans were performed for stress and rest images, with and without intravenous infusion of ATP (0.16 mg.kg-1.min-1) at intervals of 20 min. Myocardial perfusion and coronary artery were visually evaluated using MSCT and compared the results obtained from MPS and CAG. Of 36 territories, stress images of CE-MSCT described 26 hypo-perfusion areas and MPS described 22 redistributions. The agreement between MSCT and MPS was 83% (30/36, p<0.05). In 141 coronary artery segments of 9 patients undergoing CAG, rest images of CE-MSCT, which had significantly higher assessability than stress images (89% vs 48%, p<0.05), described 76% (13/17) of culprit coronary stenoses. CONCLUSIONS: Although CT-angiography should be currently assessed using rest images, ATP stress CE-MSCT can describe both ATP-induced myocardial ischemia and coronary artery stenoses in patients with coronary artery disease.     

Diagnostic accuracy of noninvasive coronary angiography using 64-slice spiral computed tomography

OBJECTIVES: The aim of our study was to evaluate the diagnostic accuracy of multislice computed tomography (MSCT) coronary angiography using a new 64-slice scanner. BACKGROUND: The new 64-slice MSCT scanner has improved spatial resolution of 0.4 mm and a faster rotation time (330 ms) compared to prior MSCT scanners. METHODS: We studied 70 consecutive patients undergoing elective invasive coronary angiography. Patients were excluded for atrial fibrillation, but not for high heart rate, coronary calcification, or obesity. All vessels were analyzed, including those <1.5 mm in diameter; MSCT lesions were analyzed quantitatively as well as by a qualitative scale and compared to quantitative coronary angiography (QCA). Results were also analyzed for significant coronary stenoses (over 50% luminal narrowing) by segment, by artery, and by patient. RESULTS: All scans showed diagnostic image quality. Of 1,065 segments, 935 (88%) could be evaluated, and 773 of 935 (83%) could be assessed quantitatively by both MSCT and QCA. The Spearman correlation coefficient between MSCT and QCA was 0.76 (p < 0.0001). Bland-Altman analysis demonstrated a mean difference in percent stenosis of 1.3 +/- 14.2%. A total of 26% of patients had calcium scores above 400 Agatston U, 25% had heart rates >70 beats/min, and 50% were obese. Specificity, sensitivity, and positive and negative predictive values for the presence of significant stenoses were: by segment (n = 935), 86%, 95%, 66%, and 98%, respectively; by artery (n = 279), 91%, 92%, 80%, and 97%, respectively; by patient (n = 70), 95%, 90%, 93%, and 93%, respectively. CONCLUSIONS: Our results indicate high quantitative and qualitative diagnostic accuracy of 64-slice MSCT in comparison to QCA in a broad spectrum of patients.     

Noninvasive coronary imaging and assessment of left ventricular function using 16-slice computed tomography

In recent years, multislice computed tomography (MSCT) has been demonstrated to be a feasible imaging modality for noninvasive coronary angiography and left ventricular function analysis. The present study evaluated overall performance of 16-slice MSCT in the detection of significant coronary artery disease, stent, or bypass graft stenosis in combination with global left ventricular function analysis. Forty-five patients underwent 16-slice MSCT. Multislice computed tomograms were used to evaluate the presence of significant coronary artery stenoses (>/=50% decrease in luminal diameter) in native coronary segments, bypass grafts, and coronary stents and were compared with conventional coronary angiograms. In addition, left ventricular ejection fraction was calculated and compared with 2-dimensional echocardiography. MSCT was performed successfully in all patients. A close correlation between MSCT and 2-dimensional echocardiography was demonstrated for the assessment of left ventricular ejection fraction (y = 0.93x +3.33, r = 0.96, p <0.001). A total of 298 of native coronary artery segments (94%) were evaluated with MSCT, whereas 81 of 94 grafts (85%) and 41 of 52 coronary stents (79%) were also evaluated. For all segments, overall sensitivity, specificity, and positive and negative predictive values were 85%, 89%, 71%, and 95%, respectively. In conclusion, 16-slice MSCT is a feasible modality for noninvasive evaluation and exclusion of coronary artery disease in patients who present with chest pain.     

Congenital coronary anomalies in adults: comparison of anatomic course visualization by catheter angiography and electron beam CT.

The objective of this study was to compare the anatomic course of anomalous coronary arteries by axial and three-dimensional volume-rendered electron beam computed tomography (EBCT) angiography and X-ray catheter angiography (CAG). We performed a blinded study where patients who previously underwent CAG with (n = 14) and without (n = 14; age- and gender-matched controls) anomalous coronary anatomy were studied with EBCT coronary angiography. Forty to 50 EKG-triggered 3 mm overlapping axial slices were acquired with 2 mm table movement within one breath hold during the i.v. injection of 140 cc of nonionic iodinated contrast (4 ml/sec). The axial source images and volume-rendered three-dimensional reconstructions were evaluated for the presence, type, and course of coronary anomalies and the results were compared to those of CAG. All normal and anomalous coronary arteries were identified by both modalities in all subjects. Identified anomalies include single coronary artery (n = 3), left-sided right coronary artery (n = 3), right-sided left main coronary artery (n = 3), anterior descending coronary artery (n = 2), circumflex coronary artery (n = 2), and separate left-sided ostia for left anterior descending and circumflex coronary arteries (n = 1). In five cases, there was discrepancy in the course of the anomalous vessels between the two modalities. Consensus reading among cardiologist and radiologists favored the interpretation of EBCT over catheter angiography. Noninvasive EBCT coronary angiography compares well with CAG in identifying anomalous coronary arteries and may provide confirmatory evaluation of their precise anatomic relationships to the heart and great vessels.     

多层面螺旋CT冠状动脉成像在冠心病中的应用

目的　评价多层面螺旋CT(MSCT)行冠状动脉血管造影和三维重建在冠心病中的应用价值。方法　对 30例冠心病患者进行了心电门控MSCT增强扫描 ,在工作站对图像资料进行了最大密度投影法 (MIP)三维重建 ,并与冠状动脉造影结果相对照。结果　 30例患者中对 12 0支冠状动脉血管 (左主干、左前降支、回旋支、右冠状动脉 )进行了MSCT三维重建 ,图像质量良好者为 84支 (70 % ) ,影响图像质量的主要因素是心脏搏动造成的伪影 ;9例冠状动脉支架和 5例冠状动脉搭桥术后均可清晰显示支架和血管桥的位置及远端血流情况 ,对于显示近中端高度 (>75 % )或完全梗阻性病有一定的准确性 (敏感性 80 % ,特异性 79.8% )。而不能显示轻度狭窄病变、远端或细小分支病变。结论　MSCT血管造影和三维重建在冠心病诊断和对病变血管的评价 ,以及血运重建术后复查等方面有一定的应用价值。     

Diagnostic accuracy of 64-slice multislice computed tomography in the noninvasive evaluation of significant coronary artery disease

The purpose of the present study was to determine the diagnostic accuracy of current 64-slice multislice computed tomography (MSCT) in the detection of significant coronary artery disease, using conventional coronary angiography as the gold standard. In 61 patients scheduled for conventional coronary angiography, 64-slice MSCT was performed and evaluated for the presence of significant (>or=50% luminal narrowing) stenoses. One patient had to be excluded because of a heart rate>90 beats/min during data acquisition. In the remaining 60 patients (46 men, 14 women; average age 60+/-11 years), 854 segments were available for evaluation. Of these segments 842 (99%) were of sufficient image quality. Conventional coronary angiography identified 73 lesions, of which 62 were detected by MSCT. The corresponding sensitivity and specificity were 85% and 97%, respectively. On a patient-per-patient analysis, sensitivity, specificity, and positive and negative predictive values were 94%, 97%, 97%, and 93%, respectively. In conclusion, the present study confirms that 64-slice MSCT enables the accurate and noninvasive evaluation of significant coronary artery stenoses.     

Visualization of coronary tree and detection of coronary artery stenosis using 16-slice, sub-millimeter computed tomography: preliminary experience

PURPOSE: multislice CT has been shown as a promising tool for coronary artery imaging. Our goal was to investigate the value of the new sixteen-slice, CT technology for non-invasive visualization of coronary arteries and assessment of coronary stenosis. MATERIALS AND METHODS: we assessed coronary artery visualization in 30 consecutive patients using 16-slice CT and compared the findings with conventional coronary angiography. The whole heart was scanned using 0.75 millimeter slices after injection of contrast medium. Retrospective ECG-gated reconstructions were performed and images were analyzed using axial CT, maximum intensity projection and 3D images, blind to the conventional angiography findings. Seventeen main coronary segments of more than 1.5 mm were analyzed and stenosis was graded on a four-point scale. RESULTS: CT angiography attained diagnostic quality for the whole coronary artery tree in 90% (27/30) of patients. Sixteen of 493 segments (4%) were not interpreted because of substantial motion artifacts (n=12) or heavy calcifications or stenting (n=4). Thirty seven of the 43 cases of significant stenosis (>50%) identified on coronary angiograms were correctly identified with multislice CT. All 6 false negatives involved stenosis of the circumflex artery or branches. Five false positive stenoses were found in 432 non stenotic segments. The sensitivity was thus 86%, specificity 99% for stenosis of more than 50%. CONCLUSION: 16-slice CT provides an excellent visualization of the coronary tree in most patients, allowing accurate non-invasive detection of significant coronary stenosis. Stenoses of the left circumflex artery remain more difficult to detect.     

Comparison between Three-Dimensional Angiographic Reconstruction and Intravascular Ultrasound Imaging for the Measurement of Cross-Sectional Luminal Dimensions in Intermediate Coronary Lesions

Background: Intravascular ultrasound (IVUS) has enabled the measurement of minimal luminal area of coronary stenoses. We evaluated the hypothesis that angiographic three-dimensional reconstruction of luminal dimensions may be able to provide similar measurements to IVUS in intermediate coronary lesions .
Methods: We retrospectively enrolled patients undergoing invasive coronary angiography and IVUS for the assessment of angiographically intermediate coronary lesions (50–70%) at a high-volume tertiary care hospital between July 1, 2006, and May 20, 2008. IVUS ( Boston Scientific, Natick Massachusetts, USA ) minimal cross-sectional area (CSA) and minimal luminal diameters (MLD) were compared with the measurements obtained using a sophisticated three-dimensional angiographic reconstruction software (CardiOP-B, Paieon, Inc., Rosh Ha'ayin , Israel), with orthogonal angiographic views used to reconstruct and calculate lesion dimensions.
Results: Data were obtained from 34 patients with 35 lesions. The lesions were assessed in the left main (n = 2), left anterior descending artery (n = 15), left circumflex/marginal artery (n = 7), and right coronary artery (n = 11). Using IVUS, the mean minimal CSA was 3.78 ± 1.60 mm², and MLD was 1.88 ± 0.43 mm. Three-dimensional reconstruction measurements of minimal CSA (3.42 ± 1.66 mm²) highly correlated in a linear fashion with the measurements by IVUS (R = 0.88, P < 0.0001).
Conclusions: A three-dimensional angiographic measurement of coronary minimal CSA is highly correlated with the measurements using IVUS. This new software technology may be a promising imaging modality to measure CSAs in coronary lesions .     

Visualization of coronary artery anomalies by contrast-enhanced multi-detector row spiral computed tomography

BACKGROUND: We investigated the potential of 16-slice multi-detector row spiral CT (MDCT) with retrospective ECG-gating for evaluation of coronary artery anomalies. METHODS: A total of 35 patients (23 men, 12 women, 19-81 years) in whom anomalous coronary arteries had been detected by invasive coronary angiography underwent MDCT (Sensation 16, Siemens, Germany). During one breathhold, a contrast-enhanced (90 ml, 5 ml/s) volume data set of the heart was acquired (16x0.75mm collimation, gantry rotation 375 ms). Images were reconstructed with a slice thickness of 1.0 mm in 0.5-mm intervals using retrospective ECG-gated reconstruction. The 35 data sets and 80 data sets of patients with angiographically normal coronary anatomy were analysed in random order concerning the origin and course of the coronary arteries. The results were compared to invasive coronary angiography. RESULTS: All patients with coronary artery anomalies and all controls with normal coronary anatomy were identified by MDCT. In addition, the origins and course concerning their anatomical relationship to adjacent cardiac structures were visualized in all patients, including right-sided origin of the left main (n=10), left anterior descending coronary artery (n=4) or left circumflex coronary artery (n=10); left-sided origin of the right coronary artery (n=6); four coronary fistula to the pulmonary artery (two from the left anterior descending, one from the right coronary artery, one from the left main), and one fistula from the circumflex coronary artery to the left atrium CONCLUSIONS: The study demonstrates that MDCT is a reliable noninvasive technique to identify and define anomalous coronary arteries and their course.     

Differential coronary artery calcification detected by electron beam computed tomography as an indicator of coronary stenosis among patients with stable angina pectoris.

BACKGROUND: The detection of coronary artery calcification by electron beam computed tomography (EBCT) has been suggested as an indicator of atherosclerosis and coronary artery disease (CAD). There is no consensus on the correlation between coronary calcification and angiographically significant stenosis on an artery-by-artery basis. OBJECTIVE: To examine the relationship between coronary calcification score (CCS) and the presence of significant CAD on an artery-by-artery basis in patients with stable angina pectoris. METHODS AND RESULTS: EBCT and coronary angiogram (CAG) were evaluated in 71 patients with stable angina and in nine control subjects. The CCSs of each of the four major coronary arteries were highest in patients with significant CAD (n=43), followed by patients with insignificant CAD (n=5), patients with syndrome X (n=23) and control subjects, respectively. Calcification scores of the four major coronary arteries appeared to have different predictive power for significant stenosis on the same vessel. For left main (LM) and left anterior descending (LAD) coronary arteries, CCSs of vessels with significant stenoses were not different from those without significant stenoses (values expressed as medians: LM 0 versus 1; LAD 98.5 versus 70; not significant). Calcification scores of left circumflex (LCX) and right coronary arteries (RCA) were significantly higher in vessels with significant stenosis (LCX 49.5 versus 0; RCA 53 versus 1; P<0.05). CCSs appeared to be moderately useful to predict significant stenoses in these two vessels (areas under receiver operating characteristic curves: LCX 0.68+/-0.08, 95% CI 0.52 to 0.81; RCA 0.71+/-0.08, 95% CI 0.55 to 0.84). CONCLUSIONS: The CCSs of RCA and LCX arteries, but not those of LM and LAD arteries, may predict significant angiographic stenosis on an artery-by-artery basis among patients with stable angina pectoris.     

Limited diagnostic yield of non-invasive coronary angiography by 16-slice multi-detector spiral computed tomography in routine patients referred for evaluation of coronary artery disease.

AIMS: Multislice spiral computed tomography (MSCT) is a promising non-invasive method to diagnose coronary artery disease (CAD). As no detailed comparative evaluation in consecutive patients referred for evaluation of CAD has been reported, this prospective study evaluating 2384 coronary segments in 149 consecutive patients was performed. METHODS AND RESULTS: The coronary artery tree was analysed in 16 segments both for coronary angiography (CA) and MSCT; a luminal narrowing > or = 50% based on visual assessment was considered significant. By MSCT, 77% of 2110 angiographically assessable segments could be evaluated, 94% per patient in proximal and 70% in distal segments (P<0.001). Sensitivity of MSCT to detect significant stenoses was 30% in all, but only 10% in peripheral segments. The main limitations were calcifications in 34% of segments and motion artefacts in 24% of patients. Overall diagnostic sensitivity for the presence of significant CAD was 86% but specificity was only 49%. CONCLUSION: When compared with invasive CA, 16-slice MSCT is of limited diagnostic value for the diagnosis of CAD in consecutive patients. Despite a clinically useful sensitivity for the overall diagnosis of significant CAD, specificity is low. Thus, relevant decisions regarding the need of and suitability for possible revascularization procedures cannot be based on MSCT findings alone.     

Detection of left main coronary artery stenosis by transesophageal color Doppler and two-dimensional echocardiography

Although transthoracic two-dimensional echocardiography can detect dilation of the coronary arteries, the reliability of this technique in the detection of coronary artery stenosis is still doubtful. The purpose of this study was to test the ability of newly developed biplane transesophageal color Doppler and two-dimensional echocardiography in the detection of left main coronary artery stenosis. Blood flow in the left main coronary artery was detected in 57 of 67 (85%) patients by transesophageal color Doppler flow imaging. Using transesophageal two-dimensional echocardiography, adequate images of the full length of the left main coronary artery and identification of the bifurcation were obtained in 60 of 67 (90%) patients. Transesophageal echocardiography clearly showed significant (greater than or equal to 50%) narrowing of the coronary lumen in 10 of 11 patients (sensitivity, 91%) and insignificant narrowing or no abnormalities of the coronary lumen in the other 49 patients (specificity, 100%). The positive predictive accuracy for left main coronary artery disease was 100%, and the negative predictive accuracy was 98%. This preliminary study suggests that biplane transesophageal color Doppler and two-dimensional echocardiography appears to be a feasible noninvasive technique for imaging the left main coronary artery and detecting hemodynamically significant luminal obstruction.     

Value of transesophageal color Doppler echocardiography in the evaluation of coronary artery anatomy and blood flow

The purpose of this study was to test the efficacy of newly developed biplane transesophageal color Doppler and two-dimensional echocardiography in the evaluation of coronary artery anatomy and blood flow. Using these two techniques, high quality images of the entire main left coronary artery (from the left coronary ostium to the bifurcation of the left anterior descending and circumflex coronary arteries), adequate for assessment of luminal diameter and percent stenosis, were obtained in 34 (89%) out of 38 patients. Transesophageal color Doppler echocardiography visualized coronary blood flow in 32 (84%) of the 38 patients. Transesophageal two-dimensional echocardiography clearly showed significant (50% of greater) narrowing of the coronary lumen in 10 out of 12 patients (sensitivity; 83%) and insignificant narrowing or no abnormalities of the coronary lumen in 23 of 26 normal individuals (specificity; 88%). This preliminary study suggests that biplane transesophageal color Doppler and two-dimensional echocardiography are feasible, noninvasive techniques for imaging the main left coronary artery and blood flow.     

Evaluation of coronary artery remodeling in patients with acute coronary syndrome and stable angina by multislice computed tomography.

BACKGROUND: Multislice computed tomography (MSCT) was used to evaluate coronary artery remodeling in patients with acute coronary syndrome (ACS) and stable angina (SA). METHODS AND RESULTS: MSCT was performed in 31 patients with ACS and 26 patients with SA and intravascular ultrasound (IVUS) was performed in 28 of these 57 patients. In both the MSCT and IVUS analyses, coronary artery remodeling was assessed by the remodeling index (RI): RI >1.10 was defined as positive coronary artery remodeling (PCAR) and RI <0.95 was defined as negative coronary artery remodeling (NCAR). The RI assessed by MSCT closely correlated with that of IVUS (r=0.86, n=28). The vessel area at the region of maximum luminal narrowing was also comparable between the MSCT and IVUS measurements (r=0.92). PCAR was present in 19 patients (61.3%) with ACS, but in none of the patients with SA (p<0.0001). However, NCAR was present in only 1 patient with ACS (3.2%), but was present in 18 patients (62.9%) with SA. The RI was significantly larger in patients with ACS (1.19+/-0.18) than in those with SA (0.89+/-0.10, p<0.0001). CONCLUSION: MSCT accurately assesses coronary artery remodeling.     

Feasibility of intravenous administration of landiolol hydrochloride for multislice computed tomography coronary angiography: initial experience

BACKGROUND: The feasibility of using landiolol hydrochloride in multislice computed tomography (MSCT) coronary angiography (CAG) was investigated in the present study. METHODS AND RESULTS: Landiolol hydrochloride was continuously administered intravenously to 145 patients before starting MSCT CAG. Hemodynamic changes [blood pressure (BP), heart rate (HR)], adverse effects, image quality using a 5-point scale, and accuracy of detecting significant stenoses (>or=50% reduction in lumen diameter) were evaluated. HR was significantly reduced during injection, and quickly recovered after cessation of administration, of landiolol hydrochloride. Neither significant changes in BP nor adverse effects occurred. Among visible segments, 1,869 (94%) displayed an excellent (83%) or good (11%) image quality. Diagnostic accuracy was evaluated in 39 of 145 patients who underwent invasive CAG within 3 weeks after MSCT. The sensitivity, specificity, positive predictive value, and negative predictive value of MSCT CAG for detection of significant stenoses in assessable segments were excellent (per artery: 94%, 98%, 92%, and 100%; per segment: 92%, 98%, 94%, and 96%, respectively). CONCLUSIONS: Intravenous administration of landiolol hydrochloride reduces HR without a significant reduction in BP, which enables favorable image quality and diagnostic accuracy without adverse effects, making this agent feasible as a premedication for MSCT CAG.