Research Progress of Percutaneous Coronary Intervention of Left Main Coronary Artery Stenoses with Intravascular Ultrasound / 沈阳医学院学报

Intravascular ultrasound (IVUS) is an invasively tomograhpic techology. As a adjunct to angiography, IVUS has important application value for percutaneous coronary intervention (PCI) . IVUS allows to assess the degree of area stenosis, optimize PCI strategy and improve clinical outcomes. Although lacking randomized trials, the currently nonrandomized studies support that IVUS-guided PCI of the left main coronary artery stenoses reduce the rate of the major adverse cardiac events (MACE, including cardiac death,myocardial infarction,and target vessel revacularization) and improve long-term outcomes compared with angiography-guided PCI.

The Utility of Multi-detector Row Spiral CT for Detection of Coronary Artery Stenoses

Contrast-enhanced multi-detector row spiral computed tomography (MDCT) was introduced as a promising noninvasive method for vascular imaging. This study examined the accuracy of this technique for detecting significant coronary artery stenoses. Both MDCT (Sensation 16, Siemens, Germany, 12 x 0.75 mm collimation and 0.42 sec rotation speed, 120 kV, 500 effective mA, and 2.7 mm/rotation table-feed) and invasive coronary angiography (CAG) were performed on 61 patients (mean age 59.2 +/- 10, 44 men) who were suspected of having coronary artery disease. All patients were treated with atenolol (25 - 50 mg) prior to imaging and the heart rate was maintained below 65 beats per minutes during image acquisition. The images were reconstructed in the diastole around TI - 400 ms with a 0.5 mm increment and a 1.0 mm thickness. All coronary arteries with a diameter of 2.0 mm or more were assessed for the presence of a stenosis (> 50% luminal narrowing). Two independent radiologists who were unaware of the results of the invasive CAG evaluated the MDCT data, and the results were compared with those from the invasive CAG (interval 1- 27, mean 11 days). An evaluation of the CT coronary angiogram (CTCA) was possible in 58 of the 61 patients (95%). Image acquisition of the major coronary arteries including the left main trunk was available in 229 out of 244 arteries. Invasive CAG showed that 35 out of 58 patients had significant coronary artery stenoses by. patient analysis of those who could be evaluated showed that CT coronary angiography correctly classified 30 out of 35 patients as having at least 1 coronary stenosis (sensitivity 85.7%, specificity 91.3%, positive predictive value 93.8%, negative predictive value 80.8%). By analyzing each coronary artery, CAG found 62 stenotic coronary arteries in the 229 coronary arteries that could be evaluated. MDCT correctly detected 50 out of 62 stenotic coronary arteries and an absence of stenosis was correctly identified in 156 out of 167 normal coronary arteries (sensitivity 80.6%, specificity 93.4%, positive predictive value 81.9%, negative predictive value 92.8%). The non-invasive technique of MDCT for examining the coronary artery appears to be a useful method for detecting coronary artery stenoses with a high accuracy particularly with the proximal portion and large arteries.

CT Coronary Angiography Using Multidetector Computed Tomography in Coronary Artery Disease : A Comparative Study to Quantitative Coronary Angiography

BACKGROUND AND OBJECTIVES: The purpose of the present study was to investigate the diagnostic accuracy of coronary stenoses in patients with ischemic heart disease using multidetector CT coronary angiography (MDCT) in the assessment of coronary artery disease. SUBJECTS AND METHODS: Forty-three patients (49-72yrs) undergoing conventional coronary angiography (CCA) were included in this study. All patients were premedicated with oral propranolol, 40-80 mg, to achieve an acceptable heart rate of less than 65 bpm, 1hr before the MDCT. All coronary arteries, including the distal segments and side branches, were assessed with respect to assessability and the presence of significant stenosis (>50%) and the results compared with those of CCA. RESULTS: Of the 645 coronary artery segments scanned, 540 were assessable (84%). A total 44 significant stenoses were detected by CCA and 49 lesions by MDCT. The overall sensitivity and specificity were 77 and 97%, respectively. The overall accuracy for the LAD, RCA and LCX was 94, 98 and 95%, respectively, and there were no differences in the accuracies in each vessel. The sensitivity in the proximal segments was much higher than in the distal segments. A total 15 segments were overestimated by the MDCT due to calcification and the small vessel size. CONCLUSION: MDCT, with improved spatial and temporal resolutions, and pre-treated with oral beta-blocker, permits the detection of coronary artery stenoses with a high degree of accuracy.

Comparison of Silent Patients with Painful Patients in Patients with Coronary Artery Stenoses during Exercise Myocardial Perfusion Scintigraphy

BACKGROUND AND OBJECTIVES: The angiographic profiles and myocardial ischemic variables were compared between patients with and without chest pain during exercise myocardial perfusion scintigraphy in patients with coronary artery stenoses. MATERIALS AND METHODS: Study population were 102 consecutive patients who have significant luminal stenoses (> 50%) on coronary angiography. They underwent symptom-limited treadmill exercise test and myocardial perfusion single photon emission computed tomography (SPECT). Tc-99m methoxylisobutyl isonitrile (MIBI) was injected intravenously at rest and one minute before the termination of exercise. Tomographic images were acquired within 1 hour of tracer injection. Electrocardiographic variables, scintigraphic summed reversibility scores and angiographic profiles were compared between patients with and without chest pain during exercise. RESULTS: Silent ischemia was noted in 52/102 (51%) of the subjects. The summed reversibility score of myocardial SPECT was not significanlty different between patients with (6.0+/-4.2) and without (5.1+/-5.0) chest pain. The extent, vessel distribution and stenosis severity of coronary artery disease were not significantly different between two groups. ST segment depression was more prominent in patients with chest pain (1.51+/-1.49 mm) than without chest pain (0.5+/-1.1 mm) during exercise stress testing. CONCLUSION: The degree of coronary stenoses and scintigraphic myocardial ischemia was not different between patients with and without chest pain during exercise stress testing.