J Cardiol 2007 Sep; 50（3）: 219– 221

Cardiovascular Imaging In-a-Month
Left Main Trunk Coronary Stenosis in an Angina Patient With Low
Coronary Risk Factors Assessed by Multi-Detector Row ComputedTomography●Ryoko MITSUTAKE, MD
Shin-ichiro MIURA, MD, FJCC
Hiroaki NISHIKAWA, MD
Keijiro SAKU, MD, FJCCBACDFig. 1──────────────────────────────────────────────
福岡大学医学部 心臓血管内科〔光武良晃，三浦伸一郎，西川宏明，朔 啓二郎〕: 〒 814−0180 福岡市城南区七隈 7−45−1
Department of Cardiology, Fukuoka University School of Medicine, Fukuoka
Address for correspondence : MIURA S, MD, FJCC, Department of Cardiology, Fukuoka University School of Medicine, Nanakuma
7−45−1, Jonan-ku, Fukuoka 814−0180 ; E-mail : miuras@cis.fukuoka-u.ac.jp
Manuscript received April 16, 2007 ; accepted May 9, 2007

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Mitsutake, Miura, Nishikawa et al

CASE
A 51-year-old woman with smoking as the only coronary risk factor was referredto our hospital after complaining of increasing chest pain on mild exertion and evenat rest. Electrocardiography at rest showed ST depression of 0.1 to 0.2 mV in leads
Ⅱ, Ⅲ, aⅤF, and Ⅴ4 to Ⅴ6. Symptoms were relieved by nitrate administration. Next,
64 multi-detector row computed tomography（MDCT）（Aquilion 64, TOSHIBA）
was performed for diagnosis（Fig. 1）.

Point of Diagnosis
MDCT has rapidly become available in many
hospitals, and permits non-invasive visualization of
the coronary lumen, coronary atherosclerotic
plaque, and coronary stenosis, 1）as well as thequantification of coronary artery calcification.2）
In this case, we detected severe stenosis of theleft main trunk coronary artery and coronary atherosclerotic plaque. The mean density of the plaqueby MDCT was analyzed on a workstation（ZIOM900 Quadra）. Plaque can be categorized into 3
levels based on its mean density.3）The mean CT
numbers for soft, intermediate, and calcified plaqueare 14 ± 26, 91 ± 21, 419 ± 194 HU, respectively.
In this case, MDCT coronary angiography showedthat the mean density of the plaque was 35.9 HU,
which was classified as acute coronary syndromeprone soft plaque. Therefore, the plaque was considered likely to cause sudden occlusion of the left
main trunk coronary artery, leading to sudden
death. This could occur when the plaque ruptures or
as a complication at catheter cannulation in the left
coronary artery. MDCT findings regarding the presence of soft plaque from the ostium before invasivecoronary angiography can contribute to a carefulcatheter procedure to avoid fatal cardiac complications. Therefore, we performed invasive coronary
angiography and very carefully introduced a 5 Fr
Judkins-type catheter（JL-3.5, Terumo）into the left
coronary artery. Invasive coronary angiographyalso showed severe stenosis of the left main trunk
coronary artery（Fig. 2）.Therefore, the patienturgently underwent two-vessel coronary artery
bypass grafting without complications. The symptoms improved after the operation, and patency ofthe bypass graft was confirmed angiographically.
Recent studies have demonstrated approximately
95 % sensitivity and specificity of MDCT angiography for the identification of significant coronary

stenosis in comparison with invasive coronary
angiography.4）Thus, findings by MDCT could be
useful for considering a safer strategy before performing invasive coronary angiography.
The present case of diagnosis of severe left main
trunk stenosis in a patient with low coronary risk
factors by MDCT coronary angiography shows thepotential for the non-invasive identification of disease of the coronary arteries, especially ostiallesions. Further development of MDCT with regard
to spatial resolution could enable coronary artery
bypass grafting without the need for invasive coronary angiography in the future.
Diagnosis : Left main trunk coronary artery stenosis
Key Words : Angina pectoris ; Angiography ; Risk factors ; Plaque ; Computed tomography
References1）Achenbach S, Ulzheimer S, Baum U, Kachelriess M,Ropers D, Giesler T, Bautz W, Daniel WG, Kalender WA,Moshage W : Noninvasive coronary angiography by retrospectively ECG-gated multislice spiral CT. Circulation
2000 ; 102 : 2823−28282）Mitsutake R, Niimura H, Miura S, Zhang B, Iwata A,
Nishikawa H, Kawamura A, Kumagai K, Shirai K,
Matsunaga A, Saku K : Clinical significance of the coronary calcification score by multidetector row computed
tomography for the evaluation of coronary stenosis inJapanese patients. Circ J 2006 ; 70 : 1122−11273）Schroeder S, Kopp AF, Baumbach A, Meisner C, Kuettner
A, Georg C, Ohnesorge B, Herdeg C, Claussen CD, Karsch
KR : Noninvasive detection and evaluation of atherosclerotic coronary plaques with multislice computed tomography. J Am Coll Cardiol 2001 ; 37 : 1430−14354）Leber AW, Knez A, von Ziegler F, Becker A, Nikolaou K,Paul S, Wintersperger B, Reiser M, Becker CR, SteinbeckG, Boekstegers P : Quantification of obstructive and nonobstructive coronary lesions by 64-slice computed tomography : A comparative study with quantitative coronary
angiography and intravascular ultrasound. J Am CollCardiol 2005 ; 46 : 147−154

J Cardiol 2007 Sep; 50（3）: 219– 221

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Fig. 1 64-multi-detector row computed tomography
coronary angiograms
A and B : Volume rendering images showed severe
left main trunk coronary stenosis.
C : Multi-planar reconstruction image demonstratedplaque.
D : Cross-sectional image identified plaque（arrow 1）
and luminal narrowing of the left main trunk coronary
artery（arrow 2）. The mean computed tomography
number of the plaque was 35.9 HU, which was classified as soft plaque.
RCA ＝ right coronary artery ; LAD ＝ left anterior
descending artery ; LCX ＝ left circumflex artery.
Fig. 2 Invasive coronary angiogram showing 90% lumiof the left main trunk coronal narrowing（arrow）
nary artery

Fig. 2J Cardiol 2007 Sep; 50（3）: 219– 221