[Intravascular ultrasound scanning assessment of plaque distribution in the left anterior descending coronary artery just distal to the bifurcation].
Coronary plaque has a distinct spatial distribution with the peak incidence on the outer wall around the bifurcation of the left main coronary artery. Intravascular ultrasound scanning was used to evaluate the distribution of the plaque in the proximal site of the left anterior descending coronary artery in 16 patients. Coronary angiography showed the examined sites were normal in all patients. A cross-sectional coronary scan was recorded in the left anterior descending coronary artery just distal to the bifurcation using a 4.3 Fr, 30 MHz intravascular ultrasound catheter. The thickness of the plaque was measured at 0, 90, 180, and 270 degrees, where 0 degree indicates the left circumflex coronary artery branching direction. The scan was divided into four areas of 90 degrees and labeled 1 to 4 in the counterclockwise direction (site 1 was the left circumflex coronary artery branching direction). The thickness and area of the plaque were measured in each site. The percentage plaque fraction was calculated as (plaque area in each site)/(plaque area of all) x 100. In 15 (94%) of the 16 patients, images of crescent shaped plaques were obtained. The mean thicknesses of the plaque at sites 1-4 were 0.25 +/- 0.07 mm, 0.46 +/- 0.21 mm, 0.82 +/- 0.19 mm, and 0.42 +/- 0.23 mm, respectively. The mean percentage plaque fractions were 7.9 +/- 3.6% (site 1), 18.1 +/- 7.2% (site 2), 55.0 +/- 8.1% (site 3), 18.7 +/- 6.9% (site 4), respectively. In site 3, opposite to the left circumflex coronary artery branching, the thickness and percentage plaque fraction were significantly greater than the remaining three sites (p < 0.001). In vivo intravascular ultrasound scanning revealed that coronary plaque in angiographically normal left anterior descending coronary artery just distal to the bifurcation has a distinct distribution with a peak incidence opposite to the left circumflex coronary artery branching.
Watanabe
H
H
Department of Cardiology, Kobe General Hospital.
Yoshikawa
J
J
Yoshida
K
K
Akasaka
T
T
Hozumi
T
T
Takagi
T
T
Honda
Y
Y
Okura
H
H
Yamamuro
A
A
D000368:Aged; D001158:Arteries / Q000000981:diagnostic imaging; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging*; D003331:Coronary Vessels / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D018084:Ultrasonography, Interventional