Characteristics of atherosclerotic plaque distribution in coronary artery bifurcations: an intravascular ultrasound analysis.
OBJECTIVE
Vessel bifurcations are prone to atherosclerotic plaque accumulation. Using volumetric intravascular ultrasound analysis, we investigated atheroma distribution at human coronary bifurcations in vivo.


METHODS
We analyzed plaque distribution in 49 left anterior descending coronary artery-diagonal and 20 left circumflex coronary artery-obtuse marginal bifurcations with <50% angiographic stenosis. Cross-sections were analyzed at 1 mm intervals in segments 5 mm proximal and distal from the bifurcation. Planimetry of the lumen and external elastic membrane (EEM) was performed and plaque thickness measured at four different points relative to the branch: 0 degrees, 90 degrees, 180 degrees and 270 degrees. EEM, lumen and plaque volume and percentage plaque burden (plaque volume/EEM volume) were calculated in the proximal and distal segments. The side-branch take-off angle was analyzed in the cross-sectional images.


RESULTS
Volumetric analysis showed that EEM, lumen and plaque were larger (P<0.001) in proximal segments than distal segments, whereas percent plaque burden was similar in these segments. Plaque accumulated on the opposite wall to the flow divider. Plaque distribution tended to be more eccentric in distal segments (P=0.05) compared to proximal segments. In 26 of 69 lesions, an asymmetric side-branch take-off was found and was associated with asymmetric plaque distribution compared to those lesions that had a symmetric side-branch take-off (P<0.01).


CONCLUSIONS
We found characteristic patterns of plaque distribution at coronary bifurcations. Proximal segments demonstrated larger plaque volume than distal segments, despite similar percentages of plaque burden. Plaque volume accumulated opposite to the flow divider, especially in distal segments. The side-branch take-off angle in the cross-sectional plane influenced the plaque distribution in bifurcation lesions.
Badak
Ozer
O
Department of Cardiology, Cleveland Clinic Foundation, Ohio 44195, USA.
Schoenhagen
Paul
P
Tsunoda
Taro
T
Magyar
William A
WA
Coughlin
Jennifer
J
Kapadia
Samir
S
Nissen
Steven E
SE
Tuzcu
E Murat
EM
D000704:Analysis of Variance; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology; D003331:Coronary Vessels / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D012044:Regression Analysis; D014463:Ultrasonography