Multislice CT coronary angiography for the detection of burden, morphology and distribution of atherosclerotic plaques in the left main bifurcation.

The aim of the study was to explore the differences in plaque burden at different segments of the left main bifurcation and its relationship with the bifurcation angle using high-resolution multislice CT coronary angiography (MSCT). Patients were evaluated using a 40-row MSCT scanner. One observer assessed the localization, severity and distribution of plaques within the left main (LMCA) bifurcation, whereas another observer defined the angle. Fifty patients were included. The mean heart rate was 59.8 +/- 7.1. Seventeen (34%) patients presented at least wall irregularities in the LMCA and in the ostial LCx, whereas the ostial LAD was affected in 32 (64%) patients. More than 90% of plaques were located opposite to the flow divider. The median bifurcation angle was 88.5 degrees (IQR 68.8 degrees, 101.4 degrees). Of the 18 patients with a normal ostial LAD, 13 (72%) had a bifurcation angle < 88.5 degrees , whereas the 63% of the patients with any LAD disease had an angle >or= 88.5 degrees (P = 0.018). In conclusion, at the left main bifurcation, atherosclerotic plaques are commonly located at the ostial LAD and opposite to the flow divider. The angle of the left main bifurcation and the presence of plaques within the bifurcation are closely related.