Intravascular Ultrasonic Analysis of Atherosclerotic Vessel Remodeling and Plaque Distribution of Stenotic Left Anterior Descending Coronary Arterial Bifurcation Lesions Upstream and Downstream of the Side Branch

Bifurcation lesions remain a challenging lesion subset, even in the era of drug-eluting stents. The aim of this study was to investigate the longitudinal remodeling pattern and cross-sectional plaque location of bifurcation lesions. Seventy-four preintervention intravascular ultrasound studies of left anterior descending bifurcation lesions were analyzed, in which the lesion was located proximal (type A, n = 32) or distal (type B, n = 42) to the side branch. Vessel area and plaque area at the lesion (VAlesion and PAlesion) and at the reference site (VAreference and PAreference) were measured. The remodeling ratio was defined as VAlesion/VAreference, and the vessel compensation ratio was defined as (VAlesion − VAreference)/(PAlesion − PAreference). The geometric center of the lumen at the lesion site was identified, and the lesion site was divided into circumferential equal arcs to compare the cross-sectional distribution of percentage plaque area (100 × [PAlesion/VAlesion]) between the 2 groups. The remodeling ratio (1.03 ± 0.15 vs 0.94 ± 0.14, p = 0.01) and the vessel compensation ratio (0.0 ± 0.36 vs −0.37 ± 0.61, p <0.01) were significantly greater in type A than in type B lesions. The circumferential distribution pattern of percentage plaque area was significantly different between the groups (analysis of variance p <0.005), with greater percentage plaque area for the vessel wall opposite from the side branch in type B lesions (46.3 ± 18.0% vs 54.6 ± 15.4%, type A vs type B lesions, p <0.05). In conclusion, these results suggest that a major side branch may affect longitudinal lesion remodeling as well as the circumferential location of atherosclerotic plaque.