Vessel remodeling and plaque distribution in side branchof complex coronary bifurcation lesions: a grayscaleintravascular ultrasound study

ABSTRACT

To investigate vessel remodeling and plaquedistribution in side branch (SB) of true coronary bifurcationlesions with SB disease extending from its ostium. A total of62 patients with single de novo true bifurcation lesions withSB with severe and extensive disease were enrolled. Of that,45 patients/lesions underwent pre-intervention intravascularultrasound (IVUS) at the SB. Left anterior descending wasthe most prevalent target vessel ([85 %). All lesions hadsignificant involvement of both branches of the bifurcation,and the majority were classified as type 1,1,1 according to theMedina classification. Considering the subset with IVUSimaging, mean lesion length, reference diameter and %diameter stenosis in the SB were 8.88 ± 4.61 mm,2.68 ± 0.59, and 70.2 ± 16.0 %, respectively. Also, meanproximal (take-off) and distal (carina) angles were142.3 ± 21.9 and 60.7 ± 22.4 , respectively. At minimumlumena area (MLA) site, mean external elastic membraneand MLA cross-sectional areas were 6.70 ± 2.08 and1.87 ± 0.93 mm2, respectively; given that the mean distancemeasured between the SB origin and MLA site was/1 mm. In addition, mean plaque burden was 67.9 % andmean remodeling index was 0.78 ± 0.21. Importantly, only9 cases out of 45 presented remodeling index [1.0.Also, plaque distribution analysis within the SB ostium demonstrated preferable plaque positioning in the oppositeside to the flow divider. In conclusions, significant negativeremodeling is a frequent encounter in SB of complex coronarybifurcation lesions presenting with extensive and severedisease; in addition, plaque distribution in the SB ostiumappears to be asymmetric in relation to the parent vessel, asplaque burden is mostly found in regions of low wall shearstress including the opposite side to the flow divider withinthe bifurcation anatomy.