Figure A1.

(A) Frequency of multilayer appearance according to plaque burden at baseline. Multilayer appearance was more frequently identified in lesions with greater plaque burden. (B) Incidence of multilayer formation during follow-up according to percentage changes in plaque volume per year. Multiple layer formation was more often identified in segments with more rapid progression, and in those both with multilayer appearance at baseline and without. Comparisons were made by a Cochran–Armitage trend test.