Optical coherence tomographic (OCT) morphologies associated with lesion progression are not well studied. The aim of this study was to determine the morphological change for untreated lesion progression using both OCT and intravascular ultrasound (IVUS).Methods and Results—
We used baseline and 8-month follow-up 3-vessel OCT and IVUS to assess 127 nonculprit lesions (IVUS plaque burden ≥40%) in 45 patients with stable angina after target lesion treatment. Lesion progression was defined as an IVUS lumen area decrease >0.5 mm2. A layered pattern was identified as a superficial layer that had a different optical intensity and a clear demarcation from underlying plaque. Lesion progression was observed in 19% (24/127) lesions, and its pattern was characterized into 3 types: type I, new superficial layered pattern at follow-up that was not present at baseline (n=9); type II, a layered pattern at baseline whose layer thickness increased at follow-up (n=7); or type III, no layered pattern at baseline or follow-up (n=8). The increase of IVUS plaque+media area was largest in type I and least in type III (1.9 mm2 [1.6–2.1], 1.1 mm2 [0.9–1.4], and 0.3 mm2 [−0.2 to 0.8], respectively; P=0.002). Type III, but not types I or II, showed negative remodeling during follow-up (IVUS vessel area; from 14.3 mm2 [11.4–17.2] to 13.5 mm2 [10.4–16.7]; P=0.02). OCT lipidic plaque was associated with lesion progression (odds ratio, 13.6; 95% confidence interval, 3.7–50.6; P<0.001).Conclusions—
Lesion progression was categorized to distinct OCT morphologies that were related to changes in plaque mass or vessel remodeling.