Layered Plaque Characteristics and Layer Burden in Acute Coronary Syndromes

Recently, layered plaque, an optical coherence tomography equivalent of healed plaque, has been gaining attention. However, detailed layered plaque characteristics including the burden of plaque layer have not been investigated. Patients with acute coronary syndromes who underwent preintervention optical coherence tomography imaging of culprit lesion were included. Layer index, a product of the mean layer arc and layer length, was correlated with the pattern of layer and culprit pathology. In addition, layer index was compared between culprit and nonculprit plaques. Finally, predictors for greater layer index were identified using general linear modeling. In 349 patients, 99 culprit plaques had layered phenotype (28.4%), whereas among 465 nonculprit plaques, 165 had layered pattern (35.5%). Layer index was greater in multilayer pattern versus single-layer pattern (1,688.5 vs 996.6, p <0.001), interrupted layer phenotype versus intact layer phenotype (1,276.5 vs 646.8, p <0.001), rupture versus erosion at culprit lesion (1,191.0 vs 861.8, p <0.001), and culprit versus nonculprit plaque (1,475.6 vs 983.4, p <0.001). The general linear modeling revealed that multilayer pattern (regression coefficient b [B] 7.332, p <0.001), interrupted layer phenotype (B 4.624, p <0.001), culprit lesion (B 2.792, p = 0.001), lipid-rich plaque (B 1.953, p = 0.032), and culprit plaque rupture (B: 1.943, p = 0.008) were the significant predictors for greater layer index. In conclusion, layer index (burden of layered plaque) was greater in multilayer pattern, interrupted layer phenotype, at culprit plaque, lipid-rich plaque, and in cases with culprit plaque rupture.