Relationship between coronary artery calcification and plaque vulnerability, a qualitative and quantitative optical...

Coronary artery calcification (CAC) is an established hallmark of advanced atherosclerosis. The detailed relationship between CAC and plaque vulnerability remains incompletely understood. We aim to investigate the relationship between calcification burden, calcification patterns, and plaque instability features.

A total of 540 patients with established coronary artery disease who underwent optical coherence tomography imaging before percutaneous coronary intervention were included. Calcified plaques were investigated using both qualitative (microcalcification, spotty calcification, and macrocalcification) and quantitative (non-calcified, low, intermediate, and high calcified plaque burden (CPB) stratified by CPB tertiles) assessments across the culprit vessel. The vulnerable features were compared between the groups.

The prevalence of thin-cap fibroatheroma (TCFA), layered plaque, cholesterol crystal, microchannel, macrophage cluster, plaque rupture, plaque erosion, and eruptive calcified nodules differed significantly in different CPB groups. Intermediate CPB was associated with a significantly higher prevalence of TCFA and plaque rupture in these groups. The prevalence of TCFA, plaque rupture, layered plaque, and microchannel was lowest in the high CPB group. Macrophage clusters and cholesterol crystals were associated with a higher number of spotty calcifications, especially in young patients. Microchannels were associated with more microcalcifications. High CPB and macrocalcifications showed the lowest level of inflammation. In the patients with calcification, age, multivessel disease, macrophage cluster, and lipid index were independently associated with CPB.

Intermediate CPB was associated with a significantly higher prevalence of TCFA and plaque rupture, while spotty calcifications correlated with macrophage clusters and cholesterol crystals.