Background Proinflammatory dendritic cells (DCs) and monocytes are critically involved in the proceeding and destabilization of atherosclerosis.Recent studies have reported potential associations of specific patterns of circulating DCs and monocytes with the incidence of coronary artery disease (CAD) and ST-elevation myocardial infarction (STEMI);however,further information of DC and monocyte subsets on plaque morphology and vulnerability is uncertain and required.