Association Between Circulating Monocyte Subsets and In-Stent Restenosis After Coronary Stent Implantation in Patients With ST-Elevation Myocardial Infarction

BACKGROUND: Recent studies have shown that monocytes in human peripheral blood are heterogeneous. The clinical significance of 2 distinct monocyte subsets as a marker of late in-stent restenosis (ISR) following implantation of bare-metal stents (BMSs) in patients with acute myocardial infarction (AMI) was examined. METHODS AND RESULTS: Seventy-one consecutive patients with AMI who underwent BMS implantation were enrolled in the study. Peripheral blood was collected 12 days after AMI onset. Two distinct monocyte subsets (CD14(+)CD16(-)CCR2(+) and CD14(+)CD16(+)CX3CR1(+)) were measured by flow cytometry. All patients underwent angiography at a scheduled follow up after 9 months. CD14(+)CD16(+)CX3CR1(+) monocyte subset counts were significantly higher in patients with restenosis than in patients without restenosis, whereas neither the total monocytes nor the CD14(+)CD16(-)CCR2(+) subset counts differed significantly between the 2 groups of patients. There was also a significant positive correlation between the CD14(+)CD16(+)CX3CR1(+) monocyte counts and angiographic late lumen loss. In multivariate analysis, the CD14(+)CD16(+)CX3CR1(+) monocyte count was an independent predictor for in-stent late lumen loss. CONCLUSIONS: CD14(+)CD16(+)CX3CR1(+) monocytes might have a role in ISR following coronary BMS implantation in patients with AMI.