['We examined whether distinct monocyte subsets relate in specific ways to coronary fibrous cap thickness (FCT) in patients with unstable angina pectoris (UAP).', 'Forty patients with UAP who underwent percutaneous coronary intervention were enrolled in this study. The changes in the non-culprit FCT were assessed by optical coherence tomography (OCT) at baseline and after 9 months. The distinct monocyte subsets (CD14+CD16-CCR2+ and CD14+CD16+CX3CR1+) were measured by flow cytometry.', 'The percent change in FCT showed significantly negative correlation with the percent changes in CD14+CD16+CX3CR1+ monocytes, but not CD14+CD16-CCR2+ monocytes. In addition, the percent change in CD14+CD16+CX3CR1+ monocytes was significantly decreased in the group of patients who received statin treatment compared with the group of patients who did not. Of interest, there was a close relationship between CD14+CD16+CX3CR1+ monocytes and levels of C-reactive protein, but not lipid profiles, including low-density lipoprotein cholesterol and low-/high-density lipoprotein cholesterol ratio.'] Does association of monocyte subset count with coronary fibrous cap thickness in patients with unstable angina pectoris?