The aim of the study was to investigate the impact of statins therapy on morphological changes of lipid-rich plaques by OCT (optical coherence tomography) in patients with known CHD (coronary heart disease), stratified by FRS. Ninety-seven lipid-rich plaques from sixty-nine patients who received statins therapy and underwent serial OCT images (baseline, 6-month and 12-month) were divided into 2 groups according to the FRS (framingham risk score): low risk group A (FRS= 10%, N=34, n=52). Fibrous cap thickness (FCT) was measured at its thinnest part 3 times. Baseline characteristics were not different between the 2 groups. FCT sustained increased from baseline to 6-month and 12-month follow up in both group A (59.8 +/- 20.4 mu m, 118.3 +/- 62.5 mu m, and 158.8 +/- 83.4 mu m respectively, P<0.001) and group B (62.2 +/- 16.8 mu m, 125.1 +/- 78.7 mu m, 163.8 +/- 75.5 mu m respectively, P<0.001). Lipid index was significantly decreased in both group A (1862.1 +/- 1164.5, 1530.3 +/- 1108.7, 1322.9 +/- 1080.4, P<0.001) and group B (1646.6 +/- 958.5, 1535.1 +/- 1049.1, 1258.6 +/- 1045, P=0.016). The incidence of TCFA was decreased statistically in both group A (P < 0.001) and group B (P < 0.001). The patients with known CHD can equivalently benefit from statins therapy by stabilizing the lipid-rich plaques. Patients with moderate to high FRS might benefit more within the first year from event time.