Lipid-lowering therapy stabilizes the complexity of non-culprit plaques in human coronary artery: a quantitative assessment using OCT bright spot algorithm.

To quantitatively evaluate the change of plaque complexity with cholesterol lowering therapy. A total of 44 non-culprit plaques from 30 patients who had serial image acquisition at baseline, 6-months, and 12-months by both optical coherence tomography (OCT) and intravascular ultrasound (IVUS) were included. Patients were treated with atorvastatin 60 mg (AT60, n = 16) or 20 mg (AT20, n = 14). We applied an OCT bright spot algorithm, which identifies a variety of plaque components including macrophages. The density of bright spot was measured within the superficial 250 µm of the vessel wall. Significant reduction of bright spot density was observed from baseline to 12-months [-0.49% (-0.95, -0.20), p < 0.001], particularly during the second 6 months [first 6 months: -0.01% (-0.57, 0.60), p = 0.939; second 6 months: -0.49% (-0.98, 0.14), p < 0.001]. Although there was no significant difference at 12 months in the reduction of bright spot density between plaques with acute coronary syndrome (ACS, n = 33) and those with stable angina (n = 11) [-0.49% (-0.93, -0.19) vs. -0.39% (-1.01, -0.21), p = 0.748], a significant reduction of bright spot density during the first 6 months was observed only in plaques with ACS. There was no significant difference in the change of bright spot density between the AT60 group (n = 22) and AT20 group (n = 22) [-0.61% (-0.93, -0.34) vs. -0.41% (-0.98, -0.19), p = 0.483]. Coronary plaque complexity evaluated by a quantitative OCT algorithm significantly decreased with 12 month atorvastatin therapy irrespective of the dose and initial clinical presentation.