Abstract 12944: Patients With Acute Coronary Syndrome, Compared to Those With Stable Angina Pectoris, Have Increased Bright Spots at the Culprit Site by Optical Coherence Tomography

Abstract

Background: Recent studies reported that bright spots detected by optical coherence tomography (OCT) represent more complex plaques including macrophages and cholesterol crystals. We hypothesized that the density and area of bright spots would be greater at the culprit lesion in patients with acute coronary syndrome (ACS) compared to those with stable angina pectoris (SAP). Aim: To compare the density and extent of bright spots in the culprit lesion between patients with ACS and with SAP. Methods: We identified 14 ACS and 17 SAP patients who underwent pre-PCI OCT imaging of the culprit lesion. Cases with poor image quality or left main disease were excluded. Bright spots within superficial 125μm of the vessel wall were identified in a 5mm length segment at the culprit site. The density was calculated as the number of bright pixels identified by the algorithm divided by the number of pixels in each frame (total 25 frames in one case). The area of bright spots was also calculated. Results: There were no significant differences in the baseline characteristics including mean age (65.9 ± 10.2 vs 65.2 ± 9.32 yrs, P=0.83) and the prevalence of coronary risk factors between ACS and SAP. Mean and maximum density of bright spots was significantly greater in ACS than in SAP (Table). The area of bright spots was also significantly larger in ACS. Among ACS patients, a subgroup with plaque rupture (n=11) had much greater mean density and area compared with SAP (1.20 [0.41-1.73] vs 0.44 [0.21-0.58], P=0.01, 5.32 [1.88-8.07] vs 2.06 [0.97-2.64], P=0.01). Conclusions: Using the novel algorithm, we demonstrate that the density and area of bright spots are significantly greater in ACS than in SAP. This result suggests that the measurement of bright spots can be useful to determine plaque vulnerability.