Three vessel optical coherence tomography assessment of macrophages accumulation in first non ST-segment acute coronary sindrome: differences between culprit and non culprit coronary plaques

Background: To investigate in patients with non ST-segment elevation acute coronary syndrome (NSTE-ACS) the prevalence and the features of optical coherence tomography (OCT)-detected macrophages accumulation (MA) in culprit plaques (CP) as compared to non culprit plaques (NCP). Methods: The study is a post-hoc analysis of a prospective study aimed at evaluating the relationship between aortic inflammation as assessed by 18F-Fluorodeoxyglucose-positron emission tomography and features of coronary plaque vulnerability as assessed by OCT. We enrolled 32 patients with first NSTE-ACS that successfully underwent 3-vessel OCT. Results: The median age was 65 (54-72) years and 27 patients (84%) were male. CPs were clinically defined. MAs were defined as signal-rich, distinct, or confluent punctuate regions that exceed the intensity of background speckle noise. Their prevalence was 4.2 per patients and MAs were more likely found in CP than NCP (84% vs. 61%, p=0.015). MA had also a higher circumferential extension in CP and the risk for CP associated with macrophages extension was higher (OR = 4.42; 95CI;2.54-9.15, p<0.001) than that associated with the mere presence of MA (OR=3.36; 95%CI;1.30-8.66, p=0.012). CP with thrombus had a lower distance between MA and the luminal surface than CP with no thrombus (0.06 vs. 0.1 mm; p=0.04). Conclusions: In patients with NSTE-ACS, MAs are more likely present in CP where they disclose also a greater extension compared to those observed in NCP. The distance between MA and the luminal surface is lower in thrombotic CP than that in non thrombotic CP.