In Vivo Diagnosis of Plaque Erosion and Calcified Nodule in Patients With Acute Coronary Syndrome by Intravascular Optical Coherence Tomography

Objectives The aim of this study was to characterize the morphological features of plaque erosion and calcified nodule in patients with acute coronary syndrome (ACS) by optical coherence tomography (OCT). Background Plaque erosion and calcified nodule have not been systematically investigated in vivo. Methods A total of 126 patients with ACS who had undergone pre-intervention OCT imaging were included. The culprit lesions were classified as plaque rupture (PR), erosion (OCT-erosion), calcified nodule (OCT-CN), or with a new set of diagnostic criteria for OCT. Results The incidences of PR, OCT-erosion, and OCT-CN were 43.7%, 31.0%, and 7.9%, respectively. Patients with OCTerosion were the youngest, compared with those with PR and OCT-CN (53.8 +/- 13.1 years vs. 60.6 +/- 11.5 years, 65.1 +/- 5.0 years, p = 0.005). Compared with patients with PR, presentation with non-ST-segment elevation ACS was more common in patients with OCT-erosion (61.5% vs. 29.1%, p = 0.008) and OCT-CN (100% vs. 29.1%, p < 0.001). The OCT-erosion had a lower frequency of lipid plaque (43.6% vs. 100%, p < 0.001), thicker fibrous cap (169.3 +/- 99.1 mu m vs. 60.4 +/- 16.6 mu m, p < 0.001), and smaller lipid arc (202.8 +/- 73.6 degrees vs. 275.8 +/- 60.4 degrees, p < 0.001) than PR. The diameter stenosis was least severe in OCT-erosion, followed by OCT-CN and PR (55.4 +/- 14.7% vs. 66.1 +/- 13.5% vs. 68.8 +/- 12.9%, p < 0.001). Conclusions Optical coherence tomography is a promising modality for identifying OCT-erosion and OCT-CN in vivo. The OCTerosion is a frequent finding in patients with ACS, especially in those with non-ST-segment elevation ACS and younger patients. The OCT-CN is the least common etiology for ACS and is more common in older patients. (The Massachusetts General Hospital Optical Coherence Tomography Registry; NCT01110538) (C) 2013 by the American College of Cardiology Foundation