Relationship of Microchannels and Plaque Erosion in Patients with ST-Segment Elevation Myocardial Infarction: An Optical Coherence Tomography Study

Objective: Microchannels are associated with the progression of atherosclerotic vulnerable plaques. However, in patients with culprit optical coherence tomography (OCT)-defined plaque erosion, the knowledge of microchannels and culprit lesion vulnerability is limited. The aim of this study was to investigate culprit lesion characteristics in patients with ST-segment elevated myocardial infarction (STEMI) caused by plaque erosion with and without microchannels using OCT. Methods: In all, 348 STEMI patients with plaque erosion who underwent OCT of the culprit lesion at the 2nd Affiliated Hospital of Harbin Medical University (Harbin, China) from August 2014 to December 2017 were included and divided into the microchannel group (n = 116, 33.3%) and no-microchannel group (n = 232, 66.7%). The clinical characteristics and OCT-derived plaque features were compared between both groups. Results: Among the 348 STEMI patients with plaque erosion, culprit lesions with microchannels had higher incidence of lipid plaque (59.5% vs. 45.3%, P = 0.012); calcification (41.4% vs. 24.6%, P = 0.002); spotty calcification (30.2% vs. 18.1%, P = 0.014); macrophages accumulation (72.4% vs. 45.7%, P < 0.001); and cholesterol crystals (32.8% vs. 14.2%, P < 0.001) than those without microchannels. In addition, minimal lumen area was smaller ((1.9 +/- 0.9) mm(2)vs. (2.8 +/- 2.3) mm(2), P < 0.001) and lumen area stenosis was greater ((71.3% +/- 13.4%) vs. (65.3% +/- 19.3%), P = 0.001) in the microchannel group than in the no-microchannel group. Conclusion: In patients with STEMI caused by plaque erosion, one-third manifested typical microchannel characteristics, and those with microchannels were associated with more severe luminal stenosis and more vulnerable plaque features than those without microchannels.