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 2 nd 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 2vs. (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.