Background: Our study sought to identify plaque characteristics and underlying morphology of culprit vessel lesions in ST Segment Elevation Myocardial Infarction (STEMI) and Non-ST-Segment Elevation Myocardial Infarction(NSTEMI)patients using optical coherence tomography(OCT)imaging.
Methods: We identified 116 patients who underwent OCT imaging during catheterization at University of Miami Hospital from 2011-2019. We selected cases that underwent cardiac catheterization in the setting of STEMI or NSTEMI. We then analyzed and interpreted each OCT image and assessed plaque morphology, lesion characteristics, presence of thrombus, and other lesions details. We used a Chi-Squared test for categorical variables, and a T-Test to compare the means.
Results: Among the 116 patients who underwent OCT imaging, 12 had STEMI and 11 had NSTEMI. The patients with NSTEMI tended to be older(64.4 vs 57.8 years old p:0.88)and have a larger BMI(33 vs 30 p:0.80). Overall, the culprit vessel for NSTEMI versus STEMI was the LAD(45% vs 58.9%)followed by the RCA(27% vs 33.3%)and LCX(18.2% vs 8.3%). Unstable plaque characteristics(82% vs 18% p:0.037)and presence of thrombus(73% vs 27% p:0.059)were more frequent in the STEMI group. The most common unstable plaque characteristic in the STEMI group was plaque rupture (63.6%) followed by plaque erosion (9%) and calcified nodule (9%). Fibroatheromatous plaque was the most common morphology in NSTEMI (54.5%). Among the culprit lesions that had <70% stenosis angiographically and underwent further evaluation with OCT, 67% underwent further PCI and 33% did not undergo further intervention but were treated with medical management. The observed incidence of in-stent restenosis (ISR) in the entire myocardial infarction population studied was 43%, the most observed location for the ISR being intra-stent (50%), and the extent of disease was most frequently focal (70%).
Conclusions: We conclude that in STEMI and NSTEMI, using OCT in addition to angiographic assessment of culprit lesion may influence and optimize the treatment strategy with PCI.