Objective: To determine the impact of inflammatory reaction levels and the culprit plaque characteristics on preprocedural Thrombolysis in
Myocardial Infarction (TIMI) flow grade in patients with
ST-segment elevation myocardial infarction (
STEMI) undergoing primary
percutaneous coronary intervention (PCI). Methods: The is a retrospective study. A total of 1 268
STEMI patients who underwent pre-intervention optical coherence tomography (OCT) examination of culprit lesion during emergency PCI were divided into 2 groups by preprocedural TIMI flow grade (TIMI 0-1 group (n =964, 76.0%) and TIMI 2-3 group (n =304, 24.0%)). Baseline clinical data of the 2 groups were collected; blood samples were collected for the detection of inflammatory markers such as
high sensitivity C-reactive protein (
hsCRP), myocardial injury marker, blood
lipid, etc.; echocardiography was used to determine left ventricular ejection fraction; coronary angiography and OCT were performed to define the lesion length, diameter
stenosis degree of the
infarct-related arteries, presence or absence of complex lesions, culprit lesion type, area
stenosis degree and vulnerability of culprit plaques. Multivariable logistic regression analysis was performed to identify independent correlation factors. The receiver operating characteristic (ROC) curve of continuous independent correlation factors was analyzed, and the best cut-off value of TIMI 0-1 was respectively determined according to the maximum value of Youden index. Results: The mean age of 1 268
STEMI patients were (57.6±11.4) years old and 923 cases were males (72.8%). Compared with TIMI 2-3 group, the patients in TIMI 0-1 group were older and had higher N-terminal-pro-
B-type natriuretic peptide level, lower cardiac
troponin I (cTnI) level, lower left ventricular ejection fraction, and higher
hsCRP level (5.16(2.06, 11.78) mg/L vs. 3.73(1.51, 10.46) mg/L). Moreover, the
hsCRP level of patients in TIMI 0-1 group was higher in the plaque
rupture subgroup (all P<0.05). Coronary angiography results showed that compared with TIMI 2-3 group, the proportion of right coronary artery (RCA) as the
infarct-related artery was higher, the angiographical lesion length was longer, minimal lumen diameter was smaller, and diameter
stenosis was larger in TIMI 0-1 group (all P<0.05). The prevalence of plaque
rupture was higher (75.8% vs. 61.2%) in TIMI 0-1 group. Plaque vulnerability was significantly higher in TIMI 0-1 group than that in TIMI 2-3 group with larger mean
lipid arc (241.27°±46.78° vs. 228.30°±46.32°), more thin-cap
fibroatheroma (TCFA, 72.4% vs. 57.9%), more frequent appearance of macrophage accumulation (84.4% vs. 70.7%) and
cholesterol crystals (39.1% vs. 25.7%). Minimal flow area was smaller [1.3(1.1-1.7)mm2 vs. 1.4(1.1-1.9)mm2, all P<0.05] and flow area
stenosis was higher (78.2%±10.6% vs. 76.3%±12.3%) in TIMI 0-1 group. Multivariable analysis showed that mean
lipid arc>255.55°,
cholesterol crystals, angiographical lesion length>16.14 mm, and
hsCRP>3.29 mg/L were the independent correlation factors of reduced preprocedural TIMI flow grade in
STEMI patients. Conclusions: Plaque vulnerability and
inflammation are closely related to reduced preprocedural TIMI flow grade in
STEMI patients.