Associations of NETs with inflammatory risk and atherosclerotic severity in ST-segment elevation myocardial infarction

Aim To investigate the association between neutrophil extracellular traps (NETs) in coronary thrombus and risk profile of patients with ST-segment elevation myocardial infarction (STEMI). Methods All participants enrolled in the Optical Coherence Tomography Examination in Acute Myocardial Infarction (NCT03593928) registry from March 2017 to November 2019 were screened and 104 patients were qualified for the current analysis. Coronary aspirated materials were collected and culprit lesion characteristics were examined by optical coherence tomography. NETs in thrombus were identified by immunofluorescence as the co-localization of anti-histone H3 and myeloperoxidase, and NETs level was assessed using a semi-quantitative score. Patient-oriented composite endpoint included all-cause death, myocardial infarction, stroke, any revascularization, and re-admission for heart failure. Results According to NETs burden, 44 patients were in the low NETs group and 60 in the high NETs group. The two groups were comparable in age, sex, and comorbidities but the high NETs group presented with significantly higher level of high-sensitivity C reactive protein than the low NETs group (median 9.3 mg/L vs 5.2 mg/L, p = 0.036). Although culprit plaque morphology did not differ between groups, the lipid arc was smaller (maximal lipid arc 320° vs 360°, p = 0.012) and the flow area was larger (median 1.85mm2 vs 1.65mm2, p = 0.041) in the high NETs group. No significant difference was observed between groups in patient-oriented composite endpoint. Conclusion Increased NETs in aspirated coronary thrombus appear to be associated with more elevated inflammation but less advanced atherosclerosis. Trial registration number: ClinicalTrials.gov: NCT03593928