Novel grading system for ischemia‒reperfusion injury manifestations in patients with acute ST-segment elevation myocardial infarction undergoing percutaneous coronary intervention.

To establish a simple myocardial ischemia‒reperfusion injury (MIRI) manifestation grading system based on clinical manifestations and coronary angiography during primary percutaneous coronary intervention (PPCI). All STEMI patients treated with PPCI from June 2018 to November 2019 were included. According to the MIRI manifestation grade, patients were divided into four grades (I-IV). Laboratory and clinical indicators of the patients and the occurrence of major adverse cardiac events (MACEs) within one year of follow-up were analyzed. A total of 300 patients were included. The higher the MIRI manifestation grade, the lower was the high-density lipoprotein cholesterol (HDL-C); the higher were the C-reactive protein (CRP), lipoprotein(a) [LP(a)], and peak levels of high-sensitivity troponin T (hs-cTnT), creatine kinase (CK-MB), and N-terminal pro-B-type natriuretic peptide (NT-proBNP); and the higher were the proportions of right coronary artery (RCA) and multivessel lesions (P < 0.05). The left ventricular end-diastolic dimension (LVEDD) and E/e' values of patients with higher grades were significantly increased, while the LVEF, left ventricular short-axis functional shortening (LVFS) and E/A values were significantly decreased (P < 0.05). The one-year cumulative incidence of major adverse cardiac events (MACEs) in patients with grade I-IV disease was 7.7% vs. 26.9% vs. 48.4% vs. 93.3%, respectively, P < 0.05. The higher the MIRI manifestation grade, the more obvious is the impact on diastolic and systolic function and the higher is the cumulative incidence of MACEs within one year, especially in patients with multivessel disease, low HDL-C, high CRP, high LP(a) levels, and the RCA as the infarction-related artery.