Oxidative Stress Markers Are Lower in MINOCA Than in MI-CAD, Despite Comparable Inflammatory Status

Myocardial infarction (MI) is defined as a clinical event in which myocardial damage is evidenced in the setting of myocardial ischemia. However, patients without occlusive coronary artery stenosis can also have myocardial infarction, which is titled Myocardial Infarction with Non-Obstructive Coronary Arteries (MINOCA). In our study, we aimed to evaluate oxidative stress and inflammation responses between MINOCA and MI with coronary artery disease (CAD) patients. In this prospective, cross-sectional study, patients with elevated cardiac markers who were admitted to the cardiology clinic between March 2024 and May 2024 with the preliminary diagnosis of acute coronary syndrome were included. Patients were consecutively collected as those with an occlusive lesion on coronary angiography and those without. Routine blood samples and oxidative stress parameters were obtained and compared between groups. A total of 88 patients, including 44 MINOCA and 44 MI-CAD patients, were included in the study. The MINOCA group was significantly younger than the MI-CAD group (56.2 ± 12.5, vs. 64.7 ± 9.3, <i>p</i>: 0.001). While inflammatory parameters were similar between groups, dityrosine (5708 FU/mL (5311-6417) vs. 4488 FU/mL (3641-5238), <i>p</i> < 0.001), lipid hydroperoxide (3.6 nmol/mL (3.4-3.9) vs. 3.4 nmol/mL (3.1-3.9), <i>p</i>: 0.023), kynurenine (3814 ± 621 FU/mL vs. 3319 ± 680 FU/mL, <i>p</i>: 0.001), and malondialdehyde (17.4 nmol/mL (13.7-19.1) vs. 13.1 nmol/mL (12-14.9), <i>p</i> < 0.001) levels were higher in the MI-CAD group than in the MINOCA group. Although inflammation parameters did not differ between MI-CAD and MINOCA patients, oxidative stress parameters were higher in the MI-CAD group. Regardless of the presence and severity of inflammation, oxidative markers can help to assess the level of myocardial cell damage, risk stratification, and diagnosis of myocardial infarction.