Abstract 14219: White Cell Inflammatory Biomarkers in Women With Myocardial Infarction With Non-Obstructive Coronary Artery Disease (MINOCA): Findings From the American Heart Association Go Red for Women Strategically Focused Research Network

Introduction: Myocardial infarction (MI) with non-obstructive coronary artery disease (MINOCA) occurs in 5-20% of women with MI. Underlying mechanisms of MINOCA are incompletely understood. Complete blood count (CBC) quantifies circulating cell types and can shed mechanistic insight into disease pathogenesis.. Methods: Peripheral blood was collected from women with MINOCA (n = 50; median 64 years [IQR 51-69]) and MI with coronary artery disease (MI-CAD; n = 71; 61 years [55-70]). Controls were women referred for elective cardiac catheterization found not to have obstructive CAD (n = 65; 62 years [57-69]). Blood was analyzed at the time of catheterization and in a subset of participants after 2 months. Associations between CBC parameters and MI subtype were estimated by multivariable logistic regression. Results: Overall, women with MI had higher WBC (p=0.008), monocyte counts (p<0.001), neutrophil counts (p=0.001), monocyte:lymphocyte ratio (p<0.001), and neutrophil:lymphocyte ratio (p<0.001) than controls. No significant difference was noted for lymphocyte count, hemoglobin, platelet count and platelet size. When comparing MINOCA versus MI-CAD, there was no significant difference in age, race/ethnicity, diabetes, hypertension, and peak troponin. Women with MINOCA had lower WBC and neutrophil counts than MI-CAD at the time of MI. Compared to controls, women with MINOCA had higher monocyte counts, monocyte:lymphocyte ratio, and neutrophil:lymphocyte ratio. After adjustment for demographics, hypertension, hyperlipidemia, and diabetes, only monocyte count (β 0.22, p=0.04) and monocyte:lymphocyte ratio (β 0.32, p=0.005) were significantly associated with MINOCA (versus controls). Among 13 women with MI-CAD and 15 with MINOCA who had blood analyzed 2 months post their MI, monocyte count and monocyte:lymphocyte ratio decreased in the MI-CAD group, but did not decrease in the MINOCA group. Controls: In contrast leukocytosis across all white cell types in MI-CAD, women with MINOCA have a higher monocyte count and monocyte:lymphocyte ratio than controls. These parameters remained elevated over time in a pattern different from MI-CAD, suggesting a mechanistic role of monocytes in the pathogenesis of MINOCA.