Comparative assessment of inflammatory biomarker levels across subtypes of Myocardial Infarction with Non-Obstructive Coronary Arteries. A pilot study

Abstract Aims Myocardial infarction with non-obstructive coronary arteries (MINOCA) is characterized by myocardial infarction features, troponin elevation, and coronary arteries with <50% stenosis. Over recent years, the concept of MINOCA has evolved into an umbrella term encompassing various mechanisms, rather than a single definitive diagnosis. It involves both coronary and non-coronary causes. This study aims to explore biomarker differences among these etiologies, proposing that inflammation-related biomarkers could provide a more precise approach to differentiating between them, thereby improving diagnosis and reducing mis/underdiagnosis. Currently, these biomarkers have not been specifically studied for each MINOCA etiology, but rather in a broader context. Methods This observational study included 72 MINOCA patients from a University Hospital between 2021-2023. According to ESC guidelines, MINOCA subtypes were classified as Takotsubo syndrome, myocarditis, ischemic MINOCA, type II-MINOCA, or undefined-MINOCA. IL-6, TNF-α, hs-CRP, CK and hs-troponin T levels were measured at admission, discharge, and two months later. Biomarker associations with MINOCA subtypes were evaluated using unadjusted and age- and sex-adjusted logistic regression models, with significance set at p<0.10 due sample size limitations. Results Among the 72 patients included, 17 were classified as ischemic MINOCA, 13 as type II-MINOCA, 10 as myocarditis, 8 as Takotsubo, and 24 as unknown origin. The mean age was 63 years, with 52% of patients being male. Comparing the characteristics of the five subgroups, type II-MINOCA was more common in older patients, while myocarditis was more prevalent in younger patients. The percentage of males was similar across all subtypes. Myocarditis patients had the highest peak levels of hs-Troponin T and CK at admission compared to other MINOCA groups. In Takotsubo syndrome, TNFα levels were the highest at admission. Regression models showed significant associations (see Table 1): At admission, higher IL-6, TNF-α, and hs-TnT levels were associated with Takotsubo syndrome (OR 1.7, OR 3.5, and OR 2.07, respectively). Myocarditis patients had elevated hs-Troponin T and CK levels (OR 2.04 and OR 3.57, respectively). The unknown group showed lower IL-6 and hs-Troponin T levels (OR 0.65 and OR 0.62, respectively), while ischemic MINOCA had lower TNF-α levels (OR 0.37). Type II-MINOCA was associated with higher hs-CRP and TNF-α levels at discharge (OR 1.57 and OR 6.13, respectively). No biomarker differences were observed during follow-up, except for type II-MINOCA, which continued to show elevated TNF-α levels (OR 3.06). See Figure 1. Conclusion This study identifies distinct biomarker profiles for different MINOCA subtypes, which may serve as key targets for future research, and provides important insights for subtype differentiation and diagnostic support.Tab1.Biomarkers' associations-subtypes Fig1.Biomarker levels in MINOCA subtypes