Abstract 4147103: Role Of Inflammation in Coronary Microvascular Function in Acute Coronary Syndromes

Introduction: CD4+ Th cells and related cytokines play a predominant role in the proinflammatory response in acute coronary syndrome (ACS). However, there is limited information on the relationship between inflammation and coronary microvascular dysfunction in ACS. Hypothesis: There is an interplay between inflammation and coronary microvascular disfunction in ACS. Methods: Coronary flow reserve as measured by Doppler flow velocity in response to adenosine (CFR) and in response to acetylcholine (endothelial CFR) was assessed in non-culprit arteries in patients with ACS. Correlation analyses with Th cell populations and plasma-related cytokines were performed. Results: A total of 26 patients diagnosed with ACS were studied (NCT03434483), with a median age of 55 years (IQR 19.8), and 96.2% were male. At presentation, 19.2% of patients had unstable angina, 42.3% had NSTEMI, and 38.5% had STEMI. There was a negative correlation between CFR (Figure 1) and Th1 cells (R -0.39, p = 0.047) and positive with IL-4 (R 0.5, p = 0.021). When analysing endothelial CFR (Figure 2), there was a positive correlation with Th17 cells (R 0.59, p = 0.016), Th1/Th17 cells (R 0.59, p = 0.015), MMP1 (R 0.6, p = 0.041), CCL2 (R 0.64, p = 0.024) and LTA (R 0.65, p = 0.022) cytokines and negative with CSF3 (R -0.61, p = 0.035). Conclusions: The study highlights the complex interactions between inflammation and coronary microvascular function in the setting of ACS. CFR seems to improve with lower levels of inflammation, but correlations with Th17 and Th1/Th17 seem to indicate the opposite in regards to endothelial CFR. The correlations with MMPs should be further explored as they are known to be directly involved in endothelial function.