Endothelial Function and Pro-Inflammatory Cytokines as Prognostic Markers in Acute Coronary Syndromes

Background: Endothelial dysfunction and inflammation are associated with the progression of coronary artery disease (CAD) and the pathophysiology of acute coronary syndrome (ACS). We examined the prognostic role of endothelial function and pro-inflammatory cytokines in patients admitted with ACS. Methods: The study population consisted of 864 subjects. From 663 subjects who presented with chest pain, ACS was diagnosed in 460. We additionally recruited 201 consecutive patients with stable CAD. Endothelial function was assessed using flow-mediated dilatation (FMD). Tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) levels were measured via ELISA. Subjects with ACS were followed up for major adverse cardiovascular events (MACE), defined as cardiovascular death, cardiac arrest, myocardial infarction, stroke, nonfatal stroke, other arterial thrombotic events, and hospitalization due to cardiovascular conditions. Results: There was a stepwise impairment in FMD, logTNF-α, and logIL-6 in patients with chest pain of non-epicardial CAD etiology compared to patients with stable CAD and those with ACS (p < 0.001 for all). Moreover, patients who presented with chest pain had increased odds of ACS in accordance with the increasing levels of TNF-α, IL-6, and impaired FMD (p < 0.05 for all). Interestingly, from all these markers, in patients with ACS, we found that only TNF-α levels above 5.19 pg/mL had a 2.5-times-increased risk of MACE compared to patients with TNF-α levels below 5.19 pg/mL, independently of other confounders. Conclusions: In the current study, we found that patients who presented with ACS had impaired endothelial function and increased levels of IL-6 and TNF-α.