BackgroundAcute coronary syndrome (ACS) is frequently reported in patients with coronavirus disease 2019 (COVID-19). Cytokine storm induced by interleukin-6 (IL-6) has been suggested to potentially cause myocardial injury in COVID-19. We investigated the association between baseline level of IL-6 and development of ACS in COVID-19 patients.MethodsDemographic and clinical data of hospitalized COVID-19 patients from 2020 to 2022 were reviewed. Extracted data including patient characteristics, laboratory biomarkers, and systemic inflammation indexes in patients with or without ACS were reviewed and analyzed. Logistic regression models were applied to analyze predictors of ACS development and receiver-operating characteristic (ROC) curves were used to assess discriminatory power of IL-6 and other risk factors for predicting ACS development.ResultsAmong 1,753 COVID-19 patients, 37 cases experienced ACS and 159 patients without main COVID-19 complications were randomly selected as controls. ACS patients were older (p = 0.001) and suffered from more comorbidities including diabetes (43% vs. 18%, p = 0.001), hypertension (40.5% vs. 24.5%, p = 0.050), ischemic heart disease (49% vs. 9%, p = 0.001), and hyperlipidemia (19% vs. 5%, p = 0.010). Also, decreased level of consciousness (31.6% vs. 2.5%, p = 0.001), ICU admission (65% vs. 2%, p = 0.001), and mortality events (70% vs. 0.6%, p = 0.001) were more prevalent in the ACS group. Baseline levels of IL-6 (p = 0.001), D-dimer (p = 0.026), troponin (p = 0.001), blood urea nitrogen (p = 0.002), and creatinine (p = 0.008) were higher in ACS patients but erythrocyte sedimentation rate (p = 0.013), hemoglobin (p = 0.033), and red blood cells (p = 0.028) were lower compared with controls. Also, age (OR: 1.06, p = 0.019), IL-6 (OR: 1.44, p = 0.047), and cardiovascular disease (CVD) (OR: 3.66, p = 0.043) were associated with ACS development. The area under the curve (AUC) of IL-6 and combined predictors respectively was 0.661 (p = 0.002) and 0.829 (p = 0.001).ConclusionsHigh IL-6 concentration at baseline is a strong predictor for ACS development in COVID-19 patients. Also, elderly and concurrent CVD are significantly associated with ACS development.