Diagnostic Impact of Hs-CRP and IL-6 for Acute Coronary Syndrome in Patients Admitted to the ED with Chest Pain: Added Value to the HEART Score?

OBJECTIVE

To investigate whether hs-CRP and IL-6 provide additional diagnostic value beyond that achieved by the HEART score in patients with chest pain suggestive of acute coronary syndrome (ACS) admitted to the emergency department (ED).

METHODS

This was a post hoc analysis using data from the RACING-MI study. Baseline data, including hs-CRP and IL-6 levels, were analyzed using the plasma from the biobank. A total of 818 patients with chest pain suggestive of ACS were included in this analysis. Of these, 98 were diagnosed with ACS (12%). Logistic regression was used to identify the independent predictors of ACS development in patients with chest pain.

RESULTS

hs-CRP levels >2 mg/L were observed in 50% of all ACS cases. IL-6 levels >1.3 pg/mL were observed in 71% of all ACS cases. hs-CRP had a sensitivity of 50% and specificity of 51% for the diagnosis of ACS, whereas IL-6 had a sensitivity of 71% and specificity of 29%. The diagnostic likelihood ratios for ACS was 1.0 for hs-CRP>2 mg/L and IL-6 > 1.3 pg/mL, respectively. Logistic regression analysis revealed that age, male gender, and ongoing smoking were associated with ACS in patients with acute chest pain. No association was found between IL-6 or hs-CRP level and ACS. This was observed for both IL-6 and hs-CRP, whether assessed on a continuous scale or using prespecified cut-off values.

CONCLUSION

Among the 818 patients admitted to the ED with chest pain suggestive of ACS, neither hs-CRP nor IL-6 provided an independent added diagnostic value. Our results suggest that inflammatory markers have limited diagnostic value in detecting patients with ACS in the ED.