Interleukin-6 and E-selectin in acute coronary syndromes and stable angina pectoris. A comparative study

The purpose of the study was to compare the serum levels of interleukin-6 (IL-6), E-selectin, and trans-fatty acids (TFA) between those with stable and unstable angina pectoris.

From September 2008 to March 2009, a case-control study was performed at two university hospitals. We included 89 patients with acute coronary syndrome (ACS) including patients with myocardial infarction and those with unstable angina pectoris (case group) and 93 patients with stable angina pectoris (control group). The two groups were matched with respect to demographic characteristics and risk factors of cardiovascular diseases. Serum levels of IL-6 and E-selectin were measured using the enzyme linked immunosorbent assay, while TFA and lipoproteins were measured using gas chromatography and enzymatic methods, respectively.

No significant differences between baseline characteristics of the two study groups were observed. Patients with stable angina had significantly higher serum levels of total cholesterol (187.0 ± 3.7 vs. 171.6 ± 4.2 mg/dl; p = 0.009), low density lipoproteins (104.8 ± 2.4 vs. 95.4 ± 2.7; p = 0.017), and TFA (1.41 ± 0.47 vs. 1.24 ± 0.69 mg/dl; p = 0.047) compared to those with ACS. Serum levels of IL-6 were found to be significantly higher in those with stable angina compared to those with ACS (102.4 ± 1.9 vs. 224.6 ± 3.6; p = 0.007). However, patients with ACS had higher levels of E-selectin (53.5 ± 25.7 vs. 49.2 ± 23.5 µg/dl; p = 0.52), but the difference did not reach statistical significance.

In the current study, inflammation as measured by IL-6 and E-selectin was not found to play an important role in progression of ischemic heart disease from stable angina to unstable angina or myocardial infarction, which is contrary to previous studies.