ABSTRACT
Increasing evidence for inflammation in acute ischemic syndromes has been recently suggested by the finding of elevated serum level of inflammatory markers including Interleukin-6 [IL-6].This seemingly attractive hypothesis needs further elucidation. This study is intended to assess the levels of IL-6 in unstable angina and to evaluate whether this serum level correlates with angiographic extent of coronary arterial disease. To achieve this goal we studied 80 ischemic patients and 20 healthy subjects with angiographically normal coronary arteries [10 F, 10 M, Mean age: 44.3 +/- 1.43yr] served as controls. Ischemic patients were divided into 2 groups, stable angina group [39 patients, 14 F, 25 M, mean age 47.7 +/- 1.31yr] and unstable angina group [41 patients, 7 F, 34 M mean age 48.9 +/- 1.012yr]. Following clinical evaluation including 12- lead ECG, patients and controls had routine laboratory investigations, liver, kidney functions and IL-6 was measured by automated chemiluminescence. Coronary artery disease was confirmed by diagnostic coronary angiography. Extent of coronary artery disease was expressed in terms of number of vessels affected according to 1-3 vessel score. Compared to control subjects and stable angina group, those with unstable angina had a significantly higher level of IL-6 [P< 0.001, P: 0.006 respectively]. In stable angina group, 26 cases had normal value [9.7 <30 pg/mL], 6 cases were moderate [>30 < 60 pg/mL] and 5 cases were severe [260 pg/mL]. In unstable angina group IL-6 evaluation revealed that 16 cases were normal [<9.7 pg/mL], 5 cases were mild [>9.7 <30 pg/mL], 2 cases were moderate [>30 <60 pg/ mL] and 18 cases were severe [>60 pg/mL], while all control subjects had normal IL-6 level. According to angiographic 1- to 3 - vessel score, IL-6 level was significantly higher in those with multivessel disease [P< 0.001]
Conclusion: Among patients with stable and unstable angina undergoing coronary angiography, the higher levels of IL-6 were significantly associated with unstable angina and correlated with the extent of coronary artery disease. This finding points to the potential role played by inflammation in the pathophysiology of unstable angina