Purpose: In the recent years, the relationship between inflammation and atherosclerosis induced, which is a chronic inflammatory disease, acute coronary syndromes, including unstable angina and acute myocard infarction, has gained importance. Acute phase reactants, as inflammation markers, play a role in both risk stratification and follow-up in coronary heart diasease independent of traditional risk factors, but in a complementary way. Endothelial-derived nitric oxide and estrogen have preventive effects on the atherosclerosis induced acute coronary syndromes. To our knowledge, there is not any study observing the changes in acute phase reactants, nitric oxide and estrogen levels in acute coronary syndromes during a period of two days. In this study, our objective was to observe the change in levels of C-reactive protein, fibrinogen, neopterin, Lp(a), nitric oxide and estrogen levels in acute coronary syndromes in a comparative fashion occuring in a short period of time.

Material and Method: 42 male patients with a complaint of chest pain, diagnosed as unstable angina or acute myocard infarction, and 30 healthy male controls were included in this study. All the subjects were categorized as control group (Group 1), unstable angina (Group 2) and myocard infarction (Group 3). Blood samples were drawn on the day of admission before any treatment (first 24 hours), the following first day (48 hours) and the following second day (72 hours). Levels of C-reactive protein and Lp(a) were assayed by immunoturbidimetric methods. Fibrinogen levels were assayed by Clauss method and neopterin levels by means of reverse-phase high performance chromatography. Nitric oxide levels were determined by Griess reaction and enzymatic methods. Estradiol levels were determined by immunassay systems.

Results: On the day of admission, levels of C-reactive protein, Lp(a), nitric oxide and estradiol levels were markedly increased in the patient groups when compared with the control. Fibrinogen and neopterin levels were indifferent between the three groups. On the first and second days, significant increases were observed in the levels of C-reactive protein, fibrinogen, Lp(a), nitric oxide and estrogen in the patient groups, displaying the highest levels in the patients with acute myocard infarction.

Conclusion: High levels of acute phase reactants, like CRP, fibrinogen, neopterin and Lp(a), support the inflammation theory underlying in the pathogenesis of acute coronary syndromes. Increased estradiol and nitric oxide levels , as antioxidants, may be interpreted as a defense mechanism against the oxidative stress due to the inflammation process occuring in acute coronary syndromes.