Association Between Nitric Oxide Levels on Myocardial Injury in Non-ST Elevation Acute Coronary Syndromes

Abstract

Background: Impairment of the release of endothelium and platelet derived-nitric oxide (NO) increases thrombus formation that is rich in platelets in non-ST elevation acute coronary syndromes (NSTE-ACS). Since intracoronary thrombus formation and distal embolization increases risk of myocardial injury, we studied the relationship between NO levels and Tn-I in patients with NSTE-ACS. Methods: Nitric oxide and Tn-I levels of 234 consecutive patients with NSTE-ACS were measured from venous samples at admission. The 137 patients whose Tn-I levels were below 0.20 ng/ml grouped as Tn-I negative and 97 patients whose Tn-I levels were equal to and above 0.21 ng/ml were grouped as Tn-I positive. Presence of visible thrombus, degree of flow in Thrombolysis in Myocardial Infarction (TIMI), and morphology of the lesion were evaluated with coronary angiographies. Results: Presence of coronary thrombus, impaired TIMI flow, frequency of complex lesions, angina and ST-T changes were more frequent and associated with Tn-I levels in Tn-I positive patients. NO levels were lower in patients who were Tn-I positive, had angina and ST-T changes. NO levels were similar between patients with simple or complex lesions, but lower in patients who had coronary thrombus or TIMI flow grade <2. There was a negative correlation between levels of Tn-I and NO (r = - 0.87, P < 0.001). Logistic regression analysis revealed that NO levels were independent predictors in the differentiation of Tn-I negatives and positives (r = 0.527, P < 0.001). Conclusion: This study revealed that NO levels are associated with myocardial injury in patients with NSTE-ACS. © Springer Science+Business Media, LLC 2007.