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.