Endothelial Nitric Oxide Level as a Predictor of Coronary Complexity in Patients With Unstable Angina Pectoris

Abstract Background The Synergy Between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery (SYNTAX) score is an anatomic scoring system based on coronary angiography that quantifies lesion severity and complexity and predicts morbidity and mortality to guide decision making between coronary artery bypass graft surgery and percutaneous coronary intervention in patients with acute coronary syndrome. The present study aimed to compare nitric oxide levels with the SYNTAX score in terms of predicting coronary complexity and the treatment decision for unstable angina pectoris in the emergency department. Methods The study included 120 patients with unstable angina pectoris and 120 control group subjects. Nitric oxide levels were compared with the SYNTAX score and the treatment decision. The UAP group was divided into 2 subgroups, first based on SYNTAX score of ≤18, >18-27 or >27 and then on the treatment decision of coronary angiography, percutaneous coronary intervention, or coronary artery bypass graft surgery. Results The mean nitric oxide levels in the unstable angina pectoris group were lower than in the control group ( P r  = −0.227, P  = 0.013; r  = −0.498, P 27 compared with >18-27 and ≤18 ( P  = 0.04-0.003, respectively). Nitric oxide levels were decreased in coronary artery bypass graft surgery subgroup compared with the coronary angiography and percutaneous coronary intervention groups ( P P Conclusions Nitric oxide may be considered as a novel biomarker in the prediction of coronary complexity in patients with unstable angina pectoris.