Objective: To investigate whether Naoxintong capsule can improve endothelial function in patients with coronary heart disease after percutaneous coronary intervention (PCI) operation. Method: Sixty patients with coronary heart disease after PCI were randomly divided into the observation group and the control group with 30 cases in each group. Patients in two groups received conventional western medicine

the observation group added Naoxintong capsule. All patients in two groups received one 12 weeks periods of treatment and 6 months follow up. The symptoms integral

endothelial function and adverse cardiovascular events in two groups were observed before and after treatment. Result: ①There was no cardiovascular death in two groups

there was one non-fatal acute myocardial infarction (AMI) in each group. The cases of rehospitalization with angina pectoris and acute coronary syndrome (ACS) were lower in the observation group than that in the control group;②The clinical symptom of the observation group were significantly improved after treatment (P<0.01)

while only the chest pain

chest tightness in the control group were improved (P<0.05). The improment of palpitations

fatigue and dyspnea in the observation group were better than that in the control group (P<0.01);③After treatment

the -mediated diameter(FMD) was improved

the serum nitric oxide(NO) was increased

the endothelin-1 (ET-1) and ET-1/NO were decreased in two groups (P<0.01);and the improvement in observation group was better than that in control group (P<0.01). Conclusion: Naoxintong capsule can significantly improve clinical symptoms of patients with coronary heart disease after PCI

reduce the incidence rate of adverse cardiovascular events and improve quality of life. Its mechanism may be relevant to the improvement of endothelial function by regulating blood ET-1

NO levels and ET-1/NO ratio.