A prospective, multi-center, double-blind, randomized, placebo-controlled trial is conducted to evaluate the efficacy and safety of Yinxingmihuan oral solution in the treatment of chest pain after percutaneous coronary intervention (PCI) in patients with stable angina. Patients should undergo at least 1-week standardized medical treatment phase before randomization. The primary end point is the 12-week angina frequency assessed on the basis of Seattle Angina Questionnaire (SAQ) subscales. The main secondary endpoint is the improvement of anxiety assessed by Hamilton Anxiety Scale (HAMA) to evaluate its effectiveness for chest pain caused by psychological factors.

Inclusion Criteria:

• male or female aged 18-85 years;
• patients with a history of percutaneous coronary intervention for coronary heart disease for more than 30 days and less than 180 days, without need of further elective coronary revascularization (PCI, CABG) judged by cardiovascular specialists;
• patients with symptoms such as chest distress, chest pain, palpitation, pain in shoulder and back, shortness of breath, weakness, activity intolerance, etc. Angina frequency (AF) score in Seattle Angina Questionnaire (SAQ) no more than 80;
• Hamilton Anxiety Scale score between 7 and 21 (mild to moderate anxiety);
• written informed consent.

Exclusion Criteria:

• women who are pregnant or preparing to be pregnant or nursing, menstruating women;
• women of child-bearing age who do not agree to use contraception during the medication phase;
• patients with severe anxiety (Hamilton Anxiety Scale score more than 21);
• patients with severe depression (Hamilton Depression Scale score not less than 24);
• patients who are currently taking anti-anxiety drug;
• participants with stable angina classified into Canadian Cardiovascular Society (CCS) Grade 4;
• uncontrolled hypertension (systolic > 180 mmHg or diastolic > 100 mmHg) despite using ongoing antihypertensive treatment;
• heart failure assessed by New York Heart Association (NYHA);
• patients with coronary heart disease and atrial fibrillation;
• clinically significant complications, including liver dysfunction (ALT or AST level more than 2 times higher than normal), renal dysfunction (serum creatinine level more than 2 times higher than normal), severe cardiopulmonary dysfunction, pulmonary hypertension, chronic obstructive pulmonary disease, history of cerebral hemorrhage or epilepsy, with need of anticonvulsant drugs;
• within 7 days of introduction period, patients who no longer have angina-related symptoms;
• within the three months before start of the study, patients with myocardial infarction or CCS 4 angina;
• patients with acute coronary syndrome confirmed by examinations and other chest pain caused by rheumatic heart disease, dilated cardiomyopathy, severe neurosis, menopausal syndrome, hyperthyroidism, cervical spondylosis, bilio-cardiac syndrome, gastroesophageal reflux, hiatal hernia, aortic dissection, pulmonary embolism, mediastinal hematoma, etc;
• history of specific bleeding or bleeding caused by warfarin;
• patients with previous hematopoietic diseases;
• patients who have undergone surgery (not including PCI) within the last 4 weeks and are prone to bleeding;
• patients who participate in any other clinical study or take any other investigational drug within 90 days;
• patients who are known or suspected to be allergic to the drug in this study or are allergic constitution;
• drug abusers who have a history of alcohol abuse or drug dependence in the past 2 years;
• psychopath;
• patients who have been judged by their doctors to be ineligible for the study;
• patient who is a family member or relative of the staff working in the centers.