A total of 144 patients, 72 in each group, selleck should be recruited in order to show a significant difference between the two groups, with a significance level of 0.05, 80% power and a drop-out rate of 15% using the PASS software. Screening of participants Screening condition Patients participation in this trial is voluntary and they should select the symptom types by themselves; physicians should note the criteria met and diagnose syndrome types. Diagnosis criteria SAP (I–III): diagnostic criteria refer to WHO for nomenclature

and criteria for diagnosis of ischaemic heart disease and the Canadian Cardiovascular Society classification standard in 1972.21 ‘Qi and blood stasis’ and ‘qi deficiency and blood stasis’ syndrome: syndrome differentiation criteria refer to the Guidelines for Clinical Research of Chinese Medicine (new drug) in 2002.22 Inclusion criteria Patients aged between 40 and 75. Patients have signed informed consent forms. Patients diagnosed with SAP. Patients with SAP of grade I, II or III. Patients with ‘qi deficiency and blood stasis’ or ‘qi stagnation and blood stasis’ syndromes. Exclusion

criteria Patients younger than 40 or older than 75 years. Patients do not conform to diagnostic standards of Western medicine; TCM pattern is diagnostic. Patients with infraction angina or Prinzmetal variant angina. Patients with other organ dysfunction and other diseases involving the

heart. Patients with uncontrolled hypertension (systolic blood pressure ≥180 mm Hg and/or diastolic blood pressure ≥110 mm Hg). Patients who have received percutaneous coronary intervention for no more than 3 months. Patients with a cardiac pacemaker. Patients with a history of allergy to the control drug or investigational drug. Patients with liver and kidney dysfunction. Patients with tumours, autoimmune disease or blood disease, or pregnant or lactating women who should not be included in the trial as adjudged by the recruiting personnel. Drug_discovery Presence of active peptic ulcers and other haemorrhagic disease. Patients involved in another clinical trial now or in the past 3 months. Termination criteria Patients withdraw of their own accord for any reason. Serious adverse events occurring during the trial. Major mistakes or serious deviations identified in the clinical trial protocol in the process of execution (though the plan is good), making it difficult to evaluate the efficacy of the drug. Trial is cancelled by the authority. Study setting We will prepare to collect cases from the first hospital and Baokang Hospital of Tianjin University of TCM, Tianjin Nankai Hospital and Wuqing hospital of TCM in China.