Traditional Chinese medicine interpretation of angina and therapeutic rules
Syndrome differentiation, also termed pattern diagnosis (Bian Zheng in Chinese pinyin), is one of the kernel theories of traditional Chinese medicine (TCM). The TCM syndrome, or Zheng, is a characteristic profile of clinical signs and symptoms manifested by a group of patients. The clinical efficacy of Chinese medicine relies heavily on the correct diagnosis of a specific TCM syndrome. According to the 2002 Guidelines for Clinical Research of Chinese Medicine (new drug)  released by the Chinese Food and Drug Administration patients with angina pectoris can be diagnosed on the basis of any one of the following eight TCM patterns: (1) qi deficiency and blood stasis syndrome, (2) heart blood stasis obstruction syndrome, (3) qi stagnation and blood stasis syndrome, (4) syndrome of phlegm obstruction in the heart vessel, (5) syndrome of congealing yin cold, (6) dual-deficiency of qi and yin syndrome, (7) heart and kidney yin deficiency syndrome and (8) yang qi debilitation syndrome. Among these criteria, the qi deficiency and blood stasis syndrome is most typically observed in Chinese angina patients.
For the management of angina pectoris patients with qi deficiency and blood stasis syndrome, herbal remedies intended to invigorate qi, activate blood circulation and transform stasis will be administered. The main function of the herbal remedy is to improve clinical signs and symptoms of the patients.
Comparative effectiveness research and traditional Chinese medicine
The concept of comparative effectiveness research (CER) was initiated in the 1990s by Mark Boutin, the deputy executive president and chief operating officer of the US National Health Council . In the years that followed, CER has been used to aid public health policy-making and introduced into the field of clinical research in a number of countries . In May 2011, Claudia M Witt (Institute of Social Medicine, Epidemiology and Health Economics, Charité University Medical Center, Berlin, Germany) proposed introducing CER techniques into TCM research at the sixth annual meeting of the International Society of Complementary Medicine Research .
Efficacy evaluation based on patient-reported outcomes
A patient-reported outcome (PRO) is a report directly from the patient, without influences from doctors or others, about how they function or feel in relation to their health status and the treatment they are receiving . The PRO measurement tools are developed to provide insights from the patient’s perspective regarding the impact of therapeutic interventions on their health. Patient-important outcomes (PIOs) are a selection of outcome measures that are considered most relevant to the patients. Examples of PIOs include pain, fatigue, quality of life and death. Efforts to assess PIOs for a particular disease or condition and to promote the use of PIOs in clinical research settings facilitate effective interpretation of the results by emphasizing the evaluation of treatment effectiveness. The integration of PIOs and PROs into Comparative Effectiveness Research could be a useful tool for the assessment of outcomes requiring patients’ subjective perceptions and judgments, such as consumer satisfaction and health-related quality of life .
Minimal clinically important differences and patient-reported outcome measurements
Minimal clinically important differences (MCIDs) are self-perceived scores that signify clinically significant improvements in PROs that can be used to identify the minimal changes in a specific aspect of a patient’s health , and it is believed to reflect the smallest change in the PRO evaluations of a clinical intervention that is meaningful to the patient.
Distribution-based methods for the determination of MCIDs have been widely used and can be subdivided into the effect size (ES) and the standard error of measurement (SEM). The latter measurement is particularly recommended for its relative independence from sample source and stability across different studies [8, 9]. In our present study, changes in PROs will be calculated using the SEM, which will represent patients’ self-reported improvements in symptoms or health-related function.
Traditional Chinese medicine for angina pectoris due to coronary heart disease
Angina pectoris is one of the most common symptoms of coronary heart disease (CHD) and afflicts a large portion of CHD patients. It has been found over the course of years of clinical practice that TCM is effective in treating angina. Because the qi deficiency and blood stasis syndrome together have been identified as a major TCM syndrome among patients with angina, in this CER study we will select two Chinese patent drugs most frequently used for treating angina patients diagnosed with this common syndrome. The patent drugs to be compared are QiShenYiQi (QSYQ) dripping pills (Tasly Pharmaceutical Co Ltd, Tianjin, China) and Tongxinluo (TXL) capsules (Yiling Pharmaceutical Co Ltd, Shijiazhuang City, China). QSYQ pills are composed mainly of Radix Astragali, Radix Salvia miltiorrhiza, Radix Notoginseng and Lignum Dalbergia Odorifera. TXL capsules are an herbal mixture of Radix Ginseng, Hirudo, Quan Xie Eupolyphaga seu Steleophaga, Scolopendra, Periostracum Cicadae, Radix Paeoniae rubra, Lignum Santali Albi, Lignum Dalbergia Odorifera, frankincense, Semen Ziziphi spinosae and borneol.