Complement use of Chinese herbal medicine after percutaneous coronary intervention: a prospective observational study

BACKGROUNDChinese herbal medicine is widely used as a complement or alternative treatment in coronary artery disease (CAD) patients after percutaneous coronary intervention (PCI) in China. We compared the incidence of the major adverse cardiovascular event (MACE) of CAD patients with or without the complement use of Chinese herbal medicine after PCI. METHODSIn this prospective, observational study that was conducted from September 2016 to August 2019 in Fuwai Hospital (China), we followed up consecutive patients who received PCI treatment for two years. MACE was defined as the composite all-cause mortality, revascularization, and myocardial infarction (MI) and was compared between those using (integrative medicine group) or those not using Chinese herbal medicine as an additional treatment to standard Western medicine, with unadjusted (Kaplan-Meier curves) and risk-adjusted (multivariable Cox regression) analyses. RESULTSA total of 5942 patients after PCI were enrolled in this study, and 5453 patients were included in the final analysis (4189 [76.8%] male; mean age: 61.9 ± 9.9% years). During the follow-ups, 2932 (53.8%) patients used only Western medicine while 2521(46.2%) patients had used Chinese herbal medicine as an additional treatment to standard Western medicine. Patients in the integrative medicine group (IM group) were older than the Western medicine group (WM group), had more females and less previous MI. The incidence of MACE was 15.3% (449/2932) in WM group and 11.54% (291/2521) in IM group. Cox regression analysis showed that cumulative incidence of MACE was 27% lower in patients of the IM group than those in WM group (hazard ratio = 0.73; 95% CI: 0.63-0.85; P < 0.0001). CONCLUSIONSFor CAD patients after PCI treatment, complement use of Chinese herbal medicine is associated with a lower 2-year MACE incidence. Randomized prospective studies are warranted to provide higher levels of benefit evidence in these patients.

Coronary artery disease (CAD) is a major public challenge and the leading cause of morbidity and mortality worldwide.^[1] Percutaneous coronary intervention (PCI) is the most common strategy for treating CAD. In 2018, 915,256 patients underwent PCI in the Chinese mainland,^[2] which increased 21.5% year over year in 2017.^[3] With the development of medical, surgical and interventional treatments, the survival rate of patients with CAD is greatly increased. PCI can achieve patients’ coronary artery reperfusion, but cannot change the etiology and pathogenesis of CAD, and may lead to vascular endothelial injury. In CAD patients after PCI who take conventional drugs including aspirin, clopidogrel and statins, about 5%-15% will have a major adverse cardiovascular event (MACE) within one year.^[4-6] In addition, conventional drugs may not be tolerated in some patients due to allergies and severe side-effects.^[7] Therefore, the secondary prevention strategy after PCI needs to be improved.In China, traditional Chinese medicine (TCM) is widely used in patients after PCI, in addition to conventional western medicine. Several previous studies showed that for CAD patients after PCI, combined use of Chinese herbal medicine and conventional western medicine may reduce recurrence angina frequency,^[8] the occurrence of adverse cardiovascular events,^[9-12] improve quality of life,^[13] and improve hemorheology, blood lipid, and inflammatory parameters.^[14] However, all these studies were limited by small sample size, short follow-up times and inconsistent data analysis methods.^[14-16] Therefore, there is a lack of reliable evidence for the efficacy and benefit of TCM in long-term management in post-PCI CAD patients. Thus, we designed this large sample, long-term follow up, observational study with the following objectives: (1) to observe the treatment effects of Chinese patients after PCI in the real-world; (2) to identify the incidence and trends in MACE after PCI; and (3) to compare the incidence of MACE within 2-year in CAD patients who have undergone PCI with and without using additional Chinese herbal medicine.