Table 6: Risk ratios of Chinese herbal medicines administered to prevent angina after PCI.

Chinese herbal medicine Number of studies Number of patients Risk ratio (RR) 95% CI of RR Followup 1 month          Shan shen tong mai he ji plus RWM versus RWM 1 [74] 102 1.18 0.95~1.45  Shen mai gua lou shi xiao power plus RWM versus RWM 1 [88] 63 1.55 1.11~2.17  Overall (CHMs plus RWM versus RWM)* 2 165 1.31 1.00~1.72 Followup 3 months          Tong guan capsule plus RWM versus RWM 1 [58] 52 1.26 0.98~1.64  Yi qu huo xue formula plus RWM versus RWM 1 [73] 101 1.07 0.98~1.16  Overall (CHMs plus RWM versus RWM)* 2 153 1.13 0.93~1.36 Followup 6 months          Xue fu zhu yu pill plus RWM versus RWM 1 [84] 84 1.02 0.57~1.84  Wen yang huo xue formula plus RWM versus RWM 1 [47] 120 1.05 0.99~1.12  Overall (CHMs plus RWM versus RWM) 2 204 1.05 0.99~1.12 Total overall (CHMs plus RWM versus RWM)* 6 522 1.13 1.02~1.26

*Random effect model CHM = Chinese herbal medicine; CI = confidence interval; PCI = percutaneous coronary intervention; RWM = routine Western medicine.