The effect of Danshen extract on lipoprotein-associated phospholipase A2 levels in patients with stable angina pectoris: study protocol for a randomized controlled trial - the DOLP... oleh A-Di Chen, Chun-Ling Wang, Yang Qin, Liang Tian, Li-Bin Chen, Xiao-Ming Yuan, Lin-Xiu Ma, Yu-Feng Wang, Ji-Rong Sun, Hao-Sen Wang, Neng Dai, DOLPHIN investigator group