OBJECTIVE: To evaluate the effectiveness and safety of Suxiao Jiuxin pill (SX) in acute coronary syndrome (ACS) treatment.METHODS: An extensive search of four English databases (Medline/PubMed,Cochrane Library,Embase,and World Health Organization International Clinical Trials Registration Platform) and four Chinese databases (Chinese National Knowledge Infrastructure,Wanfang,China Science and Technology Journal,and Chinese Biomedical Literature Service System) was performed.Randomized,controlled trials (RCTs) involving SX combined with conventional therapy versus conventional therapy were included.The extracted data included populations,interventions,outcomes,and risk of bias.The cardiovascular events served as the primary outcome.Review Manager 5.3 software was used for data analysis.Relative risks (RRs) with 95％ confidence intervals (C/s) were the effect measure.RESULTS: A total of eight RCTs with 979 patients were included.There were 559 patients with unstable angina (UA) in six RCTs and 420 patients with acute myocardial infarction (AMI) in two RCTs.Our review showed that SX plus conventional therapy might reduce the incidence of the total endpoint (RR: 0.34,95％ CI: 0.17,0.68,P =0.002),with no obvious adverse events (RR: 1.29,95％ CI: 0.60,2.77,P =0.52) compared with conventional therapy for patients with UA.Additionally,SX plus conventional therapy also reduced the incidence of the total endpoint (RR: 0.35,95％ CI: 0.18,0.68,P =0.002) compared with conventional therapy in patients with AMI.SX plus conventional therapy also reduced the incidence of ventricular fibrillation (RR: 0.23,95％ CI: 0.10,0.57,P =0.001) compared with conventional therapy in patients with AMI.CONCLUSION: Our results suggest that SX is beneficial for treating patients with UA or AMI.However,our findings should be treated with caution because of the poor methodological quality of the included trials.Therefore,more multicenter,large-sample,high-quality RCTs are required to provide high-quality evidence.