title: [Effects of low-dose aspirin on primary prevention of cardiovascular events: a systematic review].
abstract: OBJECTIVE
  To evaluate the effect and safety of low-dose aspirin for primary prevention of cardiovascular events.
  
  
  METHODS
  We searched for randomized controlled trials (RCT) in the following electronic databases: MEDLINE, EMbase, the Cochrane Library (Issue 3, 2008), CBM, CNKI. Quality assessment and data extraction were conducted by two reviewers independently. All data were analyzed using Review Manager 4.2.
  
  
  RESULTS
  Six studies (TPT, HOT, PPP, WHS, POPADAD, J-PAD) involving a total of 72,466 participants met the inclusion criteria. Meta-analysis results showed that: (1) Compared with placebo, the incidences of total cardiovascular events (RR = 0.85, 95% CI: 0.80-0.92), stroke (RR = 0.87, 95% CI: 0.77-0.98), nonfatal stroke (RR = 0.81, 95% CI: 0.70-0.95) and transient ischemic attack (RR = 0.76, 95% CI: 0.64-0.90) were significantly lower in low-dose aspirin group than those in placebo control group (all P < 0.05). (2) Nonfatal myocardial infarction (RR = 0.89, 95% CI: 0.77-1.02), death from cardiovascular causes (RR = 0.98, 95% CI: 0.86-1.13) and death from any cause (RR = 0.95, 95% CI: 0.88-1.02) were similar between the 2 groups (all P > 0.05). (3) The risk of coronary heart disease was reduced in low-dose aspirin group in the elderly (RR = 0.81, 95% CI: 0.70-0.94, P < 0.05). (4) The risk of bleeding was higher in low aspirin group compared to placebo group (RR = 1.15, 95% CI: 1.12-1.18, P < 0.01).
  
  
  CONCLUSIONS
  Low-dose aspirin use could reduce the incidences of total cardiovascular events, stroke, nonfatal stroke and transient ischemic attack but increase the risk of bleeding, the incidence of nonfatal myocardial infarction, death from cardiovascular causes and death from any cause was not affected by low-dose aspirin use. Low-dose aspirin use was also significantly reduced the risk of coronary heart disease in the elderly.
authors.affiliation: Department of Geriatrics, First Affiliated Hospital of Anhui Medical University, Hefei 230022, China. tanghq898@sina.com.cn
authors.forename: Hai-qin
authors.initials: HQ
authors.lastname: Tang
authors.forename: Lin-lin
authors.initials: LL
authors.lastname: Yang
authors.forename: Shi-lian
authors.initials: SL
authors.lastname: Hu
authors.forename: Gan
authors.initials: G
authors.lastname: Shen
authors.forename: Ye-huan
authors.initials: YH
authors.lastname: Sun
authors.forename: Xiao-hui
authors.initials: XH
authors.lastname: Huang
authors.forename: Jie-hua
authors.initials: JH
authors.lastname: Li
authors.forename: Ting-juan
authors.initials: TJ
authors.lastname: Xu
mesh_terms: D001241:Aspirin / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use*; D002318:Cardiovascular Diseases / Q000188:drug therapy*; D006801:Humans; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use*; D011322:Primary Prevention; D016032:Randomized Controlled Trials as Topic; D016896:Treatment Outcome
chemical_list: D010975:Platelet Aggregation Inhibitors; D001241:Aspirin