The Systematic Review Of Aspirin In The Long-term Prevention Of Chinese Cardiovascular Disease

Aspirin is the first-line drug of the long-term prevention of cardiovascular disease on the world. The effectiveness and safety has been testified by lots of randomized controlled trials aboard. It is considered that in the long term prevention of CVD- related diseases, aspirin can reduce the risks by about 25%, but it can increase the incidence of cerebral hemorrhage, and has closed relationship with severe upper gastrointestinal bleeding. Aspirin is still the focus of the cardiovascular diseases, because of the reasons above and other factors, such as aspirin resistance, the effectiveness and safety problems. Nowadays, most of the clinical trials and guidelines for cardiovascular diseases treatment and prevention are based on the object of the white people cohort in the western countries. Therefore, it needs more carefulness when these conclusions and guidelines are used in the cohorts of other races and in the people of different areas. However, the trials based on the Chinese even yellow people are insufficient both in the quality and quantity, and the Meta-analysis even worse in this clinical research area. There is no systematic review about aspirin in the Chinese long-term prevention of cardiovascular diseases.Objective: To evaluate the effectiveness and safety of cardiovascular diseases in the aspirin long-term usage in Chinese. To evaluate the contribution of the special dosage (50mg/d) in the long-term prevention.Methods: We searched PUBMED(1966-2008), CNKI(1990-2007), Wanfang database and Weipu Chinese Scientific Journals Database. The randomized controlled trials are enrolled, which include one or more primary end points, such as ischemic stroke, hemorrhagic stoke, non-fatal myocardial infarction, angina, coronary insufficiency, peripheral artery disease, fatal heart attack and stroke, meanwhile include one or more safety end point (major bleeding, the complaints of gastrointestinal tract, et al). The quality of every enrolled trial is scored by the quality-evaluating standards. In the analysis of aspirin and Warfarin in the Chinese long-period prevention, we included to controlled clinical trials basing on the criteria of Meta-analysis, and evaluated the trials by the related grading standard. RevMan 4.2.8 software was used for statistical analysis.Results: There are 12 RCTs and 2 CCTs, involving 10178 cases (1312 cases of atrial fibrillation) included in the systematic review. All of cases are Chinese. The 14 trials are divided into 5 different sub-groups because of the different clinical baseline data: aspirin and blank control (total number: 3974; treatment/control: 2051/1923), aspirin and other drug-comparing control (total number: 4853; treatment/control: 2984/1869), aspirin and other drug-plus control (total number: 353; treatment/control: 185/168), special dosage of aspirin (50mg/d) (total number: 1224; treatment/control: 632/592), aspirin and Warfarin comparing-group (total number: 1312; treatment/control: 643/709). Aspirin therapy was associated with a significant reduction in the risk of nonfatal stroke (odds ratio[OR], 0.46, 95%confidence interval [CI], 0.72-0.88), nonfatal MI (OR 0.54,95%CI 0.33-0.89), fatal stroke (OR0.36,95%CI 0.19-0.68). There is no significant difference in the stroke prevention in the comparison of aspirin and Ticlopidine, aspirin and PSS (OR 1.48,95%CI 0.95-2.32), as well as aspirin combining treatment with other drugs and aspirin single treatment (ischemic stroke (OR2.41,95%CI 0.66-8.72), other CVD- related diseases (OR1.98,95%CI 0.41-9.48). 50mg/d aspirin therapy can not reduce the risks of ischemic stroke and other CVD- related diseases significantly in the statistical analysis (OR0.50,95%CI 0.19-1.26,OR0.38,95%CI 0.10-1.39). Because of the limitation of the clinical data, we cannot analyze the prevention of the dosage higher than 50mg/d. In the research of the comparison of aspirin and Warfarin, the latter one has dominance in the prevention of ischemic stroke, but there may be no difference between the aspirin and Warfarin in the treatment of peripheral artery disease and CHD (coronary heart diseases). We can not ensure the relationship of aspirin and cerebral hemorrhage. Low-dose (50mg/d-100mg/d) treatment of aspirin cannot enhance the hazard (OR4.74,95%CI 0.14-160.77), while the opposite conclusion appeared in the special dosage (50mg/d) analysis. Patients treated with Warfarin were significantly more likely to experience severe bleeding (OR2.46,95%CI 1.40-4.32), but we are not sure about the relationship between Warfarin and the risk of cerebral hemorrhage.Conclusions:1. Aspirin has significant effectiveness in the prevention of ischemic stroke, non-fatal myocardial infarction and fatal stroke. But 50mg/d may not a suitable dosage for the long period prevention.2. Some medicine which were considered as the effective drug used for prevention may have no significant difference, comparing with aspirin.3. It needs further more trials to analyze the relationship of aspirin and cerebral hemorrhage.4. Although Warfarin has dominance in the reduction of ischemic stroke treatment, we can not get the conclusion that Warfarin has the same effectiveness in other CVD- related diseases therapy. Considering the severe side effects, Warfarin should be used careful in the treatment of atrial fibrillation.