Short- Term Outcomes Of Different Loading Dose Clopidogrel On Percutaneous Coronary Intervention:a Meta-analysis

Objective: Percutaneous coronary intervention has been an important and effective method to revascularization, but the major adverse coronary events after it should be paid more attention to. Clopidogrel has been proved to reduce major adverse coronary events after percutaneous coronary intervention. However,there is debate on the clopidogrel loading dose.This study will use meta–analysis to compare the short-term efficiency and safety of 600 mg loading dose clopidogrel on percutaneous coronary intervention with that of 300 mg loading dose.Methods: PubMed, highwire, english medical current contents, CNKI and wanfang database were searched up to december 2009. Randomized controlled trials comparing the efficacy and safety with different loding dose clopidogrel on percutaneous coronary intervention which have been repoted were enrolled. No language restriction was enforced. Statistical analysis was performed by using RevMan 4.2.Before meta-analysis, the studies were evaluated for heterogeneity, Relative risk (RR) and 95% confidence intervals (CIs) were calculated using fixed effects models or random effects models.Results: 9 Randomized controlled trials, which enrolled a total of 1195 patients, were included in the analysis. (614 in the 600mg group and 581 in the 300mg group). Overall, 600mg loading dose proved significantly superior to 300mg loading dose in preventing major adverse coronary events (relative risk 0.42, 95% confidence interval 0.28 to 0.64, p <0.0001). But significants difference was found when appraising the risk for myocardial infarction alone (relative risk 0.39, 95% confidence interval 0.21 to 0.72, p=0.003).The major adverse coronary events in 600 mg group were significantly less than that in 300 mg group in patients with acute coronary syndrome (relative risk 0.43, 95% confidence interval 0.24 to 0.77, p =0.005). the rate of hemorrhage between the two groups had no significants difference(relative risk 1.08, 95% confidence interval 0.71 to 1.65, p=0.72).Conclusion: 600mg loading dose clopidogrel can significantly reduce the incidence of major adverse coronary events than 300mg after percutaneous coronary intervention.It proved the similar result in patients with acute coronary syndrome. And 600mg loading dose clopidogrel will not increase the rate of hemorrhage.