Meta-analysis appraising high Clopidogrel loading in patients undergoing percutaneous coronary interventiont

Combined antiplatelet treatment with aspirin and clopidogrel is pivotal to minimize peripro-cedural adverse events in patients who undergo percutaneous coronary intervention. However, there is debate on the best clopidogrel loading dose. The investigators performed a systematic review and meta-analysis of the optimal clopidogrel loading dose. Pertinent trials comparing high (>300 mg) and standard (300 mg) clopidogrel loading doses in patients scheduled for catheterization and/or percutaneous coronary intervention were systematically searched in BioMedCentral, CENTRAL, Google Scholar, and PubMed (December 2006). The primary end point was the 1-month rate of death'or myocardial infarction. Secondary end points included other ischemic and bleeding adverse effects. Peto odds ratios were computed. A total of 10 studies (7 randomized, 3 nonrandomized) were included, enrolling 1,567 patients (712 loaded with 300 mg, 11 with 450 mg, 790 with 600 mg, and 54 with 900 mg). Overall, a high loading dose proved significantly superior to a standard loading dose in preventing cardiac death or nonfatal myocardial infarction (odds ratio 0.54,95% confidence interval 0.32 to 0.90, p = 0.02), without any statistically significant increase in major or minor bleedings (p = 0.55 and p = 0.98, respectively). Sensitivity analysis restricted to randomized trials confirmed the superiority of a high loading dose regimen (p = 0.0031). Meta-regression disclosed a significant interaction between event rate and the benefits of high loading doses (p = 0.005), suggesting that the greater the underlying risk, the greater the favorable impact of a high loading dose. In conclusion, a high clopidogrel loading dose (>300 mg) significantly reduces early ischemic events in patients scheduled for percutaneous coronary intervention. (C) 2007 Elsevier Inc. All rights reserved.