Abstract WMP104: Effect Of Addition Of Clopidogrel To Aspirin On Stroke Incidence: Meta-analysis Of Randomized Trials
Introduction: Current guidelines do not support the use of aspirin and clopidogrel for secondary stroke prevention due to a nonsignificant reduction in stroke and a significant increase in life-threatening bleeding.
Hypothesis: We assessed the hypothesis that the effect of dual antiplatelet therapy on stroke prevention would be different depending on the trial cohort.
Methods: We conducted a meta-analysis of published randomized trials comparing the combination of clopidogrel and aspirin versus aspirin alone that reported stroke incidence. Statistical heterogeneity across trials was evaluated using the I2 index and the Chi-square test for heterogeneity.
Results: Thirteen randomized trials were included with a total of 90,433 participants (mean age 63 years; 63% male) with a mean follow up of 1.0 years and 2011 strokes. Stroke was reduced 19% by dual antiplatelet therapy (OR=0.81; 95% CI 0.74-0.89) with no evidence of heterogeneity of effect across different trial populations (I2 index = 5%, p = 0.4 for heterogeneity). Dual antiplatelet therapy reduced ischemic stroke by 23% (OR=0.77; 95% CI 0.70-0.85). The risk of major bleeding was increased by 40% (OR 1.40, 95% CI 1.26-1.55) by dual antiplatelet therapy; there was a nonsignificant 2% increase in intracerebral hemorrhage (OR=1.12, 95% CI 0.86-1.46).
Conclusions: Contrary to our hypothesis, this meta-analysis demonstrates a substantial relative risk reduction in stroke by clopidogrel plus aspirin vs. aspirin alone that is consistent across different trial cohorts. Given this findings the strong proscription against the use of clopidogrel plus aspirin for secondary stroke prevention advocated by most current guidelines may warrant reconsideration.
- © 2012 by American Heart Association, Inc.