Ten studies involving 11,688 patients were included in the review: 3 RCTs (2,736 patients) and 7 registry-based studies (8,952 patients). All 10 studies were used for efficacy analyses, while 4 to 7 studies were used for safety analyses.
Efficacy.
Composite end point of death or MI at 30 days: patients using clopidogrel plus aspirin had a lower risk of death or MI than patients on ticlodipine plus aspirin (OR 0.63, 95% CI: 0.47, 0.85, P=0.003).
MACE: patients using clopidogrel plus aspirin had a non significant lower risk of MACE than patients on ticlodipine plus aspirin (OR 0.83, 95% CI: 0.66, 1.03, P=0.1).
There were no significant differences between groups for individual efficacy end points.
Safety.
Composite end point of major adverse side-effects: patients using clopidogrel plus aspirin had a lower risk of major adverse side-effects than patients on ticlodipine plus aspirin (OR 0.53, 95% CI: 0.42, 0.66, P<0.00001).
Drug intolerance: patients using clopidogrel plus aspirin had a lower risk of drug intolerance than patients on ticlodipine plus aspirin (OR 0.51, 95% CI: 0.36, 0.72, P<0.0001).
Neither differences in major bleeding (OR 1.19, 95% CI: 0.71, 1.99, P=0.5) nor neutropenia or thrombocytopenia (OR 0.58, 95% CI: 0.18, 1.81, P=0.3) were associated with the use of clopidogrel compared with ticlodipine.
The authors stated that there was significant heterogeneity between the studies (P=0.07) for the primary end point analyses, but not for the individual analyses of death or MI.
When data from RCTs only were pooled, the risk of death or MI was similar in both treatment groups (OR 1.05, 95% CI: 0.52, 2.12, P=0.9).
When the results were stratified according to having a loading dose of clopidogrel or not, the treatment advantage of clopidogrel was stronger in patients treated with a loading dose than in those treated without a loading dose; the ORs for the combined end point were 0.58 (95% CI: 0.41, 0.80) and 1.16 (95% CI: 0.58, 2.32), respectively, with and without a loading dose.
Other individual results were reported in the paper.