Five RCTs of antiplatelet therapy versus placebo with 816 participants (423 treated patients and 393 control subjects), 1 RCT of oral anticoagulants versus control and 1 RCT of oral anticoagulant therapy plus aspirin versus aspirin alone in high-risk patients were included in the review.
In the 5 trials of antiplatelet therapy versus placebo, the RR for occlusion was 0.78 (95% CI: 0.64, 0.95). Significant heterogeneity was present (P < 0.01). Statistically, for prevention of stroke, myocardial infarction and mortality, and for the composite outcome, the between group difference was not statistically significant.
In the 1 trial of oral anticoagulants versus control, the RR for occlusion was 0.55 (95% CI: 0.30, 0.99) and that for amputation was 0.30 (95% CI: 0.10, 0.87). The mortality rate did not differ significantly between the groups.
In the 1 trial of oral anticoagulant therapy plus aspirin versus aspirin alone in high-risk patients, the RR for occlusion was 0.38 (95% CI: 0.15, 0.95). There were no significant differences for prevention of amputation, myocardial infarction and mortality between the groups.
Bleeding complications related to medication were reported in two trials. There were seven bleeding complications in the treated patients versus five bleeding complications in the control patients. One gastrointestinal bleeding complication in the treatment group was fatal.
The results of a supplementary meta-analysis according to the worst- case scenario did not differ essentially from those described above.