A Cochrane review [Abstract] 1 included no randomised trials, but 36 observational studies with a total of 1285 patients. The trials compared antiplatelets with anticoagulants. The primary outcome was death from all causes. There were no significant differences in the odds of death (Peto OR 2.02, 95% CI 0.62 to 6.60), or the occurrence of ischaemic stroke (OR 0.63, 95% CI 0.21 to 1.86) (34 studies, n=1262). For the outcome of death or disability, there was a non-significant trend in favour of anticoagulants (OR 1.77, 95% CI 0.98 to 3.22; 26 studies, n=463), even though the point estimate indicates that patients treated with anticoagulants might have a more than 70% higher chance of avoiding death or disability compared with patients treated with antiplatelets. Symptomatic intracranial haemorrhages (5/627; 0.8%) and major extracranial haemorrhages (7/425; 1.6%) occurred only in the anticoagulation group; however, for both these outcomes, the estimates were imprecise and indicated no significant difference between the two treatments.
Comment: The quality of evidence is downgraded by study quality (observational trials) and imprecise results (small studies, few outcome events).
Primary/Secondary Keywords