Six RCTs (1,735 patients, after excluding 8 patients from one study for whom clinical outcome data were missing) were included.
All analyses were of heparin versus non-heparin treated groups.
Mortality: in all analyses, heparin led to non significantly lower odds of death.
All analyses: the OR was 0.91 (CI: 0.59, 1.39), corresponding to an absolute difference of 5 deaths per 1000 treated, or a 9% relative reduction in the odds of death with intravenous heparin when compared with no heparin.
Analyses of t-PA only: the OR was 0.84 (CI: 0.43, 1.64).
Analyes of streptokinase or APSAC only: the OR was 0.96 (CI: 0.55, 1.66).
Analyses with and without aspirin: the ORs were 1.01 (CI: 0.59, 1.71) and 0.72 (CI: 0.36, 1.45) for studies with and without aspirin, respectively.
Strokes and bleeding: the risk of bleeding of any severity was significantly higher (OR 1.55, CI: 1.21, 1.98).
All other outcomes (total stroke, intracranial haemorrhage and severe bleeding) were non significantly higher in all analyses. The OR values were not given.
Reinfarction and recurrent ischaemia: no significant differences were found between the heparin-treated and control groups. The OR was 1.02 (CI: 0.75, 1.37) for recurrent ischaemia and 1.04 (CI: 0.61, 1.78) for reinfarction.
No differences were seen in any of the sub-analyses and the OR values were not given.