Randomised controlled trials (RCTs) that assessed use of 12 to 24 hours unfractionated heparin infusion after PCI were eligible for inclusion. Participants in eligible trials had to receive prior aspirin and unfractionated heparin during the procedure. The outcomes of interest were the incidence of in-hospital ischaemic complications (composite of all cause death, myocardial infarction and revascularisation) and incidence of bleeding complications (need for blood transfusion, major haematoma or decrease in haemoglobin concentration greater than 3g/dL.
Most of the included studies did not use glycoprotein IIb/IIIa inhibitors (used in 1% of non-heparin group in one study) or stents (in one study 88% to 95% and in another 34%). Unfractionated heparin dosing regimens were not reported. The comparator was placebo. Other drugs used included thienopyridine, nitrates, calcium channel blockers, diltiazem, nitroglycerin, nifedipine and dipyridamole. Sheath removal occurred both before and after infusion. There were no significant differences in participant demographics between treatment and control groups (details not reported).
Two reviewers independently selected studies for inclusion. Disagreements were resolved by consensus.