Studies that compared antithrombotic triple therapy (low-dose aspirin, clopidogrel and warfarin) with dual therapy (aspirin and clopidogrel) in patients who underwent PCI were eligible for inclusion. Outcomes eligible for inclusion were bleeding complications and one or more of all-cause mortality, nonfatal myocardial infarction, coronary artery revascularisation and stroke/transient ischaemic event.
Patients in the included studies had ST-elevation myocardial infarction, non ST-elevation myocardial infarction or angina. Reason for anticoagulant therapy was atrial fibrillation, deep vein thrombosis, prophylaxis for left ventricle thrombus, pulmonary embolism, prosthetic valve, atrial flutter and total knee replacement. Mean age ranged from 59 years to 74 years. The mean proportion of males ranged from 37% to 75%. Follow-up ranged from six to 84 months. Definition of major and minor bleeding varied between studies.
More than one author selected the studies for review. It was unclear whether this was performed in duplicate or independently.