Design and Baseline Characteristics of Included Trials.

A: aspirin; C: Clopidogrel; A+C: aspirin plus clopidogrel; FU: time of follow-up; IS: ischemic stroke; C. Bal: Effect of the Thromboxane Prostaglandin Receptor Antagonist Terutroban on Arterial Thrombogenesis after Repeated Administration in Patients Treated for the Prevention of Ischemic Stroke; CLAIR:, Clopidogrel plus aspirin versus aspirin alone for reducing embolisation in patients with acute symptomatic cerebral carotid artery stenosis; FASTER: Fast assessment of stroke and transient ischaemic attack to prevent early recurrence; CARESS, Clopidogrel and Aspirin for Reduction of Emboli in Symptomatic Carotid Carotid Stenosis Evaluated Using Doppler Embolic Signal Detection; CHARISMA, The Clopidogrel for High Atherothrombotic Risk and Ischaemic Stabilisation, Management and Avoidance.