Study	Method of Randomization/ Concealment	Spectrum	Blinding – patient & operator	Interpretation of CAG, IVUS & clinical outcomes	Documentary IVUS in Angio group	Statistical Power	ITT
Gaster 2001, 2003 (28)	Drawing lots from sealed opaque envelops Concealed	Males with stable angina scheduled for PCI	No	CAG – blinded IVUS- unblinded Clinical assessment-blinded	Yes	No stated	Yes
SIPs 2000 (25)	Day-to-day block schedule each morning Concealment not stated	All patients undergoing PTCA or primary stenting in vessel 2.2–4.6 mm in diameter	No	Not stated	Not stated	Powered to detect 0.104mm chronic difference in MLD	Yes
OPTICUS 2001 (21)	By fax from central office before start of procedure Concealed	Patients with angina or documented ischemia, no long lesions or small vessel	No	Angiographic & IVUS measured blind	Not stated	Powered to detect 10% absolute ↓ in binary restenosis rate	Yes
RESIST 1998, (22) 2000 (23)	After satisfactory QCA stent deployment Method of randomization unknown Concealment unknown	Symptomatic CAD>70% stenosis in 1 or more coronary undergoing PTCA+ stenting	No	Angio analysis blinded to IVUS results	Yes	40% power to detect a 15% absolute ↓ in restenosis rate	Yes
TULIP 2003 (26)	Just before the procedure. Method not stated. Concealment unknown	Consecutive patients for elective PCI, Only long lesions ≥ 20 mm, no narrow vessels.	No	Angio analysis blinded to IVUS assignment	Not stated	Powered to detect >0.25mm difference in MLD in 6 months	Yes
AVID 1997 (31) 2000 (27)(Abstract)	Method not stated Concealment unknown	Undergoing elective stenting in vessel >2.5mm, & @ low risk for complications	No	Not stated	Yes	Not reported	Not reported

Angio or QCA quantitative coronary angiography; IVUS intravascular ultrasound; CAD coronary artery disease; MLD minimal lumen diameter; ITT intention-to-treat analysis