Table 1

Characteristics of the six included studies

				Enrollment criteria
Trial	Trial period	Location	No of centers	Time from symptom onset	Age (years)	NIHSS
PROACT II10	1996–1998	North America	54	<6 h	18–85	4–30
MELT11	2002–2005	Japan	57	<6 h	20–75	5–22
IMS III2	2006–2012	North America, Europe, Australia	58	<3 h	18–82	≥10 (≥8)*
SYNTHESIS4	2008–2012	Europe	24	<4.5 h	18–80	Any
MR RESCUE3	2004–2011	North America	22	<8 h	18–85	6–29
MR CLEAN8	2010–2014	Europe	30	<6 h	≥18	≥2

*NIHSS of 8–9 was allowed in an amendment if large vessel occlusion in internal carotid or middle cerebral artery was documented on CT angiography.
IMS, Interventional Management of Stroke; MR RESCUE, Mechanical Retrieval and Recanalization of Stroke Clots Using Embolectomy; NIHSS, National Institutes of Health Stroke Severity score.