The Pragmatic Ischaemic Stroke Thrombectomy Evaluation (PISTE) trial is a major UK research project comparing IV rtPA alone with IV rtPA and adjunctive mechanical thrombectomy in patients, eligible for treatment with IV rtPA, that have a large vessel carotid territory arterial occlusion (as confirmed on angiographic imaging).  The study commenced in 2013 and is expected to run until at least 2018.

Stroke is the leading cause of adult disability in the UK and the fourth leading cause of death.  The costs of stroke are estimated to be between £3.7 billion and £8 billion. The KEY current clinical question in acute stroke management is whether a treatment policy of intra-arterial thrombectomy (IAT) added to IV thrombolysis (IVT) improve clinical outcomes over IVT alone. If the answer is yes and it applies to most patients with large vessel occlusive stroke, then the implications for acute stroke care and NHS services are enormous.