Published: Thursday 18 February 2016
Presented at the International Stroke Conference 2016, the final results from the PISTE trial (Pragmatic Ischaemic Stroke Thrombectomy Evaluation) add new evidence for the effectiveness of mechanical clot retrieval (thrombectomy) treatment in the UK.
Although the trial was stopped early, the results are consistent with previously published trials and suggest that treatment with thrombectomy was effective within an NHS setting, and beneficial in the group of severely affected, ischaemic stroke patients who received it.
PISTE was funded by grants from the Stroke Association and the NIHR HTA.
What is thrombectomy?
Mechanical clot retrieval (thrombectomy) is a procedure by which the blood clot causing an ‘ischaemic’ stroke is pulled out of the brain, typically using a device inserted into an artery called a 'stent retriever'. It can be performed in the early hours after a stroke happens.
What was the PISTE trial?
Outside of the UK, several large, randomised controlled trials (RCTs) have already shown that thrombectomy can be an effective emergency treatment for severe ischaemic strokes, significantly improving patient outcomes.
PISTE was a randomised controlled trial of thrombectomy in severe ischaemic stroke patients, which took place across 11 hospitals in the UK. It was stopped early, as a result of the positive findings from the other, non-UK thrombectomy trials.
What happened in the PISTE trial and what do the results show?
PISTE compared the outcomes of two groups of severe ischaemic stroke patients. A group of 32 patients who were to receive standard clot-busting drug treatment (thrombolysis) within 4.5 hours of their stroke, and a group of 33 patients who were to receive standard thrombolysis with the addition of treatment with thrombectomy, aimed to be delivered within six hours of their stroke.
At three months after having a stroke, 20% more patients in the group who had received thrombectomy had made a full neurological recovery, as compared to the group who received standard treatment alone.
As PISTE was stopped early, there were too few patients to reliably assess some other outcomes the trial investigated, although the findings of PISTE are consistent with previously published trials.
Treatment with thrombectomy was safe, with no significant harmful effects.