New research studies show mechanical clot retrieval can improve ischaemic stroke outcomes

Wednesday 11 February 15

About 85% of all strokes are caused by a blood clot blocking an artery in the brain.

Mechanical clot retrieval (thrombectomy) is a procedure by which the blood clot causing a stroke is pulled out of the brain, typically using a device inserted into an artery called a 'stent retriever'.

On February 11, at the International Stroke Conference (ISC 2015 in Nashville, USA) the latest findings were released from four, large studies investigating the effect of treating patients with thrombectomy during the early hours after ischaemic (blood flow blockage) stroke.

The findings from all of the studies suggest that treatment with thrombectomy significantly improves patient outcomes for certain types of ischaemic stroke. 

The first of the studies to report such findings is called MR CLEAN, which reported its early findings at the World Stroke Congress 2014, that were published in the New England Journal of Medicine in December 2014.  The three other studies first released their findings at ISC 2015, and are called ESCAPE, EXTEND-IA and SWIFT PRIME.

This is an extremely exciting time in stroke research and care, and many have heralded the impact of the results as a game changer, showing how thrombectomy can be used alongside current standard care, including thrombolysis (clot-busting drugs) to greatly improve outcomes for people after ischaemic stroke.

Talking to the American Heart Association, Bruce Campbell, M.D., a neurologist at the Royal Melbourne Hospital, who led the Australian, EXTEND-IA study, said clinical guidelines will now change.

“It’s a difference for patients between having paralysis down one side and not being able to talk compared to getting home and back to all their usual activities,” Campbell said.

For a summary of each trial please read below:

MR CLEAN

What was the study's purpose?

To assess the effect of thrombectomy on functional outcome after a type of acute ischemic stroke (proven on brain scans), against a background of best medical management

What did the study involve?

It used brain scans to select 500 appropriate, ischaemic stroke patients.  Of these patients, 267 received standard treatment, and 233 of them received thrombectomy within 6 hours of stroke. (89% of all patients received thrombolysis within 4.5 hours after stroke).

What did the study find?

It found that thrombectomy was safe, and among the patients that took part in the trial, more who received thrombectomy were returned to functional independence 3 months after stroke, from 1 out of 5 to 1 out of 3.  There was no significant effect of thrombectomy on the number of people who died from their stroke.

For more information on MR CLEAN click here.

ESCAPE

Presented at ISC 2015, the ESCAPE results were also published simultaneously online in the New England Journal of Medicine.

What was the study's purpose?

To address the question of which is better in acute ischemic stroke, standard care or standard care combined with thrombectomy.

What did the study involve?

It used brain scans to select 316 appropriate, ischaemic stroke patients.  Within up to 12 hours of stroke onset, 150 of these patients received standard treatment (118 of which received thrombolysis within 4.5 hours of stroke), and 165 of them received thrombectomy (120 of which received thrombolysis within 4.5 hours of stroke).

What did the study find?

It found that thrombectomy increased the rate of functional independence and reduced disability and death in this population of patients, with about 10% fewer deaths.

ESCAPE was re-assessed and stopped early, in light of the positive results of MR CLEAN.

Watch an interview with the lead researcher on ESCAPE here.

EXTEND-IA

Presented at ISC 2015, the EXTEND-IA results were also published simultaneously online in the New England Journal of Medicine.

What was the study's purpose?

To test ischaemic stroke outcomes using advanced imaging selection, superior devices, and earlier intervention.

What did the study involve?

It used brain scans to select 70 appropriate, ischaemic stroke patients.  Within 4.5 hours after stroke, 35 of these patients received treatment with thrombolysis, and 35 of them received both thrombolysis and thrombectomy with a mechanical device called SOLITAIRE FR (thrombectomy administered within 6 hours after stroke).

What did the study find?

It found that the additon of thrombectomy (with the SOLITAIRE FR device) to treatment with thrombolysis improved early neurological recovery within 3 days of stroke and functional outcome 3 months after stroke.

EXTEND-IA was re-assessed and stopped early, in light of the positive results of MR CLEAN.

SWIFT PRIME

What was the study's purpose?

To see if certain acute ischaemic stroke patients have less disability when treated with thrombolysis alone, or thrombolysis plus thrombectomy with a mechanical device called the SOLITAIRE FR, within 6 hours of stroke onset.

What did the study involve?

It used brain scans to select appropriate, ischaemic stroke patients.  Of these 196 patients, 98 received treatment with thrombolysis (as part of standard care), and 98 of them received both thrombolysis and thrombectomy with the SOLITAIRE FR device.

What did the study find?

The additional use of thrombectomy with the SOLITAIRE FR device lessened post stroke disability over the entire outcome range and increased the proportion of patients who were alive and independent 3 months after stroke.

For every two and half patients treated, one more patient had a better disability outcome. For every four patients treated, one more patient was independent at long term follow up.

SWIFT PRIME was re-assessed and stopped early, in light of the positive results of MR CLEAN.

Watch a video from the lead researcher on SWIFT PRIME here

 

News type

Share