3.  Intra-arterial Stroke Treatment: Finally has a positive study (or 4)

Practice Change:  These new intraarterial interventions WORK on patients with large ACA and MCA  strokes seen on imaging.  The NNT to provide a patient with functional independence is 8.  The window of intervention is increased up to 12 hours after last seen normal.  The procedure details aren’t important, but knowing that these interventions exist and discussing them with your neurologist IS important.

Background: IA tPA and also clot retrieval devices have had a decade of questionable results, this changed in Jan 2015 with the Mr CLEAN trial in the NEJM (yes, that really was the name).  There were 3 other trials ongoing at the same time, which were all stopped early and also showed positive results.


A Randomized Trial of Intraarterial Treatment for Acute Ischemic Stroke

     – NEJM 2015


Population: 500 Dutch patients with a proximal clot in the Anterior or Middle Cerebral Artery seen on MRA or CTA  who could have treatment completed within 6 hours.

All patients were given IV tPA, then if not improving, they were THEN randomized.

Intervention: IA tPA or Thrombectomy + Usual Care

  • Therapy could include IA tPA or thrombectomy or Both

Control: Usual Care

Primary Outcomes: Modified Rankin Score at 90 days (0-2 vs 3+)

Modified Rankin Score                           Description

0 – No symptoms
1 – No Significant Disability
Able to carry out all usual activities, despite some symptoms.
2 – Slight Disability
Able to look after own affairs without assistance, but unable to carry out all previous activities.
3 – Moderate Disability
Requires some help, but able to walk unassisted.
4 – Moderately Severe
Unable to attend to own bodily needs without assistance, and unable to walk unassisted.
5 – Severe Disability
Requires constant nursing care and attention, bedridden,
6 – Dead

Secondary outcomes: NIHSS at 24 hrs and 7 days.


Time to randomization was 200 minutes, and time to groin stick was about 260 min.

Modified Rankin Score of 0-2 (Independence) at 90 days for treatment was 32.6% vs 19.1%.


NNT of 8 to move one person to functional independence from dependence.

NIHSS at 7 days for treatment was 8 in treatment vs 14 in the normal therapy

The only significant risk was for new territory stroke at 5.6% for therapy vs 0.4%

Subsequently 3 other trials with similar inclusion criterion were stopped for early analysis, and ALL THREE were positive and published in NEJM — ESCAPE and EXTEND-IA were published Feb 11, 2015, SWIFT PRIME on April 17, 2015.  The main results are in this table, followed by more details if you want them.

% of Patients with Modified Rankin of 0-2 (Independence)

Trial Name Intervention Control
ESCAPE         53% 29%
EXTEND-IA         71% 40%
SWIFT PRIME         60% 35%

CONCLUSIONS:  These studies look very promising and if the NNT really is 8 patients to give someone functional independence, that is AMAZING.  We should be trying to implement these strategies as possible.


ESCAPE – (Endovascular treatment for Small Core and Anterior circulation Proximal occlusion with Emphasis on minimizing CT to recanalization times) trial

Randomized Assessment of Rapid Endovascular Treatment of Ischemic Stroke

— NEJM 2015


This had enrollment up to 12 hours later.

Stopped after 315 pts

RESULTS:             Modified Rankin of 0-2

53.0% in thrombectomy vs. 29.3% in controls

Mortality of 10% in intervention group vs 19% in control group

EXTEND-IA – (EXtending the time for Thrombolysis in Emergency Neurological Deficits with Intra-Arterial therapy) trial

Endovascular Therapy for Ischemic Stroke with Perfusion-Imaging Selection

— NEJM 2015


Enrolled up to 8 hours after onset

Stopped at 70 pts

RESULTS:       MR 0-2 at 90 days was 71% in thrombectomy patients and 40% in controls

SWIFT PRIME – (Solitaire™ With the Intention For Thrombectomy as PRIMary treatment for acute ischemic strokE) trial

Stent-Retriever Thrombectomy after Intravenous t-PA vs. t-PA Alone in Stroke

      – NEJM 2015


Stopped at 196 pts

MR 60.2% in intervention group and 35.5% in IV rt-PA group (p < 0.001)

For a great review of this new data see Ryan Radecki’s post below from EM Lit of Note:


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