Berkhemer
et al report in NEJM
the results of a Multicenter Randomized Clinical
Trial of Endovascular Treatment of Acute Ischemic Stroke in the Netherlands (MR
CLEAN) that included patients with severe stroke and proximal-vessel occlusion.
The patients with
acute ischemic stroke were randomly
assigned to receive intra-arterial treatment plus usual care or usual care
alone. Eligible patients had a proximal arterial occlusion in the anterior
cerebral circulation that was confirmed on vessel imaging and could be treated
within 6 hours after the onset of symptoms.
The primary outcome was evaluated
based on the modified Rankin scale score at 90 days; this categorical scale
measures functional outcome, with scores ranging from 0 (no symptoms) to 6
(death).
The study involved 500 stroke patients
whose mean age was 65 years (23-96).
They were treated at 16 medical centers in the Netherlands with 233
assigned to intraarterial treatment while 267 to usual care alone. Before
the randomization 445 of (89.0%) were treated with intravenous alteplase, a
tissue plasminogen activator. Retrievable stents were used to snare and remove
the thrombus in 190 of the 233 patients (81.5%) assigned to intra-arterial
treatment. There was an absolute difference
of 13.5 percentage points in the rate of functional independence (modified
Rankin score, 0 to 2) in favor of the intervention (32.6% vs. 19.1%) after
three months. There were no significant differences in mortality or the
occurrence of symptomatic intracerebral hemorrhage about 19% in both groups at
one month.
They
concluded that in patients with acute ischemic
stroke caused by a proximal intracranial occlusion of the anterior circulation,
intra-arterial treatment administered with a mechanical device within 6 hours
after stroke onset was effective and safe.