Stent versus surgery in carotid stenosis

In a study published in NEJM Rosenfield et al report the findings of a trial that compared carotid artery stenting with “embolic protection” to carotid endarterectomy.

In this trial, the authors compared carotid-artery stenting with “embolic protection” and carotid endarterectomy in 1453 patients who were 79 years of age or younger who had severe carotid stenosis and were asymptomatic.  Patients were followed for up to 5 years. The primary composite end point of death, stroke, or myocardial infarction within 30 days after the procedure or ipsilateral stroke within 1 year was tested at a non-inferiority margin of 3 percentage points.

The rate of stroke or death within 30 days was 2.9% in the stenting group and 1.7% in the endarterectomy group (P=0.33). From 30 days to 5 years after the procedure, the rate of freedom from ipsilateral stroke was 97.8% in the stenting group and 97.3% in the endarterectomy group (P=0.51), and the overall survival rates were 87.1% and 89.4%, respectively (P=0.21). The cumulative 5-year rate of stroke-free survival was 93.1% in the stenting group and 94.7% in the endarterectomy group (P=0.44).

The authors concluded that stenting was not inferior to endarterectomy with regard to the rate of the primary composite end point at 1 year. In analyses that included up to 5 years of follow-up, there were no significant differences between the study groups in the rates of non–procedure-related stroke, all stroke, and survival.

N Engl J Med 2016; 374:1011-1020

Mechanical Thrombectomy in Ischemic Strokes; the MR CLEAN trial

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.