Stenting and endarterectomy have similar outcomes in asymptomatic patients with severe carotid stenosis

During a five-year follow-up period, asymptomatic patients with severe carotid stenosis had similar rates of stroke and survival whether they underwent carotid artery stenting with embolic protection or carotid endarterectomy.

The prospective, multicenter trial also found stenting was noninferior to endarterectomy with regard to the primary composite end point of death, stroke, or myocardial infarction within 30 days after the procedure or ipsilateral stroke within 1 year. All patients in the trial were not considered to be at high risk for surgical complications.

Study author Lawrence R. Wechsler, MD, of Massachusetts General Hospital in Boston, presented the results in a plenary session at the American Stroke Association’s (ASA) International Stroke Conference on Feb. 17. The findings were simultaneously published online in the New England Journal of Medicine. Abbott Vascular provided funding for the study.

In this study, known as ACT (Asymptomatic Carotid Trial) I, the researchers enrolled 1,453 patients between March 30, 2005, and Jan. 18, 2013. The patients were 79 years old or younger, had bifurcation carotid stenosis of 70 percent to 99 percent of the diameter of the artery and had no strokes, transient ischemic attacks or amaurosis fugax within 180 days of the study.

Patients were randomized in a 3:1 ratio to undergo stenting with the Xact device (Abbott Vascular) with distal embolic protection or carotid endarterectomy. They all received 325 mg of aspirin daily starting three days before the procedure, while patients in the stenting group received clopidogrel daily for three days before and 30 days after the procedure.

The groups were well balanced. The mean age was 68, while 40.5 percent of patients in the stenting group and 44.5 percent of patients in the endarterectomy group had contralateral stenosis.

At one year, the primary end point of death, stroke and MI within 30 days and ipsilateral stroke within 365 days was found in 3.8 percent of patients in the stenting group and 3.4 percent of patients in the endarterectomy group.

At 30 days, 0.6 percent of patients had died or had a major stroke. The 30-day rate of death of any stroke was 2.9 percent in the stenting group and 1.7 percent in the endarterectomy group because the rate of minor stroke was higher in the stenting group.

At five years, the estimated survival rate was 87.1 percent in the stenting group and 89.4 percent in the endarterectomy group. In addition, at five years, the rate of freedom from non–procedure-related ipsilateral stroke was 97.8 percent in the stenting group and 97.3 percent in the endarterectomy group, while the rate of freedom from any stroke was 93.1 percent and 94.7 percent, respectively.

The researchers noted a limitation of the study was that they did not include a treatment group that received contemporary medical therapy. They noted that certain patients with neurologic symptoms may have a reduced stroke risk if they take new treatments. In addition, they mentioned that enrollment lasted more than eight years and that they stopped the study early because of slow enrollment.

Wechsler said at a news conference at the ASA meeting that “there is a remaining question of whether either of these revascular procedusures in the current environment of aggressive medical therapy are better than medical therapy alone.” He noted that the ongoing CREST-2 trials are comparing endarterectomy with medical therapy and stenting with medical therapy.