Carotid artery stenting with embolic protection (CAS) is non-inferior to carotid endarterectomy (CEA) in patients with severe carotid artery stenosis, according to new data presented at the 2016 International Stroke Conference in Los Angeles, CA.

Two clinical trials—ACT I (Asymptomatic Carotid Trial) and CREST (Carotid Revascularization Endarterectomy vs Stenting Trial)—were designed to examine effects of the same 2 procedures. ACT I focused only on asymptomatic patients while CREST included both asymptomatic and symptomatic patients over a 10-year follow-up period.

ACT I initially planned to enroll 1658 participants, but was halted due to slow enrollment, with a total of 1453 patients randomly assigned to receive either CAS or CEA. Patients were ≤80 years of age with severe carotid stenosis who were not considered high risk for surgery and had not experienced stroke or transient ischemic attack 180 days prior to the procedure.1


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The primary composite outcome was death, stroke, and myocardial infarction within 30 days plus ipsilateral stroke within 1 year. CAS and CEA results were non-inferior (3.8% vs 3.4%; P=.011 for non-inferiority) to one another. Death and 30-day stroke rates were 2.9% with CAS compared to 1.7% with CEA (P=.33). CAS had a 97.8% rate of freedom from any stroke and CEA had a 97.3% rate from 30 days to 5 years (P=.51). The overall survival rate was 87.1% for CAS and 89.4% for CEA (P=.21).

In subsequent analyses, there were no significant differences recorded in nonprocedural stroke, all stroke, and survival up to 5 years of follow-up.

Meanwhile, CREST investigators followed 2502 patients who were considered “conventional risk” for surgery at 116 centers in the US and Canada over a median follow-up period of 7.2 years. The primary end point was similar to the end point from ACT I—stroke (including all periprocedural strokes and subsequent ipsilateral strokes), myocardial infarction, or death from any cause during the periprocedural period or ipsliateral stroke thereafter. Original study protocol was altered to evaluate differences in treatment between CEA and CAS over 10 years. Therefore, the long-term primary end point was ipsilateral stroke after 36 days post-randomization, up to 10 years.2

In the CAS group, 42 (6.9%) total strokes occurred (hazard ratio [HR]: 0.64-1.52; 95% confidence interval [CI]: 4.4-9.7; P=.96) compared to 41 (5.6%) in the CEA group (95% CI: 3.7-7.6). Number of events were almost exact between asymptomatic and symptomatic patients. During the perioprocedural period plus 10 year follow-up, 108 (11.8%) strokes occurred in the CAS group (HR: 1.10; 95% CI: 9.1-14.8; P=.51) compared to 97 (9.9%) in the CEA group (95% CI: 7.9-12.2).

Composite stroke and death constituted for 98 (11.0%) events in the CAS group (HR: 1.37; 95% CI: 8.5-13.9; P=.04)) and 71 (7.9%) events in the CEA group (95% CI: 5.9-10.0).

“Postprocedural rates of stroke for stenting or surgery are similar and less than 0.7% annually for symptomatic and asymptomatic patients,” researchers concluded. “In contrast to previous trials, symptomatic status was not a predictor of postprocedural outcomes.”

In a secondary analysis, CREST investigators found that the risk of periprocedural stroke and death, and subsequent ipsilateral stroke, was 37% higher in the CAS group than in the CEA group, but the advantage for CAS was “primarily due to perioprocedural differences.”

Disclosures: Several authors disclosed receiving grants, advisory board and/or consulting fees from various pharmaceutical companies, including Abbott Vascular, which funded the ACT I study.

More ISC 2016 coverage here.

References

  1. Rosenfield K, Matsumura JS, Chaturvedi S, et al; on behalf of the ACT I Investigators. LB 25. Randomized trial of stent vs surgery for asymptomatic carotid stenosis: initial and five-year results of the ACT I trial. Presented at the 2016 International Stroke Conference; February 17-19, 2016; Los Angeles, CA.
  2. Brott TG, Roubin GS, Mackey A, et al. LB 10. Cartoid endartectomy vs stenting for treatment of carotid artery stenosis: long-term results of the carotid revascularization endarterectomy vs stenting trial (CREST). Presented at the 2016 International Stroke Conference; February 17-19, 2016; Los Angeles, CA.