ACT I: Stenting noninferior to endarterectomy for asymptomatic carotid stenosis

In asymptomatic, nonoctogenarian patients with significant carotid stenosis at standard surgical and anatomic risk, carotid artery stenting with embolic protection was noninferior to carotid endarterectomy for the primary endpoint of death, stroke or MI within 30 days and ipsilateral stroke at 1 year. In longer-term analyses, stenting and endarterectomy were associated with similar rates of death and stroke at 5 years, according to data presented at the International Stroke Conference.

The ACT I trial had a goal enrollment of 1,658, but the study was halted early due to slow enrollment after 1,453 patients at 62 U.S. sites were enrolled from 2005 to 2013. Enrolled patients were aged 79 years and younger, had severe carotid stenosis and were asymptomatic. Patients were randomly assigned 3:1 to carotid artery stenting with embolic protection (Xact Carotid Stent System and Emboshield Protection Device, Abbott Vascular; n = 1,089) or carotid endarterectomy (n = 364) and followed for 5 years. All patients also received intensive risk-factor control, Lawrence R. Wechsler, MD, chair of the department of neurology at the University of Pittsburgh Medical Center, said during a press conference.

The primary composite endpoint was death, stroke or MI within 30 days after the procedure or ipsilateral stroke within 1 year (prespecified noninferiority margin: one-sided upper limit of 95% CI for difference in event rates 3%).

The rate of the primary composite endpoint was 3.8% with stenting vs. 3.4% with endarterectomy (P = .01 for noninferiority). The rate of stroke or death within 30 days was 2.9% in the stent group vs. 1.7% in the endarterectomy group (P = .33). The rate of freedom from ipsilateral stroke from 30 days to 5 years was 97.8% in the stent group vs. 97.3% in the endarterectomy group (P = .51). The rate of overall survival was in the stent group vs. 89.4% in the endarterectomy group (P = .21) and cumulative rate of 4-year stroke survival was 93.1% vs. 94.7%, respectively (P = .44).

The results were simultaneously published in The New England Journal of Medicine.

“Our study showed that carotid artery stenting is just as safe and just as effective in treating asymptomatic patients as carotid endarterectomy, which has been the standard treatment approach for patients who are not at high risk for open surgery,” Kenneth Rosenfield, MD, MHCDS, head of vascular medicine and intervention in the division of cardiology at Massachusetts General Hospital and Cardiology Today’s Intervention Editorial Board member, said in a press release.

Although treatment of carotid stenosis with medication alone has been an accepted practice, more research is needed to evaluate whether eliminating carotid stenosis in asymptomatic patients is still necessary, according to the researchers.

“We really do not know if patients with severe asymptomatic carotid artery stenosis can be safely treated with medications only. That is the outstanding remaining critical question,” Michael R. Jaff, DO, professor of medicine at Harvard Medical School, the Paul and Phyllis Fireman Endowed Chair in Vascular Medicine and medical director of the Fireman Vascular Center at Massachusetts General Hospital, stated in the release. Jaff is also a member of the Cardiology Today and Cardiology Today’s Intervention Editorial Boards.

The CREST 2 trial will address the question surrounding the benefit of revascularization vs. medical therapy in asymptomatic carotid stenosis with modern medical management, Wechsler said during the press conference. – by Tracey Romero

References :

Wechsler L. LB 25. Presented at: International Stroke Conference; Feb. 16-19, 2016; Los Angeles.

Rosenfield K, et al. N Engl J Med. 2016;doi:10.1056/NEJMoa1515706.

Disclosure: The study was funded by Abbott Vascular. Jaff reports personal fees from Cardinal Health, the Intersocietal Accreditation Commission and VIVA Physicians, non-financial support from Abbott Vascular, Boston Scientific, Cordis Corporation, Medtronic Vascular, and other support from Primacea outside the submitted work. Rosenfield reports receiving grant support and personal fees from Abbott Vascular during the conduct of this study. Wechsler is on the ACT I steering committee and on the scientific advisory board for Silk Road Medical.