January 10, 2012
PROTECT Demonstrates Continued Improvement of CAS for High-Risk Patients
January 11, 2012—Jon S. Matsumura, MD, et al published findings from the PROTECT (Protected Carotid Artery Stenting in Patients at High Risk for Carotid Endarterectomy) study online ahead of print in the Journal of Vascular Surgery.
According to the investigators, PROTECT was performed to evaluate the safety and effectiveness of two devices used in carotid artery stenting (CAS) for the treatment of carotid artery stenosis in patients who are at high risk for carotid endarterectomy (CEA): the Emboshield Pro embolic protection device (Abbott Vascular, Santa Clara, CA) (using the periprocedural composite endpoint of 30-day death, stroke, and myocardial infarction [DSMI]) and the Xact carotid stent system (Abbott Vascular) in conjunction with an embolic protection device (EPD) (using the DSMI periprocedural composite endpoint plus ipsilateral stroke at up to 3 years for long-term evaluation).
As detailed in the Journal of Vascular Surgery, this prospective, multicenter clinical trial enrolled 220 consecutive participants between November 29, 2006, and January 14, 2008, followed by a second cohort of 102 participants between January 14, 2008, and June 18, 2008. Enrolled participants had carotid artery stenosis that was either symptomatic (> 50%) or asymptomatic (> 80%). The first 220 subjects underwent distal EPD placement with a new, large-diameter filter, and the second cohort of 102 patients underwent placement of an older EPD that is no longer manufactured.
All 322 participants were to be treated with the Xact device, a dedicated carotid stent with a tapered, small, closed-cell design, and were to be included in the long-term evaluation. Independent neurologic assessment was performed before CAS and at 1 day, 30 days, and annually after CAS. All primary endpoint events were independently adjudicated by a central committee.
The investigators found that the periprocedural composite endpoint of DSMI (95% confidence interval) in the first 220 participants was 2.3% (0.74%, 5.22%), with a combined death and stroke rate of 1.8% (0.5%, 4.59%) and a rate of death and major stroke of 0.5% (0.01%, 2.51%). As of January 3, 2011, the median follow-up for the entire 322-subject cohort for the long-term evaluation was 2.8 years. Freedom from the periprocedural composite of DSMI plus ipsilateral stroke thereafter was 95.4%, with an annualized ipsilateral stroke rate of 0.4%.
The PROTECT investigators concluded that CAS outcomes in patients who are at high risk for CEA have improved from earlier carotid stent trials and that PROTECT, with periprocedural rates of DSMI of 2.3%, death or stroke rate of 1.8%, and death or major stroke rate of 0.5%, demonstrated the lowest rates of periprocedural complications among other comparable single-arm CAS trials in patients at high risk for CEA.