Abstract Details

Title Revascularization Risk in Symptomatic Versus Asymptomatic Patients - Relative Versus Absolute Risk: The Carotid Revascularization Endarterectomy Versus Stenting Trial (CREST)

Topic Cerebrovascular Disease and Interventional Neurology

Presentation(s) S22 - (-)

Poster/Presentation
Number 001

Objective

Background Carotid revascularization was addressed by NASCET and ACAS. NASCET showed a 2-year stroke and death of 32.3% in medical patients and a 15.8% incidence in surgical patients (16.5% absolute/51% relative reduction). Similarly, ACAS revealed an 11% 5-year risk in medical patients and 5.1% in surgical patients (5.9% absolute reduction/53% relative reduction). Absolute risk (rather than relative risk) reduction is of prime interest to the patient. However, in these studies, treatment efficacy was assessed on a relative basis, and these procedures were equally efficacious (51% vs. 53% relative risk). The higher event rates in the symptomatic patients resulted in a larger absolute risk reduction in NASCET (16.5% vs. 5.9%). CREST is the only carotid revascularization study to include both symptomatic and asymptomatic patients undergoing CEA or carotid artery stenting (CAS), and we looked at absolute and relative risks associated with both procedures.

Design/Methods Treatment differences in CREST by symptomatic status were reviewed and interaction terms analyzed.

Results Symptomatic periprocedural stroke and death rates were 6% for CAS vs. 3.2% for CEA (2.8% absolute/47% relative difference/p = 0.02), and were 2.5% for CAS vs. 1.4% for CEA (1.2% absolute/53% relative difference/p = 0.15) for asymptomatic. While treatment differences in periprocedural rates were significant for symptomatic but not asymptomatic patients, there was no difference in treatment efficacy as determined by relative risk reduction. Even the most prominent interaction terms were clearly not significant, p > 0.38.

Conclusions There is no evidence of a CAS-CEA difference in treatment efficacy by symptomatic status in CREST. There are significant findings in symptomatic patients. This is likely a product of an increased background rate of events in this strata. While symptomatic status can identify a subgroup with an increased background rate, other factors (e.g. age or stenosis) could identify subgroups of asymptomatic patients with high event rates and large absolute treatment differences.

Authors/Disclosures
PRESENTER	No disclosure on file
	No disclosure on file
James F. Meschia, MD, FAAN (Mayo Clinic)	The institution of Dr. Meschia has received research support from NINDS. The institution of Dr. Meschia has received research support from NINDS.
Brajesh K. Lal (University of Maryland)	Brajesh K. Lal has nothing to disclose.
Alice J. Sheffet, PhD (CREST Administrative CenterRutgers, the State University of New Jersey)	No disclosure on file
	No disclosure on file
Virginia J. Howard, PhD (University of Alabama At Birmingham)	The institution of Dr. Howard has received research support from NIH. The institution of an immediate family member of Dr. Howard has received research support from NIH.
George Howard, PhD (UAB School of Public Hlth)	Dr. Howard has received personal compensation in the range of $10,000-$49,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Bayer.
Thomas G. Brott, MD, FAAN (Mayo Clinic)	Dr. Brott has nothing to disclose.

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