Carotid/Vertebral Artery Stenosis

The change in practice is not supported by the clinical outcomes of the trial, researchers of new study say.

Patients over 70 years of age, including symptomatic women, are more likely to receive carotid artery stenting than endarterectomy since the release of the CREST trial data, according to a recent US database analysis published online December 4, 2017, ahead of print in JAMA Neurology. This is despite the fact that CREST actually revealed a higher rate of complications with stenting in older patients.

The trend runs “contrary to expectations,” say investigators led by Fadar Oliver Otite, MD (University of Miami Miller School of Medicine, Miami, FL). Otite and his co-authors used the 2007-2014 National Inpatient Sample to identify all 494,733 weighted carotid revascularization admissions that occurred in adults older than 70 years, based on International Classification of Disease, Ninth Revision procedural codes.

Overall, 41.8% of the patients were women, and their mean age at presentation was 78.1. A minority of stenting and endarterectomy cases (16.3% and 10.1%, respectively) were performed in patients with symptomatic stenosis. The proportion of patients older than 70 who received stents increased from 11.9% pre-CREST to 13.8% in the post-CREST era (P = 0.005).

Multivariate analysis revealed that the odds of receiving stenting was increased by a relative 13% (95% CI 1.00-1.28, P = 0.04) following the release of the CREST data in 2010. This was true for the overall group of patients as well as for symptomatic women and patients with symptomatic stenosis. The presence of symptomatic stenosis, congestive heart failure, and peripheral vascular disease were all associated with a greater likelihood of stenting, while comorbid hypertension, smoking, and weekend admission were associated with lower odds of stenting.

Factors Linked to Likelihood of Carotid Artery Stenting Following CREST

The authors suggest multiple reasons as to why patients are more likely to receive carotid artery stenting in the post-CREST era. These include differing interpretations of CREST, not all of which take into account the differences in outcomes based on patient features such as age and sex; results of the SAPPHIRE trial, which found stenting to be noninferior to endarterectomy in older, high-risk patients; and improvements in stenting technology that may mitigate the poststent stroke risk.

“Existing referral systems for carotid revascularizations and subspecialty of physicians performing these procedures may also be influencing revascularization patterns,” they add.

Changes Inconsistent With Available Evidence

Otite and colleagues acknowledge that their results showing increased use of stenting among patients over 70 years of age “are inconsistent with the results of CREST and suggest possible slow and incomplete incorporation of the trial results into clinical practice owing to interplay of a variety of factors.”

What the findings hint at, according to editorialist James F. Meschia, MD (Mayo Clinic, Jacksonville, FL), is “that surgeons and interventionists alike are focusing their energies on treating symptomatic rather than asymptomatic stenosis. This is, of course, immanently reasonable.” Specifically, Otite et al found that number of revascularizations per million hospitalizations decreased pre- versus post-CREST, but at the same time, the “proportion of revascularizations done for symptomatic stenosis increased significantly by 55%,” Meschia points out.

Yet the researchers also “showed that despite apparent diminishing enthusiasm for revascularizing in asymptomatic stenosis, most revascularizations are still done in patients with asymptomatic stenosis,” he adds. Meschia predicts the CREST-2 trial will help resolve the issue of the relatives benefits of revascularization versus intensive medical therapy.

What is more concerning is the increase in use of stenting among patients for whom the risks have been shown to outweigh the benefits. Similar to the study authors, Meschia speculates that “it is possible that the unexpected apparent enthusiasm for stenting in individuals older than 70 years relates to a perception among stent operators of a lower risk of periprocedural stroke with an evolving technology.”

“One possible interpretation of [National Inpatient Sample] trends,” he adds, “is that the results of CREST initially changed practice by slowing a rise rather than initiating a fall in the proportion of older patients receiving stenting.”

Ultimately, he concluded, the study “reminds us of the importance of observational studies of trends in procedural practice.”

 
Sources:

• Otite FO, Khandelwal P, Malik AM, et al. National patterns of carotid revascularization before and after the Carotid Revascularization Endarterectomy vs Stenting Trial (CREST). JAMA Neurol. 2017;Epub ahead of print. 
• Meschia JF. Informing vs changing the practice of carotid revascularization. JAMA Neurol. 2017;Epub ahead of print.

Disclosures:

• Otite reports no relevant conflicts of interest.
• Meschia reports receiving funding from the National Institute of Neurological Disorders and Stroke to perform his duties as co-principal investigator for the CREST-2 Clinical Coordinating Center.