It’s Time to Cover Endovascular Treatment of Asymptomatic Carotid Artery Stenosis

Current evidence supports Centers for Medicare & Medicaid Services (CMS) reimbursement for endovascular treatment of asymptomatic carotid artery stenosis in appropriate patients if it can be regulated through standardized training, data collection and reporting. So contends a multicenter group of cardiovascular clinicians in a recent review in the Journal of the American College of Cardiology featured as a “JACC review topic of the week.”

“Carotid artery stenting in asymptomatic patients is probably the most extensively studied vascular procedure that has not yet gained coverage status in the United States,” says review co-author Sean Lyden, MD, Chair of Vascular Surgery at Cleveland Clinic. “Over the past several years, significant new data have emerged on endovascular therapy in this population. We developed this review to summarize the state of carotid artery stenting in this setting and offer recommendations on next steps for its application and coverage in patient care.”

How to ensure appropriate use

The authors supplement their coverage recommendation by suggesting three methods of ensuring that carotid artery stenting (CAS) is appropriately provided to asymptomatic patients by a properly prepared workforce:

• Linking reimbursement to experience and outcomes, with specification of minimum standards for training and ongoing volumes to help ensure quality outcomes.
• Outcomes adjudication and establishment of a carotid team to standardize results reporting. The authors propose a Centers of Excellence model that involves routine audits of cases and penalties for failure to meet minimum standards.
• Creation of a mandatory and monitored CAS registry for documentation of patients, operators and sites along with pertinent patient-specific data such as NIH Stroke Scale results, history and physical exam details, etc. The authors note that their proposed Centers of Excellence model would help facilitate such a registry.

“Participation in such a registry could be linked to reimbursement, much like what is now done for coronary artery bypass grafting and other procedures,” observes Dr. Lyden.

Key points behind the endorsement

The authors support their endorsement with a review of the evolution of CAS in recent years. Points they touch upon include the following:

• Asymptomatic carotid artery stenosis represents a rare exception to the decades-long trend of an embrace of percutaneous/endovascular therapies for vascular disease by regulators and payers.
• Despite the above point, two randomized controlled trials — the Carotid Revascularization Endarterectomy vs. Stenting Trial (CREST) and the Asymptomatic Carotid Trial I (ACT I) — have now shown CAS and carotid endarterectomy (CEA) to be equivalent approaches when performed by expert operators and when patient fitness and anatomy are accounted for. Cumulative registry data further support the equivalence of the two modalities.
• Lingering questions about whether revascularization is beneficial in the setting of asymptomatic internal carotid artery stenosis should not be conflated with the issue of which revascularization modalities (CEA vs. CAS) may be used for revascularization in this setting. The authors note that the value of revascularization in asymptomatic patients is being assessed in the ongoing CREST-2 trial; in the meantime, both revascularization methods should be available when a revascularization strategy is chosen in this population.
• Improvements in endovascular therapy for carotid artery stenosis have continued even in the absence of reimbursement. These include the introduction of embolic protection methods to further lower the risk of periprocedural stroke and advancements in carotid stent design, such as closed-cell stents and greater attention to the local carotid environment.
• Registry data indicate that results for CAS continue to improve, which the authors say is likely due in large part to better case selection and growing operator experience.

All about options

“Asymptomatic internal carotid artery stenosis is likely to loom ever larger as a contributor to stroke as the U.S. population continues to age,” notes Cleveland Clinic interventional cardiologist Christopher Bajzer, MD, who was not involved in writing the JACC review. “These authors are to be commended for endorsing CMS coverage of carotid artery stenting as an additional option we can turn to in appropriate cases of significant asymptomatic stenosis. As the tools for stenting in this setting continue to become safer, limiting access to these tools becomes less defensible.”

The full review is available here.