New findings from CREST-2 are providing important evidence on the role of carotid artery stenting (CAS) in patients with severe asymptomatic carotid stenosis — while underscoring the importance of operator experience, patient selection and procedural technique in achieving favorable outcomes.
Guilherme Dabus, M.D., co-director of interventional neuroradiology at Baptist Health Miami Neuroscience Institute, recently discussed the findings at the ESMINT Congress in Marseille, France, where neurointerventional specialists gathered to share research, complex cases and advances in care. His presentation — “CREST-2: Reasons Behind the Success of Carotid Angioplasty and Stenting” — examined the factors that contributed to the outcomes seen in the stenting arm of the trial.
“The results are important, but so is understanding how those results were achieved,” Dr. Dabus said. “CREST-2 involved experienced operators, careful patient selection and a disciplined approach to carotid stenting.”
Reassessing Revascularization in the Era of Intensive Medical Therapy
CREST-2 was designed to address a central question in the management of asymptomatic carotid stenosis: Does revascularization continue to provide additional stroke protection when patients receive contemporary intensive medical therapy?
The study included two parallel randomized trials involving patients with at least 70 percent asymptomatic carotid stenosis. All participants received intensive medical management targeting systolic blood pressure below 130 mm Hg; LDL cholesterol below 70 mg/dL; and control of glycemia, smoking, weight and physical activity. One trial compared CAS plus intensive medical management with medical management alone, while the other compared carotid endarterectomy plus intensive medical management with medical management alone.
At four years, the primary outcome occurred in 2.8 percent of patients assigned to stenting plus medical therapy compared with 6.0 percent receiving medical therapy alone. In the endarterectomy trial, the corresponding rates were 3.7 percent and 5.3 percent, a difference that did not reach statistical significance.
For Dr. Dabus, the findings should be interpreted in the context of how the procedures were performed.
“CREST-2 should not be viewed simply as evidence that every patient with severe asymptomatic carotid stenosis should undergo stenting,” Dr. Dabus. “The trial shows what can be achieved when the right patients are treated by appropriately trained operators using a standardized technique.”
Operator Experience and Case Selection Matter
The CREST-2 credentialing process was highly selective. Operators were required to submit 25 consecutive recent cases, including angiograms and clinical documentation. Only 9 percent were approved on the first review, and 46 percent were ultimately approved after subsequent review. Among those who were approved, the median lifetime carotid stenting experience was 211.5 cases.
Recent procedural volume also proved important. Case rate was the only factor associated with approval at first review, while operator specialty did not affect primary approval.
“The lesson is that specialty alone does not determine proficiency,” Dr. Dabus said. “What matters is training, recent experience, appropriate case selection and consistent application of the technical principles that make the procedure safe.”
Patient and lesion selection were equally important. Anatomy discouraged or excluded in the trial included type III and some type II aortic arches, significant arch or great-vessel atherosclerosis, marked carotid tortuosity, heavy or circumferential calcification, long or noncontiguous lesions and advanced age in the setting of unfavorable anatomy.
Dr. Dabus describes this as the “discipline of saying no.”
“Good patient selection is not simply identifying who can undergo carotid stenting,” he said. “It is recognizing when the anatomy increases procedural risk and another management strategy may be more appropriate.”
Technique Was Standardized, Not Left to Preference
CREST-2 also tightly defined how carotid stenting was performed.
The protocol incorporated dual antiplatelet therapy, preprocedural statin therapy and required embolic protection. Operators were encouraged to limit angiographic runs and catheter manipulation, avoid aggressive post-dilatation and minimize embolic protection device dwell time. Local anesthesia was used in most registry procedures.
These procedural details reflect a broader evolution in CAS. As Dr. Dabus highlighted, outcomes have improved over time alongside greater operator experience, better patient selection and advances in technology.
“Successful carotid stenting is not about one device or one maneuver,” he said. “It is the cumulative effect of preparation, embolic protection, limiting unnecessary manipulation and performing the procedure with a consistent technique.”
Applying CREST-2 to Clinical Practice
For physicians managing patients with asymptomatic carotid stenosis, CREST-2 adds important evidence to an increasingly individualized treatment pathway.
Intensive medical therapy remains foundational. At the same time, the stenting arm demonstrates that appropriately performed revascularization can provide additional stroke protection in selected patients with severe asymptomatic disease.
Dr. Dabus also emphasized several limitations. Revascularization was performed only by well-trained, certified and higher-volume operators, making generalizability an important consideration. The statistical margin of benefit in the stenting trial was relatively narrow, medical therapy continued to evolve during the study and trans-carotid artery revascularization was not incorporated. Therefore, CREST-2 reflects transfemoral carotid artery stenting rather than all contemporary carotid revascularization strategies.
“CREST-2 gives us valuable evidence, but it does not eliminate the need for individualized decision-making,” Dr. Dabus said. “The question is not simply medical therapy, surgery or stenting. It is which strategy offers the best balance of risk and benefit for the individual patient based on the clinical picture, anatomy and expertise available.”
For physicians evaluating patients with carotid stenosis or other complex cerebrovascular conditions, multidisciplinary assessment can help determine the most appropriate treatment pathway. Learn more about Baptist Health Brain & Spine Care.
