Two new analyses from the CREST-2 trial deliver a clear verdict: carotid revascularization — whether via stenting or endarterectomy — does not improve cognitive function in patients with asymptomatic carotid artery stenosis. Published in JAMA, the studies found no meaningful differences in learning, attention, memory, or executive function between patients who underwent revascularization plus medical management versus medical management alone, even after up to 4 years of follow-up.

A hemodynamic substudy (CREST-H) dug deeper, using advanced MRI and CT perfusion imaging to assess whether impaired cerebral blood flow at baseline might predict who could benefit cognitively. The answer: still no. Patients with reduced cognition at baseline neither improved nor worsened — they simply stayed the same.

Key Takeaways:

• Clinicians should not counsel patients that cognition will improve after carotid revascularization for asymptomatic stenosis
• Stroke prevention remains the primary evidence-based benefit of the procedure
• Cerebral autoregulatory and collateral mechanisms may preserve cortical perfusion even in severe stenosis, explaining the lack of cognitive benefit

Why it matters: These findings put a long-debated question to rest. Many clinicians had hoped restoring blood flow might reverse cognitive decline — but CREST-2 shows that once cognitive damage from carotid disease sets in, surgery can't undo it. The takeaway for patient counseling is clear: revascularization is about preventing strokes, not improving cognition.