Carotid endarterectomy should not be based on consensus statement duplex velocity criteria

Area of Science:

• Vascular Surgery
• Neurology
• Diagnostic Imaging

Background:

• Randomized trials support carotid endarterectomy (CEA) for asymptomatic patients with ≥60% internal carotid artery (ICA) stenosis.
• The Society for Radiologists in Ultrasound Consensus Statement suggests ICA peak systolic velocity (PSV) ≥230 cm/s indicates ≥70% stenosis, potentially recommending CEA.

Purpose of the Study:

• To evaluate the natural history stroke risk in asymptomatic patients with ICA stenosis (PSV ≥230 cm/s) treated medically based on conservative carotid duplex ultrasound (CDUS) criteria.
• To determine if current consensus statement thresholds for CEA are appropriate.

Main Methods:

• Retrospective review of asymptomatic patients undergoing CDUS in 2009 with ICA PSV ≥230 cm/s but <430 cm/s (or other conservative criteria for ≥80% stenosis).
• Follow-up assessed freedom from transient ischemic attack (TIA), stroke, carotid-etiology stroke, and revascularization.

Main Results:

• 327 patients were reviewed with a mean follow-up of 4.3 years.
• Actuarial freedom from carotid-etiology stroke was 98.4% at 5 years.
• Freedom from any stroke was 93%, TIA was 95%, and revascularization was 81% at 5 years. Four strokes were potentially attributable to the index carotid artery.

Conclusions:

• Asymptomatic patients with intermediate carotid stenosis (ICA PSV 230-429 cm/s) have favorable outcomes with medical therapy and conservative monitoring.
• Current consensus velocity thresholds may lead to unnecessary CEA in a significant number of patients.
• Re-evaluation of current velocity threshold recommendations is warranted, impacting future clinical trials.