Clinical course of asymptomatic patients with carotid duplex scan end diastolic velocities of 100 to 124 centimeters per second

Objective With the decline of diagnostic angiography, clinicians increasingly rely upon duplex scan criteria to select appropriate asymptomatic candidates for carotid intervention. Some recent trials have enrolled patients for intervention based upon end diastolic velocities (EDVs) as low as 100 cm/second, and peak systolic velocities (PSVs) as low as 230 cm/second. In as much as we have used more selective duplex scan criteria, we reviewed the course of asymptomatic patients who had EDVs from 100 to 124 cm/second. Methods Of the patients evaluated in our Intersocietal Commission for the Accreditation of Vascular Laboratories (ICAVL) accredited laboratory from 2002 to 2007, 144 patients had an EDV 100 to 124 cm/second. Of these, 47 patients underwent initial carotid intervention for concomitant symptoms (10), contralateral occlusion (3), or other imaging findings felt to warrant intervention. The remaining 97 asymptomatic patients were followed. One patient had both arteries fall within this EDV range. The mean follow-up for the 98 arteries was 29.1 months (range, 2-116 months). Results Five patients (5.2%) developed ipsilateral symptoms consisting of one stroke and four transient ischemic attacks (TIAs), at a mean time of 35.3 months (range, 12-58 months). Twenty-six patients (26.8%), including 3 who also developed ipsilateral symptoms, progressed to having an EDV of ≥125 cm/second at a mean time of 24 months (range, 2-58). Two of these (2.1%) progressed directly to occlusion without symptoms and with no documented interim worsening of stenosis. Conclusion For asymptomatic individuals with an initial EDV of 100 to 124 cm/second, the risk of ipsilateral stroke is small and, therefore, medical management is appropriate in most cases. However, the risk of progression to a more severe degree of stenosis, often warranting carotid intervention, is clinically meaningful. Yearly duplex scan follow-up is necessary to assess disease progression in this patient cohort.