RR4. Clinical Course of Asymptomatic Patients with Carotid Duplex Scan End-Diastolic Velocities of 100 - 124 cm/second

Abstract

With the decline of diagnostic angiography, clinicians often rely upon Duplex criteria to select asymptomatic patients for carotid intervention. Recent trials have enrolled patients based upon end diastolic velocities (EDV) as low as 100 cm/sec, and peak systolic velocities (PSV) as low as 230 cm/sec. In as much as we have used more stringent criteria, we reviewed the course of asymptomatic patients with EDV's from 100-124 cm/sec. Of patients scanned in our ICAVL accredited laboratory from 2002-2007, 143 had an EDV 100-124 cm/sec. Some underwent initial carotid intervention for concomitant symptoms (10), contralateral occlusion (3), or other imaging findings felt to warrant intervention (34). The remaining 96 patients (97 arteries) were followed. Mean follow-up was 31.4 months (range 2-137). Six patients (6.3%) developed ipsilateral symptoms consisting of 3 strokes and 3 TIA's, at a mean of 29.6 months (range 6-58). Twenty patients (20.8%), including two that developed symptoms, progressed to an EDV of >125 cm/sec at a mean of 23 months (range 4-127). Three of these (3.1%) progressed directly to occlusion with no documented interim worsening of stenosis. Survival analysis revealed that freedom from TIA or stroke was 98.7%, 97.1% and 94.7%, while freedom from stenosis progression was 89.5%, 74.2%, and 74.2% at 12, 24, and 36 months respectively. A total of 32 patients (33.3%) eventually underwent carotid intervention for the onset of symptoms (n=7, 7.3%), progression to >125 EDV (n=14, 14.6%), or for other imaging findings (n=11, 11.5%). The mean interval to intervention was 23.9 months (range 3-137). For asymptomatic patients with an EDV of 100-124 cm/sec, the risk of ipsilateral stroke is small and conservative management is appropriate in most cases. However, the risk of progression to a more severe degree of stenosis, often warranting carotid intervention within 2 years, is clinically meaningful. Yearly Duplex follow-up is necessary to assess disease progression in this cohort.Tabled 112 Months24 Months36 MonthsFreedom from ipsilateral stroke100%100%97.1%Freedom from TIA or stroke98.7%97.1%94.7%Freedom from progression to EDV > 125 cm/sec89.5%74.2%74.2% Open table in a new tab