Outcome of nonoperative management of asymptomatic high-grade carotid stenosis.

Purpose: The purpose of this study was to determine the outcome of nonoperative management (NOM) of asymptomatic high-grade (80% to 99%) carotid stenosis.

Methods: From April 1994 to December 2000, asymptomatic high-grade (80% to 99%) carotid stenosis was identified in 196 carotid arteries in 180 male veterans. Of the original number identified, 137 carotid endarterectomies (CEs) were performed in 123 patients (OP group) and 59 carotid arteries in 57 patients were managed nonoperatively (NOM group.) The NOM group was further subdivided into those patients who refused care (NOM-R group; n = 21; 36.8%) versus those who were not offered CE on the basis of comorbid conditions (NOM-C group; n = 36; 63.2%). Clinical follow-up was obtained to determine rates of neurologic events, patient survival, and progression to occlusion.

Results: During the follow-up period, a total of 13 ipsilateral neurologic events occurred: two amaurosis fugax (15.4%), two transient ischemic attacks (15.4%), and nine strokes (69.2%). The NOM-R group had a significantly lower ipsilateral neurologic event-free rate when compared with the OP group at both 18 months (81% +/- 9.8% versus 96% +/- 1.8%; P <.02) and 2 years (81% +/- 10.6% versus 95% +/- 2.1%; P <.04.) However, the NOM-C group and the OP group had no significant difference in their ipsilateral neurologic event-free rate out to 3 years (96% +/- 6.8% versus 95% +/- 2.7%). As would be expected, the NOM-C group had a much lower patient survival rate when compared with either the OP group (59% +/- 9.2% versus 84% +/- 3.6% at 2 years; P <.002) or the NOM-R group (59% +/- 9.2% versus 100% at 2 years; p <.0001). The cumulative patency rate of carotid arteries in the NOM group was 86% +/- 7.6% at 3 years. Progression to occlusion was associated with a neurologic event in two of five occurrences. No carotid artery progressed to occlusion in the OP froup.

Conclusion: Although CE is the preferred treatment for asymptomatic high-grade carotid stenosis, NOM is an acceptable alternative in selected patients at high risk with diminished life expectancy.