The delay in reporting symptoms of carotid artery stenosis in an at-risk population. The Asymptomatic Carotid Atherosclerosis Study experience: a statement of concern regarding watchful waiting.

OBJECTIVE

To examine whether patients in the Asymptomatic Carotid Atherosclerosis Study reported symptoms of cerebral and retinal ischemia promptly to the investigating team.

DESIGN

Cohort study within the Asymptomatic Carotid Atherosclerosis Study, a prospective, randomized, multicenter clinical trial, with a median follow-up time of 2.7 years.

SETTING

Thirty-nine clinical sites across the United States and Canada.

PATIENTS: Patients with asymptomatic carotid artery stenosis (> or = 60% reduction in diameter) who experienced either a transient ischemic attack (TIA) (n = 115) or stroke (n = 127) during the follow-up period, as verified by an external committee.

MAIN OUTCOME MEASURE: Proportion of patients who reported cerebrovascular symptoms to a study nurse or physician within 3 days of occurrence.

RESULTS

Thirty-seven patients (32.2%) experiencing TIA and 57 (44.9%) experiencing stroke reported symptoms to the study staff within 3 days of onset. For TIA, there was a statistically significant inverse association between prompt reporting and the amount of time a patient was enrolled in the study before the event occurred (48% with TIA occurring within 6 months vs 9% with TIA after year 3; P = .04). For stroke, there was a statistically significant association between prompt reporting and treatment arm (56% for the surgical vs 38% for the medical group; P = .05). For either TIA or stroke, none of the other factors examined were significantly associated with prompt reporting.

CONCLUSIONS

Despite extensive education and reinforcement, fewer than 40% of all first events were reported within 3 days and fewer than 25% were reported in less than 24 hours. Frequent outpatient evaluation of high-risk patients and careful review of symptoms is necessary to determine when asymptomatic carotid artery stenosis has become symptomatic to offer appropriate forms of therapy.