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
J. E. Castaldo, J. J. Nelson, J. F. Reed 3rd, J. E. Longenecker and J. F. Toole
Department of Medicine, Lehigh Valley Hospital, Allentown, Pa., USA.
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.
