EVIDENCE-BASED ANSWER
There is no compelling evidence that outpatient diagnostic workup of patients with transient ischemic attack (TIA) is less safe than inpatient workup, or that hospitalization prevents stroke or improves stroke outcomes after TIA (strength of recommendation [SOR]: C, based on case series studies). Because the risk of stroke is substantial in the week following a TIA (SOR: A, based on a prospective cohort study), evaluation and treatment for reversible stroke risk factors should be initiated urgently and completed within a week of initial presentation (SOR: C, based on expert consensus opinion).
Risk factors for patients at highest risk for stroke or other cardiovascular events after TIA include age >60 years, diabetes, TIA lasting longer than 10 minutes, and a TIA associated with weakness or speech impairment (SOR: B, based on retrospective cohort study). Hospitalization may be prudent for patients at high risk for cardiovascular events or for those with mental status changes, an inadequate home situation, or the physician’s inability to obtain expedient evaluation (SOR: C, based on case series studies).
Evidence summary
Transient ischemic attack (Figure) is a temporary, focal brain or retinal deficit caused by vascular disease that clears completely in less than 24 hours.1 A large prospective cohort study recently estimated the risk of stroke after a TIA or minor stroke to be 8% to 12% at 7 days and 11% to 15% at 1 month.2
In a large retrospective cohort study, 5% of TIA patients returned to the emergency department with a stroke within the first 2 days after TIA.3 Another 6% returned with a stroke within 90 days. Five independent risk factors were identified: age >60 years, diabetes mellitus, duration of TIA longer than 10 minutes, signs or symptoms of weakness, and speech impairment. Thirty-four percent of patients with all 5 risk factors, and none of the patients without any risk factors, had a stroke within 90 days. Of note, 13% of the TIA patients had an arrhythmia, congestive heart failure, unstable angina, myocardial infarction, stroke, or recurrent TIA within 4 days of initial presenting with a TIA. Twenty-five percent of the patients experienced 1 of these cardiovascular events during the 3 months of follow-up.
In a retrospective case review of TIA and stroke patients, the hospital admissions of 4 of 21 TIA patients were retrospectively categorized as medically justified.4 Admission was categorized as medically justified if the patient had 1 or more of the following criteria: another diagnosis that warranted admission, inadequate home situation, altered mental status, an adverse event during hospitalization including worsening of the deficit, and if the patient underwent some hospital-based treatment that could not be provided on an out-patient basis. Ease and rapidity of evaluation was not considered medically justifiable and outcome improvement (stroke prevention) was not studied.