Evaluation of a CTA-Triage Based Transient Ischemic Attack Service: A Retrospective Single Center Cohort Study

Objective: We designed a computed tomography angiography (CTA)-based algorithm for patients presenting to hospital with a transient ischemic attack (TIA) which identified high-risk patients, as well as inpatient versus semiurgent outpatient management following MRI, and we hypothesised that this would be effective.

Methods: Patients seen in the ED at the Royal Adelaide Hospital from March 3, 2012 to November 30, 2016 with TIA-like symptoms were assessed for a cardioembolic source (clinical assessment, electrocardiogram) and underwent intra and extracranial CTA. Patients with a referable >50% stenosis were admitted and given dual antiplatelets. Most high-risk cardiac source patients were also admitted and anticoagulated. Other patients were loaded with aspirin, or changed to clopidogrel if on aspirin, and reviewed as outpatients following semiurgent MRI (3-4 days). We assessed the 90-day recurrent stroke risk in this cohort as a whole, and in those with a final cerebrovascular diagnosis.

Results: 1167 patients were diagnosed in Emergency as TIA and referred via our algorithm. A total of 150 were admitted, 78 had "high-risk" features. A total of 1017 patients were reviewed in the TIA clinic. The average age of the total cohort was 65.8 years old. Final diagnosis was TIA/minor stroke in 69% admitted patients and 30% clinic patients (P value < .0001). The 90-day recurrent stroke risk in these patients was 2.0% (5.8% admitted vs .7% clinic patients, P value < .0001). In those with noncerebrovascular diagnoses, there were no recurrent strokes within 90 days.

Conclusions: Stroke risk is very low using CTA guided semiurgent clinic review algorithm.