Clinical characteristics and outcome of amaurosis fugax due to transient retinal ischemia: Results from a contemporary cohort

Background: Whether presenting an episode of amaurosis fugax (AFx) increases the risk of ischemic stroke is controversial and there is a lack of consensus in the following management. We aimed to describe the clinical characteristics and prognosis of patients with AFx due to suspected transient retinal ischemia.

Methods: Observational, retrospective study of patients admitted in a Comprehensive Stroke Center with diagnosis of AFx due to suspected transient retinal ischemia between 2015 and 2020. Clinical characteristics and diagnostic-therapeutic data were collected, as well as recurrences (new episodes of amaurosis and/or ischemic strokes). Multivariable Cox regression analyses were performed to study factors associated with the risk of recurrence.

Results: We included 91 patients with a mean age of 67.9±14.8 years, 43(47.3%) were women. After the diagnostic workup 14(15.4%) AFx were attributed to an atherothrombotic etiology, 4(4.4%) cardioembolic source, 10(11%) other determined cause (TOAST-OC) and 63(69,2%) indeterminate etiology. 71(78%) patients started antiplatelet therapy and 2(2.2%) anticoagulant therapy. After a median follow-up of 3.5 years (IQR 1.8-5.2), at least one recurrence was recorded in eight (8.8%) patients (four new AFx and four cerebral infarctions). TOAST-OC (HR=9.66, 95% CI 2.41-38.70; p=0.001) and prior history of ischemic stroke (HR=4.21. 95% CI 1.01-17.66; p=0.049) were both independently associated with the risk of recurrence.

Conclusions: In two out of three patients, AFx due to transient retinal ischemia was of undetermined cause. The risk of stroke recurrence after a first episode of AFx in our cohort was 8.8%. Patients with TOAST-OC etiology identified were at highest risk of recurrence.