Transient Ischaemic Attacks: It’s time for timely action!

Transient ischaemic attack (TIA) is now defined as a transient episode of neurological dysfunction caused by central nervous system ischemia without acute infarction [1]. This tissue-based definition with a focus on the absence of infarction has replaced the previous time-based definition. The new definition highlights the importance of TIA as an opportunity for stroke prevention, similar to the importance of urgent treatment of unstable angina in preventing the tissue death of myocardial infarction. TIA is a major warning of an impending stroke; 15-30% of ischaemic strokes are preceded by TIAs [2-6]. The risk of stroke is highest in the immediate period following an index TIA, with 42% of all strokes during the 30 days after a first TIA occurring within the first 24 hours [6-8]. Therefore, optimal management of the first 24 hours following a TIA is critical in preventing a stroke. Early assessment and treatment of TIA have been shown to reduce recurrent stroke risk significantly. The EXPRESS study (Effect of urgent treatment of transient ischemic attack and minor stroke on the early recurrent stroke) showed a reduction of recurrent stroke risk by 80% at 90 days following an index TIA with urgent assessment and treatment using available medications. The study compared two different approaches to the management of patients with TIA and minor stroke over two time periods (phases 1 and 2). Both phases used the same treatment protocols, with the only difference being that patients in Phase 2 received more urgent assessment and treatment [9]. The median delay from symptom onset to assessment was 3 (IQR 2-5) days in phase 1 and 1 (0-3) day in phase 2. The median delay from assessment to initiation of medications, mainly aspirin, was 20 (8-53) days in phase 1 (started at primary care) and 1 (0-3) day in phase 2 (started at a TIA clinic). This intervention showed a reduction in the 90-day risk of recurrent stroke from 10.3% in phase 1 to 2.1% in phase 2. Similarly, the establishment of a hospital clinic with 24-hour access for TIAs (SOS-TIA Paris) reported a reduction of predicted 90-day stroke rate from 6.0% to 1.2% [10]. A systematic review which studied early stroke risk following TIA again highlighted the benefits of emergent management of TIAs [11]. Among 10126 TIA patients studied in 18 independent cohorts, the 7-day stroke risk following TIA was 0.9% in studies with emergency treatment, compared to 11.0% in populationbased studies without urgent treatment. These studies emphasized the importance of treating TIA as an emergency way back in 2008 [12], and led to the implementation of emergency TIA clinics in many developed countries. Ceylon Medical Journal 2020; 65: 5-8 Transient ischaemic attacks: It’s time for timely action!