Incidence and outcoMes of MInor stroke and high-risk traNsient ischEmic attack in NordicTus. IMMINENT study

Our primary aim was to investigate the incidence of non-cardioembolic minor acute ischemic stroke (AIS) and high-risk transient ischemic attack (TIA) and to identify predictors of stroke recurrence/death and severe bleeding. We also evaluated the rates of TIA, major vascular events, therapeutic management and predictors of poor functional outcome at 3 months in these patients.

We retrospectively reviewed data from all stroke patients evaluated at the emergency department of 19 hospitals belonging to the NORDICTUS stroke network between July and December 2019. Consecutive patients with non-cardioembolic minor AIS (NIHSS ≤5) and high-risk TIA (ABCD2 ≥6 or ipsilateral stenosis ≥50%) were included. We recorded clinical, neuroimaging and therapeutic variables. Follow-up was performed at 30 and 90 days. Functional prognosis was assessed with the modified Rankin scale score (mRS).

Of 8275 patients, 1679 (20%) fulfilled IMMINENT criteria (1524 AIS/155 TIA), resulting in a global incidence of 48/100,000 inhabitants per-year. Recurrent stroke/death occurred in 73 (4.3%) patients. Extracranial ipsilateral stenosis (>50%): HR 1.999 (95% CI: 1.115-3.585, p=0.020) and lack of hyperacute cerebral arterial assessment: HR 1.631 (95% CI: 1.009-2.636, p=0.046) were associated with recurrent stroke/death at 90 days. Intracranial stenosis was associated with poor prognosis (p=0.044). Reperfusion therapy was given to 147 (9%) and urgent double antiplatelet therapy (DAPT) to 320 (21%) patients.

Twenty percent of our stroke patients presented as non-cardioembolic high-risk TIA or minor AIS. Extracranial ipsilateral stenosis and lack of hyperacute cerebral arterial assessment were predictors of stroke recurrence/death; intracranial stenosis was associated with poor outcome. Despite current recommendations there was a low penetrance of DAPT.