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

Abstract

[Abstract] Background. 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. Methods. 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). Results. 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. Conclusion. 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.

[Resumen] Introducción. Nuestro objetivo principal fue investigar la incidencia de ictus minor no cardioembólico y ataque isquémico transitorio (AIT) de alto riesgo, además de identificar predictores de recurrencia de ictus/muerte y sangrado grave. Evaluamos los porcentajes de AIT, eventos vasculares mayores, manejo terapéutico y predictores de mal pronóstico funcional. Métodos. Estudio retrospectivo de todos los pacientes con ictus evaluados en urgencias de 19 hospitales de la RED NORDICTUS entre julio-diciembre de 2019. Se incluyeron pacientes consecutivos con ictus minor no cardioembólico (National Institute of Health Stroke Scale [NIHSS] ≤ 5) y AIT de alto riesgo (ABCD2 ≥ 6 o estenosis ipsilateral ≥ 50%). Registramos variables clínicas, de neuroimagen y terapéuticas. Se realizó seguimiento a los 30 y 90 días. El pronóstico funcional se determinó mediante la escala de Rankin modificada (mRS). Resultados. De 8.275 pacientes, 1.679 (20%) cumplieron criterios del estudio IMMINENT (1.524 ictus/155 AIT), la incidencia global fue 48/100.000 h habitantes-año. Hubo recurrencias de ictus/muerte en 73 (4,3%) pacientes. La estenosis extracraneal ipsilateral (>50%): HR 1.999 (IC 95%: 1.115-3.585); p = 0,020 y la ausencia de estudio cerebrovascular hiperagudo: HR 1.631 (IC 95%: 1.009-2.636); p = 0.046, fueron predictores de ictus/muerte a 90 días. La estenosis intracraneal se asoció a mal pronóstico (p = 0,044). Se administró terapia de reperfusión a 147 (9%) y doble antiagregación a 320 (21%) pacientes. Conclusión. Un 20% de los pacientes se presentó como ictus minor o AIT de alto riesgo. La estenosis extracraneal ipsilateral y la ausencia de estudio neurovascular hiperagudo fueron predictores de ictus/muerte; la estenosis intracraneal se asoció con mal pronóstico. A pesar de las recomendaciones actuales hay baja penetrancia de doble antiagregación.