Abstract Background/Objective: There is controversy regarding the need to use advanced imaging to select candidates for thrombectomy in late window acute ischemic stroke (AIS). Hypoattenuation on CT angiography source images (CTA-SI) in arterial phase has been shown to be more sensitive than Alberta Stroke Program Early CT Score (ASPECTS) of brain parenchyma to determine tissue at risk of ischemia. Our hypothesis is that the addition of a second acquisition at 35-50 seconds could complement the assessment of hypoperfused tissue that fails to receive flow through pial vessels. Methods: Patients with large vessel occlusion and 6-24 hours from symptom onset, admitted between August 2019 and July 2023, were evaluated with dual-phase CT angiography (CTA) and CT-Perfusion. A vascular neurologist estimated CTA-SI ASPECTS in both phases at the time of data entry into the RECCA registry. In contrast, the post-processing of CT-Perfusion images was performed in an automated way through RAPID© software. The association between automated CT-perfusion values and dual-phase CTA-SI ASPECTS was assessed through a correlation coefficient. Results: Pearson’s coefficient demonstrated a high correlation between ischemic core volume and delayed phase CTA (CTA-DP) ASPECTS with an inverse association of −0.93 and between Tmax ≥ 6 sec volume and arterial phase CTA (CTA-AP) ASPECTS with a value of −0.88. Conclusions: CTA-derived source images (CTA-SI) in two phases may be useful in the selection of patients with AIS presenting beyond the 6-hour window.

Resumen Introducción/Objetivo: La recomendación actual es realizar el tamizaje de pacientes con ataque cerebrovascular ACV y oclusión de grades vasos LVO (por sus siglas en ingles) potencialmente candidatos a trombectomía mecánica en ventana extendida a través de un estudio de TC perfusión con post procesamiento automatizado. El acceso a TC perfusión no está ampliamente disponible en el mundo, por lo que existe controversia en relación a que sea una herramienta imprescindible. Métodos: Este es un estudio prospectivo de un registro retrospectivo unicéntrico con pacientes con ACV de circulación anterior, LVO y un tiempo entre 6-24 horas desde el inicio de los síntomas hasta la realización del estudio imagenológico. A todos los pacientes se les realizó un AngioTC en 2 fases, con evaluación de sus imágenes fuentes CTA-SI (por sus siglas en ingles) y un estudio de perfusión con post procesamiento por software RAPID. Resultados: El coeficiente de Pearson’s mostró una alta correlación entre el volumen de núcleo isquémico medido por FSC < 30% y el valor CTA-SI ASPECTS en fase tardía, con una asociación inversa de −0.93. Conclusión: La interpretación de CTA-SI ASPECTS en 2 fases entrega información congruentes con los resultados automatizados de los mapas de TC perfusión.

Abstract Background The efficacy of intravenous thrombolysis (IVT) is time-dependent. Objective To compare the door-to-needle (DTN) time of stroke neurologists (SNs) versus non-stroke neurologists (NSNs) and emergency room physicians (EPs). Additionally, we aimed to determine elements associated with DTN ≤ 20 minutes. Methods Prospective study of patients with IVT treated at Clínica Alemana between June 2016 and September 2021. Results A total of 301 patients underwent treatment for IVT. The mean DTN time was 43.3 ± 23.6 minutes. One hundred seventy-three (57.4%) patients were evaluated by SNs, 122 (40.5%) by NSNs, and 6 (2.1%) by EPs. The mean DTN times were 40.8 ± 23, 46 ± 24.7, and 58 ± 22.5 minutes, respectively. Door-to-needle time ≤ 20 minutes occurred more frequently when patients were treated by SNs compared to NSNs and EPs: 15%, 4%, and 0%, respectively (odds ratio [OR]: 4.3, 95% confidence interval [95%CI]: 1.66–11.5, p = 0.004). In univariate analysis DTN time ≤ 20 minutes was associated with treatment by a SN (p = 0.002), coronavirus disease 2019 pandemic period (p = 0.21), time to emergency room (ER) (p = 0.21), presence of diabetes (p = 0.142), hypercholesterolemia (p = 0.007), atrial fibrillation (p < 0.09), score on the National Institutes of Health Stroke Scale (NIHSS) (p = 0.001), lower systolic (p = 0.143) and diastolic (p = 0.21) blood pressures, the Alberta Stroke Program Early CT Score (ASPECTS; p = 0.09), vessel occlusion (p = 0.05), use of tenecteplase (p = 0.18), thrombectomy (p = 0.13), and years of experience of the physician (p < 0.001). After multivariate analysis, being treated by a SN (OR: 3.95; 95%CI: 1.44–10.8; p = 0.007), NIHSS (OR: 1.07; 95%CI: 1.02–1.12; p < 0.002) and lower systolic blood pressure (OR: 0.98; 95%CI: 0.96–0.99; p < 0.003) remained significant. Conclusions Treatment by a SN resulted in a higher probability of treating the patient in a DTN time within 20 minutes. (IVT timedependent. timedependent dependent. dependent time-dependent doortoneedle door needle (DTN (SNs nonstroke non (NSNs EPs . (EPs) Additionally 2 201 2021 30 433 43 3 43. 236 23 23. seventythree seventy three 57.4% 574 57 4 (57.4% 12 40.5% 405 40 5 (40.5% 2.1% 21 1 (2.1% 408 8 40. 247 24 7 24.7 225 22 22. Doortoneedle Door 15 15% 4% 0 0% odds OR [OR] 4.3 95 95%CI 95CI CI [95%CI] 166115 66 11 1.66–11.5 0.004. 0004 0.004 004 0.004) 0.002, 0002 0.002 , 002 0.21, 021 0.21 ER (ER 0.142, 0142 0.142 142 0.142) 0.007, 0007 0.007 007 0.007) 0.09, 009 0.09 09 0.09) (NIHSS 0.001, 0001 0.001 001 0.001) 0.143 0143 143 pressures ASPECTS (ASPECTS 0.05, 005 0.05 05 0.05) 0.18, 018 0.18 18 0.18) 0.13, 013 0.13 13 0.13) 0.001. (OR 3.95 395 1.44–10.8 144108 44 10 1.07 107 07 1.02–1.12 102112 02 0.98 098 98 0.96–0.99 096099 96 99 0.003 0003 003 significant (EPs 202 57.4 (57.4 40.5 (40.5 2.1 (2.1 24. [OR 4. 9 [95%CI 16611 1.66–11. 000 0.00 00 0.2 014 0.14 14 0.0 01 0.1 3.9 39 1.44–10. 14410 1.0 1.02–1.1 10211 0.9 0.96–0.9 09609 57. (57. (40. 2. (2. 1661 1.66–11 0. 3. 1.44–10 1441 1. 1.02–1. 1021 0.96–0. 0960 (57 (40 (2 166 1.66–1 1.44–1 144 1.02–1 102 0.96–0 096 (5 (4 ( 16 1.66– 1.44– 1.02– 0.96– 1.66 1.44 1.02 0.96 1.6 1.4

Resumen Antecedentes La respuesta a la trombólisis intravenosa (TIV) es dependiente del tiempo. Objetivo Comparar los tiempo puerta-aguja (TPAs) de neurólogos vasculares (NVs) contra los de neurólogos no vasculares (NNVs) y médicos emergencistas (MEs), y determinar los elementos asociados a un PTA ≤ 20 minutos. Métodos Análisis observacional prospectivo de pacientes con TIV tratados en Clínica Alemana entre junio de 2016 y septiembre de 2021. Resultados En total, 301 pacientes con TIV fueron tratados. El TPA promedio fue de 43,3 ± 23,6 minutos. Un total de 173 (57,4%) pacientes fueron evaluados por NVs, 122 (40,5%), por NNVs, y 6 (2,1%), por MEs; los TPAs promedios fueron de 40,8 ± 23; 46 ± 24,7 y 58 ± 22,5 minutos, respectivamente. Los TPAs ≤ 20 minutos fueron más frecuentes en pacientes tratados por NVs versus NNVs y MEs: 15%, 4% y 0%, respectivamente (odds ratio [OR]: 4,3; intervalo de confianza del 95% [IC95%]: 1,66–11,5; p = 0,004). El análisis univariado demostró que TPA ≤ 20 minutos se asoció con: tratamiento por NVs (p = 0,002), periodo de la pandemia de enfermedad por coronavirus 2019 (COVID-19; p = 0,21), tiempo a urgencia (p = 0,21), diabetes (p = 0,142), hipercolesterolemia (p = 0,007), fibrilación auricular (p < 0,09), puntaje en la National Institutes of Health Stroke Scale [NIHSS] (p = 0,001), presión arterial sistólica (p = 0,143) y diastólica menores (p = 0,21), Alberta Stroke Program Early CT Score (ASPECTS ; p = 0,09), oclusión de vasos cerebrales (p =0,05), uso de tecneteplase (p = 0,18), trombectomía (p = 0,13) y años de experiencia del médico (p < 0,001). El análisis multivariado demostró que ser tratado por NVs (OR: 3,95; IC95%: 1,44–10,8; p = 0,007), el puntaje en la NIHSS (OR: 1,07; IC95%: 1,02–1,12; p < 0,002) y la presión arterial sistólica (OR: 0,98; IC95%: 0,96–0,99; p < 0,003) se asociaron a TPA ≤ 20 minutos. Conclusões El tratamiento por NVs resultó en un TPA menor y en una mayor probabilidad de tratamiento ≤ 20 minutos. (TIV puertaaguja puerta aguja (TPAs (NVs (NNVs MEs, MEs , (MEs) 2 201 2021 30 433 43 3 43, 236 23 23, 17 57,4% 574 57 4 (57,4% 12 40,5%, 405 40,5% 40 5 (40,5%) 2,1%, 21 2,1% 1 (2,1%) 408 8 40, 247 24 7 24, 225 22 22, 15 15% 0 0% odds OR [OR] 4,3 95 IC95% IC95 IC [IC95%] 1,66–11,5 166115 66 11 0,004. 0004 0,004 . 004 0,004) 0,002, 0002 0,002 002 COVID19 COVID 19 (COVID-19 0,21, 021 0,21 0,21) 0,142, 0142 0,142 142 0,142) 0,007, 0007 0,007 007 0,007) 0,09, 009 0,09 09 0,09) [NIHSS 0,001, 0001 0,001 001 0,001) 0,143 0143 143 ASPECTS =0,05, 005 =0,05 05 =0,05) 0,18, 018 0,18 18 0,18) 0,13 013 13 0,001. (OR 3,95 395 1,44–10,8 144108 44 10 1,07 107 07 1,02–1,12 102112 02 0,98 098 98 0,96–0,99 096099 96 99 0,003 0003 003 (MEs 202 57,4 (57,4 40,5 (40,5% 2,1 (2,1% [OR 4, 9 IC9 [IC95% 1,66–11, 16611 000 0,00 00 COVID1 (COVID-1 0,2 014 0,14 14 0,0 =0,0 01 0,1 3,9 39 1,44–10, 14410 1,0 1,02–1,1 10211 0,9 0,96–0,9 09609 57, (57, (40,5 2, (2,1 [IC95 1,66–11 1661 (COVID- 0, =0, 3, 1,44–10 1441 1, 1,02–1, 1021 0,96–0, 0960 (57 (40, (2, [IC9 1,66–1 166 (COVID =0 1,44–1 144 1,02–1 102 0,96–0 096 (5 (40 (2 [IC 1,66– 16 1,44– 1,02– 0,96– ( (4 1,66 1,44 1,02 0,96 1,6 1,4

Background: Intravenous thrombolysis (IT) in acute ischemic stroke (AIS) is time dependent. The time elapsed from hospital admission to the thrombolytic bolus is named door to needle time (DNT) and is recommend to be of less than 60 min. Aim: To describe the DNT in our center and determine those factors associated with a DNT longer than 60 min. Material and Methods: Prospective analysis of patients treated with IT at a private hospital between June 2016 and June 2019. The percentage of patients with DNT exceeding 60 min, and the causes for this delay were evaluated. Results: IT was used in 205 patients. DNT was 43.6 ± 23.8 min. Forty patients (19.5% (95% CI, 14.4-25.7), had a DNT longer than 60 min. Uni-varied analysis demonstrated that AIS with infratentorial symptomatology (ITS), was significantly associated with DNTs exceeding 60 min. A history of hypertension, a higher NIH Stroke Scale score, the presence of an hyperdense sign in brain tomography (p = 0.001) and the need for endovascular therapy (p = 0.019), were associated with DNT shorter than 60 min. Multivariate analysis ratified the relationship between ITS and DNT longer than 60 min (Odds ratio: 3.19, 95% confidence intervals 1.26-8). Conclusions: The individual elements that correlated with a DNT longer than 60 min were the failure to detect the AIS during triage and doubts about its diagnosis.