Safety of Endovascular Thrombectomy in Isolated Cervical Internal Carotid Artery Occlusion While on Oral Anticoagulation

Article information

J Stroke. 2026;28(2):321-325

Publication date (electronic) : 2026 May 28

doi : https://doi.org/10.5853/jos.2025.05918

Lukas Mayer-Suess^,1,*, Christoph Riegler^2,3,*, João Pedro Marto^4,5, Pimrapat Gebert^6,7, Tilman Reiff⁸, Marek Sykora^9,10, Marcin Wiącek¹¹, David Pakizer¹², André Araújo¹³, Adrien ter Schiphorst¹⁴, João André Sousa¹⁵, Arno Reich¹⁶, Belen Flores Pina¹⁷, Cristina Hobeanu¹⁸, Marialuisa Zedde¹⁹, João Nuno Ramos²⁰, Georgios Tsivgoulis²¹, Pedro Castro²², Sven Poli^23,24, José Nuno Alves²⁵, Anne Dusart²⁶, Blanca Fuentes²⁷, Herbert Tejada Meza^28,29, Jelle Demeestere³⁰, Susanne Wegener^31,32, Lars Kellert³³, Patricia Calleja³⁴, Cristina Panea^35,36, Christoph Vollmuth³⁷, Karl Georg Haeusler³⁸, Liliana Pereira³⁹, Ronen Leker⁴⁰, Timo Uphaus⁴¹, Andrea Zini⁴², Henrik Gensicke^43,44, Gauthier Duloquin⁴⁵, Taraneh Ebrahimi⁴⁶, Alexander Salerno⁴⁷, Cristina Tiu⁴⁸, Thanh N. Nguyen⁴⁹, Sebastian García-Madrona⁵⁰, Marta Bilik⁵¹, Shadi Yaghi⁵², Halina Sienkiewicz-Jarosz⁵³, Michał Karliński⁵⁴, Stefan Krebs⁹, Eva Hurtíková⁵⁵, Nathalia Ferreira¹⁵, João Sargento-Freitas¹⁵, João Pinho¹⁶, Isabel Rodriguez Caamaño¹⁷, Elke Ruth Gizewski⁵⁶, Pierre Seners^18,57, Rosario Pascarella⁵⁸, Klearchos Psychogios⁵⁹, Alexandra Gómez-Expósito^23,24, Sara Gomes²⁵, Flavio Bellante²⁶, Jorge Rodríguez-Pardo²⁷, Mario Bautista Lacambra^29,60, Robin Lemmens³⁰, Corinne Inauen³¹, Johannes Wischmann³³, Fernando Ostos³⁴, Vlad Tiu^35,36, Miguel Rodrigues³⁹, Issa Metanis⁴⁰, Marianne Hahn⁴¹, Maria Maddalena Viola⁴², Simon Truessel⁴³, Yannick Béjot⁴⁵, Louisa Nitsch⁴⁶, Davide Strambo⁴⁷, Elena Oana Terecoasa⁴⁸, Mohamad Abdalkader⁴⁹, Alicia De Felipe⁵⁰, Farhan Khan⁵², Caroline Arquizan¹⁴, Manuel Ribeiro¹³, Martin Roubec^12,55, Izabella Tomaszewska-Lampart¹¹, Julia Ferrari⁹, Peter Ringleb⁸, Christian H. Nolte^2,3,6,61

¹Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria

²Department of Neurology, Charité – Universitätsmedizin Berlin, Berlin, Germany

³Center for Stroke Research Berlin (CSB), Charité – Universitätsmedizin Berlin, Berlin, Germany

⁴Department of Neurology, Hospital de Egas Moniz, Centro Hospitalar Lisboa Ocidental, Lisbon, Portugal

⁵Lisbon Clinical Academic Center, NOVA Medical School, Universidade NOVA de Lisboa, Lisbon, Portugal

⁶Berlin Institute of Health at Charité – Universitätsmedizin Berlin, Berlin, Germany

⁷Charité – Universitätsmedizin Berlin, Institute of Biometry and Clinical Epidemiology, Berlin, Germany

⁸Department of Neurology, Heidelberg University Hospital, Heidelberg, Germany

⁹Department of Neurology, St. John’s Hospital, Vienna, Austria

¹⁰Medical Faculty, Sigmund Freud University Vienna, Vienna, Austria

¹¹Department of Neurology, Institute of Medical Sciences, Medical College of Rzeszow University, Rzeszow, Poland

¹²Centre for Health Research, Faculty of Medicine, University of Ostrava, Ostrava, Czech Republic

¹³Department of Neuroradiology, Centro Hospitalar de Vila Nova de Gaia/Espinho, Gaia, Portugal

¹⁴Department of Neurology, Centre Hospitalier Universitaire Gui de Chauliac, Montpellier, France

¹⁵Department of Neurology, Centro Hospitalar Universitário de Coimbra, Coimbra, Portugal

¹⁶Department of Neurology, University Hospital RWTH Aachen, Aachen, Germany

¹⁷Department of Neurology, Germans Trias Hospital, Barcelona, Spain

¹⁸Neurology Department, Rothschild Foundation Hospital, Paris, France

¹⁹Neurology Unit, Stroke Unit, Azienda Unità Sanitaria Locale-IRCCS di Reggio Emilia, Reggio Emilia, Italy

²⁰Department of Neuroradiology, Hospital de Egas Moniz, Centro Hospitalar Lisboa Ocidental, Lisbon, Portugal

²¹Second Department of Neurology, National & Kapodistrian University of Athens, Attikon University Hospital, School of Medicine, Athens, Greece

²²Department of Neurology, Centro Hospitalar Universitário São João, Porto, Portugal

²³Department of Neurology & Stroke, University of Tübingen, Tübingen, Germany

²⁴Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany

²⁵Department of Neurology, Hospital de Braga, Braga, Portugal

²⁶Department of Neurology, CHU Charleroi, Hôpital Civil Marie Curie, Charleroi, Belgium

²⁷Department of Neurology and Stroke Center, Hospital La Paz Institute for Health Research-IdiPAZ (La Paz University Hospital-Universidad Autónoma de Madrid), Madrid, Spain

²⁸Stroke Unit, Department of Neurology and Interventional Neuroradiology Unit, Department of Radiology, Hospital Universitario Miguel Servet, Zaragoza, Spain

²⁹Instituto de Investigación Sanitaria (IIS) Aragón, Zaragoza, Spain

³⁰Neurology Department, Leuven University Hospital, Leuven, Belgium

³¹Department of Neurology, University Hospital Zurich and University of Zurich, Zurich, Switzerland

³²Clinical Neuroscience Center, University Hospital Zurich and University of Zurich, Zurich, Switzerland

³³Department of Neurology, Ludwig Maximilian University, University Hospital, Munich, Germany

³⁴Department of Neurology and Stroke Centre, 12 de Octubre University Hospital, Instituto de Investigación Hospital 12 de Octubre (i+12), Madrid, Spain

³⁵Department of Clinical Neuroscience, Carol Davila University of Medicine and Pharmacy, Bucharest, Romania

³⁶Neurology Department, Elias University Emergency Hospital, Bucharest, Romania

³⁷Department of Neurology, Universitätsklinikum Würzburg (UKW), Würzburg, Germany

³⁸Department of Neurology, Universitätsklinikum Ulm, Ulm, Germany

³⁹Department of Neurology, Hospital Garcia de Orta, Almada, Portugal

⁴⁰Department of Neurology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel

⁴¹Department of Neurology and Focus Program Translational Neuroscience, Rhine Main Neuroscience Network, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany

⁴²IRCCS Istituto delle Scienze Neurologiche di Bologna, Department of Neurology and Stroke Center, Maggiore Hospital, Bologna, Italy

⁴³Stroke Center and Department of Neurology, University Hospital Basel and University of Basel, Basel, Switzerland

⁴⁴Neurology and Neurorehabilitation, University Department of Geriatric Medicine Felix Platter, University of Basel, Basel, Switzerland

⁴⁵Université Bourgogne, Europe, CHU Dijon Bourgogne, Department of Neurology, Dijon Stroke Registry PEC2 EA7460, Dijon, France

⁴⁶Division of Vascular Neurology, University Hospital Bonn, Bonn, Germany

⁴⁷Stroke Center, Department of Neurological Sciences, Lausanne University Hospital, Lausanne, Switzerland

⁴⁸Department of Neurology, University Emergency Hospital Bucharest, Bucharest, Romania

⁴⁹Department of Radiology and Neurology, Boston University Chobanian and Avedisian School of Medicine, Boston, MA, USA

⁵⁰Department of Neurology and Stroke Center, Hospital Ramón y Cajal, Madrid, Spain

⁵¹Oddział Neurologiczny z Pododdziałem Udarowym, SPS Szpital Zachodni im. Św Jana Pawła II, Grodzisk Mazowiecki, Poland

⁵²Department of Neurology, Brown University, Providence, RI, USA

⁵³1st Department of Neurology, Institute of Psychiatry and Neurology, Warsaw, Poland

⁵⁴2nd Department of Neurology, Institute of Psychiatry and Neurology, Warsaw, Poland

⁵⁵Comprehensive Stroke Center, Department of Neurology, University Hospital Ostrava, Ostrava, Czech Republic

⁵⁶Department of Radiology, Medical University of Innsbruck, Innsbruck, Austria

⁵⁷Institut de Psychiatrie et Neurosciences de Paris, Université Paris Cité, Paris, France

⁵⁸Neuroradiology Unit, Ospedale Santa Maria della Misericordia, AULSS5 Polesana, Rovigo, Italy

⁵⁹Acute Stroke Unit, Metropolitan Hospital, Athens, Greece

⁶⁰Stroke Unit, Department of Neurology, Hospital Universitario Miguel Servet, Zaragoza, Spain

⁶¹Deutsches Zentrum für Herz-Kreislaufforschung DZHK, Berlin, Germany

Correspondence: Lukas Mayer-Suess Department of Neurology, Medical University of Innsbruck, Anichstraße 35, Innsbruck A-6020, Austria Tel: +43-512-504-83127 E-mail: Lukas.Mayer@i-med.ac.at

*These authors contributed equally as first author.

Received 2025 November 19; Revised 2026 January 21; Accepted 2026 March 26.

Dear Sir:

Recently, the large international observational Endovascular Treatment for Isolated Cervical Internal Carotid Artery Occlusion (ETIICA) study investigated the safety and efficacy of acute endovascular therapy (EVT) in patients with acute ischemic stroke and isolated cervical internal carotid artery occlusion (c-ICA-O) [1]. Three-month functional outcomes after EVT were similar to those in patients receiving best medical treatment (BMT) alone [1]. As other registries report similar findings, a randomized controlled trial seems warranted [2]. However, safety concerns in a subset of patients remain, as an increased risk of symptomatic intracranial hemorrhage (ICH) was observed in the EVT group of ETIICA compared with those receiving BMT alone (8 [1.6%] vs. 0 [0.0%]) [1]. This raises the question of the potential risk of EVT in patients with an increased risk of ICH, such as those taking oral anticoagulation (OAC) at the time of stroke.

Studies in patients undergoing EVT due to intracranial largevessel occlusion stroke have reported that prior OAC intake does not place patients at a higher risk of ICH, especially if taking a direct oral anticoagulant (DOAC) [3,4]. However, whether this holds true for patients with isolated c-ICA-O remains unknown [5].

Therefore, we aimed to evaluate the effect of OAC intake before the index stroke on the safety and efficacy of EVT in patients with isolated c-ICA-O.

Details of the ETIICA study have been published [1]. In short, the registry included patients with ischemic stroke and isolated c-ICA-Os presenting within 24 hours from the last-seen-well. This study compared BMT alone with BMT plus EVT. ETIICA included patients treated between 2018 and 2022 at 42 sites in Europe and North America. This subgroup analysis compared patients with ETIICA who underwent EVT and were on pre-stroke OAC (vitamin K antagonists or DOACs) with those who underwent EVT and were not on OAC. Patients who received bridging intravenous thrombolysis (IVT) were excluded because IVT is a confounder of ICH. Outcomes of interest were symptomatic ICH (defined as parenchymal hematoma type 2 [PH2] with an increase of at least four points on the National Institutes of Health Stroke Scale [NIHSS] score) or any hemorrhage at 24–36 hours postintervention, as well as ordinal 3-month modified Rankin Scale (mRS) scores (shift) [6].

Continuous variables are presented as mean with standard deviation and median with interquartile range, depending on the data distribution. Categorical variables are presented as absolute numbers and percentages. The baseline characteristics of patients with and without prior OAC use were compared using the chi-square test for categorical variables and either the independent t-test or the Mann-Whitney U test for continuous variables, as appropriate.

Shift analysis was performed for the 3-month mRS scores. Binary logistic regression analysis was performed for both ICH and symptomatic ICH. To adjust for potential confounding factors, we applied normalized Inverse Probability of Treatment Weighting based on a propensity score estimated using logistic regression. The model included the following predefined covariates: age, sex, pre-mRS score, NIHSS score at admission, atrial fibrillation, heart failure, arterial hypertension, current or recent smoking, previous stroke or transient ischemic attack, atherosclerosis, cardioembolism, dissection, antiplatelet use, and carotid artery stenting. Age and NIHSS score were modelled as restricted cubic splines with three knots. Statistical testing was done within an exploratory framework at a two-sided significance level of α=0.05. Statistical analyses were performed using Stata MP/18 (StataCorp. 2023, College Station, TX, USA).

A total of 285 of the 998 (28.6%) patients with ETIICA were eligible for this analysis (exclusions: 511 patients did not undergo EVT and 202 patients underwent bridging thrombolysis), of whom 64 patients had prior OAC. Table 1 presents the patient characteristics, including risk factors, stroke etiology, and clinical status at admission and during treatment.

Table 1.

Patient and treatment characteristics of c-ICA-O patients with and without prior OACs

Notably, even though there was a numerical difference in PH2 between patients with and without prior OAC (2 [3.2%] vs. 2 [0.9%]), no difference in occurrence risk of any ICH (9/63 [14.3%] vs. 29/220 [13.2%]; adjusted odds ratio, aOR, 1.31 [95% confidence interval, CI, 0.39–4.44]) or symptomatic ICH (2/63 [3.2%] vs. 3/220 [1.4%]; aOR, 1.26 [95% CI, 0.19–8.51]) (Figure 1 for details) was observed. This was also true in the crude, unadjusted analysis (data not shown). Furthermore, the mRS-defined functional outcome at 3 months was similar between patients with and without OAC use before EVT (aOR, 1.00 [95% CI, 0.35– 2.90]).

Figure 1.

Outcomes of EVT for acute isolated c-ICA-O with regard to prior OAC intake. (A) Effect of prior OAC on clinical (mRS) and safety outcomes after EVT for acute isolated c-ICA-O. (B) Occurrence of hemorrhage types in EVT treated participants with acute isolated c-ICA-O with regard to prior OAC intake. mRS, modified Rankin Scale; OAC, oral anticoagulation; OR, odds ratio; CI, confidence interval; PH, parenchymal hematoma; EVT, endovascular therapy; c-ICA-O, cervical internal carotid artery occlusion.

To date, the optimal care for isolated c-ICA-O remains unknown, with the safety and efficacy of acute revascularization measures being in question [2,7-9]. The ETIICA registry, the largest international registry collecting observational data of this patient population, has enabled a detailed assessment of individual treatment aspects [1]. Our subgroup analysis adds data to the safety of EVT in patients with acute stroke and isolated c-ICA-O [1]. Although ETIICA found higher rates of ICH in patients undergoing EVT compared with BMT alone, this increased risk of ICH did not stem from prior OAC use.

Our results support the notion that prior OAC use does not increase the risk of adverse bleeding outcomes in stroke patients with c-ICA-O undergoing EVT (Figure 1). This is reassuring, as approximately 1 in 7 patients with isolated c-ICA-O presented with OAC, indicating that c-ICA-O is not exclusively caused by atherosclerosis or dissection but by comorbidities requiring OAC [1]. As the call for randomized controlled clinical trials in this patient population continues, observational data defining patient characteristics that may or may not be recruited safely into such trials in the future are crucial. Although acknowledging the retrospective data collection, selection bias, lack of central reading, unblinded outcome assessment, and the missing data on OAC type (i.e., vitamin K antagonists, DOACs) and compliance, we contend that prior OAC should not be an exclusion criterion when designing a future treatment trial.