{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,11]],"date-time":"2026-06-11T13:57:54Z","timestamp":1781186274475,"version":"3.54.1"},"reference-count":33,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2026,6,10]],"date-time":"2026-06-10T00:00:00Z","timestamp":1781049600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Neurology International"],"abstract":"<jats:p>Objective: To evaluate whether ABO blood group is associated with venous thromboembolic events (VTEs), cerebral severe vasospasm (CSV), delayed cerebral ischemia (DCI), and clinical or cognitive outcomes after aneurysmal subarachnoid hemorrhage (aSAH). Materials and Methods: A retrospective observational two-center cohort study of collected registry data, including 169 patients treated between September 2021 and November 2025. Outcomes were compared across ABO subtypes using univariate testing and multivariable logistic regression. Results: No ABO subtype was independently associated with VTE (7.7%), CSV\/DCI (21.9%), intracranial hemorrhage, or in-hospital mortality (all p &gt; 0.05). Higher age (OR 1.08, 95% CI 1.031\u20131.144, p = 0.003) was independently associated with increased in-hospital mortality, whereas single peri-interventional antiplatelet therapy (PIAT) (OR 0.076, 95% CI 0.004\u20130.506, p = 0.029) was associated with lower in-hospital mortality. ABO blood group was not associated with functional outcome (mRS) or cognitive performance (MoCA) in this cohort. Conclusions: In this two-center retrospective cohort, no independent association between ABO blood group and early cerebrovascular complications, functional outcome, or cognitive outcome after aSAH was detected. These findings suggest that short-term prognosis may be more strongly influenced by established patient- and treatment-related factors, particularly age and single PIAT. Further studies with larger cohorts are warranted to clarify the potential effect of ABO blood group on outcomes after aSAH.<\/jats:p>","DOI":"10.3390\/neurolint18060115","type":"journal-article","created":{"date-parts":[[2026,6,11]],"date-time":"2026-06-11T00:48:35Z","timestamp":1781138915000},"page":"115","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Impact of ABO Blood Group on Vascular Complications and on Clinical and Functional Outcome After Aneurysmal Subarachnoid Hemorrhage"],"prefix":"10.3390","volume":"18","author":[{"given":"Vera","family":"Marschal","sequence":"first","affiliation":[{"name":"Department of Neurosurgery, University Hospital Ulm, Albert-Einstein-Allee 23, 89081 Ulm, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Andreas","family":"Ziebart","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, University Hospital Ulm, Albert-Einstein-Allee 23, 89081 Ulm, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Maryam","family":"Abdoullahi","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, District Hospital G\u00fcnzburg, 89312 G\u00fcnzburg, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Daniel","family":"Werkmann","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, District Hospital G\u00fcnzburg, 89312 G\u00fcnzburg, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ralph","family":"K\u00f6nig","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, District Hospital G\u00fcnzburg, 89312 G\u00fcnzburg, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Thomas","family":"Kapapa","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, University Hospital Ulm, Albert-Einstein-Allee 23, 89081 Ulm, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1042-9006","authenticated-orcid":false,"given":"Benjamin","family":"Mayer","sequence":"additional","affiliation":[{"name":"Institute of Epidemiology and Medical Biometry, University of Ulm, 89081 Ulm, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Johannes","family":"Rosskopf","sequence":"additional","affiliation":[{"name":"Department of Neuroradiology, District Hospital G\u00fcnzburg, 89312 G\u00fcnzburg, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lennart","family":"Marschal","sequence":"additional","affiliation":[{"name":"Department of Internal Medicine, Klinikum Heidenheim gGmbH, 89522 Heidenheim, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Christian Rainer","family":"Wirtz","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, University Hospital Ulm, Albert-Einstein-Allee 23, 89081 Ulm, Germany"},{"name":"Department of Neurosurgery, District Hospital G\u00fcnzburg, 89312 G\u00fcnzburg, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Andrej","family":"Pala","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, District Hospital G\u00fcnzburg, 89312 G\u00fcnzburg, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gregor","family":"Durner","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, District Hospital G\u00fcnzburg, 89312 G\u00fcnzburg, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,6,10]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"698","DOI":"10.3171\/2015.5.JNS142115","article-title":"The falling rates of hospital admission, case fatality, and population-based mortality for subarachnoid hemorrhage in England, 1999\u20132010","volume":"125","author":"Mukhtar","year":"2016","journal-title":"J. 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