Intracerebral Hemorrhage etiological classification systems and their correlation with neurological deterioration

Introduction Unlike ischemic stroke, the etiological classification of patients with intracerebral hemorrhage (CH) lacks consensus. Our study focuses on two commonly-used classification systems: SMASH-U and H-ATOMIC. The main difference between them lies in the fact that the H-ATOMIC system considers the simultaneous presence of different etiologies in a single patient. The association between the two classifications with relation to neurological deterioration (ND) and clinical outcomes remains so far unexplored. Methods We recruited consecutive ICH patients from 2015 to 2022, determining etiology was on discharge. Demographic, radiological and clinical characteristics were recorded. ND during hospitalization in the 7 days after stroke was the main clinical endpoint. Results 301 patients were recruited. 124 patients (41.2%) experienced ND. The hypertensive subtype was the most frequent etiology with both classifications. In 149 (49.5%) more than one possible etiology for the ICH were recognized. The most frequent combination was hypertension + either probable or possible amyloid angiopathy, in 64 patients (21.3%). Significant differences in ND proportions were observed across groups with both systems. ICH related to anticoagulation was associated with a greater risk of ND: 63.5 % in SMASH-U and 62.5% in patients with a combination of Hypertension and Oral Anticoagulants in H-ATOMIC. Both these etiological groups and that containing combined etiologies were statistically significant according to multivariate analysis. Intraventricular extension, blood pressure control and initial volume were also related to ND. Conclusion Etiology of the ICH could be related to the risk of ND during hospitalization. Anticoagulation-related etiologies may present the highest risk, especially when combined with hypertension. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement The study was supported by a grant from INVICTUS plus Research Network (Carlos III Health Institute: RD16-0019-0017), Government of Catalonia-Agència de Gestió d'Ajuts Universitaris i de Recerca (2017SGR1628 and 2021SGR01479); Carlos III Health Institute and co-funded by European Union (ERDF/ESF, "Investing in your future" and "A way to build Europe"): PI20/01575 ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The ethics committee from the Hospital Universitari Arnau de Vilanova de Lleida approved the study (HUAV, code: 2168), and written informed consent was obtained from all participants. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes Requests for access to the data reported in this article will be considered by the corresponding author