Neurodegeneration is strongly linked to heart failure severity and outcomes: framing the cardiocerebral syndrome

Background and Objectives Cognitive impairment is prevalent in patients with heart failure with reduced ejection fraction (HFrEF), affecting self-care and outcomes. Novel blood-based biomarkers have emerged as potential diagnostic tools for neurodegeneration. This study aimed to assess neurodegeneration in HFrEF by measuring neurofilament light chain (NfL), total tau (t-tau), amyloid-beta 42 (Aβ42), and 40 (Aβ40) in a large, well-characterised cohort. Methods The study included 470 HFrEF patients from a biobank-linked prospective registry at the Medical University of Vienna. High-sensitivity single-molecule assays were used for measurement. Unplanned hospitalisations and all-cause death were recorded as outcome parameters. Results All markers, but not the Aβ42/Aβ40 ratio, correlated with heart failure (HF) severity, i.e. NTproBNP and NYHA class, comorbidity burden and were significantly associated with all-cause death and HF-hospitalisations [crude HR for 1-log unit increase (95%CI): 4.44 (3.02-6.53), 5.04 (2.97-8-58), 3.90 (2.27-6.72) and 5.14 (2.84-9.32) for all-cause death and 2.48 (1.60-3.85), 3.44 (1.95-6.04), 3.13 (1.84-5.34) and 3.48 (1.93-6.27) for HHF, p<0.001 for all]. These markers remained significant after adjustment in multivariate models including NT-proBNP. NfL and t-tau showed the highest prognostic ability in the receiver operating characteristic analysis [AUC: 0.72, 0.68, 0.66, 0.67 for NfL, t-tau, Aβ40 and Aβ42, respectively]. The performance of NfL was comparable to that of NT-proBNP [C-index: 0.70 vs 0.72, p=0.225]. Conclusions Neurodegeneration is directly interwoven with the progression of HF. Biomarkers, particularly NfL, may help identify patients profiting from detailed neurological workups. Further research is necessary to test if early diagnosis or optimised HFrEF treatment can preserve cognitive function. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This project was funded by an unrestricted grant of the Austrian Cardiac Society (OEsterreichische Kardiologische Gesellschaft). ### 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 study protocol adheres to the Declaration of Helsinki and was approved by the Ethics Committee of the Medical University of Vienna (EK1612/2015). 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 The data that support the findings of this study are available from the corresponding author upon reasonable request.