Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub. 2019, 163(3):241-246 | DOI: 10.5507/bp.2019.043

A case series on the value of tau and neurofilament protein levels to predict and detect delirium in cardiac surgery patients

Thomas Saller^a, Axel Petzold^b, Henrik Zetterberg^c,d,e,f, Jens Kuhle^g, Daniel Chappell^a, Vera von Dossowⁱ, Felix Klawitter^j, Tobias Schürholz^j, Christian Hagl^k, Daniel A Reuter^j, Bernhard Zwissler^a, Johannes Ehler^j

^a Department of Anaesthesiology, University Hospital, LMU Munich, Munich, Germany

^b UCL Queen Square Institute of Neurology, The National Hospital for Neurology and Neurosurgery, Moorfields Eye Hospital, London, United Kingdom and Amsterdam UMC, The Netherlands

^c UK Dementia Research Institute at UCL, London, United Kingdom

^d Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London, United Kingdom

^e Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Molndal, Sweden

^f Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, the Sahlgrenska Academy at the University of Gothenburg, Molndal, Sweden

^g Neurologic Clinic and Policlinic, Departments of Medicine, Biomedicine and Clinical Research, University Hospital Basel, University of Basel, Switzerland

ⁱ Institute for Anesthesiology, Heart and Diabetes Center NRW, Ruhr University of Bochum, Bad Oeynhausen, Germany

^j Department of Anesthesiology and Intensive Care Medicine, University Medical Center Rostock, Rostock, Germany

^k Department of Cardiac Surgery, University Hospital, LMU Munich, Munich, Germany

Background: Delirium following cardiac surgery is a relevant complication in the majority of elderly patients but its prediction is challenging. Cardiopulmonary bypass, essential for many interventions in cardiac surgery, is responsible for a severe inflammatory response leading to neuroinflammation and subsequent delirium. Neurofilament light protein (NfL) and tau protein (tau) are specific biomarkers to detect neuroaxonal injury as well as glial fibrillary acidic protein (GFAP), a marker of astrocytic activation.

Methods: We thought to examine the perioperative course of these markers in a case series of each three cardiac surgery patients under off-pump cardiac arterial bypass without evolving delirium (OPCAB-NDEL), patients with a procedure under cardio-pulmonary bypass (CPB) without delirium (CPB-NDEL) and delirium after a CPB procedure (CPB-DEL). Delirium was diagnosed by the Confusion Assessment Method for the ICU and chart reviews.

Results: We observed increased preoperative levels of tau in patients with later delirium, whereas values of NfL and GFAP did not differ. In the postoperative course, all biomarkers increased multi-fold. NfL levels sharply increased in patients with CPB reaching the highest levels in the CPB-DEL group.

Conclusion: Tau and NfL might be of benefit to identify patients in cardiac surgery at risk for delirium and to detect patients with the postoperative emergence of delirium.

Keywords: cardiac surgery, neuroinflammation, delirium, biomarker, neurofilaments, tau protein

Received: May 3, 2019; Revised: July 11, 2019; Accepted: August 22, 2019; Prepublished online: September 16, 2019; Published: September 23, 2019  Show citation