Cardiac Alpha-Synuclein Is Present in Alpha-Synucleinopathies

BACKGROUND: Alpha-synucleinopathies (AS) are characterized by pathologic aggregations of alpha-synuclein (α-syn) in the central nervous system, and comprise dementia with Lewy bodies, Parkinson's disease, and multiple system atrophy. Previous studies on AS have reported findings of α-syn pathology in the peripheral nervous system of multiple organs, including the heart. OBJECTIVE: The aim of this study was to further investigate and confirm the presence of cardiac α-syn in AS compared to other major neurocognitive disorders in a neuropathologically confirmed cohort. METHODS: All deceased patients with performed autopsy and with neuropathologically confirmed AS at the Clinical Department of Pathology in Lund 2010-May 2021 were evaluated for inclusion. Cases with insufficiently sampled cardiac tissue or only limited neuropathological investigation were excluded. An age-matched group of individuals with other neurodegenerative diseases, having no α-syn in the CNS, served as controls. In total, 68 AS and 32 control cases were included in the study. Immunohistochemistry for detection of cardiac α-syn aggregates was performed. RESULTS: The AS group had a significantly higher prevalence of cardiac α-syn pathology (p≤0.001) than the control group, 82% and 0%, respectively. CONCLUSION: This study confirms the association between AS and the presence of cardiac α-syn in a neuropathologically confirmed cohort. This motivates further research on potential pathophysiological effects on cardiac function in AS patients.