A SIMPLE blood biomarker linked to nerve damage has been shown to predict major cardiovascular events in patients with atrial fibrillation (AF), offering a potential new tool for risk stratification.
AF is one of the most common cardiac rhythm disorders and is strongly associated with stroke, heart failure, and premature death. While clinicians rely on established risk scores and clinical factors, accurately identifying patients at highest risk of adverse outcomes remains a challenge. Serum neurofilament light chain (sNfL), a marker of neuronal injury, is elevated in patients with AF and has recently emerged as a candidate biomarker reflecting broader systemic vulnerability.
Neurofilament Light Chain and Atrial Fibrillation Outcomes
In a large prospective cohort of 2,311 patients with AF, researchers investigated whether circulating levels of sNfL were associated with long-term cardiovascular outcomes. Participants, with a mean age of 73 years, were followed for a median of 8.0 years, providing robust longitudinal data.
The findings showed a clear and consistent association between higher sNfL levels and worse outcomes. Each doubling of sNfL concentration increased the risk of major vascular events by 35% (adjusted hazard ratio: 1.35; 95% CI: 1.22–1.50; p<0.001). Elevated levels were also linked to increased risks of nonfatal stroke, cardiovascular death, heart failure-related hospitalisation, and all-cause mortality.
Interestingly, no significant association was observed between sNfL and myocardial infarction, suggesting that the biomarker may reflect specific pathophysiological pathways, potentially related to neurovascular or systemic stress rather than atherosclerotic events alone.
Expanding Risk Prediction Beyond Traditional Factors
Neurofilament light chain is typically released into the bloodstream following neuronal injury and has been widely studied in neurological diseases. Its association with cardiovascular outcomes highlights the growing recognition of heart–brain interactions in chronic disease.
The study suggested that sNfL may capture underlying processes not accounted for by traditional cardiovascular risk factors, such as subclinical cerebrovascular damage or systemic frailty. This could make it particularly valuable in older populations with AF, where multimorbidity is common.
However, the observational design means causality cannot be established, and residual confounding may remain. Additionally, sNfL was measured at baseline only, leaving uncertainty around how changes over time may influence risk.
Overall, these findings position sNfL as a promising biomarker for refining cardiovascular risk assessment in AF. Future research will be needed to determine whether incorporating sNfL into clinical decision-making can improve patient outcomes or guide personalised treatment strategies.
Reference
Baskaran G et al. Serum neurofilament light chain and cardiovascular outcomes in patients with atrial fibrillation. JAMA Cardiol. 2026;DOI:10.1001/jamacardio.2026.0922.
Featured image: Nuthawut on Adobe Stock
