A debate has erupted in Spain’s medical community: traditional methods of assessing patients after cardiac arrest may soon give way to a new biomarker. The focus is on a specific polypeptide neurofilament, which, according to recent data, appears to predict patient outcomes more accurately than other indicators. Physicians and researchers from multiple countries, including Spain, are closely examining the latest results of a large-scale international study involving hundreds of patients.
Traditionally, neurologic recovery after cardiac arrest is assessed using clinical tests, neuroimaging, and blood analysis for specific proteins. However, these methods do not always provide definitive answers. This is especially true for two widely used biomarkers: neuron-specific enolase and S100 protein. The first can give false results due to hemolysis, while the second is produced not only in the brain but also in other tissues, which can confuse clinicians.
The Spanish perspective
In Spain, where thousands of out-of-hospital cardiac arrests are recorded every year, the need for precise prognosis is particularly urgent. Physicians point out that each extra day of delay in making a decision can cost patients their chance at recovery. That’s why the emergence of this new marker has drawn such keen interest among specialists.
In an international study involving clinics from the UK, Denmark, China, Norway, the US, France, Sweden, and the Czech Republic, researchers compared the effectiveness of several biomarkers. Special attention was given to neurofilament light chain and glial fibrillary acidic protein. Spanish experts have already begun implementing these new approaches in their intensive care units to test how applicable the findings are to their patients.
Results and figures
The study included 819 patients with a median age of 64. Some of them underwent therapeutic hypothermia—a procedure that lowers body temperature to protect the brain. Biomarker levels were measured immediately upon admission to intensive care, and then at 24, 48, and 72 hours. Neurological outcomes were assessed using the Rankin Scale, ranging from full recovery to severe disability or death.
The most impressive results were shown by the neurofilament light chain. As early as one day after cardiac arrest, its level could predict the outcome with high accuracy. After two days, the prognostic value of this protein peaked: the area under the curve reached 0.93, significantly higher than that of other markers. By comparison, glial fibrillary acidic protein and neuron-specific enolase yielded more modest results.
Practical conclusions
Spanish doctors note that the new biomarker could be a real breakthrough in intensive care. Its high specificity and sensitivity allow for quicker decision-making in treatment strategies. This is especially important for patients who are unconscious, when standard assessment methods are ineffective.
Furthermore, the study found that higher concentrations of neurofilament light chain are linked to an increased risk of death within six months after cardiac arrest. This opens up new possibilities for long-term monitoring and rehabilitation of patients. Doctors emphasize that final conclusions on the applicability of this marker in Spain will be made after further research, but it is already clear: conventional approaches may change.
The Future of Diagnostics
The introduction of new biomarkers into clinical practice is not a quick process. Additional trials, staff training, and laboratory equipment upgrades are necessary. However, interest in neurofilament light chain is growing in Spanish hospitals. Some clinics have already begun using it to assess the condition of patients after cardiac arrest, and the results of initial observations confirm the findings of international colleagues.
Doctors are confident: if the effectiveness of the new marker is confirmed in large-scale studies, it will not only increase the accuracy of predictions but also optimize treatment, reduce unnecessary procedures, and improve patients’ quality of life. In the coming years, Spain may become one of the countries where these new diagnostic methods are implemented the fastest.
If you didn’t know, neurofilament light chain (NfL) is a protein that has long been used in neurology to assess nerve tissue damage. Its levels rise in various brain diseases, as well as after extreme stress, for example, in astronauts returning to Earth. In recent years, interest in this biomarker has surged, and now it may become a key tool in resuscitation and intensive care.
