Cerebrospinal fluid haemoglobin as a monitoring biomarker for secondary brain injury after aneurysmal subarachnoid haemorrhage: prospective international multicentre validation study (HeMoVal)

Preclinical animal models link cell-free haemoglobin in cerebrospinal fluid (CSF-Hb) to secondary brain injury after aneurysmal subarachnoid haemorrhage (SAH-SBI).

A single-centre study reported strong associations between daily external ventricular drain (EVD)-derived CSF-Hb levels and SAH-SBI, and suggested a strong predictive potential (area under the curve 0.89).

CSF-Hb monitoring has therefore been proposed as a bedside biomarker, but it has not undergone multicentre validation.

In a preregistered multicentre cohort of 366 patients from eight neurosurgical centres, once-daily EVD-derived CSF-Hb measurements showed poor same-day discrimination for SAH-SBI (area under the curve 0.59) and substantial between-centre heterogeneity.

In a post-hoc exploratory analysis, higher CSF methaemoglobin was associated with SAH-SBI; higher acute-phase CSF-Hb was related to chronic hydrocephalus and a worse 3 month functional outcome.

These...