Background: Cerebral vasospasm complicating subarachnoid hemorrhage causes ischemic stroke and worsens the neurological outcome. The potential role of endothelin-1 in vasospasm pathogenesis may provide therapeutic opportunities. A recent meta-analysis however, did not support the use of endothelin antagonists. Apart from clinical assessment, transcranial Doppler and interval angiography, there are no sensitive screening markers for evolving vasospasm. We investigate the ability of serial measurement of endothelin-1 to predict the development of vasospasm following subarachnoid hemorrhage.
Methods: Endothelin-1 levels in cerebrospinal fluid and blood were measured daily in 20 patients admitted to the ICU with subarachnoid hemorrhage from days 1 to 10 following the inception bleed. In addition to clinical assessment, patients had daily transcranial Doppler. Digital subtraction angiography was performed on the suspicion of vasospasm based upon clinical or transcranial Doppler assessment. Neuron-specific enolase and SB100 were measured in blood as comparative biomarkers of neurological injury.
Results: Mean plasma endothelin-1 on day 5, was 4.2 mcg/L (CI 3.1-5.8) in patients with vasospasm compared to 2.5 mcg/L (CI 1.5-4.0) in those without vasospasm (P = 0.047). There were no time-related differences in cerebrospinal fluid endothelin-1, plasma NSE, or SB100 for patients with and without vasospasm.
Conclusions: In patients with subarachnoid hemorrhage and vasospasm, endothelin-1 is significantly higher in plasma than in CSF on day 5. Neither NSE nor SB100 is associated with the development of vasospasm. Measurement of serial plasma endothelin-1 concentration is a potential screening marker of vasospasm.