Plasma endothelin concentrations after aneurysmal subarachnoid hemorrhage

Area of Science:

• Neuroscience
• Cardiovascular Research
• Endocrinology

Background:

• Cerebral vasospasm and delayed ischemia are complex complications following subarachnoid hemorrhage (SAH).
• Endothelin (ET), a potent vasoconstrictor, is implicated as a key mediator in chronic vasospasm.

Purpose of the Study:

• To investigate the correlation between serial plasma endothelin (ET) concentrations and the development of ischemic symptoms.
• To examine the relationship between ET levels, angiographically confirmed vasospasm, and computerized tomography (CT) findings post-aneurysmal SAH.

Main Methods:

• Plasma endothelin-1 (ET-1) immunoreactivity was measured in 70 aneurysmal SAH patients and 25 healthy volunteers using an immunometric assay.
• Serial ET concentrations were analyzed in relation to clinical outcomes, angiographic vasospasm severity, and CT-detected cerebral infarction.

Main Results:

• Mean plasma ET concentrations did not differ between SAH patients and healthy volunteers overall.
• Significantly higher ET levels were observed in patients experiencing delayed cerebral ischemia, severe vasospasm, or larger cerebral infarctions.
• Elevated ET was particularly noted in the early (Days 0-5) and later (Days 6-14) post-SAH periods for these patient groups.

Conclusions:

• Plasma endothelin (ET) concentrations correlate with delayed cerebral ischemia and vasospasm following subarachnoid hemorrhage (SAH).
• High ET levels are predictive of ischemic symptoms and vasospasm, and may exacerbate ischemia in hypertensive patients.
• ET is likely a significant factor in the pathogenesis of vasospasm after SAH, though its precise role requires further investigation.