The predictive value of serum myeloperoxidase for vasospasm in patients with aneurysmal subarachnoid hemorrhage.

Vasospasm is a major contributor to morbidity and mortality in aneurysmal subarachnoid hemorrhage (SAH), with inflammation playing a key role in its pathophysiology. Myeloperoxidase (MPO), an inflammatory marker, was examined as a potential marker of vasospasm in patients with SAH. Daily serum samples from patients with aneurysmal SAH were assayed for MPO, and transcranial Doppler (TCDs) and neurological exams were assessed to determine vasospasm. Suspected vasospasm was confirmed by angiography. Peak MPO levels were then compared with timing of onset of vasospasm, based on clinical exams, TCDs and cerebral angiography. Patients with vasospasm had a mean MPO level of 115.5 ng/ml, compared to 59.4 ng/ml in those without vasospasm, 42.0 ng/ml in those with unruptured aneurysms, and 4.3 ng/ml in normal controls. In patients who experienced vasospasm, MPO was elevated above the threshold on the day of, or at any point prior to, vasospasm in 10 of 15 events (66.7%), and on the day of, or within 2 days prior to, vasospasm in 8 of 15 events (53.3%). Elevated serum MPO correlates with clinically evident vasospasm following aneurysmal SAH. The potential utility of MPO as a marker of vasospasm is discussed.