Soluble Fms-Like Tyrosine Kinase 1 (sFlt-1) and Risk of Cerebral Vasospasm After Aneurysmal Subarachnoid Hemorrhage

Abstract

The molecular mechanisms underlying cerebral vasospasm and delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (aSAH) are incompletely understood. We hypothesized that circulating antiangiogenic factors, such as soluble Fms-like tyrosine kinase 1 (sFlt-1) and soluble transforming growth factor β coreceptor, soluble endoglin (sEng), are important markers of their pathophysiology. We performed a prospective study in patients with aSAH and measured cerebrospinal fluid and serum levels of sFlt-1 and sEng on postbleed day 1 and 6 and correlated levels with incidence and severity of cerebral vasospasm and DCI. Twenty-seven patients with aSAH were enrolled in the study. Severe angiographic vasospasm was present in 14.8% of patients and DCI occurred in 33.3%. Serum sFlt1 levels were increased on postbleed day 6 in patients who developed vasospasm. However, on postbleed day 1, there were no differences in patients who developed vasospasm. Increased serum sFlt-1 levels on postbleed day 1 were found to predict the development of severe angiographic vasospasm with an area under the curve of 0.818 with an optimal cutoff value of 95 pg/mL. Alterations in sFlt1 were not associated with DCI. Serum and cerebrospinal fluid sEng levels did not correlate with vasospasm or DCI. Serum levels of sFlt-1 are increased in patients with aSAH who are at risk for severe vasospasm. Further studies with larger sample sizes are needed to evaluate whether sFlt-1 levels may predict onset of severe vasospasm and DCI.