Association of asymptomatic cerebral vasospasm with outcomes in survivors of aneurysmal subarachnoid hemorrhage

Background: Cerebral vasospasm (cVSP) is a common complication in aneurysmal subarachnoid hemorrhage (aSAH) and is associated with worse outcomes. How-ever, clinical significance of asymptomatic cVSP is poorly understood. We sought to determine the association of asymptomatic cVSP with functional outcome and hospital length of stay (LOS). Methods: We performed a retrospective study of a pro-spectively collected cohort of patients with aSAH who survived hospitalization at an academic center between 2016 and 2021. We defined cVSP based on transcranial Doppler criteria. Multivariate logistic and multiple linear regression analyses were used to determine the association of asymptomatic cVSP with poor functional out-come (defined as modified Rankin scale 3-6 at 3 months after discharge) and hospi-tal length of stay (LOS). Results: The cohort consisted of 201 aSAH patients with a mean age 54.9 years (SD 13.6) and 60% were female. One hundred nine patients (54%) experienced cVSP, of whom 43 patients (39%) were asymptomatic. Patients with asymptomatic cVSP were younger (mean 50.5 years [SD 10.6] vs 61 years [SD12.5]; p < 0.001) and had longer ICU LOS (median 13 days [IQR12-20] vs median 12 days [IQR9-15], p = 0.018) compared to those without cVSP. However, after adjusting with other variables asymptomatic cVSP was not associated with longer ICU or hospital LOS. Asymptomatic cVSP was not associated with poor out-come either (p = 0.14). Conclusion: Asymptomatic cVSP, which was more common in younger patients, was neither associated with poor functional outcome nor hos-pital LOS. Larger prospective studies are needed to assess the significance of asymptomatic cVSP on long-term outcomes.