1117. In-Hospital Complications and Clinical Outcomes in Angiographically Negative Subarachnoid Hemorrhage

Authors: Cody Lee Nesvick, MD; Soliman Oushy, MD; Lorenzo Rinaldo, MD, PhD; Eelco Wijdicks, MD, PhD; Giuseppe Lanzino, MD; Alejandro Rabinstein, MD (Rochester, MN)

Introduction: Many patients with subarachnoid hemorrhage will have a normal cerebral angiogram. The complications and outcomes of patients with angiographically negative subarachnoid hemorrhage (anSAH) are not well-defined. The goal of this study was to define the hospital course, complications and outcomes of patients with aneurysmal-pattern anSAH (aanSAH) compared to those with perimesencephalic-pattern anSAH (panSAH) and aneurysmal subarachnoid hemorrhage (aSAH). Methods: We performed a retrospective cohort study of patients with aneurysmal and angiographically negative subarachnoid hemorrhage treated at Mayo Clinic between 2006 and 2018. Ninety-nine patients with anSAH (33 aanSAH, 66 panSAH) and 474 patients with aSAH were included. Results: Patients with aanSAH and panSAH had similar rates of DCI and radiologic infarction, and patients with aanSAH had significantly lower rates compared to aSAH (DCI: OR = 0.090, 95% CI 0.012 – 0.66; infarction: OR 0.26, 95% CI 0.078 – 0.86). Patients with aanSAH were more likely than those with panSAH to require temporary CSF diversion (OR 6.25, 95% CI 2.50 – 15.6) and ventriculoperitoneal shunting (VPS; OR 4.67, 95% CI 1.09 – 20.04), with similar rates to those seen in aSAH (CSF diversion: OR 1.04, 95% CI 0.49 – 2.19; VPS: OR 0.62, 95% CI 0.25 – 1.55). Compared to those with aSAH, patients with aanSAH were less likely to have a poor functional outcome (modified Rankin score > 2, including death) within one year of ictus (OR 0.25, 95% CI 0.086 – 0.72) and at last follow-up (HR 0.27, 95% CI 0.17 – 0.43). Conclusion: These results demonstrate that DCI is very uncommon in anSAH, but patients with aanSAH have a similar need for CSF diversion to patients with aSAH. Patients with aanSAH have a significantly better short- and long-term prognosis compared to patients with aSAH.