High-Grade Aneurysmal Subarachnoid Hemorrhage: Predictors of Functional Outcome

Background: Because the prognosis of high-grade aneurysmal subarachnoid hemorrhage (aSAH), classified as World Federation of Neurosurgical Societies (WFNS) grade IV–V, is generally poor, the functional outcomes of survivors have not been thoroughly explored. The aim of this retrospective cohort study is to determine predictors of functional independence in patients who survive a high-grade aSAH. Methods: We retrospectively evaluated consecutive patients with aSAH admitted to a single institution from January 2000 to April 2015. Adult (age ≥18 years) patients with WFNS grade IV–V aSAH were included for analysis. Patients without sufficient baseline data, those who died before discharge, and those without follow-up data were excluded. Univariable and multivariable logistic regression analyses were used to identify factors associated with functional independence, defined as a modified Rankin Scale score of 0–2, at last follow-up. Results: Of the 260 patients with a WFNS grade IV–V aSAH during the study period, 139 met the inclusion criteria. After a mean follow-up of 6.3 months, functional independence was achieved in 73% of high-grade aSAH survivors (101/139 patients) and in 39% of all high-grade aSAH cases (101/260 patients). Only a lack of cerebrospinal fluid shunt placement was found to be an independent predictor of functional independence in the multivariable analysis (odds ratio 0.28 [0.109–0.722]; P = 0.008). Conclusions: Because functional independence can be achieved in the majority of high-grade aSAH survivors, aggressive initial management of high-grade aSAH is warranted. Strategies that reduce the need for permanent cerebrospinal fluid diversion may improve functional outcomes in survivors of high-grade aSAH.