Long-term Outcomes of Poor-grade Aneurysmal Subarachnoid Haemorrhage: A Multicentre Observational Cohort Study

BACKGROUNDDespite advancements in neurosurgery and intensive care that reduce overall mortality, poor-grade aneurysmal subarachnoid haemorrhage (aSAH) (World Federation of Neurosurgical Societies [WFNS] grades IV and V) remains a significant clinical challenge and is associated with persistently high mortality rates. The aim of this study was to assess the long-term outcomes of poor-grade aSAH and to identify factors influencing patient prognosis to guide clinical management. METHODSA multicentre, observational cohort study was conducted across 12 regional centres in northern China. The study included patients with poor-grade aSAH admitted from 2017 to 2020. The baseline data included demographics, clinical presentation, aneurysm characteristics, and treatment modalities. Outcome data, including survival status, mortality along with its associated causes and timing, and modified Rankin scale (mRS) scores, were collected prospectively at the last medical follow-up. Changes in case fatality over time were quantified with weighted linear regression. Survival analysis was performed to estimate survival and hazard ratios for death. Binary logistic regression was performed to estimate the odds ratio for dependency (mRS=3-5). RESULTSAmong the 1,589 enrolled patients, 1,339 were successfully followed, with an average follow-up of 26.37 months. Among them, 61.5% (824/1,339) were dependent or died. The overall mortality rate was 51% (684/1,339), and 21.3% (140/655) of the survivors were dependent. The risk factors for mortality included age [≥]65 years, previous history of stroke, and WFNS grade V. Additionally, conservative treatment and endovascular treatment were identified as risk factors and protective factors, respectively, compared with surgical treatment. WFNS grade V and middle cerebral artery aneurysms are independent risk factors for dependency. CONCLUSIONSAlthough there has been a downward trend in recent years, the long-term mortality rate for poor-grade aSAH has remained significantly high at 51%, with 21.3% of survivors being dependent. Active aneurysm treatment, to the extent possible, is crucial for improving the prognosis of these patients.