Age-Related Differences in Clinical Characteristics and Outcomes of Aneurysmal Subarachnoid Hemorrhage: A Retrospective Study of 657 Patients.

Background: Aneurysmal subarachnoid hemorrhage (aSAH) has an incidence of 6-7 per 100,000 person-years. Despite advancements in treatment, 26% of patients die and 19% remain dependent after hemorrhage. Long-term neuropsychological sequelae affect about half of the survivors, significantly affecting their quality of life. This study aims to assess aSAH characteristics and identify predictive factors of clinical outcomes in young patients.

Methods: A retrospective study analyzed 657 patients with aSAH treated at 2 South Korean medical centers from January 2011 to December 2023. Data on demographics, comorbidities, smoking history, clinical grades, aneurysm size and location, and outcomes were collected. Outcomes were classified using the modified Rankin Scale, with scores ≤2 indicating good outcomes.

Results: The cohort included 233 men and 424 women (male/female ratio 1:1.8). Most patients were middle-aged (74.4%), followed by young (16.7%) and old (8.8%) groups. Young patients showed male predominance (56.8%), lower hypertension (12.7%) and diabetes (1.8%) rates, and higher smoking rates (39.6%). Older patients had higher hypertension (44.6%) and diabetes (23.3%) rates and were predominantly female (69.1%). Aneurysms in young patients were smaller (P = 0.04). Multivariate analysis identified poor Hunt-Hess grade, permanent cerebral infarction, and aneurysmal recurrence or rebleeding as predictors of poor outcomes in young patients. Middle-aged patients had additional predictors, including diabetes and hydrocephalus. In older patients, only poor Hunt-Hess grade was significant.

Conclusions: Young patients with aSAH show distinct characteristics and prognostic factors compared with older patients. Despite higher postoperative complications, young patients generally have better outcomes, emphasizing the need for age-specific management strategies in aSAH.