Mortality among patients with aneurysmal SAH in a nationwide unselected cohort

Aneurysmal subarachnoid haemorrhage is a severe condition with reported in-hospital mortality ranging from 7.1% to 24.1%, but the term in-hospital mortality is not consistently defined, and methodological limitations persist in studies investigating mortality and potential risk factors for mortality. In Denmark, nearly all patients with aSAH are admitted to a neurosurgical department and recorded in a nationwide registry.

Using nationwide clinical data we aimed to estimate mortality within the primary admission to a neurosurgical department and identify risk factors associated with mortality in an unselected aSAH cohort.

All patients with aSAH recorded in the Danish Stroke Registry between January 1st 2017 and August 31st, 2022 were included. Associations between potential risk factors and mortality were examined using univariate and multivariate logistic regression models, adjusting for age, sex and neurosurgical admission. Subgroup analyses were conducted among patients who underwent closure of the aneurysm.

The cohort comprised 1374 patients. Overall mortality was 22.0%. Mortality among patients who underwent aneurysm treatment was 11.9%. Lower Glasgow Coma Scale score, higher World Federation of Neurological Surgeons score, higher Fisher scale score, aneurysm size >12 mm, posterior circulation location, rebleeding and cerebral infarction were significantly associated with mortality.

In conclusion, this nationwide clinical register-based study showed that mortality after aSAH remained substantial, with 22.0% among all patients admitted to a neurosurgical department in Denmark and 11.9% among those who underwent closure of the aneurysm. Mortality was mainly related to initial clinical severity and complications rather than pre-existing comorbidity.