Predictors of survival after aneurysmal subarachnoid hemorrhage: The long-term observational cohort study

Objective: Despite recent advances in neuro-intensive care, there is still considerable mortality in patients with aneurysmal subarachnoid hemorrhage (SAH). In this long-term monocentric observational cohort study, we aimed to analyze the rates, timing, and predictors of mortality after SAH.

Methods: All consecutive SAH cases treated between January 2003 and June 2016 were included. Patients' demographic characteristics, previous medical history, SAH-related parameters, and available post-treatment follow-up data were collected and evaluated as potential mortality predictors in univariate and multivariate analyses.

Results: Of 992 patients, 179 died during the initial treatment and 33 during the follow-up time reaching an overall mortality rate of 21.4 %. Of over 119 tested variables, we identified the following independent predictors in the final multivariate Cox regression analysis: age >55 years (p<0.0001); World Federation of Neurosurgical Societies (WFNS) admission grade IV or V (p=0.025); Hijdra sum score ≥15 points (p=0.003); intracranial pressure (ICP) increase (p<0.0001); and delayed cerebral ischemia (DCI) (p<0.0001). Being exposed to all five risk factors resulted in the case fatality rate of 75 % within a median survival of 14 days, compared to 2.5 % within a median of 1525 days when none of these features were present.

Conclusions: The initial impact of aneurysmal bleeding is amongst the major mortality causes after SAH. Of potentially preventable adverse events, ICP increase and DCI occurring during initial treatment also present eminent clinical relevance for patients' survival in the long-term follow-up. Further ICP and DCI management optimization might help to decrease the mortality rate after SAH.