Unfavorable Outcome in Patients with Aneurysmal Subarachnoid Hemorrhage WFNS Grade I.

Background: Patients with an aneurysmal subarachnoid hemorrhage (aSAH) and World Federation of Neurosurgical Societies (WFNS) grade I on admission are generally considered to have a good clinical outcome.

Objective: The objective of this study was to assess the actual clinical outcome of WFNS grade I aSAH patients, and to determine which factors are associated with unfavourable outcome.

Methods: For this prospective cohort study, 132 consecutive patients (age 18 years or older) with a WFNS grade I aSAH admitted to our hospital between December 2011 and January 2016 were eligible. Clinical outcome was measured using the modified Rankin Scale (mRS) at 6-month follow-up. Unfavorable outcome was defined as an mRS score of 3-6. Univariable analyses were performed using logistic regression models.

Results: Of 116 patients, only 5 patients (4%) had an mRS score of 0 and most (65%) had an mRS score of 2. Twenty-five patients (22%) had an unfavorable outcome. Nine (8%) patients died, of whom 4 died during admission. Factors associated with unfavorable outcome were age (per increasing decade: odds ratio [OR]. 1.78; 95% confidence interval [CI], 1.16-2.72), delayed cerebral ischemia (OR, 4.32; 95% CI, 1.63-11.44), pneumonia (OR, 10.75; 95% CI, 1.94-59.46) and meningitis (OR, 28.47; 95% CI, 1.42-571.15).

Conclusions: Despite their neurologically optimal clinical condition on admission, 1 in 5 patients with WFNS grade I aSAH has an unfavorable clinical outcome or is dead at 6-month follow-up. Additional multivariable analysis in larger patient cohorts is necessary to identify the extent to which preventable complications contribute to unfavorable outcomes in these patients.