BACKGROUND: Patients with an aneurysmal subarachnoid haemorrhage (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 (≥ 18 years old) 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 six months' follow-up. Unfavourable outcome was defined as an mRS score of 3-6. Univariable analyses were performed using logistic regression models.
RESULTS: Of 116 patients, only five (4%) had an mRS score of 0 and most (65%) had an mRS score of 2. Twenty-five (22%) patients had an unfavourable outcome. Nine (8%) patients died, of whom four during admission. Factors associated with unfavourable outcome (OR; 95% CI) were age (per increasing decade: 1.78; 1.16-2.72), delayed cerebral ischemia (4.32; 1.63-11.44), pneumonia (10.75; 1.94-59.46) and meningitis 28.47 (1.42-571.15).
CONCLUSIONS: Despite their neurologically optimal clinical condition on admission, one out of five WFNS grade I aSAH patients has an unfavourable clinical outcome, or is dead, at six months' follow-up. Additional multivariable analysis in larger patient cohorts is necessary to identify the extent to which preventable complications contribute to unfavourable outcome in these patients.