Phosphatase alkaline levels are not associated with poor outcomes in subarachnoid hemorrhage patients

Introduction: Alkaline phosphatase (ALP) levels are often elevated in cerebrovascular and cardiovascular disease. Their prognostic role after subarachnoid hemorrhage (SAH) remains to be elucidated. Methods: We performed a retrospective single center study of patients with non-traumatic SAH admitted to the intensive care unit (ICU) of Erasme Hospital (Brussels, Belgium) from 2006 to 2019. Exclusion criteria were previous history of liver cirrhosis or malignancies and early death (i.e. within 24 h from ICU admission). Baseline information, clinical data, radiologic data were collected, the occurrence of DCI as well as serum ALP levels during the first 12 days of ICU stay. Unfavorable neurological outcome (UO) at 3 months was defined as a Glasgow Outcome Scale of 1-3. Results: Six hundred and fifty patients were included; ALP levels increased from baseline after day 6 from admission, in particular among patients with an initial poor clinical status. There was no difference in the ALP levels between patients with or without DCI over time. Patients with UO had higher ALP levels over time than others; however, in the multivariable analysis, nor ALP levels on admission or the highest ALP value during the ICU stay were independently associated with UO. Conclusions: The results of this study suggested that ALP levels had no prognostic role in SAH patients. Other possible prognostic biomarkers should be evaluated in this setting.