gms | German Medical Science

Objective: In neurosurgery generally, and especially regarding subarachnoid hemorrhage (SAH) - being a severe and complex pathology with dreaded both ischemic and hemorrhagic complications - the optimal prophylactic heparin regimen is still controversial. The goal of this study was to analyse the impact of the timepoint of heparin initiation (ToH) on the incidence of ischemic and haemorrhagic events after SAH.

Methods: Patients who received acute treatment for non-traumatic SAH between 2011 and 2018 were considered for this retrospective study. 370 patients were included. The influence of the ToH on the incidence of ischemic and haemorrhagic events and changes in outcome scores was assessed. Therefore, the period between admission or, if possible, securing the source of bleeding (SOB) and ToH in hours was calculated. Statistical analysis was performed using Mann-Whitney U-Test, Chi-square test, Fisher’s exact test and univariate binomial logistic regression. P-values lower than 0.05 were considered statistically significant.

Results: The incidence of extracranial ischemia was 4.6%, thrombembolic intracranial ischemia 12.2% and intracranial re-bleeding 14.6%.The ToH as a continuous parameter significantly affects the incidence of extracranial ischemia (p=0.009), but does not have an impact on intracranial ischemia or rebleeding. Patients anticoagulated within 48 hours have a significantly lower incidence of extracranial ischemia than those with later ToH (p=0.020). Yet, the outcome at discharge did not diverge. When starting heparin later than 72h after admission or securing the SOB, extracranial ischemia occurs significantly more often (p=0.037), along with a significantly worse outcome at discharge (modified Rankin Scale (mRS) p=0.031, Glasgow Outcome Scale (GOS) p=0.026) and after 12 months (mRS p=0.014, GOS p=0.019), but without differences in mortality or readmission rates. No significant differences in the occurrence of initial World Federation of Neurosurgical Societies (WFNS) Scores above 3 could be detected between the time windows.

Conclusion: While later initiation of heparin is associated with higher incidence of extracranial ischemia, it does not influence the incidence of intracranial ischemia or intracranial re-bleeding. All patients suffering from SAH can therefore be administered heparin within 24 hours after admission or securing of SOB, respectively, as prophylactic doses do not promote re-bleeding.