Predictors of Outcomes Six Months after Endovascular Coil Embolization of Poor-Grade Aneurysmal Subarachnoid Hemorrhage

OBJECTIVE: To identify factors associated with the outcome and prognosis of coil embolization for poor-grade aneurysmal subarachnoid hemorrhage (aSAH). METHODS: We retrospectively reviewed 118 patients with World Federation of Neurosurgical Societies (WFNS) grade IV or V subarachnoid hemorrhage at our institute between January 2010 and December 2020. Outcomes were assessed using modified Rankin Scale (mRS) scores at discharge and at six months after aSAH onset. In addition, patient background, aneurysm characteristics, and treatment outcome were compared between patients showing favorable (mRS scores: 0–2) and unfavorable (mRS scores: 3–6) outcomes at six months. Factors for change of mRS during follow-up were explored, and cut off values were calculated for age using the receiver operating characteristic analysis. RESULTS: Endovascular treatment was performed in 51 of the 118 enrolled patients. Data were analyzed for 43 of these patients who underwent coil embolization of ruptured aneurysms and had complete datasets. The mean age was 61.7 years and 24 (55.8%) patients had WFNS grade V aSAH. Coil embolization-related complications were observed in three patients. There were no treatment-related deaths; however, eight patients (18.6%) died at three months. Multivariate analysis showed that the maximum diameter of the aneurysm (p=0.041) and the postoperative dual antiplatelet therapy (DAPT) (p=0.040) were associated with unfavorable and favorable outcomes, respectively. Older age (p=0.033) was independently associated with mRS score deterioration following discharge. Age 72 years and older was the cut off value for mRS deterioration. CONCLUSION: Aneurysm size and postoperative DAPT might be associated with outcomes at 6 months. Moreover, we identified older age as an independent factor that influences mRS deterioration following discharge; thus, especially in cases of elderly patients over 72 years of age, it is highly likely that long-term care to prevent disuse and regular follow-up on imaging will be necessary.