Establishment And Verification Of Preoperative Risk Prediction Model For Delayed Cerebral Ischemia After Aneurysmal Subarachnoid Hemorrhage

Objective: To establish a reliable preoperative risk prediction model for predicting the occurrence of delayed cerebral ischemia(DCI)in patients with aneurysmal subarachnoid hemorrhage(a SAH).Methods: We collected data from 887 eligible consecutive patients who underwent surgical clipping or endovascular coiling for a SAH at the Neurosurgery Department of the First People’s Hospital of Lianyungang from January 1,2013 to July 30,2019.Among them,patients who had previously undergone surgery formed the training cohort(n = 621)for the development of the nomogram and those who underwent surgery later formed the validation cohort(n = 266)to confirm the performance of the model.A multivariate logistic regression was used to determine the independent risk factors associated with DCI,which were then incorporated into the nomogram.The predictive performance of the nomogram was measured by the concordance index(C index)and calibrated with 1,000 bootstrap samples to decrease any overfit bias.Result: DCI was identified in 158 of 621 patients(25.4%)in the training cohort and66 of 266 patients(24.8%)in the validation cohort.Preoperative factors associated with DCI were age >65 years(OR = 1.89,95% CI 1.19-3.01),modified Fisher grade of 3-4(OR = 2.48,95% CI 1.51-4.07),Hunt-Hess grade of 4-5(OR = 4.41,95% CI2.52-7.72),high blood pressure on admission(OR = 1.63,95% CI 1.00-2.65),and plasma homocysteine(Hcy)level ≥10 μmol/L(OR = 2.90,95% CI 1.91-4.39);protective factor was ruptured aneurysm in the posterior circulation(OR = 0.17,95%CI 0.08-0.34).Incorporating these 6 factors,the nomogram achieved efficient concordance indices of 0.73(95% CI,0.68-0.77)and 0.65(95% CI,0.57-0.72)in predicting DCI in the training and validation cohorts,respectively.Conclusion: Preoperative factors associated with DCI were age >65 years,modified Fisher grade of 3-4,Hunt-Hess grade of 4-5,high blood pressure on admission and plasma homocysteine(Hcy)level ≥10 μmol/L;protective factor was ruptured aneurysm in the posterior circulation.Incorporating these 6 factors,we established a preoperative risk prediction model for delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage in the form of a nomogram,providing an effective preoperative assessment of the risk of DCI risk in patients with a SAH.