Prognostic value of cerebral perfusion-computed tomography in the acute stage after subarachnoid hemorrhage for the development of delayed cerebral ischemia.

BACKGROUND AND PURPOSE Delayed cerebral ischemia (DCI) is an important cause of death and disability after subarachnoid hemorrhage. We studied the additional prognostic value of brain perfusion to 3 established predictors (age, clinical condition on admission, and amount of subarachnoid blood) for the development of DCI. METHODS We included 69 patients scanned with perfusion--computed tomography within 72 hours after subarachnoid hemorrhage. For each patient, we determined cerebral blood flow (CBF) ratios of prespecified opposite regions of interest and the 3 established predictors. We calculated adjusted hazard ratios (HRs) for the CBF ratio and the 3 established predictors by means of multivariate analysis (Cox regression). The additional prognostic value of CBF ratios was assessed by comparing the area under the receiver operating characteristic curve (AUC) of 2 models: 1 with and 1 without addition of the CBF ratio to the 3 established predictors. RESULTS The CBF ratio was an independent predictor for the development of DCI (HR, 0.63; 95% CI, 0.46 to 0.86) as was clinical condition (HR, 1.47; 95% CI, 1.01 to 2.13). By adding the CBF ratio to the model with the 3 established predictors, the AUC of the receiver operating characteristic curve increased from 0.76 (95% CI, 0.65 to 0.89) to 0.81 (95% CI, 0.71 to 0.91). This trend toward an increased AUC suggests an improved predictive value. CONCLUSIONS The CBF ratio is an independent predictor for the development of DCI and can contribute to a better identification of patients at high risk for DCI.