Transcranial Doppler pulsatility index variability association with clinical outcome after aneurysmal subarachnoid...

Transcranial Doppler mean flow velocity (MFV) and pulsatility index (PI) are used for ancillary monitoring in aneurysmal subarachnoid hemorrhage (SAH). We evaluated PI and MFV variables in the middle cerebral arteries (MCA) for potential associations with delayed cerebral ischemia (DCI) and clinical outcome.

We retrospectively evaluated patients with SAH over a six-year period. Poor outcome was defined as a three-month Modified Rankin Scale (Rajajee et al., 2012; Bellner et al., n.d.; Chang et al., 2023), and DCI was defined by presence of vascular infarcts on brain imaging. Serial PI and MFV values for each patient were compiled to obtain four PI and MFV variables, including maximum absolute change in daily PI values (AbsΔPI). Multivariate logistic regression was performed to identify subsets of variables that maximized area under curve-receiver operating characteristic (AUC-ROC) for clinical outcome. Multivariate logistic regression analysis using clinical outcome and DCI was generated using PI variables, MFV variables, and demographic variables.

268 patients met inclusion criteria and were evaluated. PI, MFV, and demographic variables yielded an AUC-ROC value of 0.84 for clinical outcome. Multivariate logistic regression analysis showed that AbsΔPI (p = 0.01), older age (p < 0.001), Hunt Hess score (p < 0.001), and Fisher score (p = 0.05) were significant predictors for poor clinical outcome. No MFV variable had significant associations with clinical outcome.

We found that PI variability in the MCAs had a significant association with clinical outcome in patients with SAH: every 0.1 variability in PI resulted in 1.4-times higher odds of poor clinical outcome. Further studies are needed for confirmation.