EP 089 The Impact of Transcranial Doppler on the Outcome of Delayed Cerebral Ischaemia: A Propensity Matched Analysis

Background Vasospasm following aneurysmal subarachnoid hemorrhage (aSAH) is typically diagnosed using CT or catheter angiograms. Transcranial Doppler (TCD) offers a bedside, radiation-free alternative but has limited widespread use. This study assessed whether the implementation of routine TCD in aSAH patients influenced the incidence of DCI and long-term functional outcomes following aSAH. Methods aSAH patients treated before (2019–2020) and after (2021–2022) the introduction of routine TCD monitoring were compared. Clinico-demographic data were analyzed, with propensity score matching (PSM) and multivariable regression used to control for confounders. The primary outcome was the modified Rankin Scale (mRS) at six months, with DCI incidence as a secondary outcome. Results In a cohort of 466 patients (239 pre-TCD, 227 post-TCD), the overall 6-month favorable functional outcome (mRS 0–2) was comparable between groups (74.5% vs. 73.6%, p=0.906). The incidence of delayed cerebral ischemia (DCI) was lower in the post-TCD cohort (18.1% vs. 25.5%) and multivariable analysis confirmed a protective effect of routine TCD monitoring on the incidence of DCI (OR 0.48, p=0.004). Counterfactual analysis indicated an absolute risk reduction for clinical DCI of 5.3% (p=0.026) and a relative risk reduction of 18.7% in association with the use of TCD. Conclusion The implementation of routine TCD monitoring was associated with improved functional outcomes and a reduced incidence of DCI in patients with aSAH. These findings support routine TCD use for early vasospasm detection and timely intervention, but require prospective, multi-centre validation.