A Prospective Evaluation of Clinical Outcomes in Acute Ischemic Stroke after Endovascular Treatment Using Transcranial Doppler (PRECISE-TCD): Study Protocol

Endovascular thrombectomy (EVT) improves outcomes in acute ischemic stroke caused by large vessel occlusion. Despite successful recanalization, early neurological deterioration (END) remains frequent and predicts poor outcomes. Disturbances in cerebral autoregulation may contribute to END, yet reliable bedside predictors are limited. Transcranial Doppler (TCD) provides noninvasive bedside assessment of cerebral blood flow velocities and may identify hemodynamic patterns associated with post-EVT deterioration. PRECISE-TCD is a prospective, single-center observational study enrolling 180-300 patients undergoing EVT for anterior circulation large vessel occlusion at a tertiary academic medical center. TCD examinations will be performed as soon as feasible after EVT, daily through 72 hours, and near END events. Hemodynamic parameters including peak systolic velocity (PSV), end-diastolic velocity (EDV), mean flow velocity (MFV), and pulsatility index (PI) will be measured in bilateral MCA, ACA, PCA, carotid siphon, vertebrobasilar, and ophthalmic artery territories. The primary outcome is the association between TCD-derived parameters and END within 72 hours, defined as an increase of [≥]4 points in total NIHSS score, an increase of [≥]1 point in NIHSS subcategory 1a, radiologic evidence of intracranial hemorrhage within 72 hours, or any neurological change prompting emergent head CT at clinician discretion. Secondary outcomes include NIHSS at 24 hours and discharge, discharge disposition, and modified Rankin Scale (mRS) at 90 {+/-} 10 days after hospital discharge. Joint models for longitudinal and time-to-event data will determine the association between TCD parameter trajectories and time to END. Unsupervised clustering will identify TCD-based hemodynamic phenotypes using vessel velocities, pulsatility indices, hemispheric asymmetry measures, collateral flow, and temporal trajectory patterns. We hypothesize that abnormal post-EVT hemodynamic phenotypes will correlate with END and hemorrhagic transformation. Identifying such signatures may support development of TCD-guided, individualized blood pressure strategies to reduce secondary injury after reperfusion and inform future interventional trials. The study is registered at ClinicalTrials.gov (NCT07013396).