Early neurological deterioration before endovascular treatment in patients with mild stroke. MINORCAT-END-EVT study.

BACKGROUND AND PURPOSE The management of patients with anterior circulation large vessel occlusion (LVO) presenting with mild neurological symptoms remains a matter of debate. Early neurological deterioration (END) may influence the decision to perform endovascular treatment (EVT); however, evidence regarding its impact on clinical outcomes is limited.

METHODS We conducted a retrospective analysis of prospectively collected data from the Catalan Stroke Registry (2016-2021). Patients with anterior circulation LVO, baseline NIHSS ≤5, baseline mRS score 0-1, and treatment with EVT were included. END was defined as an increase of ≥4 NIHSS points from hospital admission to EVT initiation. Proximal occlusion was defined as occlusion of the extracranial or terminal internal carotid artery or the M1 segment of the middle cerebral artery. The primary outcome was excellent functional outcome at 90 days (mRS 0-1). Good functional outcome (mRS 0-2) was considered a secondary outcome. Mortality and symptomatic intracranial hemorrhage were assessed as safety outcomes.

RESULTS Among 244 patients, 58 (23.8%) experienced END before EVT. At 90 days, 131 patients (53.7%) achieved mRS 0-1 and 162 (66.4%) achieved mRS 0-2. Fourteen patients (5.7%) died during follow-up, and 8 (3.3%) experienced symptomatic intracranial hemorrhage. In multivariable analysis, successful recanalization was independently associated with the primary outcome (OR 4.54, 95% CI 1.73-13.83), whereas END before EVT (OR 1.24, 95% CI 0.40-3.98), proximal occlusion (OR 1.37, 95% CI 0.69-2.71), and their interaction (OR 0.42, 95% CI 0.10-1.67) were not independently associated with excellent functional outcome.

CONCLUSIONS In this cohort of patients with mild ischemic stroke treated with EVT, END before EVT was not independently associated with functional outcomes, whereas successful recanalization remained the main determinant of excellent recovery. Pending evidence from randomized clinical trials, these findings suggest that close clinical monitoring with rescue EVT may be an appropriate approach in selected patients.