Objective:

We aim to evaluate the longitudinal outcomes of EVT compared to medical management in patients with AIS and NIHSS≤6.

Background:

Endovascular thrombectomy (EVT) is an established, effective treatment method for acute ischemic stroke (AIS), particularly in patients with severe deficits indicated by a National Institutes of Health Stroke Scale (NIHSS) score≥6. However, there is ongoing debate regarding the role of EVT in patients presenting with NIHSS≤6 due to the exclusion of such patients from major randomized clinical trials.

Design/Methods:

This retrospective study used the TriNetX Research Network to analyze data from patients diagnosed with AIS and with NIHSS≤6 on presentation. Patients with AIS receiving EVT were compared to patients receiving medical management. ICD-10 and CPT codes were used to identify diagnoses and procedures. Cox proportional hazard models assessed 7-day changes in NIHSS, hazards of mortality and other secondary outcomes controlling for age, sex, and the Charlson Comorbidity Index criteria.

Results:

We identified 90,740 patients with AIS and NIHSS≤6, of which 2,475 (2.7%) underwent EVT. EVT was associated with an overall improvement in 7-day NIHSS compared to medical management, significantly increasing the likelihood of improvement at all initial NIHSS levels except for an NIHSS of five. Concurrently, EVT was associated with significantly increased 7-day hazards of hemorrhage (2.732 [2.507, 2.977]) and mechanical ventilation (6.297 [5.551, 7.144]).

Conclusions:

Patients with mild stroke treated with EVT had better clinical outcomes, but had higher rates of complications. These findings may be attributable to residual confounding factors, such as deterioration following initially low NIHSS scores, or the risks of treatment with a procedure. Our findings suggest the benefit of EVT in AIS patients with low NIHSS scores.