Thrombectomy vs medical management in low NIHSS acute anterior circulation stroke

Background: Endovascular thrombectomy (EVT) is highly effective for acute ischemic stroke with large vessel occlusion (LVO) and moderate to severe neurologic deficits. Objective: To undertake an effectiveness and safety analysis of EVT in patients with LVO and NIHSS ≤6 using datasets of multicentre and multinational nature. Methods: We pooled patients with anterior circulation occlusion from 3 prospective international cohorts. Patients were eligible if presentation occurred within 12 hours from last known well and baseline NIHSS ≤6. Primary outcome was mRS 0-1 at 90 days. Secondary outcomes included neurologic deterioration at 24 hours (change in NIHSS of ≥2 points), mRS 0-2 at 90-day and 90-day all-cause mortality. We used propensity score matching to adjust for non-randomized treatment allocation. Results: Among 236 patients who fit inclusion criteria, 139 received EVT and 97 received medical management. Compared to medical management, the EVT group was younger (65 vs 72 years; p < 0.001), had more proximal occlusions (p < 0.001), and less frequently received concurrent intravenous thrombolysis (57.7% vs 71.2%; p = 0.04). After propensity score matching, clinical outcomes between the 2 groups were not significantly different. EVT patients had an 8.6% (95% CI: -8.8% to 26.1%) higher rate of excellent 90-day outcome, despite a 22.3% (95% CI: 3.0%-41.6%) higher risk of neurologic deterioration at 24 hours. Conclusions: EVT for LVO in patients with low NIHSS was associated with increased risk of neurologic deterioration at 24 hours. However, both EVT and medical management resulted in similar proportions of excellent clinical outcomes at 90 days.