Too good to intervene? Thrombectomy for large vessel occlusion strokes with minimal symptoms: an intention-to-treat analysis.

INTRODUCTION: The minimal stroke severity justifying endovascular intervention remains elusive; however, a significant proportion of patients presenting with large vessel occlusion (LVO) and mild symptoms subsequently decline and face poor outcomes. OBJECTIVE: To evaluate our experience with these patients by comparing best medical therapy with thrombectomy in an intention-to-treat analysis. METHODS: Analysis of prospectively collected data of all consecutive patients with National Institutes of Health Stroke Scale (NIHSS) score ≤5, LVO on CT angiography, and baseline modified Rankin Scale (mRS) score 0-2 from November 2014 to May 2016. After careful discussion with patients/family, a decision to pursue medical or interventional therapy was made. Deterioration (development of aphasia, neglect, and/or significant weakness) triggered reconsideration of thrombectomy. The primary outcome measure was NIHSS shift (discharge NIHSS score minus admission NIHSS score). RESULTS: Of the 32 patients qualifying for the study, 22 (69%) were primarily treated with medical therapy and 10 (31%) intervention. Baseline characteristics were comparable. Nine (41%) medically treated patients had subsequent deterioration requiring thrombectomy. Median time from arrival to deterioration was 5.2 hours (2.0-25.0). Successful reperfusion (modified Treatment in Cerebral Infarction 2b-3) was achieved in all 19 thrombectomy patients. The NIHSS shift significantly favored thrombectomy (-2.5 vs 0; p<0.01). The median NIHSS score at discharge was low with both thrombectomy (1 (0-3)) and medical therapy (2 (0.5-4.5)). 90-Day mRS 0-2 rates were 100% and 77%, respectively (p=0.15). Multivariable linear regression indicated that thrombectomy was independently associated with a beneficial NIHSS shift (unstandardized ß -4.2 (95% CI -8.2 to -0.1); p=0.04). CONCLUSIONS: Thrombectomy led to a shift towards a lower NIHSS in patients with LVO presenting with minimal stroke symptoms. Despite the overall perception that this condition is benign, nearly a quarter of patients primarily treated with medical therapy did not achieve independence at 90 days.