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 β -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.