Predictors of unexplained early neurological deterioration after thrombectomy for posterior circulation infarction: a reanalysis of the BASILAR study

OBJECTIVE The efficacy of endovascular thrombectomy in patients with posterior circulation ischemic stroke remains controversial. Early neurological deterioration (END) as an important predictor of poor outcome is poorly understood, except in cases of symptomatic intracranial hemorrhage, recanalization failure, and malignant cerebral edema. The objective of this study was to assess predictors of unexplained END (UnEND) after endovascular thrombectomy. METHODS The BASILAR study is a multicenter prospective observational study in which 647 patients with vertebrobasilar occlusion on imaging within 24 hours of stroke onset and who underwent endovascular treatment were enrolled, of whom 477 who had undergone successful recanalization were included in this study. Multivariate analysis was used to identify the predictors of UnEND, defined as a ≥ 4-point increase in National Institutes of Health Stroke Scale (NIHSS) score at 24 hours after endovascular thrombectomy. RESULTS Among the 477 eligible patients included, UnEND occurred in 86 (18%) patients. The predictors of UnEND were stress hyperglycemic ratio (SHR) (OR 2.2, 95% CI 1.1–4.6; p = 0.031), baseline NIHSS score (OR 0.9, 95% CI 0.83–0.95; p = 0.001), and asymptomatic intracerebral hemorrhage (aICH) (OR 5.9, 95% CI 1.7–20.0; p = 0.004). The occurrence rate of a favorable outcome, defined as a modified Rankin Scale score of 0–2 at 90 days, was lower in the UnEND group (5.8% vs 47.6%, p < 0.001) compared with the group without END, and the UnEND group had higher mortality at 90 days (66.3% vs 27.4%, p < 0.001). CONCLUSIONS UnEND may be associated with poor outcome after endovascular thrombectomy in patients with acute vertebrobasilar occlusion. Some modifiable factors such as SHR and aICH could be targeted to improve the efficacy of endovascular thrombectomy.