Predictors of Good Functional Outcomes in Posterior Circulation Stroke After Mechanical Thrombectomy With Stent Retrievers: An Individual Patient‐Data Pooled Analysis From the TRACK and NASA Registries

BACKGROUND Recent randomized clinical trials have demonstrated that endovascular therapy for basilar artery occlusion is safe and potentially effective, predominantly in the non‐White population. The aim of this study was to identify predictors of good functional outcome in posterior circulation strokes in US population after mechanical thrombectomy from the TRACK (Trevo Stent‐Retriever Acute Stroke) and the NASA (North American Solitaire Stent Retriever Acute Stroke) registries from North America. METHODS Patient‐level data from the TRACK and NASA registries were pooled, and patients with posterior circulation stroke were included in this analysis. Patients were dichotomized into those with 90‐day good functional outcome (modified Rankin scale [mRS] score 0–2) and poor functional outcome (mRS score ≥3). Baseline and procedural data were compared between the 2 cohorts. Multivariate logistic regression was performed to identify predictors of functional outcome. P < 0.05 was considered significant. RESULTS Of 119 posterior stroke patients (99 [83.2%] basilar artery, 16 [13.4%] vertebral artery, and 4 [3.4%] posterior cerebral artery), 110 patients had 90‐day mRS data available on follow‐up. Good functional outcome was observed in 44 patients (40%). Patients with mRS score 0–2 were less likely to have hypertension (61.4% versus 83.3%; P = 0.01), hyperlipidemia (38.6% versus 62.1%; P = 0.016), and diabetes (18.2% versus 36.4%; P = 0.040). Patients with mRS score 0–2 had a lower mean presentation National Institutes of Health Stroke Scale score (15.2±9.95 versus 22.6±9.50; P < 0.001) and more likelihood of achieving Thrombolysis in Cerebral Infarction 3 (79.5% versus 42.2%; P < 0.001). There was no difference between 2 cohorts in time to puncture, use of balloon guide catheter, use of general anesthesia, and number of passes. On multivariate analysis, higher presentation National Institutes of Health Stroke Scale and hypertension were associated with worse functional outcomes. Complete recanalization and the receipt of intravenous tissue‐type plasminogen activator were associated with higher odds of achieving good functional outcomes. CONCLUSION In this pooled analysis of the NASA and TRACK registries, patients with posterior circulation stroke achieving good outcomes were more likely to have lower presentation National Institutes of Health Stroke Scale and fewer comorbidities. Use of intravenous tissue‐type plasminogen activator, hypertension, final Thrombolysis in Cerebral Infarction 3, and lower baseline National Institutes of Health Stroke Scale score were independent predictors of functional outcome.