Semi-automated tortuosity measurements confirm generalizability of IMPERATIVE trial results to real-world patients with acute ischemic stroke undergoing thrombectomy

Background: Criticism of clinical trials of endovascular therapy of acute ischemic stroke due to large vessel occlusion includes their lack of generalizability. We aimed to evaluate the impact of vessel tortuosity on the outcomes of large-bore and super-bore aspiration catheters in the Imperative Trial and to compare trial's selection of patients to a real-world setting. Methods: Using baseline craniocervical angiography, we performed semi-automated analysis of various tortuosity characteristics. Comparison of tortuosity characteristics was made to a previously published cohort of 100 consecutive patients treated with thrombectomy (real-world cohort). Results: Of the 249 Imperative Trial patients with anterior circulation strokes, 187 (89%) had complete tortuosity assessments from the aortic arch to the occlusion site. Tortuosity indexes for the common carotid, extracranial and intracranial internal carotid artery segments were similar for both cohorts (right side 0.18 ± 0.10, 0.17 ± 0.09, 0.45 ± 0.09 vs. 0.20 ± 0.09, 0.17 ± 0.09, 0.45 ± 0.09; left side: 0.12 ± 0.08, 0.19 ± 0.09, 0.44 ± 0.07 vs. 0.15 ± 0.08, 0.18 ± 0.08, 0.47 ± 0.07 in the Imperative Trial and in the real-world cohort, respectively). The proportion of patients with type 3 aortic arches was higher in the Imperative Trial than the real-word cohort (26% vs. 15%, p = .038). Conclusions: Imperative trial patients treated with aspiration thrombectomy had similar vascular tortuosity characteristics compared to patients treated with thrombectomy in a real-world clinical setting. This confirms the generalizability of Imperative Trial findings to real-world clinical practice.