Clear and Robust Benefit From Solitaire Stent Retriever in Acute Ischemic Stroke: Pooled Analysis From 4 Clinical Trials
Jay Shah, MD
Campbell BCV, Hill MD, Rubiera M, Menon BK, Demchuk A, Donnan GA, et al. Safety and Efficacy of Solitaire Stent Thrombectomy: Individual Patient Data Meta-Analysis of Randomized Trials. Stroke. 2016
The five positive endovascular trials in acute ischemic stroke have revolutionized the management of acute cerebral ischemia and established endovascular revascularization as standard of care in eligible patients. However, there were differences in device type and procedures in the trials. Thus, the authors of all trials agreed to pool patient data in order to potentially detect subgroup differences. In this study, data from 4 trials (SWIFT PRIME, ESCAPE, EXTEND-IA, and REVASCAT) were pooled to examine treatment effects in patients specifically treated with Solitaire stent retriever. The primary outcome was degree of disability at 90 days as evaluated by modified rankin scale (mRS).
In total, 787 anterior circulation ischemic strokes were included and 401 were randomized to thrombectomy. The odds ratio for improvement in mRS was 2.7 with a number needed to treat of 2.5 patients to improve at least one level on the mRS. There was benefit in secondary outcomes as well such as early neurological recovery. These benefits were consistent across various patient characteristics such age, gender, stroke severity, site of occlusion, presence of tandem cervical carotid occlusion, ASPECT score, and time to randomization.
There is clear benefit to endovascular intervention in patients with acute ischemic stroke. The benefit is likely a direct result of recanalization and reestablishing perfusion rather than a direct effect of the device itself. With increasing experience, the use of stent retrievers such as Solitaire will likely increase and patient selection will broaden. The subgroup analysis of this study suggests that patients >80 age showed benefit and age should not be sole exclusion criterion. Similarly, there was equal benefit in “low” stroke scale < 15 compared to >20 although decision to intervene on NIHSS < 6 should be made on an individual basis as the trials had very few patients within this category. Lastly, similar to IV-tPA, there is a declining probability of good outcome with time so once a treatment decision is made in an expedited but judicious manner, the focus should then tailor to minimizing delays. However, clinical utility in patients with low ASPECT scores and poor collaterals is unclear and should be addressed in future trials.