Abstract W P13: Which Patients are Informative About Benefits of Neurothrombectomy?: Analysis of the Pooled SWIFT and STAR Trials Dataset
BACKGROUND: To demonstrate treatment benefit, neurothrombectomy clinical trials should enroll patients who show better outcome with reperfusion than non-reperfusion.
METHODS: We analyzed the pooled dataset of prospective Solitaire neurothrombectomy trials. Solitaire-treated patients were categorized as reperfusers (TICI 2a-3) and non-reperfusers (TICI 0-1).
RESULTS: Among 271 Solitaire-treated patients, any reperfusion (TICI 2a-3) was achieved in 90.0%. Reperfusers and non-reperfusers did not differ in age (67.5 vs 69.4, p = 0.46), baseline NIHSS (16.7 vs 17.2, p=0.62), target vessel distribution, or onset to arterial puncture time (4.5h vs 4.9h, p=0.24). Across the entire cohort, reperfusion was strongly associated with freedom from disability (mRS 0-2, 57.5% vs 20.0%, p<0.001), freedom from dependence (mRS 0-3, 72.9% vs 36.0%, p<0.001), and shift in disability (mRS mean 2.3 vs 3.6, Wilcoxon Rank Sum p <0.001), but not with increased survival (90.0% vs 88.0%, p=0.73). Among 12 baseline prognostic subgroups, defined by age, NIHSS, and time to treatment quartiles, the most informative endpoint analyses were: shift analysis (informative in 10); mRS 0-3 (informative in 9); mRS 0-2 (informative in 6); and survival (informative in 2). Only 1 of the 12 subgroups was not informative on any analysis - very young patients, 25-60y (ceiling effect). While both mRS 0-2 and shift analysis were informative in patients of moderate age (61-77y), mild to moderate severity (NIHSS 8-13, 18-20), and very rapid treatment (1.6-3.5h), shift analysis was also informative in patients with older age (78-88y), an additional band of moderate stroke severity (NIHSS 14-17), and longer time to treatment (3.6 to >5.6h).
CONCLUSIONS: Reperfusion with the Solitaire stent retriever is strongly associated with improved disability outcomes. Compared with dichotomizing at freedom from disability (mRS 0-2), analyzing all substantial reductions in disability (mRS ranks analysis) additionally detects benefit in patients of older age, greater stroke severity, and later treatment times, expanding the informative clinical trial population by over 40%.
Author Disclosures: J.L. Saver: Other; Modest; The University of California receives funds from Covidien for Dr. Saver's consulting on clinical trial design and performance, The University of California has intellectual property rights in retriever technology. V.M. Pereira: Consultant/Advisory Board; Modest; Covidien. J. Gralla: Consultant/Advisory Board; Modest; Covidien. R. Jahan: Other; Modest; The University of California receives funds from Covidien for Dr. Jahan’s consulting on clinical trial design and performance, The University of California has intellectual property rights in retriever technology.
- © 2014 by American Heart Association, Inc.