Abstract WMP94: Quantifying the Enhanced Clinical Benefit of Endovascular Thrombectomy Performed With Contemporary Workflows and Devices

Abstract

Background: To date, the magnitude of the benefit of endovascular thrombectomy (EVT) over medical management in acute ischemic stroke has been quantified by the data of the five breakthrough RCTs of 2015. But contemporary EVT care has faster EVT workflow speeds and achieves higher rates of reperfusion. Updated quantitative estimates of the benefit of EVT vs medical management are needed. Methods: Contemporary FDA-monitored (TIGER/ARISE II) and pivotal (HERMES) EVT trial group differences were quantified for workflow speed (door-to-reperfusion time) and reperfusion rates (eTICI distribution). The projected effect of the faster workflow speed in further improving disability (mRS) outcomes were calculated using established HERMES treatment time-benefit models and the projected effect of higher reperfusion rates using established HERMES eTICI tier-specific outcomes. Results: Contemporary EVT trial groups, compared with pivotal trial EVT groups, had door-to-reperfusion 57 minutes faster (146m vs 89m), successful reperfusion 22.6% more often (71.0% vs 93.6%), and excellent reperfusion 45.1% more often (29.4% vs 74.5%). Figure 1 shows the resulting projected improvements in mRS distributions. For functional independence (mRS 0-2), outcome rates for MM vs pivotal EVT vs contemporary EVT were 25.2% vs 44.6% vs 74.5%. The number needed to treat (NNT) for 1 more patient to achieve functional independence improved from 5.2 to 2.5. For nondisabled outcome (mRS 0-1), outcome rates were 10.1% vs 27.4% vs 46.0%. The NNT for 1 more patient to achieve nondisabled outcome improved from 5.8 to 2.8. Over the entire mRS range, the NNT for 1 more patient to have less disability by at least one mRS level improved from 2.6 to 1.6. Conclusion: Formal modeling indicates that contemporary EVT confers substantially enhanced benefits over medical management. Among every 100 patients treated with EVT, 63 will have a less disabled long-term outcome including 36 more becoming disability-free.