20: A Bayesian Analysis of the EVT Effects Related to Time to Randomization

Music City Center 

Severe ischemic stroke happens when blood flow is blocked and unable to reach the brain; this is a life-threatening emergency condition requiring treatment from doctors. Six recent clinical trials investigated the treatment effect of endovascular thrombectomy (EVT) relative to medical management. The results of these trials conclusively support EVT for patients with a large ischemic core. However, the trials vary in their median time from onset to randomization. We hypothesize that delaying treatment negatively impacts EVT effects. We fit a Bayesian linear regression with a flat prior. It models EVT's mean trial treatment effect on median time from onset to randomization. We calculated a posterior probability (PP) of a slope relationship. The results indicate that the posterior mean slope is a .0085 (PP = .9915) drop in treatment effect for every one-hour increase in median time to randomization. These results can help clinicians predict treatment effects in clinical practice and inform future clinical trials in the StrokeNet Thrombectomy Platform (STEP).

Combining Trials

large ischemic core

severe ischemic stroke 

Biopharmaceutical Section