STEP is a Randomized, Multifactorial, Adaptive Platform trial that seeks to optimize the care of patients with acute ischemic stroke (AIS) due to large or medium vessel occlusions (LVOs and MVOs).STEP is a registry-based trial; it uses data from existing registries to record information for a subset of the trial Case Report Form (CRF). Additional registry data from non-randomized STEP patients may be used for trial screening, planning, and generalizability assessment purposes.

The purpose of the study is to compare the effects of apixaban (also known as Eliquis®) with aspirin in patients with atrial fibrillation and a recent brain hemorrhage to see which is better in preventing strokes and death.

Subjects will be in the research study for up to 3 years (minimum of 1 year). About 700 people will take part in this study at approximately 125 sites throughout the United States.