A Global, Phase 2, Randomized, Double-Blind, Placebo-Controlled, Response- Adaptive Dose-Ranging Study of BMS-986177, an Oral Factor XIa Inhibitor, for the Prevention of New Ischemic Stroke or New Covert Brain Infarction in Patients Receiving Aspirin and Clopidogrel Following Acute Ischemic Stroke or Transient Ischemic Attack (TIA) (The AXIOMATIC-SSP trial)