Abstract 20285: Relationship Between INR and Outcomes in Modern Trials With Warfarin Controls

Introduction: A target INR of 2-3 has been recommended for patients with atrial fibrillation (AF) and risk factors for thromboembolism. This recommendation is largely based on evidence from observational studies a decade ago. Our study utilized collective data from modern trials with warfarin controls to examine the longitudinal relationship between warfarin anticoagulation, as assessed by INR, on the clinical outcome events of interest. Methods: We obtained subject-level data for warfarin-treated patients from three large clinical studies supporting the approval of dabigatran (Pradax®), apixaban (Eliquis®) and edoxaban (SAVAYSA®). Ischemic stroke, intracranial hemorrhagic (ICH) and all-cause mortality were selected as the outcome events of interest. We performed multivariate Cox regression modeling to examine the association between time-dependent INR and each outcome event. Benefit-Risk analysis was assessed by summing estimated annual event rate for both ischemic stroke and ICH. Results: A total of 21,...