Abstract 19300: Real-life Evidence of Stroke Prevention in Patients With Atrial Fibrillation: The RELIEF Study

Abstract

Introduction: Limited data is available on real-world outcomes in rivaroxaban compared to vitamin K antagonist (VKA) users with non-valvular atrial fibrillation (NVAF). Hypothesis: To assess the effectiveness of newly initiated rivaroxaban or VKA therapy among NVAF patients. Methods: The ‘REal-LIfe Evidence on stroke prevention in patients with atrial Fibrillation’ (RELIEF) study was a retrospective analysis performed in the outpatient setting in Germany using data from the Primary Care Physician panel of a longitudinal electronic medical record database ( IMS Disease Analyzer). Patients had to be ≥18 years of age, newly initiated on rivaroxaban or a VKA (mostly phenprocoumon in Germany) between January 2012 and October 2013, have a diagnosis of NVAF on the day of the first qualifying anticoagulant prescription (index date) or anytime during the 365 days prior, and have follow-up ≥360 days after the index date. Patients were 1:1 propensity score matched. The primary endpoint was the composite of ischemic stroke (International Classification of Disease, Tenth Revision [ICD-10] code I63), transient ischemic attack (TIA) (ICD-10 code G45, except G45.3), intracerebral hemorrhage (ICD-10 code I61), other non-traumatic intracranial hemorrhage (ICD-10 code I62), systemic embolism (ICD-10 code I74) and myocardial infarction (ICD-10 codes I21, I22). Kaplan-Meier survival analysis on the primary endpoint in the matched cohorts was performed, and the time-to-event was reported as a hazard ratio (HR) and 95% confidence interval (CI). Results: A total of 1,039 VKA and 1,039 rivaroxaban users were included and 57 events (20 in rivaroxaban, 37 in VKA) were identified during a one-year follow-up. The incidence of the composite endpoint was significantly lower in rivaroxaban compared to VKA users (1.97 vs. 3.68 events/100 person-years) corresponding to a hazard ratio of 0.536 (95%CI: 0.311-0.923; p=0.0245). Ischemic stroke (0.69 vs. 1.58 events/100 person-years) and TIA (0.59 vs. 1.08 events/100 person-years) were less frequent in the rivaroxaban cohort . Conclusions: The findings indicate that rivaroxaban may be associated with superior effectiveness compared to a VKA when utilized in a real-world setting.