Abstract 15651: The Burden of Nontreatment or Undertreatment Among Non-valvular Atrial Fibrillation Patients With Elevated Stroke Risk: A Systematic Literature Review of Real-world Evidence

Abstract

Introduction: Global treatment guidelines (e.g., AHA/ACC/HRS, ESC, JCS) recommend treatment with oral anticoagulants (OACs) for patients with non-valvular atrial fibrillation (NVAF) and an elevated stroke risk, defined by CHA 2 DS 2 -VASc score ≥2. However, not all patients with NVAF and an elevated stroke risk receive guideline-recommended therapy. A systematic literature review of observational studies was undertaken based on PRISMA guidelines to identify the body of evidence on untreated and undertreated NVAF among patients with elevated stroke risk, and assess its epidemiological and clinical burden. Methods: An extensive search of MEDLINE, GoogleScholar, the Cochrane Library, relevant conference proceedings, and health technology assessments (HTAs) was conducted for RWE studies. Studies published between 1/2010-4/2020 were included if they evaluated rates of nontreatment or undertreatment in NVAF. Nontreatment was defined as absence of OACs, while undertreatment was defined as treatment with only antiplatelet agents. Studies focusing on valvular AF were excluded. Results: Thirty-nine published studies (13 countries) met inclusion criteria. Rates of nontreatment for patients with elevated stroke risk ranged from 2.0%-51.1% (median: 23.3%), while rates of undertreatment ranged from 10.0%-45.1% (median: 34.6%). Few studies assessed the relationship between nontreatment or undertreatment and clinical outcomes in the evaluated population. Among US outpatients with NVAF and an elevated stroke risk, those undertreated had a higher likelihood of death (HR: 1.22; 95% CI: 1.05-1.41; p=.006) compared to patients treated with OACs. Also, in a separate US study of NVAF patients with varying levels of warfarin exposure, patients with no warfarin exposure had significantly higher rates of ischemic stroke than patients with low adherence (4.41 vs. 1.87 per 100 person-years, p<.001) or high adherence (4.41 vs. 0.72 per 100 person years, p<.001). Conclusion: Rates of nontreatment and undertreatment among NVAF patients with elevated stroke risk remain high and are associated with potentially preventable cardiovascular events and death. Strategies to increase rates of treatment may reduce adverse clinical outcomes.