Abstract P107: Trends In Oral Anticoagulation Therapy In Non-valvular Atrial Fibrillation Patients At High-risk Of Stroke After The 2019 AHA/ACC/HRS Update For The Management Of Patients With Atrial Fibrillation Guidelines

Abstract

Background: Oral anticoagulation (OAC) reduces the risk of ischemic stroke in patients with atrial fibrillation (AF) but is underutilized in high-risk patients. We aimed to assess the impact of the 2019 guideline-recommended use of non-vitamin K OAC (NOACs) as first line therapy over warfarin for high-risk patients with non-valvular AF. Methods: Adult patients at Essentia Health with AF or atrial flutter on their problem list, seen in an ambulatory clinic between 7/1/2020-7/12/2021, were included in the baseline cohort. Patients were excluded if they had moderate to severe rheumatic mitral stenosis or mechanical heart valves, or were deceased or missing 1-year follow-up data. High-risk AF was defined as males with a CHA2DS2-VASc score ≥2 and females with a score ≥3. ATRIA bleed score was calculated using electronic health record data and divided into 3 groups: low-risk (0-3), intermediate (4) or high-risk (5-10). Patients were separated into three groups: warfarin, NOAC, or no OAC therapy. Results: Of the 12,014 patients in the baseline non-valvular AF registry, 8,032 were high-risk (mean age 75.9 ± 9.8 years, 57.5% male). Over half (57.1%, n=4619) were age ≥ 75 years and 63.4% (n=5095) were rural dwelling. Compared to baseline, at 1-year follow up, high-risk AF patients had similar use of any OAC (75.6%; n=6069 at baseline vs. 75.7%; n=6083 at 1-year follow-up). The use of warfarin decreased 2.3% [from 39.3% (n=3160) to 37.0% (n=2973), p <0.001] while NOAC use increased 2.4% [from 36.2% (n=2909) to 38.7% (n=3110; p <0.001]. Eliquis was the most prevalent NOAC prescribed (57.9%; n=1802). At 1-year follow-up, patients with high-risk AF and low-risk ATRIA bleed score, the use of any OAC therapy increased by 0.9% while those at high-risk AF and high-risk ATRIA bleed score, the use of any OAC therapy decreased 1%. In the multivariate logistical model, age, male sex, CHA2DS2-VASc score 4-6, hypertension, stroke/transient ischemic attack/thromboembolism, and cardiology visit within the last 3 years showed an increased association with prescription of any OAC (p<0.05). Vascular disease, high risk ATRIA bleed score, severe renal risk, prior hemorrhage, and left atrial appendage occlusion device (WATCHMAN) had a decreased odds of any OAC use (p<0.05). Conclusion: Implementation of the 2019 ACC/AHA/HRS guidelines that established NOACs as first line therapy over warfarin for non-valvular AF resulted in a slight increase in NOAC use and decrease in warfarin use in a large high-risk non-valvular AF population. Approximately one in four high risk patients with AF are not on any OAC therapy and may benefit from treatment to reduce thromboembolic risk.