Oral anticoagulation use in non-valvular atrial fibrillation patients in rural setting

Abstract

Background: The 2019 ACC/AHA/HRS guidelines established direct oral anticoagulants (DOACs) as first line therapy over warfarin for non-valvular atrial fibrillation (AF).

Methods: Ambulatory clinic patients with non-valvular AF or atrial flutter seen between 10/1/2019-7/12/2020 included. High-risk AF defined as males CHA₂DS₂-VASc score ≥2 and females ≥3. Patients were separated into: warfarin, DOAC, or no oral anticoagulation (OAC). ATRIA bleed score calculated. A provider survey assessing knowledge and barriers to anticoagulation completed via REDCap between 3/5-4/16/2020.

Results: Of 12,014 subjects with AF, 8,032 were high risk (mean age 75.9 ± 9.8 years; 57.5% male). There were 4,619 (57.1%) ≥ 75 years and 63.4% were rural dwelling. There was no significant difference between the number of subjects on anticoagulation before and after the guideline publication (75.6% vs. 75.7%, p = 0.79). Warfarin use decreased 2.3% over 1 year (39.3% to 37.0%), while DOACs increased 2.4% (36.2% to 38.7%, p < 0.001 for both). At 1-year, age, male gender, CHA₂DS₂-VASc score 4-6, hypertension, stroke and cardiology consult increased prescription of OAC (p<0.05). Vascular disease, high risk ATRIA bleed, renal disease, prior hemorrhage, and left atrial appendage occlusion were associated with decreased OAC use (p < 0.05). Left atrial appendage occlusion device use was low (<1%). In a survey, majority of providers noted bleeding risk (35.1%) and cost (25.0%) to be the biggest barriers to DOAC use.

Conclusions: The new guidelines caused a slight increase in DOACs over time. Significant barriers to DOAC use exist in rural areas; one in four high risk AF patient remains without OAC therapy.

Keywords: Anticoagulation; Atrial fibrillation; Atrial flutter; Barriers; Education; Outcomes; Risk; Stroke.

Fig. 1

Flow diagram of the study cohort review process and categorization of atrial fibrillation patients’ anticoagulation treatment regimens at baseline. AF indicates atrial fibrillation; NOAC, non-vitamin K oral anticoagulant; OAC, oral anticoagulation. CHA₂DS₂-VASc conditions key: C: Congestive Heart Failure, H: Hypertension, Age ≥75, D: Diabetes Mellitus, S: Stroke or Transient Ischemic Attack, V: Vascular Disease, A: 65 to 74 years, S: Female.

Fig. 2

Example of the automatic CHA₂DS₂-VASc calculator and smart phrase available in the electronic health record (EHR) for providers to use. A, Sample pop-up CHA₂DS₂-VASc calculator. B, smart phrase available in the EHR to auto populate the recording of the CHA₂DS₂-VASc score into the provider's note. A) LAA indicates left atrial appendage; LV, left ventricular; MI, myocardial infarction; PAD, peripheral artery disease; TE, thromboembolism; TIA, transient ischemic attack. B) LV indicates left ventricular; MI, myocardial infarction; PAD, peripheral artery disease; TE, thromboembolism; TIA, transient ischemic attack. CHA₂DS₂-VASc conditions key: C: Congestive Heart Failure, H: Hypertension, Age ≥75, D: Diabetes Mellitus, S: Stroke or Transient Ischemic Attack, V: Vascular Disease, A: 65 to 74 years, S: Female.

Fig. 3

Baseline prevalence of anticoagulation therapy in the study cohort (non-valvular atrial fibrillation or atrial flutter patients with a high-risk CHA₂DS₂-VASc score and 1-year follow-up data; N = 8,032), sorted by CHA₂DS₂-VASc score. M = male; F = female. CHA₂DS₂-VASc conditions key: C: Congestive Heart Failure, H: Hypertension, A: Age ≥75 years, D: Diabetes Mellitus, S: Stroke or Transient Ischemic Attack, V: Vascular Disease, A: 65 to 74 years, S: Female sex.