Abstract 12678: Oral Anticoagulation Use in High Risk Atrial Fibrillation Patients is Much Higher Than Previously Reported

Abstract

Introduction: Guidelines recommend oral anticoagulants (OAC) in high risk atrial fibrillation (HRAF) patients. It has been reported that >40% of such patients are not taking an OAC. We observed that active AF often was not present in patients labeled as having AF (either because of wrong diagnosis or no AF in last 5 years). Hypothesis: We undertook a systematic electronic medical record (EMR) review to determine the presence or absence of active AF to accurately identify HRAF patients requiring an OAC. Methods: We reviewed 6514 patients with presumed AF and 2 or more outpatient visits documented by at least one of: billing diagnosis, EMR encounter diagnosis, EMR problem list, or EKG interpretation. Results: Active AF was noted in 4555/6514 patients (69.7%) after 1959 patients with no prior history of AF or inactive AF were withdrawn from further analysis. In active AF patients, 3869 had HRAF with CHA 2 DS 2 -VASc ≥2. OAC use was statistically higher (p<0.0001 by McNamer’s test) in the active HRAF group [3090/3869 (79.9%) compared to the presumed HRAF group (62.9%)], Figure 1. There was no statistically significant difference in the use of OAC between men (80.7%) and women (78.8%), even in women with a CHA 2 DS 2 -VASc ≥3 (79.9%). In HRAF patients not taking an OAC (20.1%), expert review frequently disagreed with that recommendation suggesting that OACs can be taken in up to 92% of HRAF patients. Conclusions: 1) Current registries with un-adjudicated EMR diagnoses over-report the number of HRAF patients not taking an OAC; 2) Expert adjudication of active AF diagnosis identifies a smaller OAC treatment gap than previously described; 3) absolute contraindication or repeated refusal to take an OAC exists in less than 10% of HRAF patients; and, 4) there were no gender differences in OAC use.