2017 HSR&D/QUERI National Conference

4023 — Medication Use Evaluation of Digoxin Monotherapy for Atrial Fibrillation in Absence of Heart Failure

Lead/Presenter: Muriel Burk
All Authors: Burk ML (VA PBM Center for Medication Safety) McCarren M (VA PBM Center for Medication Safety) Wang Y (VA PBM Center for Medication Safety) Furmaga EM (VA PBM Services) Good CB (VA Pittsburgh Healthcare System) Glassman PA (VA Greater Los Angeles Healthcare System) Cunningham FE (VA PBM Center for Medication Safety)

Objectives:
Digoxin is no longer considered a preferred therapy for atrial fibrillation (AF) because some studies suggest increased mortality with digoxin. The goal of this medication use evaluation was to assess Veterans with AF, in the absence of Heart Failure (HF), who were on digoxin monotherapy with no prior or concomitant use of guideline-preferred therapies, beta blockers or non-dihydropyridine calcium channel blockers (target population)

Methods:
Volunteer VA Medical Centers (VAMCs) conducted chart reviews to confirm target population criteria and collect the following data: contraindications to preferred AF therapy; indication, dose, and duration of digoxin therapy; monitoring of serum chemistries and digoxin levels; prescriber specialty; demographics. Reviewers used clinical judgment to adjudicate whether a patient could benefit from discontinuation of digoxin and initiation of preferred therapy. The abstraction tool created site-level summaries that were submitted to the coordinating center where they were averaged for the report.

Results:
Sixteen VAMCs reviewed 323 patients meeting criteria. The mean patient age was 80 years, and 72% of patients were co-managed by VA and non-VA physicians. Many (64%) received care at a VA community-based outreach clinic. Digoxin prescriptions were first ordered by primary care in 58% of patients and renewed by primary care in 92%. Eighty-eight percent had a documented indication for digoxin, while 3% had a documented risk/benefit assessment for digoxin monotherapy. Fifty-eight percent had been on digoxin for > 6 years. Contraindications or past intolerance to preferred therapy was documented in 6%. Co-morbidity of potential concern was present in 44% of patients. Reviewers adjudicated that 61% of patients would benefit from re-evaluation of digoxin therapy.

Implications:
Few patients on digoxin monotherapy had a contraindication to treatment with current preferred AF therapy. The cohort's long duration of digoxin therapy and advanced age likely reflect prescribing habits from an era with different treatment standards for AF. The high rates of co-management and primary care renewals present an opportunity for provider education, and suggest the need for improved VA/non-VA provider communication.

Impacts:
Awareness of recent reports on all-cause mortality in patients with AF (without HF) should motivate prescribers to re-evaluate digoxin monotherapy.