Evaluation of Adherence to Guideline-Directed Antithrombotic Therapy for Atrial Fibrillation at Hospital Discharge

Abstract

Background: Risk stratification for stroke in patients with atrial fibrillation is a vital step in identifying whether antithrombotic therapy is indicated for stroke prevention in this common arrhythmia.

Purpose: The aim of this study was to determine adherence to guideline-directed antithrombotic therapy based on Congestive Heart Failure (1 point), Hypertension (1 point), Age (≥75 years old is 2 points and 65-74 is 1 point), Diabetes (1 point), prior Stroke (2 points), Vascular Disease (1 point), and Sex Category (1 point if female; CHA₂DS₂-VASc) score in patients with atrial fibrillation (AF) on hospital discharge.

Methods: A total of 293 patients discharged from this academic medical center with a history of atrial fibrillation from June 2014 to June 2016 were enrolled. Demographic data and indicators for antithrombotic therapy based on the CHA₂DS₂-VASc score were recorded, and factors that affected adherence to guideline-directed therapy, such as bleeding risk, falls, and alcohol abuse, were collected and analyzed.

Results: At hospital discharge, 63% of patients with AF were on appropriate antithrombotic therapy, 50% with a CHA₂DS₂-VASc score ≥2. The odds ratio of appropriate therapy in patients with a CHA₂DS₂-VASc score ≥2 was 1.17 (95% confidence interval [CI]: 0.95-1.30; P = .18). When chart documentation for reasons to withhold anticoagulation was considered as appropriate therapy, 81% of patients with AF were discharged on appropriate antithrombotic therapy with an odds ratio of 1.57 (95% CI: 1.26 -1.96, P < .0001), with bleeding and falls risk as the most common reasons to withhold anticoagulation.

Conclusion: Based on risk stratification of stroke through the CHA₂DS₂-VASc score, the majority of patients with AF were discharged from the hospital on appropriate antithrombotic therapy. Withholding anticoagulation due to falls risk should be reconsidered as a result of the known benefits of stroke prevention in atrial fibrillation.

Keywords: CHA2DS2–VASc score; anticoagulation; antiplatelet therapy; atrial fibrillation < heart disease; stroke.