Antithrombotic Therapy Underutilization in Patients With Atrial Flutter

Patients with atrial fibrillation not being adequately treated with oral anticoagulant (OAC) therapy, with therapy underutilization or premature termination, have been commonly reported. However, studies on the utilization pattern of OAC therapy for patients with atrial flutter (AFL) are few. The aim of this study was to investigate the utilization of OAC therapy, and its influencing factors for patients with AFL in South Korea, as well as the types and percentages of anticoagulants used.

We analyzed Aged Population Sample data compiled by the Health Insurance Review & Assessment Service from 2011 to 2015. We identified patients with AFL having the KCD-6 code I48.1. Patients at high risk of stroke with a congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, stroke (or transient ischemic attack), vascular disease, sex score of ≥2 and at low risk of bleeding with an anticoagulation and risk factors in atrial fibrillation score of ≤4 were included in the study. Oral anticoagulant therapy underutilization was estimated in these patients using anticoagulant underutilization (ACU) scales. Demographic and clinical factors associated with OAC therapy underutilization were investigated using a logistic regression model.

The mean ACU value was calculated as 67.4% between 2011 and 2015. Positive risk factors for ACU were identified as follows: female sex, aspirin utilization, and limited anticoagulant options. Negative risk factors included comorbidities, such as congestive heart failure and valvular heart disease, and a history of stroke or transient ischemic attack.

Our study demonstrates that two-third of patients with AFL in South Korea failed to obtain adequate stroke prevention treatment, even in the era of direct OAC availability. This tendency was more profound in women or those on aspirin therapy.