Direct oral anticoagulant use in hospitalized patients with atrial fibrillation across body mass index categories: design and rationale for a retrospective cohort study

Abstract

Background:

Atrial fibrillation (AF) and obesity are common conditions globally; yet, there remains suboptimal pharmacological management contributing to high rates of hospitalization in patients with AF. The altered pathophysiology of both obese and underweight individuals may influence the pharmacology of medications, including those used to manage AF. This, in turn, increases the risk of adverse events and impacts patient risk for stroke and rehospitalization. Despite the well-established complications of obesity, research investigating the relationship between obesity and AF is scant.

Objectives:

The primary aim of this study is to describe cardiovascular-related hospitalization in AF patients according to BMI categories. A secondary aim is to describe anticoagulant and antiarrhythmic prescribing practice patterns in patients with AF, according to the BMI category.

Design:

A retrospective, exploratory descriptive observational cohort study, using routinely collected electronic medical record data from five public hospitals within a single health district, with a population dominantly that is culturally and linguistically diverse, and has a low socioeconomic status.

Methods and analysis:

Data extraction will include a 24-month period (January 2017 to December 2018) with a 12-month follow-up. All adult (⩾18 years) patients at discharge diagnosed with AF, prescribed any oral anticoagulant and/or oral rate/rhythm control agent, will be eligible for inclusion.

Ethics and dissemination:

Ethics approval from the health district and the University of Wollongong has been granted. Findings will seek to demonstrate associations between management strategies and patient outcomes, as well as describe patterns of acute care management from prescribers. These data will be used to inform and generate hypotheses for large-scale studies examining the impact of body weight on anticoagulation prescribing at national and global scales.

Plain language summary

Designing a study that examines the use of blood thinners in hospitalised patients with irregular heartbeat at different body weights

Background:

Across the world, two of the most common conditions include obesity and a heart disease that causes irregular heartbeat which is known as Atrial Fibrillation (AF). As a result of the excessive over or underweight of an individual with AF, can affect how some of the medications used manage AF work, in turn potentially affecting their health.

Purpose:

The main purpose of this study is to describe how often people with AF end up in the hospital because of heart-related problems based on their weight category. We also want to describe how doctors prescribe blood thinners and medicines that control the heart rhythm, in patients with AF based on their body weight.

Design and method:

To do this we will examine old electronic medical records over a two-year period, from January 2017 to December 2018 from five public hospitals, and we will see what happens after one year if they were hospitalised. These hospitals serve a diverse population with a mix of languages and cultures and are low-income earning households. We will only examine the electronic medical records of adults (18 years and over) who were diagnosed with AF and were prescribed blood thinners and/or heart rate or rhythm-controlling medications at the time of leaving the hospital. All adult (⩾18 years) patients at discharge diagnosed with AF, prescribed any oral anticoagulant and/or oral rate/rhythm control agent, will be eligible for inclusion. We have already gotten approval from the hospital and the University of Wollongong to conduct this study ethically. We anticipate that the results from this study will help us understand how different treatments and body weights are connected, and this knowledge can be used to plan bigger studies on a national and global scale to improve how we care for people with irregular heartbeats.