A global effort to transform atrial fibrillation detection and treatment

A new international research effort, AF-B-STEP, launched on February 4, 2026, aims to fundamentally change how atrial fibrillation (AF) is understood and treated. The four-year project will systematically measure the “AF burden” – the amount of time an individual spends in an irregular heartbeat – and determine how this burden impacts health risks like stroke and heart failure.

Understanding Atrial Fibrillation and the Need for Change

Atrial fibrillation is the most common sustained cardiac arrhythmia globally. It affects roughly one-third of people over the age of 55 and currently accounts for up to three percent of healthcare spending in both Europe and North America. Currently, AF is often treated as a simple “yes or no” diagnosis, but AF-B-STEP seeks to move beyond this binary approach.

Did You Know? The AF-B-STEP project will analyze anonymized data from more than 100,000 patients worldwide.

A Collaborative Approach

Eighteen partners from Europe and Canada are collaborating on this initiative. The project’s goal is to develop standardized methods for detecting and quantifying AF burden using both implantable cardiac devices and consumer technologies like smartwatches and fitness trackers. This standardization is crucial for reliable data collection and analysis.

“The results are intended to help physicians make more precise decisions about who needs which treatment based on the AF burden,” stated Prof. Dr. Paulus Kirchhof, Director of the Department of Cardiology at the University Medical Center Hamburg Eppendorf (UKE) and coordinator of the AF-B-STEP project.

Defining AF Burden and its Impact

AF-B-STEP aims to categorize AF burden into three levels:

Low AF burden: No further investigations or therapy would be required.
Moderate AF burden: Additional diagnostic evaluation would be needed.
High AF burden: Immediate initiation of anticoagulation and rhythm control therapy would be recommended.

Expert Insight: The development of these clear burden categories could significantly improve how patients are stratified for treatment, potentially leading to more tailored and effective care plans. This approach could also inform future clinical guidelines.

By linking AF burden to outcomes like stroke, heart failure, cardiovascular death, quality of life, and cognitive and cardiac function, researchers hope to precisely quantify the clinical risks associated with varying levels of AF burden. This data could lead to a measurable reduction in strokes and heart failure, while also minimizing unnecessary treatments.

What’s Next?

If successful, AF-B-STEP could lead to a shift in clinical practice, with treatment decisions more closely tied to a patient’s individual AF burden. Future treatment guidelines may incorporate these new burden categories, and the standardized methods developed by the consortium could become widely adopted. We see also possible that the project’s findings will spur further research into the long-term effects of different AF burden levels. The project is funded with approximately €18 million from the Innovative Health Initiative (IHI), with contributions from the European Union and industry partners.

Frequently Asked Questions

What is the primary goal of the AF-B-STEP project?

The primary goal is to improve how atrial fibrillation is detected, quantified, and treated worldwide by developing reliable, standardized methods to measure AF burden.

Who is involved in the AF-B-STEP project?

Eighteen partners from Europe and Canada are involved in the project, including manufacturers of implantable cardiac devices and wearable technologies.

How will AF burden be categorized according to AF-B-STEP?

AF burden will be categorized as low, moderate, or high, with different recommendations for investigation and therapy based on each level.

How might a more precise understanding of AF burden impact your conversations with your healthcare provider about heart health?