August 19, 2026

An interview with Joakim Bo Kunkel, M.D., Ph.D., on wearable technology and the early detection of atherosclerosis

A chronic cardiovascular condition, atherosclerosis is characterized by the accumulation of fatty plaques in arteries, which leads to an increased chance of heart attack or stroke. Cardiovascular diseases (CVDs) are the leading cause of death globally, impacting more than 600 million worldwide; 19–20 million people die due to CVDs annually and atherosclerosis is one of the leading contributors¹. Despite its severity, it often develops asymptomatically over several decades, making early detection and prevention critical steps for reducing premature cardiac incidents.

Due to the prevalence of atherosclerosis around the world, Dr. Kunkel of Copenhagen University Hospital was invited to share his thoughts on REACT, one of the largest prospective atherosclerosis prevalence studies in Europe. The project uses data from the Garmin Health Connected Ecosystem (GHCE) as part its quantitative approach.

What is the REACT Wear study and how does it contribute to the overarching REACT Study?

Most people don’t realize they have heart disease until something goes wrong: a heart attack, a stroke. By then, the disease of atherosclerosis has often been silently developing for decades.

The REACT study, run by researchers at Rigshospitalet, Copenhagen University Hospital and our partners Spanish National Center for Cardiovascular Research (CNIC) in Madrid, is trying to change that. We’re looking for the earliest possible signs of cardiovascular disease, long before symptoms appear, using advanced scans and blood tests.

React Wear, an app developed by CNIC to include data from GHCE, adds a new dimension to this: Instead of just seeing participants in the clinic a few times, we follow them in their everyday lives, through their wrists. Continuous data from GHCE lets us see how the heart and body behave during sleep, exercise, stress and everything in between.

What do you hope the project accomplishes?

Simply put, the vision is to detect atherosclerosis while it is silent and act sooner. The earlier we detect that an individual is at increased risk of heart disease, the more we can do about it and the better we expect the outcomes.

REACT Wear helps us understand what a healthy (and less healthy) cardiovascular trajectory looks like day to day and what early warning signs might look like when compared to conventional analyses, such as scans and blood tests.

Ultimately, we want to give people and their doctors more time to act.

Why did you choose the Garmin Health Connected Ecosystem and how is data collected used in this project?

We needed a device people would wear consistently, that could measure meaningful health signals, and infrastructure that could reliably transfer data to our research systems. GHCE ticked all those boxes by capturing a rich set of physiological signals: heart rate, heart rate variability, sleep quality, activity levels, Pulse Ox and more, while giving us a secure way to receive that data continuously².

After participants provide consent for us to access their data, they wear a Garmin smartwatch as they normally would. Then, data flows automatically into our study platform through a dedicated app and back end we’ve built for REACT Wear, ending in a secure, high-performance computing environment that’s dedicated to our research effort. It’s designed to be as low friction as possible: Participants contribute to cutting-edge cardiovascular research without changing their daily routines. Garmin Health API and Companion SDK are used for the data integration.

How does your project operationalize data-driven prevention in practice?

Traditional prevention is a bit like issuing the same weather forecast to an entire country. Data-driven prevention is more like a personal weather app, one that knows your specific situation and adapts accordingly.

In REACT Wear, we’re combining what we learn in the clinic (imaging, blood tests, conventional risk factors) with what the wearable tells us about how someone actually lives: how well they sleep, how active they are, how their heart responds to stress. By looking at all this together, we can start to build a much more precise picture of individual risk and eventually identify the people who may need attention before conventional tests would flag anything.

What are the main limitations/risks in this project?

People who voluntarily wear a smartwatch for a research study may tend to be more health conscious than average, so we must be careful not to assume our findings apply to everyone. Wearable data collection is influenced by participant behavior in everyday settings. For example, devices may be removed temporarily or not charged…