REACT study evaluates impact of daily movement on arterial health
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 characterised 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 realise 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 operationalise 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 behaviour in everyday settings. For example, devices may be removed temporarily or not charged consistently. A major focus of our work is understanding these behavioural patterns and their impact on data continuity.
Privacy is another priority. We work within strict data-protection regulations and informed consent, and participant data is handled with the same care as any other sensitive medical information. Research like this only works if participants trust us, and we take that seriously.
What measurable impact could prevention-focused approaches like yours have on individual health outcomes?
Cardiovascular disease is still the world’s leading cause of death, and a large proportion of those deaths happen in people who were not previously recognised as being at high risk.
If we can identify risks earlier and intervene sooner, even modest improvements could translate into enormous benefits at the population level with fewer heart attacks, fewer strokes, longer and healthier lives.
At the individual level, it means more options. Lifestyle changes, medications and closer monitoring are generally more effective when started early. The goal of REACT Wear is to help make “early” the norm rather than the exception.
How do you think wearables are changing research, in general, and what is the long-term impact?
For most of medical history, researchers could only study people at scheduled appointments and receive periodic snapshots of someone’s health. Wearables and GHCE give us something entirely new: the ability to gather real-time data and biometric insights about people through real life, continuously, over months and years. That changes everything about the quality and relevance of what we can learn.
Looking further ahead, I think we’ll see wearables become more integral to healthcare, not just recording data but helping people understand their own health in real time and flagging changes that warrant a conversation with a doctor.
There’s an important bridge to cross, however. Because wearables are already a part of many people’s everyday lives, it’s important to use them within the framework of clinical, scientific rigor and integrate them into how we prevent and treat disease.
Garmin Health supports research collaborations across the globe through product and data integrations via Garmin Health Connected Ecosystem. Learn more about previous research initiatives and upcoming webinars.
12025 Heart Disease & Stroke Statistics Update (Global Burden of Disease data)
2Garmin wearable devices are consumer wellness devices and are not medical devices under the regulation of any jurisdiction, including Regulation (EU) 2017/745. They are not intended for the diagnosis, prevention, monitoring, or treatment of any disease. Any medical or clinical functionality described is provided by a third-party solution and is solely based on their interpretation of data gathered from various data sources.
