A Step Beyond: New Metric Combines Step Counts With Heart Rate | ACC 2025

Step counts are easy to measure and capture a common form of physical activity, which is broadly protective against cardiovascular disease.

But Zhanlin Chen believes that there might be another metric, based on easy-to-make measurements and calculations, that does a better job of capturing direct information about heart health.

Chen, a Northwestern University Feinberg School of Medicine student, was scheduled to report findings about the metric, average daily heart per step (DHRPS), tomorrow at the American Academy of Cardiology meeting in Chicago.

DHRPS is computed by dividing the average daily heart rate — say, 80 beats per minute — by the number of steps taken that day — say, 10,000. The lower the average daily heart rate and the higher the daily step count, the better the DHRPS will be.

"We truly believe that it's not just about measuring how fast your heart is beating or how many steps you're counting, but rather, your heart rate in the context of the demand of your physical activity that actually reflects how your heart is doing," Chen said in an interview with Managed Healthcare Executive.

Chen and his colleagues used data from approximately 7,000 adults to conduct their study. They tapped data generated by Fitbit and electronic health records from the National Institute of Health's All of Us research program to look for correlations between DHRPS and cardiovascular risk factors and outcomes. They found that people with elevated DHRPS numbers (the top quartile) were twice as likely to have Type 2 diabetes as people with lower DHRPS numbers (the bottom quartile). Heart failure, high blood pressure and coronary atherosclerosis were also correlated with high DHRPS numbers.

Moreover, in a small — just 21 participants — group of those who had treadmill stress tests, DHRPS was more strongly correlated with maximum metabolic equivalents than daily heart rate or step counts alone.

Because this is a cross-sectional study, the results don't establish a temporal sequence between DHRPS and cardiovascular disease. In a news release, Chen said prospective studies would shed some light on the sequence.

If these initial findings hold up as more research is done, Chen envisions DHRPS being incorporated into wearables and be used by clinicians and patients to assess heart disease risk assessments.

"When you look at the heart rate as a number outside of the context of that person, their age, their sex, their BMI [body mass index] and their level of activity, it doesn't really mean anything," Chen said. "We really have to take all of that into consideration to find people with underlying coronary disease."