Heart Rate Metrics During 6-Minute Walk Test Linked to Hospital Use in COPD

Heart rate metrics captured during routine 6-minute walk testing may help identify patients with chronic obstructive pulmonary disease (COPD) at greater risk for hospital utilization and exacerbations, according to late-breaking findings presented at the 2026 American Thoracic Society (ATS) International Conference in Orlando, Florida.

The ongoing phase 3 randomized controlled HiFlo trial evaluated associations between heart rate responses during 6-minute walk testing and prior hospital utilization among patients with moderate-to-severe COPD. In an interview at ATS 2026, Andrew Truong-An Ho, MD, from Temple University Hospital, said the findings represent an early effort to better characterize physiologic differences among patients enrolled in the study investigating high-flow nasal therapy (HFNT).

“This is just a starting point when we’re looking at the trial as a whole,” Ho said.

HiFlo is comparing HFNT plus usual care versus usual care alone over at least 1 year in patients with COPD. Investigators are assessing whether HFNT can reduce exacerbations through several physiologic mechanisms, including reducing gas trapping, improving ventilatory efficiency, and decreasing dynamic hyperinflation.

“There’s a few key mechanisms from high-flow nasal therapy that might help reduce COPD exacerbations,” Ho said. “There’s the ability to wash out the dead space, improve ventilatory efficiency for patients with COPD, small amounts of PEEP that are generated with high flow, and humidified air, which can help loosen mucus plugs and make it easier for patients to breathe.”

The current analysis focused on baseline 6-minute walk (6MW) heart rate parameters among 267 patients with COPD enrolled in the trial. Participants had a mean age of 67.9 years, a mean FEV1 of 41% predicted, and an average of 2.2 hospitalizations in the prior year.

Investigators evaluated resting heart rate, peak heart rate during exertion, and delta heart rate during the 6MW test. Small but statistically significant positive associations emerged between several heart rate metrics and both moderate exacerbations and hospitalizations in the prior year.

Delta heart rate and peak heart rate were associated with moderate exacerbations, while pre-walk resting heart rate and peak heart rate correlated with prior hospitalizations. Patients with emergency department visits in the previous year had greater baseline heart rates before the walk test, while patients with more than 1 hospitalization demonstrated greater exertional heart rate changes and higher peak heart rates.

Ho emphasized that COPD remains a highly heterogeneous disease, making physiologic stratification challenging.

“Sometimes it’s for dyspnea, sometimes it’s for phlegm production, other times it’s just exacerbations that lead to dynamic hyperinflation,” Ho said. “The heart rate can reflect [some of] these measures. It shows if there’s a higher burden or demand at baseline.”

Rather than focusing exclusively on walk distance, Ho suggested heart rate responses may provide additional insight into cardiopulmonary reserve and physiological stress during exertion.

“This gives a more functional way to see how the patient progresses, rather than just looking at distance,” he said.

Still, Ho cautioned clinicians against overinterpreting the findings at this stage. Correlations between heart rate metrics and outcomes were modest, with coefficients ranging approximately from 0.12 to 0.16. Ho emphasized that this is an exploratory analysis, and while it observed a trend, it does not display the full picture.

Investigators ultimately hope baseline physiologic measures may help identify which patients are most likely to benefit from HFNT as additional data from the HiFlo trial become available.

“Depending on the results of the study, we want to see where high-flow nasal therapy fits in the picture of managing a patient’s COPD,” Ho said. “There’s other forms of ventilation that can be used, so it will be important to see where this fits in.”

References

Ho A, Dachert S, Criner L, et al. (Poster Board # P1979) Association Between Hospital Utilization and 6mw Heart Rate Metrics From the Hiflo Study. Late-breaking poster presented at ATS 2026 in Orlando, Florida, on May 17.