Comparison of in-clinic assessment of 6MWT by conventional method and using wearable sensors for patients with ATTR-CM.

Introduction: The 6-minute walk test (6MWT) is used to assess submaximal exercise capacity in clinical trials. Conducting the 6MWT can be challenging when patients cannot visit the clinic due to physical/travel limitations. This pilot study assessed the feasibility of conducting the 6MWT using wearable sensors for patients with transthyretin amyloid cardiomyopathy.

Methods: Participants were enrolled in the phase 3 ATTRibute-CM trial. Sensors were positioned on patients' feet and lower back during the 6MWT. The 6-minute walk distance (6MWD) was compared with the distance measured by a trained observer during a concurrent conventional test. Pearson and concordance correlation coefficients were estimated.

Results: Twelve participants from five centers participated; 11 had evaluable data. Mean 6MWD was 330.3 m (conventional method) and 335.1 m (wearable sensors); mean difference (SD) was 4.7 m (10.95). Pearson and concordance correlation coefficients for 6MWD were 0.998 (95% CI: 0.992-0.999) and 0.997 (95% CI: 0.991-0.999), respectively.

Conclusions: The 6MWD measured using wearable sensors and by the conventional method were closely correlated. Conducting the 6MWT with wearable sensors may be feasible and as reliable as the conventional method in a monitored clinic setting. Whether at-home 6MWD measured by wearable sensors correlates with in-clinic monitoring deserves further study.

Clinical Trial Registration: ClinicalTrials.gov identifier is NCT03860935.