ABSTRACT Remote 6‐min walk testing (6MWT) has been shown to be safe in pulmonary hypertension, but limited data exist on its longitudinal durability and relationship to supervised in‐clinic testing. Cardiac Effort (CE), defined as total heartbeats divided by walk distance, provides physiologic context beyond distance alone. We evaluated the longitudinal performance of a home‐based 6MWT and CE performed on a modified indoor walking space using a wearable chest sensor and compared results with in‐clinic testing over 8 weeks. This single‐center prospective study was conducted with institutional review board approval. Participants with PH performed supervised in‐clinic and unsupervised home 6MWTs at baseline and Week 8. A chest‐based wearable sensor recorded acceleration and heart rate data to estimate walk distance and calculate CE. Mixed‐effects repeated‐measures models were used to compare sensor‐estimated and directly observed walk distance and CE in the clinic and at home over time. Agreement was assessed using Bland–Altman analyses, intraclass correlation coefficients (ICC), and Spearman correlations. Twenty‐nine participants were enrolled, and no adverse events occurred. Sensor‐estimated 6MWT distance and CE demonstrated minimal bias and excellent agreement with directly observed in‐clinic measurements (6MWD bias 0.04%, ICC 0.995; CE bias −0.04%, ICC 0.995). Home‐based 6MWD was approximately 40 m lower than supervised clinic testing. Mixed‐effects models showed similar longitudinal changes between home and clinic testing. Changes in home 6MWD and CE correlated with corresponding in‐clinic changes (6MWD: r = 0.40, p = 0.045; CE: r = 0.42, p = 0.03). Home‐based 6MWT and CE obtained using a wearable chest sensor provide a safe, feasible method for remote functional assessment in PH that tracks with in‐clinic testing. Frequent home assessment may facilitate earlier detection of clinical change, support therapeutic titration, and expand access to standardized physiologic monitoring.
Lachant et al. (Thu,) studied this question.