Introduction: The 6-minute walk test is heavily ingrained in the management of pulmonary arterial hypertension (PAH). The current monitoring solution does not allow for real-time measurements of cardiac status therefore we developed an experimental setup to help patients conduct a self-administered 6-minute walk test at home using wearable technology.
Method: We analyzed data from 50 individuals including 13 health subjects (H), 37 PAH including 18 stable (S), 7 with treatment intensification (TI), and 12 with treatment initiation (TN). During the walk, they wore Biostamp (MC10, Cambridge, MA ) collecting single-lead ECG and accelerometry signals. We report HR at baseline (HRb), maximum HR (HRm), HR acceleration during exercise (HRa), HR at 1-minute recovery (HRr), SDNN during recovery, and number of laps. Patients performed two tests at different times across groups (H:8 ±8, S:19 ± 19, TI:51 ± 19, TN:58 ± 31 days) . We reported absolute value (val), within subject standard deviation (Sw), and repeatability coefficient (RC) across the patient cohorts.
Results: We collected ECG and accelerometry signals during 6-min walk tests using a single patch. We extracted measurements before, during, and after the test in 4 distinctive groups. We demonstrated good repeatability in healthy subjects at a week interval, and we reported clinically valid measures in PAH patients (see table).
Conclusion: We have devised a range of measurements derived from signals recorded by a patch during a 6-minute test in PAH patients. Our novel monitoring setup provides an instantaneous assessment of cardiac status that can be performed remotely.