Abstract 17496: Diagnostic Accuracy of a Smartphone based Six-Minute Walk Test
Introduction: Timely and accurate diagnosis of heart failure exacerbation after discharge is an unmet medical need with enormous societal costs. Six-minute walk tests (6MWT) powerfully predict heart failure exacerbation, but require a clinic visit and valuable personnel time. We sought to determine the diagnostic accuracy of a 6MWT recorded on a novel smartphone App (6MWTApp), which we aim to integrate into a comprehensive digital heart failure monitoring program within the Health eHeart Study.
Hypothesis: We hypothesized that distance calculated using the smartphone measurements would correlate well with physically measured walk distance, at the time of a clinical 6MWT (defined by an r ≥ 0.80).
Methods: Six-Minute Walk Tests were conducted on a clinical 6MWT course by participants who wore, on a hip holster and in a front pocket, iPhones that ran the 6MWTApp. Distances traveled were calculated based on a linear regression model that incorporated the smartphone-measured steps and the patient height, and were compared to the physically measured distance walked at the time of the test.
Results: The 6MWTApp was tested in 52 participants half of whom had heart failure or pulmonary hypertension. The App demonstrated good correlation with measured distance, r = 0.89 95% CI (0.82-0.95). For those with pHTN or CHF the correlation (r) was 0.75 95% CI (0.54-0.96) and for those with neither pHTN or CHF the correlation (r) was 0.92 95% CI (0.85-0.98). There was no difference between phone placement in the front pocket vs worn in a holster on the hip.
Conclusions: Distance walked during a 6MWT is accurately predicted by a 6MWTApp.
Author Disclosures: G.C. Brooks: None. E. Vittinghoff: None. S. Iyer: None. G.M. Marcus: Research Grant; Significant; SentreHeart, Medtronic, Pfizer, NIH, AHA. M.J. Pletcher: None. J.E. Olgin: None.
- © 2014 by American Heart Association, Inc.