Commercially available iOS/watchOS-based devices have demonstrated efficacy as a monitoring platform for individuals with heart failure, according to a study recently published in ESC Heart Failure. These devices allow for reporting of relevant patient‐reported outcome measures.
This prospective feasibility trial included 10 participants hospitalized for heart failure with decreased ejection fraction, each of whom were given clinical examinations 3 times throughout the 2-month postdischarge study period. Additionally, participants were monitored continuously using the cardio patient monitoring platform (CPMP), and comparisons were made between CPMP data and traditional measures using the paired t-test (α=0.05). The CPMP included an iOS-based mobile application for the user’s smartwatch or smartphone, as well as an equivalent application for physicians. This provided a means of continuous data transmission of activity, self-reported physiological measures, and symptoms as reported by the patient. The relationship between conventional clinical measures and mHealth data was examined using the Pearson product-moment correlation coefficient, r.
A promising patient-reported outcome measure was the 14-day average daily step count, which increased throughout the study period from 3612±3311 at baseline to 6927±4871 at first follow-up to 7069±5006 by the end of the study (P <.0001 for both). This parameter showed a significant association with traditional measures of cardiac activity such as left ventricular ejection fraction (r = 0.44; 95% CI, 0.07-0.71; P =.0232), health-related quality of life questionnaire scores, and 6-minute walk test (r = 0.67; 95% CI, 0.38-0.84; P =.0002).
Participants demonstrated satisfactory adherence to self-measured data, with an 82.95% adherence rate for blood pressure and 78.18% for body weight.
Limitations to this study include a small sample size, no control group, inability to detect the effects of the intervention on certain clinical outcomes, selection bias, and the reliance on participants comfortable with technology.
Researchers conclude that “[our] study demonstrates the feasibility of a newly designed mobile application for [telemonitoring] of patients after [heart failure] hospitalization. The system allows for continuous and secure transmission of the patients’ relevant health data to the treating physician. In our trial, we are the first to show that daily step count measured by iOS/watchOS devices in free‐living conditions is a valid surrogate parameter of daily [physical activity] and correlates to established clinical parameters.…[We] suggest smart device‐based monitoring and in particular measurement of activity as new diagnostic parameter in [telemonitoring] concepts and a new end point in clinical [heart failure] trials.”
Werhahn SM, Dathe H, Rottmann T, et al. Designing meaningful outcome parameters using mobile technology: a new mobile application for telemonitoring of patients with heart failure. ESC Heart Fail. 2019;6(3):516-525.