PMID- 31758777 OWN - NLM STAT- PubMed-not-MEDLINE LR - 20230502 IS - 2561-1011 (Electronic) IS - 2561-1011 (Linking) VI - 3 IP - 1 DP - 2019 May 17 TI - Use of Free-Living Step Count Monitoring for Heart Failure Functional Classification: Validation Study. PG - e12122 LID - 10.2196/12122 [doi] LID - e12122 AB - BACKGROUND: The New York Heart Association (NYHA) functional classification system has poor inter-rater reproducibility. A previously published pilot study showed a statistically significant difference between the daily step counts of heart failure (with reduced ejection fraction) patients classified as NYHA functional class II and III as measured by wrist-worn activity monitors. However, the study's small sample size severely limits scientific confidence in the generalizability of this finding to a larger heart failure (HF) population. OBJECTIVE: This study aimed to validate the pilot study on a larger sample of patients with HF with reduced ejection fraction (HFrEF) and attempt to characterize the step count distribution to gain insight into a more objective method of assessing NYHA functional class. METHODS: We repeated the analysis performed during the pilot study on an independently recorded dataset comprising a total of 50 patients with HFrEF (35 NYHA II and 15 NYHA III) patients. Participants were monitored for step count with a Fitbit Flex for a period of 2 weeks in a free-living environment. RESULTS: Comparing group medians, patients exhibiting NYHA class III symptoms had significantly lower recorded 2-week mean daily total step count (3541 vs 5729 [steps], P=.04), lower 2-week maximum daily total step count (10,792 vs 5904 [steps], P=.03), lower 2-week recorded mean daily mean step count (4.0 vs 2.5 [steps/minute], P=.04,), and lower 2-week mean and 2-week maximum daily per minute step count maximums (88.1 vs 96.1 and 111.0 vs 123.0 [steps/minute]; P=.02 and .004, respectively). CONCLUSIONS: Patients with NYHA II and III symptoms differed significantly by various aggregate measures of free-living step count including the (1) mean and (2) maximum daily total step count as well as by the (3) mean of daily mean step count and by the (4) mean and (5) maximum of the daily per minute step count maximum. These findings affirm that the degree of exercise intolerance of NYHA II and III patients as a group is quantifiable in a replicable manner. This is a novel and promising finding that suggests the existence of a possible, completely objective measure of assessing HF functional class, something which would be a great boon in the continuing quest to improve patient outcomes for this burdensome and costly disease. CI - (c)Jonathan-F Baril, Simon Bromberg, Yasbanoo Moayedi, Babak Taati, Cedric Manlhiot, Heather Joan Ross, Joseph Cafazzo. Originally published in JMIR Cardio (http://cardio.jmir.org), 17.05.2019. FAU - Baril, Jonathan-F AU - Baril JF AUID- ORCID: 0000-0002-0292-5600 AD - Centre for Global eHealth Innovation, Techna Institute, University Health Network, Toronto, ON, Canada. AD - Institute of Biomaterials & Biomedical Engineering, University of Toronto, Toronto, ON, Canada. FAU - Bromberg, Simon AU - Bromberg S AUID- ORCID: 0000-0003-3347-5689 AD - Centre for Global eHealth Innovation, Techna Institute, University Health Network, Toronto, ON, Canada. AD - Institute of Biomaterials & Biomedical Engineering, University of Toronto, Toronto, ON, Canada. FAU - Moayedi, Yasbanoo AU - Moayedi Y AUID- ORCID: 0000-0002-3288-7393 AD - Ted Rogers Centre of Excellence in Heart Function, University Health Network, Toronto, ON, Canada. FAU - Taati, Babak AU - Taati B AUID- ORCID: 0000-0001-9763-4293 AD - Institute of Biomaterials & Biomedical Engineering, University of Toronto, Toronto, ON, Canada. AD - Toronto Rehabilitation Institute, University Health Network, Toronto, ON, Canada. FAU - Manlhiot, Cedric AU - Manlhiot C AUID- ORCID: 0000-0001-9419-7681 AD - Ted Rogers Centre of Excellence in Heart Function, University Health Network, Toronto, ON, Canada. FAU - Ross, Heather Joan AU - Ross HJ AUID- ORCID: 0000-0003-4384-3027 AD - Institute of Biomaterials & Biomedical Engineering, University of Toronto, Toronto, ON, Canada. AD - Ted Rogers Centre of Excellence in Heart Function, University Health Network, Toronto, ON, Canada. FAU - Cafazzo, Joseph AU - Cafazzo J AUID- ORCID: 0000-0002-3114-4440 AD - Centre for Global eHealth Innovation, Techna Institute, University Health Network, Toronto, ON, Canada. AD - Institute of Biomaterials & Biomedical Engineering, University of Toronto, Toronto, ON, Canada. AD - Institute of Health Policy, Management and Evaluation, Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada. LA - eng PT - Journal Article DEP - 20190517 PL - Canada TA - JMIR Cardio JT - JMIR cardio JID - 101718325 PMC - PMC6834224 OTO - NOTNLM OT - Fitbit OT - ambulatory monitoring OT - cardiopulmonary exercise test OT - exercise physiology OT - heart failure OT - heart rate tracker OT - steps OT - wrist worn devices COIS- Conflicts of Interest: SB owns shares of the manufacturer of the experimental device used in this study (Fitbit). The other coauthors have no conflicts of interest to disclose. EDAT- 2019/11/24 06:00 MHDA- 2019/11/24 06:01 PMCR- 2019/05/17 CRDT- 2019/11/24 06:00 PHST- 2018/09/07 00:00 [received] PHST- 2019/05/02 00:00 [accepted] PHST- 2018/12/13 00:00 [revised] PHST- 2019/11/24 06:00 [entrez] PHST- 2019/11/24 06:00 [pubmed] PHST- 2019/11/24 06:01 [medline] PHST- 2019/05/17 00:00 [pmc-release] AID - v3i1e12122 [pii] AID - 10.2196/12122 [doi] PST - epublish SO - JMIR Cardio. 2019 May 17;3(1):e12122. doi: 10.2196/12122.