Dynamic Factor Analysis of Seasonal Variation in Daily Physical Activity in Individuals with Heart Failure and Implanted Cardiac Devices
Description
PURPOSE: Improving daily physical activity (PA) is an important clinical outcome in individuals with heart failure (HF) in regard to prognosis and mortality. Seasonal variation may confound studies investigating interventions to improve daily PA, although the presence and magnitude of seasonal variation has yet to be established in this population. The purpose of the present study was to determine the presence and magnitude of seasonal variation in daily physical activity (PA) in those with heart failure. SUBJECTS: 435 patients managed by Spectrum Health Cardiac Device Clinic in West Michigan with HF and Medtronic implanted cardioverter defibrillator and cardiac resynchronization devices (ICD/CRTs) with daily PA data between November 1, 2016-October 31, 2017 were included. METHODS AND MATERIALS: The present study was retrospective. Medtronic ICD/CRT devices with a single-axis accelerometer recorded daily PA. Local/in-system electronic health record data was utilized for inclusion and exclusion of patients. Meteorological data was obtained from the Local Climate Dataset. ANALYSES: Dynamic factor analysis (DFA) of Patient Activity data from Medtronic ICD/CRTs was utilized to identify common states/trends in multivariate PA time series data, while accounting for clinical characteristics/explanatory covariates and meteorological data/covariates. Univariate analyses were used to compare patient groups based upon relevant clinical characteristics identified by the DFA. RESULTS: In the data set of 435 patients, distinct states/trends were identified by DFA, which were associated with specific clinical characteristics. These trends included both a classic, sinusoidal pattern of seasonal variation for some patients, and a pattern of decline over the course of the year for others. CONCLUSIONS: Those with HF and Medtronic ICD/CRTs with low comorbidities, better NYHA Class, higher BMI, no hospitalization, and male sex demonstrated greater seasonal variation of at least 40 minutes per day. Those with HF and Medtronic ICD/CRTs with female sex and hospitalization demonstrated overall downward trajectories of approximately 40 and 80 minutes, respectively, over the course of the year.
Dynamic Factor Analysis of Seasonal Variation in Daily Physical Activity in Individuals with Heart Failure and Implanted Cardiac Devices
PURPOSE: Improving daily physical activity (PA) is an important clinical outcome in individuals with heart failure (HF) in regard to prognosis and mortality. Seasonal variation may confound studies investigating interventions to improve daily PA, although the presence and magnitude of seasonal variation has yet to be established in this population. The purpose of the present study was to determine the presence and magnitude of seasonal variation in daily physical activity (PA) in those with heart failure. SUBJECTS: 435 patients managed by Spectrum Health Cardiac Device Clinic in West Michigan with HF and Medtronic implanted cardioverter defibrillator and cardiac resynchronization devices (ICD/CRTs) with daily PA data between November 1, 2016-October 31, 2017 were included. METHODS AND MATERIALS: The present study was retrospective. Medtronic ICD/CRT devices with a single-axis accelerometer recorded daily PA. Local/in-system electronic health record data was utilized for inclusion and exclusion of patients. Meteorological data was obtained from the Local Climate Dataset. ANALYSES: Dynamic factor analysis (DFA) of Patient Activity data from Medtronic ICD/CRTs was utilized to identify common states/trends in multivariate PA time series data, while accounting for clinical characteristics/explanatory covariates and meteorological data/covariates. Univariate analyses were used to compare patient groups based upon relevant clinical characteristics identified by the DFA. RESULTS: In the data set of 435 patients, distinct states/trends were identified by DFA, which were associated with specific clinical characteristics. These trends included both a classic, sinusoidal pattern of seasonal variation for some patients, and a pattern of decline over the course of the year for others. CONCLUSIONS: Those with HF and Medtronic ICD/CRTs with low comorbidities, better NYHA Class, higher BMI, no hospitalization, and male sex demonstrated greater seasonal variation of at least 40 minutes per day. Those with HF and Medtronic ICD/CRTs with female sex and hospitalization demonstrated overall downward trajectories of approximately 40 and 80 minutes, respectively, over the course of the year.