Accelerometer-Measured Daily Activity in Heart Failure With Preserved Ejection Fraction

Abstract

Background Daily physical activity assessed by accelerometers represents a novel method to assess the impact of interventions on heart failure (HF) patients’ functional status. We hypothesized that daily activity varies by patient characteristics and correlates with established measures of HF severity in HF with preserved ejection fraction (HFpEF). Methods and Results In this ancillary study of Nitrate’s Effects on Activity Tolerance in HFpEF (NEAT-HFpEF) trial, average daily accelerometer units (ADAU) and hours active per day (HAPD) were assessed over a 14-day period prior to starting isosorbide mononitrate (ISMN) or Placebo (n=110). Baseline ADAU was negatively associated with age, female sex, height and body mass index and these variables accounted for 28% of the variability in ADAU (p<0.007 for all). Adjusting for these factors, patients with lower ADAU were more likely to have had a HF hospitalization, orthopnea, diabetes and anemia, be treated with beta blockers, have higher EF, relative wall thickness and left atrial volume and worse NYHA class, HF specific quality of life (QOL) scores, six minute walk distance (6MWD) and NT-proBNP (p<0.05 for all). Associations between HAPD and clinical characteristics were similar. Relative to baseline, there were no significant associations between changes in ADAU or HAPD and changes in standard functional assessments (NYHA, QOL, 6MWD, NT-proBNP) with ISMN. Conclusions Daily activity is a measure of HF-related and global functional status in HFpEF. As compared to intermittently assessed standard HF assessments, change in daily activity may provide unique information regarding the impact of HF interventions on functional status. Clinical Trial Registration https://clinicaltrials.gov/. Unique Identifier: NCT02053493

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