Abstract P159: Relationships Between Objectively Measured Physical Activity, Exercise Performance, and Quality of Life in Older Obese HFpEF Patients

Abstract

Introduction: Heart failure with preserved ejection fraction (HFpEF) is the most rapidly increasing type of heart failure. Markedly reduced exercise capacity (peak VO 2 ) is the primary manifestation of chronic HFpEF and impacts quality of life (QOL); however, its relationship to objectively measured physical activity (PA) levels is unknown. Accordingly, we prospectively measured PA, exercise performance, and QOL in older patients with chronic obese HFpEF. Hypothesis: PA levels would be low in obese HFpEF patients and would be strongly correlated with reduced exercise performance and QOL. Methods: Obese HFpEF patients ≥60 years old (N=58) wore Kenz Lifecorder EX accelerometers to obtain light PA (LPA), moderate-vigorous PA (MVPA), PA energy expenditure (PAEE), and steps. Peak VO 2 and ventilatory anaerobic threshold (VAT) were assessed by cardiopulmonary exercise testing, and six-minute walk distance (6MWD) was assessed using the Guyatt method. QOL was assessed using the Kansas City Cardiomyopathy Questionnaire (KCCQ), Minnesota Living with Heart Failure Questionnaire (MLHF), and Short Form 36 (SF-36). Pearson correlations were performed to examine relationships between PA, exercise performance, and QOL. Results: Patients were 68.0±5.7 years old, 78% (45 of 58) female, 59% (34 of 58) white, obese (BMI 39.1±6.1 kg/m 2 ), and had predominantly NYHA class II symptoms (62%, 36 of 58). Patients had low PA levels with 33.4±12.6 min/day of LPA, 10.4±6.7 min/day of MVPA, 3785±1436 steps/day, and a PAEE of 147±57 kcal/day. Patients also had low exercise performance with peak VO 2 of 14.4±2.7 ml/kg/min, VAT of 9.7±1.9 ml/kg/min, and 6MWD of 410±75 meters. LPA (r=0.32, p=0.014) and steps/day (r =0.30, p=0.022) were modestly correlated with peak VO 2 , but MVPA and PAEE were not. All PA measures were moderately correlated with 6MWD (r=0.41-0.49, all p<0.002). None of the PA measures were correlated with any of the QOL assessments (KCCQ r=0.00-0.15, p=0.25-0.99; MLHF r=-0.13-0.00, p=0.33-0.99; SF-36 r=0.05-0.11, p=0.41-0.70). Conclusion: Obese HFpEF patients had low levels of objectively measured daily PA and low exercise performance. Contrary to our hypothesis, PA levels were only modestly correlated with exercise performance including peak VO 2 and 6MWD. PA was not correlated with any assessment of QOL. This indicates that measures of PA, exercise capacity, and QOL assess different aspects of the patient experience in obese HFpEF and are largely independent of each other. While each remains a valid potential target for intervention, they should not be considered interchangeable.