Comparison of questionnaire and accelerometer-based assessments of physical activity in patients with heart failure with preserved ejection fraction: clinical and prognostic implications.

Objective. (i) To compare daily physical activity (PA) levels evaluated by the International Physical Activity Questionnaire (IPAQ) and by triaxial accelerometry in heart failure with preserved ejection fraction (HFpEF) patients; (ii) to describe daily PA patterns based in objective measurements; and (iii) to observe the association between prognostic indicators and PA measurements. Design. This is a cross-sectional study with 24 stable HFpEF patients. PA was assessed through the IPAQ short version and triaxial accelerometer. Time spent in moderate-to-vigorous PA (MVPA) from IPAQ was computed as self-reported walking and MVPA. Prognostic indicators were: distance on the 6-minute-walking test (6MWT), oxygen consumption (VO2) during the test, quality of life (QoL), BNP plasma level, and E/e' ratio. Results. Compared to accelerometry, IPAQ underestimated sedentary time (253 ± 156 vs. 392 ± 104 min/day, p = .001) and overestimated MVPA (44 ± 56 vs. 19.3 ± 26 min/day, p < .001). Accelerometer-derived data showed that HFpEF patients spent 50% of their waking time in sedentary behaviours and 2.5% in MVPA. Of measured surrogate prognostic markers, functional capacity (6MWT, r = 0.652, p = .04; VO2, r = 0.512, p = .02) and QoL (r=-0.490, p = .04) were correlated with MVPA. Conclusions. The IPAQ underestimated sedentary time and over-estimated MVPA in HFpEF patients. Using accelerometer-derived data, HFpEF patients spent only a minority of their time involved in MVPA, which was the only PA pattern positively associated with prognostic indicators.