Purpose: Exercise capacity is usually evaluated by peak oxygen consumption (peak-VO2). However, assessment of peak-VO2 in patients with a left ventricular assist device (LVAD) might not be the best method to provide insight into their daily life activity. The aim of this study was to assess the postoperative activity of LVAD patients using actigraphy and to compare these patients to a healthy and a heart-transplanted (HTx) population.
Methods: Activity was continuously monitored using wrist-accelerometers in LVAD patients after implantation, during 4 weeks of rehabilitation following hospital discharge, and at 2 follow-up assessments. Peak-VO2 values measured during rehabilitation were correlated with activity. Additionally, actigraphy data from LVAD recipients were compared with data measured in healthy and HTx subjects.
Results: After hospital discharge a significant increase in physical activity of LVAD recipients was observed (55 ± 28 vs. 102 ± 23 Activity Scores, n = 11, p = 0.002). During rehabilitation as well as at the follow-ups (140 ± 43 and 253 ± 33 days post-implantation) no significant increase in activity was observed. Peak-VO2 values correlated to daily activity both in LVAD and HTx patients (r > 0.5). Average daily activity was significantly lower in LVAD and HTx patients than in the healthy population (130 ± 30 and 148 ± 60 vs. 245 ± 63 Activity Score; n = 18 in each group, p < 0.001).
Conclusions: Activity in LVAD recipients increased substantially after hospital discharge with no further significant improvement observed during a period of 8.5 months. Similarly to the peak-VO2, also the daily activity of LVAD recipients was 53% compared to healthy subjects. These results highlight the need for an optimized physical therapy in this patient cohort.