Effects of sarcopenia on functional improvement over the first year after cardiac surgery: a cohort study

Background: Sarcopenia is linked with poor postoperative outcomes. Aims: To evaluate the effects of sarcopenia on first-year functional changes after cardiac surgery. Methods: In this prospective cohort study, functional changes (physical activity levels in metabolic equivalent hours/week, 6-minute walking distance in metres, and grip strength in kg) from preoperative baseline to 1, 3, 6 and 12 months postoperatively were compared in adult patients with and without sarcopenia undergoing cardiac surgery at a tertiary medical centre. Presurgical sarcopenia was defined as low muscle mass plus either low strength or poor physical performance (i.e. reduced gait speed). Secondary outcomes (length of hospital stay and 1-year mortality) were compared between sarcopenia and non-sarcopenia groups. Results: Sarcopenia presented in 27.7% ( n=67) of 242 participants. Participants with sarcopenia were significantly older, predominantly women, and had lower body mass index and higher cardiac surgery risk (measured by the EuroSCORE II) than those without sarcopenia. For both groups, physical activity levels, walking distance and grip strength steadily improved over the year following cardiac surgery. Independent of EuroSCORE II, changes in physical activity levels, walking distance and grip strength did not differ significantly between the sarcopenia and non-sarcopenia groups 1, 3, 6 and 12 months after surgery. Nevertheless, the sarcopenia group had a significantly longer length of hospital stay than the non-sarcopenia group (19.4 vs. 15.3 days; β=2.9, P=0.02) but 1-year mortality (3.4 vs. 3.9% for non-sarcopenia group) was comparable. Conclusions: Despite a longer length of hospital stay for the sarcopenia group, sarcopenia was not a restriction for cardiac surgery given their comparable functional improvement and mortality 1 year following surgery.