Relevant factors of leg strength at hospital discharge in patients hospitalized due to acute decompensated heart failure: multi-institutional prospective observational study

Background Lower leg strength at hospital discharge is strongly associated with poor prognosis in older patients with acute decompensated heart failure (ADHF). Improving leg strength is important in acute-phase cardiac rehabilitation (CR). Aims This study aimed to clarify whether a change in leg strength occurs during hospitalization of older ADHF patients receiving CR and whether it affects leg strength at discharge. Methods and results We enrolled 247 ADHF patients who underwent CR during hospitalization. They were divided into the non-older patient group (<75 years; n = 142) and older patient group (>= 75 years; n = 105). Quadriceps isometric strength (QIS), body mass-corrected QIS (%BM QIS), and change in QIS during hospitalization (QIS ratio) were evaluated in all patients. Physical function in the stable phase was measured by the Performance Measure for Activities of Daily Living-8 (PMADL-8). The QIS value increased during hospitalization in the non-older patient group (30.0 +/- 11.1 vs. 31.6 +/- 10.9 kgf, P < 0.001) but did not increase in the older patient group (19.1 +/- 6.3 vs. 19.5 +/- 6.1 kgf, P = 0.275). Multiple regression analysis revealed that PMADL-8 significantly predicted %BM QIS at discharge in the non-older patient group (beta = -0.254, P = 0.004), whereas in the older patient group, QIS ratio and PMADL-8 significantly predicted %BM QIS at discharge (beta = 0.264, P = 0.008 for QIS ratio and beta = -0.307, P = 0.003 for PMADL-8). Conclusions Leg strength was not improved in older ADHF patients during hospitalization even if they received CR, and this affected leg strength at discharge, suggesting that careful skeletal muscle intervention should be provided during hospitalization, and patients need to continue exercise after discharge.