Improved appendicular muscle strength predicts lower mortality in patients with heart failure.

Background: A decrease in general muscle strength is associated with a poor prognosis and lower physical function in patients with heart failure (HF). We examined whether improved appendicular muscle weakness (dynapenia) conditions would predict a better prognosis and improved physical functions in patients with HF.

Methods: Handgrip and leg strength were assessed before discharge (baseline) and after outpatient cardiac rehabilitation (CR) (follow-up), based on which patients were divided into four dynapenia conditions: non-dynapenia at baseline/follow-up, dynapenia at baseline/non-dynapenia at follow-up, non-dynapenia at baseline/dynapenia at follow-up, and dynapenia at baseline/follow-up. Cox regression and mixed-effects analyses were performed to examine associations between changes in the dynapenia condition and all-cause mortality and physical functions (6-minute walking distance and gait speed).

Results: Of 607 patients included in the analyses (median age 70 years, 64% male), 92 patients died during the follow-up period (median 2.81 years). The dynapenia at baseline/follow-up group (adjusted hazard ratio [aHR]: 1.936, 95% confidence interval [CI]: 1.086-3.451) and non-dynapenia at baseline/dynapenia at follow-up group (aHR: 2.442, 95% CI: 1.032-5.766) had higher mortality rates compared to the non-dynapenia at baseline/follow-up group. The mortality risk was not different between the group with dynapenia at baseline/non-dynapenia at follow-up (aHR: 1.270, 95% CI: 0.670-2.409) and the group with non-dynapenia at baseline/follow-up. Improved dynapenia conditions were associated with increased 6-minute walking distance (p = 0.004) but not significantly associated with gait speed (p = 0.173).

Conclusions: Dynapenia following CR is associated with a higher risk of mortality and lower exercise capacity in patients with HF.