Frailty and maximal exercise capacity in adult lung transplant candidates

Layton AM, Armstrong HF, Baldwin MR, Podolanczuk AJ, Pieszchata
NM, Singer JP, Arcasoy SM, Meza KS, D’Ovidio F, Lederer DJ

Respir Med. 2017 Oct;131:70-76. doi: 10.1016/j.rmed.2017.08.010. Epub 2017 Aug

BACKGROUND: Frail lung transplant candidates are more likely to be delisted or
die without receiving a transplant. Further knowledge of what frailty represents
in this population will assist in developing interventions to prevent frailty
from developing. We set out to determine whether frail lung transplant candidates
have reduced exercise capacity independent of disease severity and diagnosis.
METHODS: Sixty-eight adult lung transplant candidates underwent cardiopulmonary
exercise testing (CPET) and a frailty assessment (Fried’s Frailty Phenotype
(FFP)). Primary outcomes were peak workload and peak aerobic capacity (V˙O2). We
used linear regression to adjust for age, gender, diagnosis, and lung allocation
score (LAS).
RESULTS: The mean ± SD age was 57 ± 11 years, 51% were women, 57% had
interstitial lung disease, 32% had chronic obstructive pulmonary disease, 11% had
cystic fibrosis, and the mean LAS was 40.2 (range 19.2-94.5). In adjusted models,
peak workload decreased by 10 W (95% CI 4.7 to 14.6) and peak V˙O2 decreased by
1.8 mL/kg/min (95% CI 0.6 to 2.9) per 1 unit increment in FFP score. After
adjustment, exercise tolerance was 38 W lower (95% CI 18.4 to 58.1) and peak V˙O2
was 8.5 mL/kg/min lower (95% CI 3.3 to 13.7) among frail participants compared to
non-frail participants. Frailty accounted for 16% of the variance (R2) of watts
and 19% of the variance of V˙O2 in adjusted models.
CONCLUSION: Frailty contributes to reduced exercise capacity among lung
transplant candidates independent of disease severity.