Translation of the Frailty Paradigm from Older Adults to Children with Cardiac Disease

Children and adolescents with cardiac disease (CCD) have significant morbidity and lower quality of life. However, there are no broadly applicable tools similar to the frailty score as described in the elderly, to define functional phenotype in terms of physical capability and psychosocial wellbeing in CCD. The purpose of this study is to investigate the domains of the frailty in CCD. We prospectively recruited CCD (8–17.5 years old, 70% single ventricle, 27% heart failure, 12% pulmonary hypertension; NYHA classes I, II and III) and age and gender matched healthy controls (total n = 56; CCD n = 34, controls n = 22; age 12.6 ± 2.6 years; 39.3% female). We measured the five domains of frailty: slowness, weakness, exhaustion, body composition and physical activity using developmentally appropriate methods. Age and gender-based population norms were used to obtain Z scores and percentiles for each measurement. Two-tailed t-tests were used to compare the two groups. The CCD group performed significantly worse in all five domains of frailty compared to healthy controls. Slowness: 6-min walk test with Z score −3.9 ± 1.3 vs −1.4 ± 1.3, p < 0.001; weakness: handgrip strength percentile 18.9 ± 20.9 vs 57.9 ± 26.0, p < 0.001; exhaustion: multidimensional fatigue scale percentile 63.7 ± 13.5 vs 83.3 ± 14.4, p < 0.001; body composition: height percentile 43.4 ± 29.5 vs 71.4 ± 25.2, p < 0.001, weight percentile 46.0 ± 36.0 vs 70.9 ± 24.3, p = 0.006, BMI percentile 48.4 ± 35.5 vs 66.9 ± 24.2, p = 0.04, triceps skinfold thickness 41.0 ± 24.0 vs 54.4 ± 22.1, p = 0.04; physical activity: pediatric activity questionnaire score 2 ± 0.6 vs 2.7 ± 0.6, p < 0.001. The domains of frailty can be quantified in children using developmentally appropriate methods. CCD differ significantly from controls in all five domains, supporting the concept of quantifying the domains of frailty. Larger longitudinal studies are needed to study frailty in CCD and examine if it predicts adverse health outcomes. Clinical Trial Registration: The ClinicalTrials.gov identification number is NCT02999438. https://clinicaltrials.gov/ct2/show/NCT02999438.