Decreased Muscle Strength in Children With Repaired Tetralogy of Fallot:Relation With Exercise Capacity

Background: The aim of this study is to describe muscle strength in pediatric patients with repaired tetralogy of Fallot compared with healthy peers and to analyze the correlation between muscle strength and peak oxygen uptake, exercise capacity (mL/min).Methods and Results: A prospective, cross-sectional study was carried out in the University Medical Center Groningen between March 2016 and December 2019, which included 8 -to-19-year-old patients with repaired tetralogy of Fallot. Exclusion criteria comprised the following: Down syndrome, unstable pulmonary disease and severe scoliosis affecting pulmonary function, neuromuscular disease, and mental or physical limitations that prohibit the execution of the functional tests. Muscle strength was compared with 2 healthy pediatric cohorts from the Northern Netherlands. Handgrip strength, maximal voluntary isometric contraction, and dynamic muscle strength in correlation with peak oxygen uptake, exercise capacity (mL/min) were the main outcomes of the study. The 67 patients with repaired tetralogy of Fallot (42% female; aged 12.9 [interquartile range, 10.0-16.3] years old) were compared with healthy children. The patients showed reduced grip strength ( z-score [mean±SD] -1.5±1.2, P&lt;0.001), and total muscle strength ( z-score -0.9±1.3, P&lt;0.001). Dynamic strength (Bruininks-Oseretsky test) was significantly reduced ( z-score -0.3±0.8, P=0.001), but running, speed, and agility were normal ( z-score 0.1±0.7, P=0.4). Univariate correlation analyses showed strong correlations between absolute peak oxygen uptake, exercise capacity (mL/min), and muscle strength (grip strength r=0.83, total muscle strength r=0.88; P&lt;0.001). In multivariate analyses, including correction for age and sex, total muscle strength (B 0.3; P=0.009), and forced vital capacity (B 0.5; P=0.02) correlated with peak oxygen uptake, exercise capacity (mL/min), independent of conventional cardiovascular parameters.Conclusions: Children with repaired tetralogy of Fallot show reduced muscle strength, which strongly correlated with their exercise performance. </p

Sex differences in patients with repaired tetralogy of Fallot support a tailored approach for males and females:a cardiac magnetic resonance study

Purpose Substantial differences between sexes exist with respect to cardiovascular diseases, including congenital heart disease. Nevertheless, clinical decisions in the long-term follow-up of patients with repaired tetralogy of Fallot (rTOF) are currently based on unisex thresholds for cardiac magnetic resonance (CMR) measurements. This study aimed to assess whether sex differences exist in cardiac adaptation to hemodynamic loading conditions in patients with rTOF. Methods and Results This cross-sectional, two-center, combined pediatric and adult cohort included 320 rTOF patients (163 males, 51%) who underwent routine CMR. Despite similar age (median and interquartile range [m + IQR] 23.4 [15.2-34.4] years), surgical history, and hemodynamic loading, males with rTOF demonstrated higher biventricular CMR-derived volumes and masses, indexed for body surface area, compared to females (e.g. m + IQR right ventricular (RV) end-diastolic volume: males 123 [100-151] mL/m2, females 114 [94-131] mL/m2, P = 0.007). Sex-specific Z-scores of biventricular volumes and masses were similar for males and females. RV volumes and masses correlated with hemodynamic loading, but these relations did not differ between sexes. Biventricular ejection fraction (EF) appeared to be lower in male patients, compared to female patients (e.g. m + IQR RVEF: males 48 [43-54]%, females 52 [46-57]%, P < 0.001). Conclusion Indexed ventricular volumes and masses are higher in males with rTOF, compared to females, similar to the healthy population. RV hypertrophy and dilatation correlated to loading conditions similarly for both sexes. However, under comparable loading conditions, males demonstrated more severe functional impairment. These results indicate that sex-differences should no longer be ignored in treatment strategies, including timing of pulmonary valve replacement