Alberto Guevara-Tirado, Facultad de Ciencias de la Salud, Universidad Científica del Sur, Lima, Perú
Background: Marfan syndrome presents with aortic dilation and pulmonary involvement due to connective-tissue abnormalities, vascular elasticity loss, and progressive structural remodeling. This study evaluated whether body surface area (BSA) mediates the association between the maximum diameter of the aortic root and that of the main pulmonary artery in pediatric and juvenile populations with Marfan syndrome. Methods: Cross-sectional study using secondary data from 320 complete records from form A100 of the Pediatric Heart Network-Marfan Study. The dependent variable was the maximum diameter of the main pulmonary artery, the independent variable was the maximum diameter of the aortic root, and the mediator was BSA, with sex and age as covariates. The analysis employed Hayes’ PROCESS macro (model 4), estimating direct and indirect effects through linear regression and 5,000 resamples using the bootstrap method. Data source: Pediatric Heart Network- Marfan Trial, Form A100 (“Past Echo Data”). Results: The analysis revealed that the maximum aortic root diameter had a direct effect on the main pulmonary artery diameter (B = 0.135; p = 0.018) and a relevant indirect effect mediated by BSA (B = 0.111; 95% CI: 0.0394-0.183). In the mediator model, aortic diameter, age, and sex were associated with BSA. The dependent variable model identified BSA and aortic diameter as significant factors, explaining 47.67% of the variability in pulmonary measurement. Conclusions: BSA partially mediates the relationship between the aortic root and pulmonary artery in pediatric and juvenile Marfan syndrome, independently of age and sex.
Keywords: Marfan syndrome. Aorta. Pulmonary artery. Body surface area. Models. Cardiovascular. Mediation analysis.