Intrinsic cardiomyopathy in pediatric Marfan syndrome: predictive factors and risk assessments.

Background: Marfan syndrome (MFS) is associated with cardiovascular complications, particularly valvulopathies; however, its association with primary cardiomyopathy remains unclear.

Methods: This retrospective cohort study examined the cardiomyopathy characteristics (CMCs) in pediatric patients with MFS. CMCs were defined as meeting at least one of the following echocardiography or clinical parameters: (1) cardiac index (CI) too low for patient's age, (2) ejection fraction (EF) <50%, and (3) diastolic dysfunction. The predictive factors for CMCs were determined using a multivariable logistic regression model.

Results: Among 83 patients with MFS (age, median [range], 12.5 [0.4-22.3] years), 39.8% exhibited CMCs. Only 4 patients (5%) showed heart failure symptoms (NYHA > 1). Independent predictors for CMCs included a systemic score of ≥7 (revised Ghent criteria) and likely pathogenic or pathogenic variants in FBN1, including variants that introduce a premature stop codon, splice site variants, and missense variants involving cysteine. A multivariable score was constructed with an AUC of 0.733.

Conclusion: This study offers valuable insights into the prevalence and predictors of CMC in pediatric patients with MFS and presents potential strategies for risk assessment of cardiomyopathy.

Impact: The objective of this study was to elucidate the contentious issue of intrinsic cardiomyopathy in Marfan syndrome and demonstrate its notable occurrence even in pediatric patients who do not exhibit heart failure symptoms or valvular complications. We highlighted the importance of specific FBN1 variants and higher systemic scores in identifying the potential for intrinsic cardiomyopathy in pediatric patients with Marfan syndrome.