Abstract 2793: Prospective Longitudinal Study of Coagulation Profiles in Children with Hypoplastic Left Heart Syndrome (HLHS) from stage I through Fontan completion
Objective: Abnormal pro-and anti-coagulant factor levels have been reported prior to and after the Fontan operation. It is unknown whether children with univentricular heart disease have anintrinsic coagulation anomaly or acquire a defect during the course of the staged repair. This prospective, longitudinal study evaluated changes in coagulation and hemodynamic profiles in a cohort of patients with the same diagnosis (hypoplastic left heart syndrome, HLHS) from Stage I palliation through completion of the Fontan operation.
Methods: 37 children with HLHS were enrolled, 18 patients completed all stages of repair. Data were collected in each patient pre Stage I (4 ± 2 days), pre bidirectional Glenn (5.9 ± 1.8 months), pre Fontan (27.1 ± 6.6 months) and post Fontan procedure (49 ± 17.6 months). Concentration of factors II, V, VII, VIII, IX, X, Protein C and S, plasminogen, fibrinogen, antithrombin III, serum albumin and liver enzymes were measured. Reference ranges based on healthy control patients were defined by 95% confidence intervals. Demographic, hemodynamic variables and time after the fontan procedure were evaluated as possible predictors of coagulation abnormalities.
Results: The mean ± SD concentrations of all coagulation factors were significantly different between each stage through to the Fontan procedure. When comparing post Fontan coagulation factors with pre Fontan values, factor VIII was significant higher (p<0.001), 8 patients (47%) had a factor VIII value >160%. No specific hemodynamic variables or liver function tests were predictive of coagulation abnormalities.
Conclusion: The increase in pro- and anticoagulant factors between stages were similar to changes observed in controls over time and consistent with maturation. The large increase in factor VIII post Fontan procedure appears to be an acquired defect, the cause of which remains to be determined. Elevated factor VIII level is an independent risk factor for thrombosis in adults, and could help determine a subset of Fontan patients who would benefit from long-term anticoagulation.