Altered endothelial function following the Fontan procedure.
OBJECTIVE
Thrombosis has been widely described after the Fontan procedure. The vascular endothelium plays a central role in the control of coagulation and fibrinolysis. The aim of this study was to investigate if patients undergoing a modified Fontan procedure have impaired endothelial function and fibrinolysis in the late postoperative course.


METHODS
We compared 23 patients aged from 7 to 26 years with age-matched healthy volunteers, collecting blood samples prior to and following standardized venous occlusion testing. Plasma levels of von Willebrand factor antigen, tissue-type plasminogen activator antigen, plasminogen activator inhibitor-1, and D-dimer were measured with enzyme-linked immunosorbent assay.


RESULTS
We found increased plasma levels of von Willebrand factor antigen in patients when compared to controls (p = 0.003). At the basal condition, concentrations of tissue-type plasminogen activator antigen and plasminogen activator inhibitor-1 antigen in the plasma, as well as their activity, were not significantly different between patients and controls. Following venous occlusion, concentrations of tissue-type plasminogen activator antigen in the plasma were significantly increased both in patients and controls, compared to pre-occlusion values. D-dimer was within the reference range. Multivariate discriminant analysis differentiated patients and their controls on the basis of differences for plasminogen activator inhibitor-1 and von Willebrand factor antigen (p = 0.0016).


CONCLUSIONS
Our data suggest that patients with the Fontan circulation may have endothelial dysfunction, as indicated by raised levels of von Willebrand factor. Fibrinolysis seems to be relatively preserved, as suggested by appropriate response to venous occlusion.
Binotto
Maria A
MA
Department of Paediatric Cardiology and Adult Congenital Heart Disease, Heart Institute (InCor), Universidade de São Paulo, Avenida Dr Eneas Carvalho de Aguiar 44, São Paulo, Brazil. angelica.binotto@incor.usp.br
Maeda
Nair Y
NY
Lopes
Antonio A
AA
D000293:Adolescent; D000941:Antigens / Q000097:blood; D015415:Biomarkers / Q000097:blood*; D001777:Blood Coagulation / Q000502:physiology*; D002648:Child; D002675:Child, Preschool; D004730:Endothelium, Vascular / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000378:metabolism; D005500:Follow-Up Studies; D018729:Fontan Procedure; D006330:Heart Defects, Congenital / Q000097:blood / Q000601:surgery*; D006352:Heart Ventricles / Q000002:abnormalities* / Q000601:surgery; D006801:Humans; D007223:Infant; D008297:Male; D017395:Plasminogen Activator Inhibitor 1 / Q000097:blood; D011183:Postoperative Complications; D011379:Prognosis; D012307:Risk Factors; D013927:Thrombosis / Q000097:blood / Q000209:etiology / Q000503:physiopathology; D010959:Tissue Plasminogen Activator / Q000097:blood; D014841:von Willebrand Factor / Q000276:immunology
D000941:Antigens; D015415:Biomarkers; D005338:Fibrin Fibrinogen Degradation Products; D017395:Plasminogen Activator Inhibitor 1; C029417:Von Willebrand antigen; C036309:fibrin fragment D; D014841:von Willebrand Factor; D010959:Tissue Plasminogen Activator