Although 85% of patients with
univentricular heart after
Fontan procedure survive twenty years after operation, the procedure alone seems to be an inadequate treatment as a permanent clinical
solution. Patients with a "Fontan physiology" additionally have to face a various extra-cardiac complications, including thyroid, liver and kidney dysfunction, which are not only potentially life-threatening, but also can potentiate the circulatory insufficiency.
AIM: 54 patients after
Fontan procedure (age=25.1±7 years, time after operation =19.8±6.3 years, age at the time of the procedure =5.3±4.3 years) and 30 controls (26.2±5.8 years) were included to the study. Clinical and laboratory examinations were performed including: hematologic, hepatic, renal and thyroid function tests. The following laboratory tests were performed: red blood cell counts (RBC), hematocrit (Ht),
hemoglobin (Hb), platelets count, red blood cell distribution width (RDW),
iron level; Btype
natriuretic peptide (
NT-proBNP), proteinogram blood test,
alanine aminotransferase (ALT),
aspartate aminotransferase (AST), gammaglutamyl
transpeptidase (
GGTP),
alkaline phosphatase (ALP), total
bilirubin,
alpha fetoprotein (AFP) level. Furthermore
creatinine level;
cystatin C, urine
albumin to creatynine ratio (ACR) and urinalysis were assessed. To assess a thyroid function free
triiodothyronine (fT3), free
thyroxine (fT4) and
thyroid stimulating hormone (TSH) were measured. Furthermore an abdomen ultrasonography was performed.
RESULTS: In terms of the hematological disorders Fontan patients had a statistically significant higher level of RBC (5.6±0,8 vs 4.8±0.4 109/μl; p<0,001), Hb (16.5±2.8 vs 14.2±1.2 g/dl; p<0,001), HCT (48.7±8.1 vs 42.1±3 %; p<0,001), RDW (14±2.6 vs 12.8±0.5 %; p=0.001), as compared to control group, while PLT level was statistically lower in Fontan group (156.2±61.4 vs 224.2±48 103/μl; p<0,0001). Hepatic parameters in Fontan patients were statistically significant higher, as depicted by the level of: ALT (28.5±10.5 vs 21.5±6 U/l, p<0,001),
GGTP (85.6±48.8 vs 19.3±9 U/ l, p<0,001), total
bilirubin (26.6±24.8 vs 8.9±4.7 μmol/l; p<0,001), ALP (82.4±31.5 vs 51.2±16 U/l; p<0,001) and INR (1.21±0.3 vs 0.98±0.2; p<0,001). Other parameters such as: AFP, total
protein and
albumin level did not statistically significantly differ. Additionally five patients (9%) according to clinical symptoms and
serum albumin level were diagnosed
protein-losing enteropathy (PLE). There was no difference in serum
creatinine level between Fontan patients and control group (79.6±23.6 vs 75.9±18.9 μmol/l; p=0.8) as well as in
uric acid level (342.7±102 vs 303±105 μmol/l; p=0.2).
Cystatin C level was significantly higher in Fontan group in comparison to controls (1.1±0.6 vs 0.8±0.1 ng/ml; p=0,05). Furthermore four Fontan patients (7%) had abnormal microalbumin/creatynine ratio. Urine testing preformed in 30 Fontan patients pointed to 7 cases (23%) where
hematuria was observed, while
proteinuria was detected in 4 cases (13%) and
urobilinogen in 2 (7%). Dysfunction of the thyroid gland was found in 30% of patients after
Fontan operation (7% in the control group, p=0,034). Among disorders of the thyroid gland: 13% of patients were diagnosed with
hyperthyroidism, 54% diagnosed with subclinical
hypothyroidism, and the remaining 33% with
hypothyroidism.
CONCLUSIONS: