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Time course of endothelin-1 and adrenomedullin after the Fontan procedure
T Hiramatsu1, Y Imai, Y Takanashi
1Department of Pediatric Cardiac Surgery, Tokyo Women's Medical University, Heart Institute of Japan.
Insights
After the Fontan procedure, elevated endothelin-1 (ET-1) and decreased adrenomedullin (AM) were observed. This imbalance may contribute to vasoconstriction, highlighting ET-1's role in post-Fontan cardiovascular regulation.
Area of Science:
- Cardiovascular Physiology
- Pediatric Cardiology
- Vascular Biology
Background:
- Endothelin-1 (ET-1) is a vasoconstrictor implicated in cardiovascular disease.
- Adrenomedullin (AM) is a vasodilator crucial for cardiovascular homeostasis.
- Pulmonary vascular resistance is key for Fontan procedure indications, but its post-operative cytokine profile is unknown.
Purpose of the Study:
- To investigate the time course of plasma endothelin-1 (ET-1) and adrenomedullin (AM) levels after the Fontan procedure.
- To assess the relationship between ET-1 and pulmonary vascular resistance post-Fontan surgery.
Main Methods:
- Plasma ET-1 and AM levels were measured in 8 Fontan patients and 8 controls.
- Measurements were taken before, immediately after, and 6 and 24 hours after cardiopulmonary bypass.
- Pulmonary vascular resistance was calculated and correlated with ET-1 levels in the Fontan group.
Main Results:
- Plasma ET-1 levels were higher in the Fontan group compared to controls at 6 and 24 hours post-operation.
- Plasma AM levels were lower in the Fontan group at 6 and 24 hours post-operation.
- A significant positive correlation was found between plasma ET-1 levels and pulmonary vascular resistance (r = 0.475).
Conclusions:
- An imbalance of increased ET-1 and decreased AM post-Fontan procedure may promote vasoconstriction.
- ET-1 likely plays a significant role in maintaining vasoconstriction following the Fontan procedure.
Background:
The endothelium-derived vasoconstrictor endothelin (ET)-1 might contribute to the physiology of blood flow regulation and play a role in cardiovascular disease. Adrenomedullin (AM) is a potent vasodilator peptide that has major effects on cardiovascular function and has multiple biologic effects involved in cardiovascular homeostasis. Although pulmonary vascular resistance is known to be one of the most important factors to determine the indications for a Fontan procedure, the time course of the plasma cytokine before and after the Fontan procedure is not known.
Methods:
Sixteen patients were divided into two groups, 8 patients (1 to 14 years) who had the Fontan procedure (atriopulmonary connection) and 8 age-matched controls who had biventricular repair with normal central venous pressure. Plasma ET-1 and adrenomedullin levels were measured in both groups immediately before cardiopulmonary bypass, immediately after cardiopulmonary bypass, and 6 and 24 hours after cardiopulmonary bypass. A thermodilution catheter was inserted during the operation, and mean pulmonary arterial pressure, pulmonary wedge pressure, and cardiac output were measured, and pulmonary vascular resistance was calculated at the same time points. Correlation between the plasma ET-1 levels and pulmonary vascular resistance data were obtained in the Fontan group.
Results:
Plasma ET-1 levels in the Fontan group were elevated after operation and were higher than the control group at 6 and 24 hours after cardiopulmonary bypass. Plasma adrenomedullin in the Fontan group was lower than in the control group at 6 and 24 hours after cardiopulmonary bypass. A significant positive correlation was obtained between the plasma ET-1 and pulmonary vascular resistance data (r = 0.475).
Conclusions:
Imbalance between increased ET-1 and relatively decreased adrenomedullin after cardiopulmonary bypass in the Fontan procedure could contribute to dominant effects of ET-1, which might induce vasoconstriction after the Fontan procedure. ET-1 might play an important role in maintaining vasoconstriction after the Fontan procedure.