Induction of aggressive arterial and venous dilation therapy in addition to pulmonary dilation therapy (super-Fontan strategy) improves Fontan circulation both at rest and during treadmill exercise.

Objective: Fontan circulation maintains preload and cardiac output by reducing venous capacitance and increasing central venous pressure (CVP). The resultant congestive end-organ damage affects patient prognosis. Therefore, a better circulatory management strategy to ameliorate organ congestion is required in patients with Fontan circulation. We sought to verify whether aggressive arterial and venous dilation therapy in addition to pulmonary dilation (super-Fontan strategy) can improve Fontan circulation and reduce congestion. Methods: Patients after Fontan surgery who received the super-Fontan strategy in a single center were recruited. Participants were examined using medical records between 2010 and 2018. We retrospectively analyzed the changes in hemodynamics at rest and during treadmill exercise before and after the introduction of this therapy. Results: The therapy significantly increased venous capacitance (3.21 ± 1.27 mL/kg/mm Hg to 3.79 ± 1.30 mL/kg/mm Hg, P = .017) and decreased total pulmonary resistance, leading to significantly reduced CVP (11.7 ± 2.4 mm Hg to 9.7 ± 2.2 mm Hg, P < .001) and increased cardiac index (CI) (3.09 ± 1.01 L/min/m2 to 3.54 ± 1.19 L/min/m2, P = .047). Furthermore, this strategy significantly reduced the elevations in CVP (19.6 ± 5.3 mm Hg to 15.4 ± 2.7 mm Hg, P = .002) with preserved CI in response to exercise. CVP at rest and during exercise was significantly positively correlated with serum markers of hepatic congestion and fibrosis, respectively. Conclusions: The super-Fontan strategy is a therapy that turns the heart failure condition of Fontan circulation into a more physiological condition. However, whether the strategy improves long-term prognosis warrants further studies.

Prevalence of Short Stature and Growth Hormone Deficiency and Factors Associated With Short Stature After Fontan Surgery.

Background: Fontan circulation is characterized by many features commonly observed in heart failure that may affect physical growth regardless of pituitary gland dysfunction status. The aims of the present study were to investigate the prevalence of short stature and growth hormone deficiency (GHD) and determine the factors associated with short stature after Fontan surgery. Methods and Results: On retrospective evaluation of 47 patients after Fontan surgery, a very high prevalence of short stature was observed (38.3%). In the short stature group, 5 patients were diagnosed with GHD (10.6% of patients after Fontan Surgery), which is much higher than the frequency of 1/10,000 in the general population. Central venous pressure (CVP) was significantly higher (14.6±4.5 vs. 12.2±1.9 mmHg, P<0.05) and the blood pressure and arterial oxygen saturation were significantly lower in the short stature group. Laboratory data also indicated volume retention and congestion in the short stature group. Mean change in stature from catheterization 1 year after Fontan surgery to the most recent visit was significantly lower in the short stature group (-1.1±1.1 SD vs. 0.0±0.8 SD, P<0.05) and significantly negatively correlated with CVP (r=-0.42, P<0.05). Conclusions: Volume retention and congestion, the prominent features of Fontan circulation, affect physical growth partly due to pituitary gland dysfunction, highlighting the need for the screening for and treatment of this condition after Fontan surgery.

Assessment of central venous physiology of Fontan circulation using peripheral venous pressure.

OBJECTIVE: Elevated central venous pressure is a major cause of morbidity and mortality after the Fontan operation. The difference between mean circulatory filling pressure and central venous pressure, a driving force of venous return, is important in determining dynamic changes in central venous pressure in response to changes in ventricular properties or loading conditions. Thus, noninvasive central venous pressure and mean circulatory filling pressure estimation may contribute to optimal management in patients undergoing the Fontan operation. We tested the hypothesis that central venous pressure and mean circulatory filling pressure in those undergoing the Fontan operation can be simply estimated using peripheral venous pressure and arm equilibrium pressure, respectively. METHODS: This study included 30 patients after the Fontan operation who underwent cardiac catheterization (median 8.6, 3.4-42 years). Peripheral venous pressure was measured at the peripheral vein in the upper extremities. Mean circulatory filling pressure was calculated by the changes of arterial pressure and central venous pressure during the Valsalva maneuver. Arm equilibrium pressure was measured as equilibrated venous pressure by rapidly inflating a blood pressure cuff to 200 mm Hg. RESULTS: Central venous pressure and peripheral venous pressure were highly correlated (central venous pressure = 1.6 + 0.68 × peripheral venous pressure, R = 0.86, P < .0001). Stepwise multivariable regression analysis showed that only peripheral venous pressure was a significant determinant of central venous pressure. Central venous pressure was accurately estimated using regression after volume loading by contrast injection (R = 0.82, P < .0001). In addition, arm equilibrium pressure measurements were highly reproducible and robustly reflected invasively measured mean circulatory filling pressure (mean circulatory filling pressure = 9.1 + 0.63 × arm equilibrium pressure, R = 0.88, P < .0001). CONCLUSIONS: Central venous pressure and mean circulatory filling pressure can be noninvasively estimated by peripheral venous pressure and arm equilibrium pressure, respectively. This should help clarify unidentified Fontan pathophysiology and the mechanisms of Fontan failure progression, thereby helping construct effective tailor-made approaches to prevent Fontan failure.

Usefulness of cystatin C in the postoperative management of pediatric patients with congenital heart disease.

BACKGROUND: The characteristics of the renal marker cystatin C (Cys-C) in association with the postoperative management of children with congenital heart disease (CHD) remain unclear. METHODS AND RESULTS: Serum Cys-C and creatinine (Cr) levels were measured preoperatively and on the third postoperative day in 53 consecutive CHD patients (age, 1 day-11 years). On the third postoperative day, the patients were divided into 2 groups: the clinically severe group, requiring continuous infusion of diuretic drugs or peritoneal dialysis; and the non-severe group, composed of those without such needs. Preoperative Cys-C level decreased with age (by month) during the first year of life and remained almost constant thereafter, while Cr level increased with age. The Cys-C ratio (Cys-C level on the third postoperative day/preoperative level) was positively correlated with Cr ratio (R=0.57, P<0.001). Both Cys-C and Cr levels increased in correlation with the clinical severity of renal impairment. Receiver operating characteristic curve analysis failed to demonstrate an advantage of Cys-C over Cr in detecting severity. CONCLUSIONS: Cys-C may be a useful marker of renal function in terms of hemodynamic status in the postoperative management of CHD, although its superiority over Cr could not be confirmed. Future studies should clarify the role of Cys-C in clinical decision-making and evaluate the relationship of Cys-C with factors that may affect its levels.