N-terminal pro-brain natriuretic peptide serum levels reflect attrition of the Fontan circulation.

OBJECTIVE: N-terminal pro-brain natriuretic peptide has an established role in the diagnosis and prognosis of heart failure. In Fontan patients, this peptide is often increased, but its diagnostic value in this particular non-physiologic, univentricular circulation is unclear. We investigated whether N-terminal pro-brain natriuretic peptide represents ventricular function or other key variables in Fontan patients. METHODS AND RESULTS: Ninety-five consecutive Fontan patients ≥10 years old who attended the outpatient clinic of the Center for Congenital Heart Diseases in 2012-2013 were included. Time since Fontan completion was 16 ± 9 years. Median N-terminal pro-brain natriuretic peptide was 114 (61-264) ng/l and was higher than gender-and age-dependent normal values in 54% of the patients. Peptide Z-scores were higher in patients in NYHA class III/IV compared to those in class I/II, but did not correlate with ventricular function assessed by MRI and echocardiography, nor with peak exercise capacity. Instead, peptide Z-scores significantly correlated with follow-up duration after Fontan completion (p < 0.001), right ventricular morphology (p = 0.004), indexed ventricular mass (p = 0.001), and inferior caval vein diameter (p < 0.001) (adjusted R2 = 0.615). CONCLUSIONS: N-terminal pro-brain natriuretic peptide levels in Fontan patients correlate with functional class, but do not necessarily indicate ventricular dysfunction. Increased peptide levels were associated with a longer existence of the Fontan circulation, morphologic ventricular characteristics, and signs of increased systemic venous congestion. Since the latter are known to be key determinants of the performance of the Fontan circulation, these findings suggest increase in N-terminal pro-brain natriuretic peptide levels to indicate attrition of the Fontan circulation, independent of ventricular function.

GDF-15 (Growth Differentiation Factor 15) Is Associated With Hospitalization and Mortality in Patients With a Fontan Circulation.

Background We investigated serial serum levels of GDF-15 (growth differentiation factor 15) in Fontan patients and their relation to outcome. Methods and Results In this single-center prospective study of consecutive Fontan patients, serial serum GDF-15 measurement and clinical assessment was done at baseline (n=81) and after 2 years (n=51). The association between GDF-15 and the combined end point of all-cause mortality, heart transplant listing, and Fontan-related hospitalization was investigated. Median age at baseline was 21 years (interquartile range: 15-28 years). Median GDF-15 serum levels at baseline were 552 pg/mL (interquartile range: 453-729 pg/mL). GDF-15 serum levels correlated positively with age, age at Fontan initiation, New York Heart Association class, and serum levels of NT-proBNP (N-terminal pro-B-type natriuretic peptide) and É£GT (γ-glutamyltransferase) and negatively with exercise capacity. During a median follow-up of 4.8 years (interquartile range: 3.3-5.5 years), the combined end point occurred in 30 patients (37%). Multivariate Cox regression showed that patients with the highest baseline GDF-15 (n=20, defined as the upper quartile) had a higher risk of hospitalization or death than the lowest 3 quartiles (hazard ratio [HR], 2.76; 95% CI, 1.27-6.00; P=0.011). After 2 years of follow-up, patients in whom serum level of GDF-15 increased to >70 pg/mL (n=13) had a higher risk of hospitalization or death than the lowest 3 quartiles (HR, 2.69; 95% CI, 1.03-6.99; P=0.043). Conclusions In Fontan patients, elevated serum levels of GDF-15 are associated with worse functional status and predict Fontan-related events. Furthermore, serial measurements showed that an increase in GDF-15 serum level was associated with increased risk for adverse outcome.

Serial cardiovascular magnetic resonance feature tracking indicates early worsening of cardiac function in Fontan patients.

BACKGROUND: In Fontan patients, attrition of ventricular function is well recognized, but early detection of ventricular dysfunction is difficult. The aim of this study is to longitudinally assess ventricular strain in Fontan patients using a new method for cardiac magnetic resonance (CMR) feature tracking, and to investigate the relationship between ventricular strain and cardiac systolic function. METHODS AND RESULTS: In this prospective, standardized follow-up study in 51 Fontan patients, age ≥ 10 years, CMR and concomitant clinical assessment was done at the start of the study and after 2 years. CMR feature tracking was done combining the dominant and hypoplastic ventricles. Global longitudinal strain (GLS) (-17.3% versus -15.9%, P = 0.041) and global circumferential strain (GCS) (-17.7 versus -16.1, P = 0.047) decreased over 2 years' time. Ejection fraction (EF) (57%), cardiac index (CI) (2.7 l/min/m2) and NYHA functional class (97% in class I/II) were preserved. The strain values of the combined dominant and hypoplastic ventricles were significantly worse compared to those of the dominant ventricle only (GLS -16.8 (-19.5 to -14.0) versus -18.8 (-21.3 to -15.3) respectively, P = 0.001, GCS -18.3 (-22.1 to -14.8) versus -22.5 (-26.3 to -19.4) respectively, P < 0.001). CONCLUSIONS: This study showed a decrease in cardiac strain over 2 years in Fontan patients without clinical signs of Fontan failure, where EF, CI and clinical status were still preserved. Cardiac strain might be a sensitive early indicator of systolic ventricular decline. Furthermore, combined strain of the hypoplastic and dominant ventricles seems a more accurate representation of cardiac strain in functionally univentricular hearts.

[Use of cannabidiol oil in children]. / CBD-olie bij kinderen.

Useof cannabidiol oil in children The use of cannabidioloil (CBD oil), a cannabis-derived chemical, is increasing. CBD oil is freely available in the Netherlands, but its composition and quality are not monitored. However, the alternative, pharmacist-prepared oil, is more expensive and difficult to acquire. Common reasons for CBD oil use in children include impulsive behaviour, itch, epilepsy, stress, pain and sleeping problems. However, evidence of its effectiveness is scarce and focuses primarily on the effectiveness of the oil in reducing epileptic seizures. Known side-effects are vomiting, diarrhoea, fever, sleepiness, and abnormal liver function test results. We advise medical professionals who encounter young patients who may potentially be using CBD oil, to discuss its questionable quality and potential side effects and interactions. If a patient presents with poorly-understood fever, diarrhoea, vomiting or drowsiness, then the side effects of CBD oil should be considered. Finally, CBD should be differentiated from delta-THC, a cannabis-derived chemical with a psychoactive effect, the use of which should be discouraged in children.

Quality of life and sexual well-being in patients with a Fontan circulation: An explorative pilot study with a mixed method design.

OBJECTIVE: To get an impression of the quality of life (QOL) and sexual well-being in the Fontan population, and to generate hypotheses for future research. METHODS: For this cross-sectional pilot study, questionnaires regarding health-related QOL, sexual function and fertility/pregnancy were completed by 21 patients with a Fontan circulation >16 years old, followed at the University Medical Center Groningen, the Netherlands. Semi-structured qualitative interviews were conducted in 8 patients. RESULTS: Fontan patients scored significantly lower on general health than their healthy peers (t(19)=-3.0, P = .008), whereas their scores on other QOL domains and sexual well-being were comparable to normal values. During childhood, most patients experienced physical limitations and the feeling of being an outsider, and frequently faced bullying. Regarding sexual well-being, large interindividual differences were noted. Four interviewed patients (25-30 years) reported a good sexual well-being, whereas the other interviewed patients (33-47 years) reported erectile dysfunction, low self-esteem and avoidance of sexual intercourse. Both the QOL domains mental health and role restrictions due to emotional problems were associated with female avoidance (P = .083, respectively, P = .089) and dyspareunia (P = ns respectively P = .094). In males, role restrictions due to physical problems and health change were related to sexual dissatisfaction (P = .056) respectively nonsensuality (P = .025). CONCLUSIONS: Overall, Fontan patients have a relatively preserved quality of life and sexual wellbeing but face more social isolation and bullying during childhood/adolescence than their healthy peers. Sexual problems were mainly associated with physical limitations in males and with psychosocial limitations in females. Finally, sexual dysfunction was more common in older Fontan patients, and future research has to clarify whether progressive attrition of the Fontan circulation affects the patients' QOL and sexual well-being.

Fontan Circulation over Time.

The unique, unphysiological Fontan circulation is associated with an impaired functional status of the patients that is suggested to deteriorate over time. Unfortunately, previous studies did not integrate both pulmonary and cardiac determinants of functional status. In addition, a comparison with the natural decrease in exercise capacity in healthy subjects (in both children and adults) is lacking. This single-center study aims to investigate the functional status in a cohort of Fontan patients in relation to time since Fontan completion and to identify its determinants, including cardiac characteristics and pulmonary characteristics. Eighty-five consecutive Fontan patients ≥10 years who performed adequate cardiopulmonary exercise testing (respiratory exchange ratio >1.01) were included. Mean time since Fontan completion was 15 ± 9 years (range 2 to 37 years). New York Heart Association functional class was I in 36 patients (42%), II in 41 patients (48%), and III in 8 patients (9%). Peak oxygen uptake during exercise (VO2 index) was 25.7 ± 7.9 ml/min/m2 (58 ± 14% of predicted). New York Heart Association functional class and peak VO2 index both correlated with time since the Fontan operation; however, peak VO2 as percentage of predicted (VO2(pred)) did not. In multivariate analyses, peak VO2(pred) was independently associated with maximum heart rate, oxygen pulse at peak exercise, and forced expiratory volume in 1 second (R2 = 0.579) but not with cardiac output in rest. In conclusion, the present data suggest that functional status in Fontan patients is impaired already shortly after Fontan completion, whereas its subsequent deterioration seems to follow the natural decline of aging. Furthermore, functional status in Fontan patients correlates with pulmonary function and cardiac functional parameters during exercise but not with conventional cardiac measurements at rest.

Diminished liver microperfusion in Fontan patients: A biexponential DWI study.

It has been demonstrated that hepatic apparent diffusion coefficients (ADC) are decreasing in patients with a Fontan circulation. It remains however unclear whether this is a true decrease of molecular diffusion, or rather reflects decreased microperfusion due to decreased portal blood flow. The purpose of this study was therefore to differentiate diffusion and microperfusion using intravoxel incoherent motion (IVIM) modeled diffusion-weighted imaging (DWI) for different liver segments in patients with a Fontan circulation, compare to a control group, and relate with liver function, chronic hepatic congestion and hepatic disease. For that purpose, livers of 59 consecutively included patients with Fontan circulation (29 men; mean-age, 19.1 years) were examined (Oct 2012─Dec 2013) with 1.5T MRI and DWI (b = 0,50,100,250,500,750,1500,1750 s/mm2). IVIM (Dslow, Dfast, ffast) and ADC were calculated for eight liver segments, compared to a control group (19 volunteers; 10 men; mean-age, 32.9 years), and correlated to follow-up duration, clinical variables, and laboratory measurements associated with liver function. The results demonstrated that microperfusion was reduced (p<0.001) in Fontan livers compared to controls with ─38.1% for Dfast and ─32.6% for ffast. Molecular diffusion (Dslow) was similar between patients and controls, while ADC was significantly lower (─14.3%) in patients (p<0.001). ADC decreased significantly with follow-up duration after Fontan operation (r = ─0.657). Dslow showed significant inverse correlations (r = ─0.591) with follow-up duration whereas Dfast and ffast did not. From these results it was concluded that the decreasing ADC values in Fontan livers compared with controls reflect decreases in hepatic microperfusion rather than any change in molecular diffusion. However, with the time elapsed since the Fontan operation molecular diffusion and ADC decreased while microperfusion remained stable. This indicates that after Fontan operation initial blood flow effects on the liver are followed by intracellular changes preceding the formation of fibrosis and cirrhosis.

Surgical options after Fontan failure.

OBJECTIVE: The objective of this European multicenter study was to report surgical outcomes of Fontan takedown, Fontan conversion and heart transplantation (HTX) for failing Fontan patients in terms of all-cause mortality and (re-)HTX. METHODS: A retrospective international study was conducted by the European Congenital Heart Surgeons Association among 22 member centres. Outcome of surgery to address failing Fontan was collected in 225 patients among which were patients with Fontan takedown (n=38; 17%), Fontan conversion (n=137; 61%) or HTX (n=50; 22%). RESULTS: The most prevalent indication for failing Fontan surgery was arrhythmia (43.6%), but indications differed across the surgical groups (p<0.001). Fontan takedown was mostly performed in the early postoperative phase after Fontan completion, while Fontan conversion and HTX were mainly treatment options for late failure. Early (30 days) mortality was high for Fontan takedown (ie, 26%). Median follow-up was 5.9 years (range 0-23.7 years). The combined end point mortality/HTX was reached in 44.7% of the Fontan takedown patients, in 26.3% of the Fontan conversion patients and in 34.0% of the HTX patients, respectively (log rank p=0.08). Survival analysis showed no difference between Fontan conversion and HTX (p=0.13), but their ventricular function differed significantly. In patients who underwent Fontan conversion or HTX ventricular systolic dysfunction appeared to be the strongest predictor of mortality or (re-)HTX. Patients with valveless atriopulmonary connection (APC) take more advantage of Fontan conversion than patients with a valve-containing APC (p=0.04). CONCLUSIONS: Takedown surgery for failing Fontan is mostly performed in the early postoperative phase, with a high risk of mortality. There is no difference in survival after Fontan conversion or HTX.

The Fontan circulation and the liver: A magnetic resonance diffusion-weighted imaging study.

BACKGROUND: Patients with a Fontan circulation tend to develop liver fibrosis, liver cirrhosis and even hepatocellular carcinoma. The aim of this study is to use the magnetic resonance technique diffusing-weighted imaging (DWI) for detecting liver fibrosis/cirrhosis in Fontan patients and to establish whether DWI results are associated with functional aspects of the Fontan circulation. METHODS: In a cross-sectional study, 59 Fontan patients were evaluated by liver DWI. The association between apparent diffusion coefficients (ADC) and patient characteristics, laboratory measurements and functional aspects of the Fontan circulation (NYHA class, maximum oxygen uptake during exercise and cardiac index) was assessed. RESULTS: Liver ADC values were low (0.82×10(-3)±0.11×10(-3) mm2/s) compared with literature values for healthy volunteers and correlated negatively with calculated liver fibrosis/cirrhosis scores (Fib-4 score, p=0.019; AST/ALT ratio, p=0.009) and gamma-glutamyl transferase (p=0.001). Furthermore, ADC values correlated negatively with follow-up duration (p<0.001) and positively with cardiac index (p=0.019). No correlation between ADC values and exercise tests was found. In multivariable analysis, the ADC values were independently correlated with follow-up duration after Fontan completion. CONCLUSIONS: The results of the current study suggest that progressive liver damage due to chronic congestion and potential hypoperfusion is reflected in the liver ADC values in Fontan patients. This study highlights that liver damage in the context of the Fontan circulation might be far more common than previously thought, and that the implementation of liver assessment in the routine follow-up of Fontan patients is recommendable.

Adverse pulmonary vascular remodeling in the Fontan circulation.

BACKGROUND: The Fontan circulation is a palliation for patients with a functionally univentricular heart. It is characterized by gradual attrition over time. An increase in pulmonary vascular resistance could be a key factor in the long-term failure of the Fontan circulation. In this study we aimed to identify pulmonary vascular remodeling in patients with a Fontan circulation. METHODS: Pulmonary vascular histomorphometric analysis and immunohistochemistry were performed in lung tissue obtained at autopsy from 12 Fontan patients. These patients had died either peri-operatively (Group A: death during or <15 days after Fontan completion; n = 5) or in mid to long-term follow-up (Group B: death >5 years after Fontan completion; n = 7). Two age-matched control groups (n = 10 and n = 14, respectively) were included. RESULTS: Intra-acinar pulmonary vessels in the Fontan Group B patients showed decreased medial thickness (p = 0.028) compared with age-matched controls, whereas intimal thickness was increased (p = 0.002). Intimal thickness in the Fontan Group B patients correlated with age at death (r = 0.964, p < 0.001) and with the length of time that the Fontan circulation had been in place (r = 0.714, p = 0.036). Immunohistochemistry revealed a reduction of vascular smooth muscles cells in the medial layer of the intra-acinar pulmonary vessels. The eccentric intimal thickening was composed of mainly acellular fibrosis with collagen deposition. CONCLUSIONS: We observed a unique pattern of adverse pulmonary vascular remodeling in patients with a long-standing Fontan circulation who had died during follow-up. This remodeling pattern may play a major role in long-term attrition of the Fontan circulation.

Favourable mid-term outcome after heart transplantation for late Fontan failure.

OBJECTIVES: Fontan failure (FF) represents a growing and challenging indication for paediatric orthotopic heart transplantation (OHT). The aim of this study was to identify predictors of the best mid-term outcome in OHT after FF. METHODS: Twenty-year multi-institutional retrospective analysis on OHT for FF. RESULTS: Between 1991 and 2011, 61 patients, mean age 15.0 ± 9.7 years, underwent OHT for failing atriopulmonary connection (17 patients = 27.8%) or total cavopulmonary connection (44 patients = 72.2%). Modality of FF included arrhythmia (14.8%), complex obstructions in the Fontan circuit (16.4%), protein-losing enteropathy (PLE) (22.9%), impaired ventricular function (31.1%) or a combination of the above (14.8%). The mean time interval between Fontan completion and OHT was 10.7 ± 6.6 years. Early FF occurred in 18%, requiring OHT 0.8 ± 0.5 years after Fontan. The hospital mortality rate was 18.3%, mainly secondary to infection (36.4%) and graft failure (27.3%). The mean follow-up was 66.8 ± 54.2 months. The overall Kaplan-Meier survival estimate was 81.9 ± 1.8% at 1 year, 73 ± 2.7% at 5 years and 56.8 ± 4.3% at 10 years. The Kaplan-Meier 5-year survival estimate was 82.3 ± 5.9% in late FF and 32.7 ± 15.0% in early FF (P = 0.0007). Late FF with poor ventricular function exhibited a 91.5 ± 5.8% 5-year OHT survival. PLE was cured in 77.7% of hospital survivors, but the 5-year Kaplan-Meier survival estimate in PLE was 46.3 ± 14.4 vs 84.3 ± 5.5% in non-PLE (P = 0.0147). Cox proportional hazards identified early FF (P = 0.0005), complex Fontan pathway obstruction (P = 0.0043) and PLE (P = 0.0033) as independent predictors of 5-year mortality. CONCLUSIONS: OHT is an excellent surgical option for late FF with impaired ventricular function. Protein dispersion improves with OHT, but PLE negatively affects the mid-term OHT outcome, mainly for early infective complications.

Trends in mortality (1975-2011) after one- and two-stage Fontan surgery, including bidirectional Glenn through Fontan completion.

OBJECTIVES: Techniques and strategies in the Fontan procedure have evolved over the years, including the evolution from a one- to two-stage procedure. With such adjustments made, attention should shift towards survival analysis, including bidirectional cavopulmonary shunt (BCPS) and interstage mortality. The purpose of this study was to investigate the trends in the overall mortality of all patients who underwent a BCPS or one-stage Fontan procedure at our institution in the period of 1975-2011. METHODS: Using a single-institution, retrospective design, we reviewed the patient records of 203 patients from the University Medical Center Groningen, Netherlands, who underwent a Fontan procedure or a BCPS (with the intention to complete cavopulmonary connection at a second later stage) between 1975 and 2011. Trends in mortality were investigated by comparing survival rates during four consecutive decades (1975-84; 1985-94; 1995-2004; 2005-11), and predictors for mortality were identified. RESULTS: During a mean follow-up of 12 years, survival was 69%. Overall mortality declined significantly during the past decades (P = 0.017). This was driven by a decrease in early mortality (P = 0.016), whereas no changes in late mortality could be demonstrated. Multivariate analyses identified a diagnosis of heterotaxy (P = 0.049) and an atriopulmonary connection type of Fontan circulation (P = 0.015) as independent risk factors for overall mortality. CONCLUSIONS: We demonstrate that, with the inclusion of first-stage and interstage mortality also, overall survival after Fontan procedures improved over time. This improvement, however, is mainly caused by a decline in early mortality. Improvement in long-term survival of patients operated on over the past four decades could not (yet) be demonstrated in this series.