Prevalence and clinical correlates and characteristics of "Super Fontan".

BACKGROUND: Super-Fontan (SF) is an excellent phenotype of patients with Fontan circulation and normal exercise capacity. This study aimed to clarify the prevalence and clinical correlates and characteristics of SF. METHODS: We reviewed 404 Fontan patients who had undergone cardiopulmonary exercise testing, and the results were compared with clinical profiles. RESULTS: Seventy-seven (19%) patients had SF, and the postoperative prevalence at 5, 10, 15, 20, and ≥ 25 years was 16 (35%), 30 (39%), 18 (19%), 13 (14%), and 0 (0%), respectively. Compared with non-SF, SF patients were younger (P < .001) and were mostly men (P < .05). SF was characterized by a current high arterial blood pressure and oxygen saturation (SaO2), low systemic ventricle (SV) end-diastolic pressure, favorable body composition, superior pulmonary function, preserved hepatorenal and hemostatic functions, and better glucose tolerance (P < .05-.001). Pre-Fontan better SV function, low pulmonary artery resistance, and high SaO2 were associated with current SF (P < .05-.01). Furthermore, positive trajectory of exercise capacity and high daily activity during childhood were associated with current adult SF (P < .05). During the follow-up, 25 patients died, and 74 patients were unexpectedly hospitalized. There was no death in the SF group, and the rate of hospitalization was 67% lower than that of the non-SF group (P < .01-.001). CONCLUSIONS: The prevalence of SF gradually decreased over time. SF was characterized by preserved multi-end-organ function and an excellent prognosis. Pre-Fontan hemodynamics and post-Fontan childhood daily activity were associated with being adult SF.

Determinants and prognostic value of albuminuria in adult patients with congenital heart disease.

BACKGROUND: The determinants and prognostic value of albuminuria remain unclear in patients with adult congenital heart disease (ACHD), especially in those with Fontan circulation (FC). METHODS: We retrospectively reviewed 512 consecutive ACHD patients and investigated the determinants of urinary albumin-to-creatinine ratio (ACR) and albuminuria (MAU) and their association with all-cause mortality. Demographic data and laboratory and hemodynamic parameters were collected. Regression analysis and Cox proportional hazard models were used to identify the relationship between log ACR and variables, and clinical factors and all-cause mortality, respectively. RESULTS: Body mass index, aortic systolic blood pressure (ASP), arterial oxygen saturation (SaO2), glycated hemoglobin (HbA1c), B-type natriuretic peptide, and diuretic use were independently associated with log ACR. ASP, SaO2, and HbA1c were independently associated with MAU (P < .05-0.001). The prevalence of MAU was highest in unrepaired patients with low SaO2 (50%; P < .0001). Log ACR and MAU were associated with exercise capacity and all-cause mortality (P < .0001 for both) independent of renal function. Patients with ACHD, MAU, and renal dysfunction (n = 23) had the highest risk of all-cause mortality, while those without MAU or renal dysfunction had the lowest risk (P < .0001). These prognostic values remained significant in separate analyses of Fontan and biventricular circulation (P < .0001). CONCLUSIONS: ASP, SaO2, and HbA1c levels were independently associated with MAU in ACHD patients. MAU and log ACR were associated with all-cause mortality in patients with Fontan and biventricular circulation, independent of renal dysfunction.

Clinicopathologic Study of Placentas From Women With a Fontan Circulation.

BACKGROUND: Pregnant women with a Fontan circulation have a high risk of obstetric complications, such as preterm delivery and small for gestational age (SGA), which may be affected by low blood flow to the placenta and hypoxia. This study investigated placental pathology in a Fontan circulation.Methods and Results:Eighteen pregnancies in 11 women with a Fontan circulation were reviewed. Pregnancy outcomes showed 9 miscarriages and 9 live births, with 4 preterm deliveries. Five neonates were SGA (<5th percentile). Eight placentas from live births in 7 women were available for the study. Five placentas had low weight placenta for gestational age, and 7 grossly showed a chronic subchorionic hematoma. Histological examination revealed all placentas had some form of histological hypoxic lesions: maternal vascular malperfusion in 7, fetal vascular malperfusion in 1, and other hypoxia-related lesions in 8. Quantitative analyses, including immunohistochemistry (CD31, CD68, and hypoxia inducible factor-1α antibodies) and Masson's trichrome staining, were also performed and compared with 5 control placentas. Capillary density and the area of fibrosis were significantly greater in placentas from women with a Fontan circulation than in control placentas. CONCLUSIONS: Placentas in a Fontan circulation were characterized by a high frequency of low placental weight, chronic subchorionic hematoma, and constant histological hypoxic changes, which could reflect altered maternal cardiac conditions and lead to poor pregnancy outcomes.

Morphological changes and number of candidates for transcatheter pulmonary valve implantation in conduits involving heterograft and artificial material.

Heterograft and artificial materials have been used for extracardiac conduit implantation to create right ventricular (RV) to pulmonary artery (PA) continuity for biventricular repair in Japan because of the limited availability of homograft valves. However, few studies have examined morphological changes and number of candidates for transcatheter pulmonary valve implantation (TPVI) in which the conduit includes more than one type of material. Overall, 88 patients who underwent biventricular repair with an external conduit were included in this evaluation. Based on catheterization data and surgical records, we estimated morphological change in the RV outflow tract for each material and the number of candidates for Melody valve implantation based on premarket approval application criteria established by the U.S. Food and Drug Administration. There were 63 candidates for TPVI (72%, 63/88). Median anteroposterior and lateral diameter of the RV outflow tract was 20.4 mm (range 9.0-41.5) and 17.8 mm (range 9.5-34.9), respectively. Bovine pericardium tended to dilate by 11.2%. Polytetrafluoroethylene (ePTFE), homograft, and Dacron polyethylene terephthalate (PET) tended to become stenotic by 11.1%, 28.0%, and 13.4%, respectively. While ePTFE (27/33, 82%) and Dacron PET (2/2, 100%) were highly suitable for TPVI, bovine pericardium (32/48, 67%) was less suitable. In Japan, many patients with hemodynamic indications for TPVI following extracardiac conduit implantation to create RV to PA continuity may also meet the morphological indications.

Electrocardiographic features of arrhythmogenic right ventricular cardiomyopathy in school-aged children.

It can be difficult to distinguish children with early-stage arrhythmogenic right ventricular cardiomyopathy (ARVC) from those with benign premature ventricular contraction (PVC). We retrospectively evaluated six school-aged children with ARVC and compared with those of 20 with benign PVC. The median age at initial presentation was 11.4 and 10.2 years in ARVC and benign PVC, respectively. None of the ARVC patients fulfilled the diagnostic criteria of ARVC at initial presentation. At ARVC diagnosis, the treadmill exercise test and Holter monitoring showed provoked PVC during exercise and pleomorphic PVC in all ARVC cases, respectively. During the observation period, terminal activation duration (TAD) was prolonged in all ARVC patients. In addition, ΔTAD (5.5 [3-10] ms) were significantly longer than those with benign PVC (p < 0.001). A new notched S-wave in V1 appeared in four (67%) ARVC patients, who had myocardial abnormalities in the right ventricle, and in zero benign PVC. Our electrocardiographic findings, such as provoked PVC during exercise, pleomorphic PVC, prolonged TAD, and a new notched S-wave in V1 could contribute to the early detection of ARVC in school-aged children.

Long-Term Outcomes After Fenestration Closure in High-Risk Fontan Candidates.

The study aimed to assess the long-term outcomes after fenestration closure in patients at risk for Fontan failure. Of 119 patients who underwent Fontan operation between 1995 and 2004, fenestration was not created in 89 patients (NF group) and created in 30 patients with hypoplastic left heart syndrome, heterotaxy syndrome, high pulmonary arterial pressure, high systemic ventricular end-diastolic pressure, low ventricular ejection fraction, or atrioventricular valve regurgitation. All fenestrations were closed spontaneously or by catheter/surgical interventions, excepting two patients, and therefore, they were excluded. In fenestration group, patients with pre-Fontan mean pulmonary arterial pressure ≥ 15 mmHg or systemic atrioventricular valve regurgitation ≥ moderate were classified as high-risk Fontan candidates (F-HR group, n = 16), and the remaining patients were as standard-risk (F-SR group, n = 12). Protein-losing enteropathy-free survival rates did not differ among the three groups (p = 0.72). Serial follow-up catheter examinations after Fontan operation were completed in 69 patients in NF group and 11 patients in both F-SR and F-HR groups. Cardiac index and pulmonary vascular resistance significantly and similarly decreased over time in all groups, though the F-HR group showed lowest arterial oxygen saturation, lowest cardiac index, and highest pulmonary vascular resistance. The F-HR group also showed much veno-venous collaterals (p = 0.049), low peak oxygen consumption (p = 0.019), and low anaerobic threshold (p = 0.023) as compared to those in the F-SR group. In F-HR group, cyanosis remained after fenestration closure due to transformation from fenestration to veno-venous collaterals, which resulted in elevation of pulmonary vascular resistance, low cardiac index, and deterioration of exercise tolerance.

Systemic Artery Vasoconstrictor Therapy in Fontan Patients with High Cardiac Output-Heart Failure: A Single-Center Experience.

Failed Fontan Patients with high cardiac output (CO) heart failure (HF) might have vasodilatory syndrome and markedly high mortality rates. The aim of this study was to review the clinical effects of vasoconstrictor therapy (VCT) for failed Fontan hemodynamics. We retrospectively reviewed 10 consecutive patients with Fontan failure (median age, 33 years) and high CO-HF who had received VCT. The hemodynamics were characterized by high central venous pressure (CVP: median, 16 mm Hg), low systolic blood pressure (median, 83 mm Hg), low systemic vascular resistance (median, 8.8 U·m2), high cardiac index (median, 4.6 L/min/m2), and low arterial oxygen saturation (median, 89%). VCT included intravenous noradrenaline infusion for five unstable patients, oral midodrine administration for nine stable patients, and both for four patients. After VCT introduction with a median interval of 1.7 months, the median systolic blood pressure (102 mm Hg, p = 0.004), arterial oxygen saturation (90%, p = 0.03), and systemic vascular resistance (12.1 U·m2, p = 0.13) increased without significant changes in CVP or cardiac index. After a median follow-up of 21 months, the number of readmissions per year decreased from 4 (1-11) to 1 (0-9) (p = 0.25), and there were no VCT-related complications; however, five patients (50%) developed hepatic encephalopathy, and six patients (60%) eventually died. VCT was safely introduced and could prevent the rapidly deteriorating Fontan hemodynamics. VCT could be an effective therapeutic strategy for failed Fontan patients with high CO-HF.

Abnormal glucose metabolism in patients with Fontan circulation: Unique characteristics and associations with Fontan pathophysiology.

BACKGROUND: Fontan patients exhibit a high prevalence of abnormal glucose metabolism (AGM). We aimed to characterize AGM and clarify its association with Fontan pathophysiology. METHODS: We prospectively evaluated AGM with plasma glucose dynamics [mg/dL; fasting glucose (FPG), and maximum glucose increase (PG-spike)] during oral glucose tolerance test and hemoglobin A1c (HbA1c) in 276 consecutive Fontan patients (aged 19 ±â€¯7 years). Of these, 176 patients had serial AGM assessments with a mean interval of 6.5 years. RESULTS: Initial analysis revealed a high prevalence of impaired glucose tolerance (38.4%) and diabetes mellitus (DM) (4.7%), and positive family history, high HbA1c, and high central venous pressure independently predicted presence of DM. HbA1c was independently determined by hypersplenism and presence of DM (P < .05). Serial assessments revealed an increased PG-spike and a decreased HbA1c (P < .001 for both). Prevalence of DM increased (6.3% to 10.3%), and positive family history, high liver enzymes, and AGM predicted new onset of DM (P < .05 for all). Twenty-one patients died during 7.1-year follow-up. FPG (P < .01) and PG-spike (P < .05) independently predicted all-cause mortality. Particularly, patients with FPG ≤ 74 and/or PG-spike ≥85 had a mortality rate 8.7 times higher than those without (P = .0129). CONCLUSIONS: AGM progressed even in young adult Fontan patients, and HbA1c showed limited predictive value for progression. Oral glucose tolerance test plays important roles in uncovering unique Fontan AGM as well as predicting all-cause mortality.

Evaluating the response to cardiac resynchronization therapy performed with a new ventricular morphology-based strategy for congenital heart disease.

BACKGROUND: In cardiac resynchronization therapy (CRT) for patients with congenital heart disease (CHD) and a ventricular morphology other than a systemic left ventricle (LV), we previously proposed pacing sites that are different from those used for a systemic LV. The leads should be placed laterally on opposite sides of both ventricles in patients with short-axis dyssynchrony and a single ventricular physiology with two ventricles, whereas they should be placed at the farthest sites along the longitudinal direction in the right ventricle (RV) in patients with long-axis dyssynchrony of the RV. Moreover, in patients with interventricular dyssynchrony and a biventricular physiology with a systemic RV, they should be placed at sites that both ventricles can contract simultaneously. We retrospectively investigated 27 consecutive procedures in 24 patients with CHD who underwent CRT to evaluate the effectiveness of a new ventricular morphology-based CRT strategy. The responder rate was 63% (17/27). The reasons for a non-response to CRT in 10 cases were as follows: non-optimal lead positions during CRT, 4; no systemic ventricular conduction delay or heart failure symptoms before the CRT, 5; short follow-up periods after the CRT, 2; and an extremely dilated systemic RV, 1. The responder rate became 88% (14/16), after excluding the procedures without a ventricular conduction delay or heart failure symptoms and those with non-optimal lead positions. This new strategy for CRT can provide favorable results for CHD patients with a systemic ventricular conduction delay and heart failure.

Impact of Pregnancy on Aortic Root in Women with Repaired Conotruncal Anomalies.

The effect of pregnancy on aortic root in women with repaired conotruncal anomalies (CTA) has not been clarified. This study examined aortic diameters during and after pregnancy in women with repaired CTA. A retrospective review of consecutive pregnant women with repaired CTA was performed for results of echocardiography from 1 year before pregnancy to 3 years after delivery and compared with findings from healthy pregnant volunteers. Participants comprised 42 subjects and 49 deliveries with repaired CTA (CTA group), and 47 healthy pregnant women (control group). Although no maternal aortic events were encountered, aortic diameters during pregnancy increased by 1.0 ± 2.2 mm (maximum, 7.0 mm) in the CTA group and 0.6 ± 1.3 mm (maximum, 3.4 mm) in the control group (p = 0.13). The CTA subgroup with increase in aortic diameter ≥ 3.5 mm during pregnancy showed no reversion to baseline diameter at follow-up > 6 months after delivery. Significant risk factors for increased aortic diameter and no reversal included pulmonary atresia, history of aortopulmonary shunt, older age at repair, and smaller left ventricular end-diastolic diameter pre-pregnancy. Women with repaired CTA tolerated pregnancy and delivery well. However, the aortic root progressively dilated during pregnancy and 1/4 of them, especially those with longstanding high aortic blood flow before repair, showed an increase of aortic root size of ≥ 3.5 mm during the peripartum period; this dilatation tended not to revert to the pre-pregnancy diameter. Therefore, serial measurement of the aortic root during pregnancy and after delivery is recommended in these women.

Extremely short setting of optimal sensed atrioventricular interval in patients after Fontan procedure with implanted dual-chamber pacemaker.

BACKGROUND: Atrioventricular interval optimisation is important in patients with dual-chamber pacing, especially with heart failure. In patients with CHD, especially in those with Fontan circulation, the systemic atrial contraction is supposed to be more important than in patients without structural heart disease. METHODS: We retrospectively evaluated two patients after Fontan procedure with dual-chamber pacemaker with a unique setting of optimal sensed atrioventricular interval. RESULTS: The optimal sensed atrioventricular interval determined by echocardiogram was extremely short sensed atrioventricular interval at 25 and 30 ms in both cases; however, the actual P wave and ventricular pacing interval showed 180 and 140 ms, respectively. In both cases, the atrial epicardial leads were implanted on the opposite site of the origin of their own atrial rhythm. The time differences between sensed atrioventricular interval and actual P wave and ventricular pacing interval occurred because of the site of the epicardial atrial pacing leads and the intra-atrial conduction delay. CONCLUSION: We need to consider the origin of the atrial rhythm, the site of the epicardial atrial lead, and the atrial conduction delay by using electrocardiogram and X-ray when we set the optimal sensed atrioventricular interval in complicated CHD.

Clinical Characteristics of Adult Patients With Congenital Heart Disease Hospitalized for Acute Heart Failure.

BACKGROUND: Heart failure (HF) is an important complication in adults with congenital heart disease (CHD), but because only a few studies have focused on acute HF hospitalization in adults with CHD, we study aimed to define the clinical characteristics of such patients and examine the differences in acute HF between adults with CHD and acquired heart disease.Methods and Results:We retrospectively evaluated 50 adults with CHD admitted for treatment of acute HF and compared their data with those from Japanese HF registries. Patient mean age was 37±15 years and 58% were male. In total, 86% of the patients had complex forms of CHD and 62% had undergone corrective surgery, including the Fontan procedure; 66% of patients showed right heart hemodynamic abnormality. In-hospital mortality was 4%, which was comparable to the Japanese HF registries. Survival rate was 93% at 1 year and 75% at 3 years, which was similarly poor to the rates of HF secondary to acquired heart disease. CONCLUSIONS: We clarified the clinical characteristics of adults with CHD requiring HF hospitalization. Young adults with complex CHD were hospitalized for management of acute right HF. Short-term and mid-term outcomes were similarly poor compared with acute HF secondary to acquired heart disease.

Liver Cirrhosis and/or Hepatocellular Carcinoma Occurring Late After the Fontan Procedure　- A Nationwide Survey in Japan.

BACKGROUND: Fontan-associated liver disease (FALD) is an important late complication involving liver dysfunction, such as liver cirrhosis (LC) and hepatocellular carcinoma (HCC), in patients undergoing the Fontan procedure. However, the prevalence, clinical manifestation, and methods of diagnosis of FALD are still not well established.Methods and Results:This study comprised 2 nationwide surveys in Japan. First, the prevalence of LC and/or HCC in patients undergoing the Fontan procedure was determined. Second, clinical manifestations in patients with LC and/or HCC were analyzed, along with data from blood tests, echocardiography, and right heart catheterization. In the 1st survey, of the 2,700 patients who underwent the Fontan procedure, 31 were diagnosed with LC and/or HCC (1.15%), and 5 died due to liver diseases (mortality: 0.19%). In the 2nd survey, data were collected from 17 patients (12 with LC, 2 with HCC, and 3 with LC+HCC. Of these 17 patients, 5 died (mortality: 29.4%). The mean age at diagnosis of LC and HCC was 23 and 31 years, respectively. Computed tomography followed by ultrasound was most frequently used for diagnosis. Blood tests revealed low platelet counts, increased hemoglobin, aspartate aminotransferase, γ-guanosine triphosphate, and total bilirubin levels, and an elevated international normalized ratio of prothrombin time. CONCLUSIONS: LC and/or HCC in patients undergoing the Fontan procedure were not rare late complications and were associated with high mortality rates.

Comparison of Clinical Profiles in Patients with Protein-Losing Enteropathy With and Without Fontan Circulation.

Protein-losing enteropathy (PLE) is a life-threatening complication in patients following the Fontan operation. However, PLE also develops in some patients with congenital heart disease (CHD) after biventricular repair (BVR). This study compared clinical profiles of PLE patients following the Fontan operation with those after BVR. We retrospectively reviewed clinical charts of postoperative CHD patients with PLE. The study population comprised 42 PLE patients (14BVR, 28Fontan). Postoperative follow-up period until onset was significantly shorter in the Fontan group than in the BVR group (14 ± 2 vs. 8 ± 1 years, p = 0.02), while there was no difference in PLE onset age between groups. Furthermore, there were no differences in prevalence of clinically relevant arrhythmias, cardiac output, or central venous pressure between the two groups at PLE onset. Percentage of structural lesions (valve regurgitation and/or stenotic lesions) responsible for development of PLE and ventricular end-diastolic pressure were higher in the BVR group than in the Fontan group (93 vs. 50%, p < 0.01), (13.4 ± 6.3 vs. 7.5 ± 4.1, p < 0.0001). Catheter intervention was applied in 2Fontan and 6BVR patients, while surgical intervention was required in 8BVR and 7Fontan patients. Of these, catheter intervention was effective in 2 (25%, 1Fontan, 1BVR) and surgical intervention was effective in 4 (26.7%, 1Fontan, 3BVR). Only one patient (5.3%) improved without intervention. Complete PLE remission rate was higher in the BVR group than in the Fontan group (38 vs. 7%, p = 0.02). During follow-up, death of 2 BVR and 8 Fontan patients occurred. There were no group differences in 5- to 10-year survival rates after PLE onset (81 vs. 81%, BVR, 81 vs. 66%, Fontan). Although BVR patients may have greater chance of PLE remission when compared with those exhibiting Fontan pathophysiology, mortality in PLE-CHD patients was significantly high regardless of postoperative hemodynamics.

Hemodynamic determinants of mortality after Fontan operation.

BACKGROUND: Elevated central venous pressure (CVP), low cardiac output, and mild hypoxia are common early and late after Fontan operations. However, the association of these characteristics with late mortality is unclear. We aimed to elucidate the hemodynamic determinants of mortality after Fontan operation. METHOD: We evaluated early (group early; 0.5-5years postoperatively, n=387) and late (group late; ≥15years postoperatively, n=161) Fontan hemodynamics that included CVP (mm Hg), cardiac index (CI; L/min per m2), systemic ventricular end-diastolic volume index (mL/m2), ejection fraction (EF; %), and arterial blood oxygen saturation (%). We examined the effect of these variables on 5-year all-cause mortality. RESULTS: Mortality was higher in group late than in group early (17 vs 11, P<.0001). In both groups, higher CVP (hazard ratio [HR]1.46 and 1.38, respectively; P<.001-.0001) and lower arterial blood oxygen saturation (HR 1.12, P<.001 for both) were associated with increased mortality. Greater end-diastolic volume index (HR per 20: 1.73) and lower EF (HR per 10%: 3.38) were associated with increased mortality only in group early (P<.0001 for both). In contrast, only in group late was higher CI associated with increased mortality (HR 2.50, 95% CI 1.30-4.55, P<.01). Seven patients in group late with both high CVP (≥14) and CI (≥3.0) had the highest mortality (HR 18.1, 5.55-52.4, P<.0001). CONCLUSIONS: Elevated CVP and low arterial blood oxygen saturation correlate with mortality in both early and late Fontan survivors. End-diastolic volume index and EF are associated with mortality only in the earlier cohort, whereas interestingly, elevated cardiac output is associated with increased mortality in the later cohort.

Mid-Term Follow-up of School-Aged Children With Borderline Long QT Interval.

BACKGROUND: There are no definitive diagnostic criteria or follow-up strategies for long QT syndrome (LQTS) in children with a borderline long QT interval (b-LQT).Methods and Results:We retrospectively evaluated the clinical course, genetic testing results, corrected QT interval (QTc), and LQTS score of 59 school-aged children (5-18 years old) with a b-LQT (400≤QTc<500 ms). Syncope, but neither aborted cardiac arrest nor sudden cardiac death, occurred in 2 patients during the follow-up (6±3.4 years) with LQTS scores ≥4.5 points. The genetic testing results were positive in 92%, 57%, and 67% of patients with high, intermediate, and low probabilities of LQTS, respectively. The maximum and mean QTc during the follow-up significantly differed among the categories with a probability of LQTS, but not the minimum QTc. However, the QTc at rest and at the recovery point after exercise stress testing dramatically changed at the last follow-up. Consequently, the probability of LQTS changed in half of the patients. CONCLUSIONS: The LQTS score is a reasonable indicator for evaluating school-aged children with a b-LQT, and patients with a low LQTS score appear to be at low risk for cardiac events. However, the LQTS score can change during follow-up. Therefore, when there is doubt or concern for patients with a b-LQT, it is preferable to continue following them. Guidelines on follow-up strategies are desired for b-LQT.

Interventricular dyssynchrony in a patient with a biventricular physiology and a systemic right ventricle.

We describe of a unique pattern of cardiac dyssynchrony in a patient with a biventricular physiology and systemic right ventricle (RV): the interventricular dyssynchrony due to a contraction delay between the left ventricle and RV. In the present case, the cineangiography and intracardiac electrocardiography of the RV did not reveal intraventricular dyssynchrony of the RV, but revealed interventricular dyssynchrony. In addition, the pressure curves of the ventricles exhibited time phase differences between the two ventricles. The cardiac resynchronization therapy determining the pacing lead positions based on the idea of interventricular dyssynchrony induced reverse cardiac remodeling in this patient with systemic RV dysfunction.