A Multimodal Score Accurately Classifies Fontan Failure and Late Mortality in Adult Fontan Patients

Impact of diaphragm paralysis and its surgical interventions on outcomes after the staged Fontan procedure

OBJECTIVES

This study aimed to investigate the incidence of diaphragm paralysis and its impact on outcomes after the Fontan procedure in patients with single ventricles.

METHODS

Patients undergoing staged Fontan palliation between 1994 and 2023 were reviewed. Patients who had diaphragm paralysis were identified, and the impact of diaphragm paralysis on outcomes after Fontan completion was evaluated.

RESULTS

Among 601 patients who underwent staged Fontan completion during the study period, diaphragm paralysis was observed in 79 patients (13.1%) before Fontan (33 after stage I palliation and 46 after Glenn) and in 32 patients (5.3%) after the Fontan. Among 111 patients with diaphragm paralysis, 77 had spontaneous recovery, 13 recovered after plication and 21 remained without recovery. Patients with diaphragm paralysis before the Fontan demonstrated higher pulmonary arterial pressure (median 10 vs 9 mmHg, P = 0.045) and lower pulmonary artery symmetry index (median 0.54 vs 0.59, P = 0.046) than those without diaphragm paralysis. The use of an autologous pericardial patch in stage 1 was a risk factor for diaphragm paralysis development (odds ratio: 2.61, P = 0.012). Diaphragm paralysis was associated with an increased risk of protein-losing enteropathy (hazard ratio: 2.31, P = 0.003), particularly in patients without recovery after plication (hazard ratio: 4.85, P = 0.031).

CONCLUSIONS

Diaphragm paralysis following Fontan completion significantly increases the risk of protein-losing enteropathy and long-term mortality, particularly in patients who fail to recover after plication. Early identification and appropriate management of diaphragm paralysis may be crucial for optimizing outcomes.

Are Arrhythmias Adequately Incorporated into Studies on Long-Term Outcomes After the Fontan Operation?

Arrhythmias are common after the Fontan operation and increase risk of morbidity and mortality. Their impact on late outcomes remains poorly understood. Our objective was to assess whether long-term studies after the Fontan incorporated the impact of arrhythmia characteristics on outcome. We reviewed the literature since 2005 for studies evaluating the impact of multiple risk factors on long-term outcomes and mortality after the Fontan. Studies focusing only on one or two risk factors (including arrhythmias) and those with a mean follow-up < 10 years were excluded. Of the 17 studies analyzed, only six mentioned rhythm at follow-up. Nine lumped all arrhythmias (tachyarrhythmia, bradyarrhythmia, paced rhythm, early and late arrhythmia) into one single category. Only eight of the 17 studies reported the incidence of tachyarrhythmias in detail and only two studies described bradyarrhythmias in detail as sinus or atrioventricular (AV) node dysfunction subgroups. Five studies reported on treatment of tachyarrhythmias including Fontan revision surgeries, catheter ablation, pacemaker placement and or the use of antiarrhythmic drugs. However, only one included information on the impact of treatment on outcomes. Out of 15 studies that conducted a multivariate analysis of Fontan outcomes, arrhythmia was included in the univariate model in 14 and in the multivariate model in 9. Overall, we found most studies on late outcomes after the Fontan do not include rhythm and arrhythmia characteristics in data collection and analysis. Incorporating more granular rhythm information in large databases and in multivariate analyses will help better determine and contextualize the impact of arrhythmias on outcomes after the Fontan.

Serial changes of systemic ventricular function and atrioventricular valve function in patients with failing Fontan

OBJECTIVES

This study investigated the longitudinal changes in ventricular function and atrioventricular valve function to clarify the timing and the mechanisms of failing Fontan.

METHODS

Patients who underwent total cavopulmonary connection between 1994 and 2023 were reviewed, and longitudinal echocardiographic examinations of ventricular function and atrioventricular valve regurgitation were analysed.

RESULTS

A total of 650 patients were included. The most frequent primary diagnosis was hypoplastic left heart syndrome in 175 patients. Dominant right ventricle was observed in 337 patients (51.8%). The median age at total cavopulmonary connection was 2.3 (1.8-3.3) years. Failing Fontan was observed in 78 patients (12%) during the median follow-up of 6.2 years. Among them, dominant right ventricle was observed in 51 patients (65.4%). Patients with protein-losing enteropathy or plastic bronchitis (n = 37) developed Fontan failure early (median 2.6 years post-total cavopulmonary connection). Still, patients maintained ventricular function (93.1% normal at 5 years) and atrioventricular valve competence (no case of moderate/severe regurgitation at 5 years) over time. Patients who developed failing Fontan associated with progression of heart failure (n = 41) had later onset (median 8.3 years post-total cavopulmonary connection) but indicated progressive ventricular dysfunction (68.3% normal at 5 years, 53.8% normal at 10 years) and atrioventricular valve regurgitation (12.3% moderate/severe at 5 years, 15.3% moderate/severe at 10 years).

CONCLUSIONS

Patients with failing Fontan indicated different serial ventricular and atrioventricular valve function profiles. Ventricular function was preserved in failing Fontan patients with protein-losing enteropathy or plastic bronchitis, whereas progressive ventricular dysfunction was observed in failing Fontan patients with heart failure.

Incidence, pathophysiology, and treatment of failing Fontan after the total cavopulmonary connection

BACKGROUND

Failing Fontan poses a significant clinical challenge. This study aims to improve patients' outcomes by comprehensively understanding the incidence, pathophysiology, risk factors, and treatment of failing Fontan after total cavopulmonary connection.

METHODS

We performed a retrospective analysis of patients who underwent total cavopulmonary connection at the German Heart Center Munich between 1994 and 2022. The onset of failing Fontan was defined as: protein-losing enteropathy, plastic bronchitis, NYHA class IV, NYHA class III for > one year, unscheduled hospital admissions for heart failure symptoms, and evaluation for heart transplantation.

RESULTS

Among 634 patients, 76 patients presented with failing Fontan, and the incidence was 1.48 per 100 patient-years. Manifestations included protein-losing enteropathy (n = 34), hospital readmission (n = 28), NYHA III (n = 18), plastic bronchitis (n = 16), evaluation for heart transplantation (n = 14), and NYHA IV (n = 4). Risk factors for the onset of failing Fontan were dominant right ventricle (p = 0.010) and higher pulmonary artery pressure before total cavopulmonary connection (p = 0.004). A total of 72 interventions were performed in 59 patients, including balloon dilatation/stent implantation in the total cavopulmonary connection pathway (n = 49) and embolization of collaterals (n = 24). Heart transplantation was performed in four patients. The survival after the onset of Fontan failure was 77% at 10 years. Patients with failing Fontan revealed significantly higher zlog-NT-proBNP levels after onset compared to those without (p = 0.021).

CONCLUSIONS

The incidence of Fontan failure was 1.5 per 100 patient years. Dominant right ventricle and higher pulmonary artery pressure before total cavopulmonary connection were significant risks for the onset of failing Fontan. Zlog-NT-proBNP is only a late marker of Fontan failure.

Effect of liver abnormalities on mortality in Fontan patients: a systematic review and meta-analysis

BACKGROUND

Fontan-associated liver disease (FALD) is one of the most common complications following Fontan procedure, but the impact of FALD on survival outcomes remains controversial. The aim of this systematic review and meta-analysis was to examine and quantify the influence of liver disease on the survival of Fontan patients.

METHODS

The Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines were followed, and relevant human studies published from inception up to 12 August 2022 were searched. Stata (version 17.0) was applied to perform the meta-analysis, using random effects (Mantel-Haenszel) models. The I2 statistic was used to assess the heterogeneity. Subgroup analysis and meta-regression were employed to explore the potential sources of heterogeneity and sensitivity analysis was performed to determine the potential influence of each study on the overall pooled results.

RESULTS

A total of 312 records were initially identified and 8 studies involving 2,466 patients were selected for inclusion. Results revealed a significant association between the severity of liver disease following Fontan procedure and mortality, which was confirmed by sensitivity analysis and subgroup analysis assessing post-HT mortality. Meta-regression showed that diagnostic methods for liver disease may be a source of heterogeneity. After removal of the FALD patients identified by international classification of disease codes, heterogeneity was markedly reduced, and the positive association between all-cause mortality and the severity of liver disease became significant.

CONCLUSIONS

This meta-analysis showed the severity of liver disease following the Fontan procedure has a significant association with mortality. Lifelong follow-up is necessary and imaging examinations are recommended for routine surveillance of liver disease. Among patients with failing Fontan and advanced liver disease, combined heart-liver transplantation may provide additional survival benefits.

Pacemaker-Related Factors and Outcomes of Fontan Patients - Impact of Paced QRS Duration

BACKGROUND

Permanent pacemaker (PPM) implantation has been identified as a risk factor for morbidity and mortality after Fontan operation. This study investigated the factors associated with outcomes in patients with Fontan physiology who underwent PPM implantation.

METHODS AND RESULTS

We retrospectively reviewed 508 patients who underwent Fontan surgery at Asan Medical Center between September 1992 and August 2022. Of these patients, 37 (7.3%) received PPM implantation. Five patients were excluded, leaving 32 patients, of whom 11 were categorized into the poor outcome group. Poor outcomes comprised death, heart transplantation, and "Fontan failure". Clinical, Fontan procedure-related, and PPM-related factors were compared between the poor and good outcome groups. Ventricular morphology, Fontan procedure-associated factors, pacing mode, high ventricular pacing rate, and time from first arrhythmia to PPM implantation did not differ significantly between the 2 groups. However, the poor outcome group exhibited a significantly longer mean paced QRS duration (P=0.044). Receiver operating characteristic curve analysis revealed a paced QRS duration cut-off value of 153 ms with an area under the curve of 0.73 (P=0.035).

CONCLUSIONS

A longer paced QRS duration was associated with poor outcomes, indicating its potential to predict adverse outcomes among Fontan patients.

EASL-ERN position paper on liver involvement in patients with Fontan-type circulation

Fontan-type surgery is the final step in the sequential palliative surgical treatment of infants born with a univentricular heart. The resulting long-term haemodynamic changes promote liver damage, leading to Fontan-associated liver disease (FALD), in virtually all patients with Fontan circulation. Owing to the lack of a uniform definition of FALD and the competitive risk of other complications developed by Fontan patients, the impact of FALD on the prognosis of these patients is currently debatable. However, based on the increasing number of adult Fontan patients and recent research interest, the European Association for The Study of the Liver and the European Reference Network on Rare Liver Diseases thought a position paper timely. The aims of the current paper are: (1) to provide a clear definition and description of FALD, including clinical, analytical, radiological, haemodynamic, and histological features; (2) to facilitate guidance for staging the liver disease; and (3) to provide evidence- and experience-based recommendations for the management of different clinical scenarios.

Anatomical Compliance of Cavopulmonary Assist Device Designs: A Virtual Fitting Study in Fontan Patients

Several device designs for cavopulmonary mechanical circulatory support (MCS) are under investigation, however, challenged by the Fontan population's heterogeneity in size, cardiovascular and thoracic anatomy. This study aimed to preclinically assess the anatomical compliance of proposed device designs in silico. Representative double- and single-outlet cavopulmonary assist device (CPAD) designs were virtually implanted into CT imaging data of 10 patients previously palliated with total cavopulmonary connection (TCPC) for functionally univentricular hearts. Anatomical device compatibility was characterized concerning pump proximity to cardiovascular, respiratory and thoracic structures, as well as pump in- and outflow graft configuration. In 10 Fontan patients with a median age of 10.4 years (interquartile range [IQR] 5.0-15.3 years) and a median body surface area of 1.09 m2 (IQR 0.76-1.28 m2), implantation of a double-outlet CPAD was feasible in 1 patient (10%). In all other, adverse device intersection with the trachea and (neo-)aorta, or posterior pulmonary artery outflow graft kinking were observed. A single-outlet design permitted enhanced device mobilization adapting to individual anatomical conditions, resulting in device fit in nine of 10 patients (90%). Despite vast anatomical variations among single ventricle patients, a single-outlet device design may provide intracorporeal cavopulmonary MCS to a broad spectrum of failing Fontan patients.

Impact of Ventricular Dominance on Long-Term Fontan Outcomes: A 25-year Single-institution Study

BACKGROUND

The long-term impact of ventricular dominance on Fontan outcomes is controversial. This study examined this issue in a 25-year cohort.

METHODS

Patients undergoing the Fontan operation at a single institution (Duke University Medical Center, Durham, NC) from October 1998 to February 2022 were reviewed. Primary outcomes were transplant-free survival and Fontan failure (death, heart transplantation, takedown, protein-losing enteropathy, or plastic bronchitis). Secondary outcomes included hospital and intensive care lengths of stay. Kaplan-Meier methodology compared outcomes by ventricular dominance. Multiphase parametric risk hazard analysis identified risk factors for primary outcomes.

RESULTS

There were 195 patients (104 right ventricular dominant) included in the study. Baseline characteristics were comparable. Perioperative survival was similar (right ventricular dominant, 98%; non-right ventricular dominant, 100%; P = .51). The proportion of patients experiencing death or heart transplantation was 8.7%, and the rate of Fontan failure was 11.8% during a median follow-up of 4.5 years (interquartile range, 0.3-9.8 years). Right ventricular-dominant patients had reduced transplant-free survival (10-year estimates: 80% [95% CI, 70%-91%] vs 92% [95% CI, 83%-100%]; P = .04) and freedom from Fontan failure (73% [95% CI, 62%-86%] vs 92% [95% CI, 83%-100%]; P = .04). Multiphase hazard modeling resolved 2 risk phases. The early phase spanned from surgery to approximately 6 months afterward. The late phase spanned from approximately 6 months after surgery onward. In multivariable analysis, right ventricular dominance was an independent risk factor for death or heart transplantation (parameter estimate, 1.3 ± 0.6; P = .04) and Fontan failure (1.1 ± 0.5; P = .04) during the second phase, with no significant first-phase risk factors.

CONCLUSIONS

Right ventricular dominance was associated with long-term complications after Fontan procedures, including mortality, heart transplantation, and Fontan failure. This cohort may benefit from heightened surveillance in a multidisciplinary Fontan clinic after the perioperative period.

Pregnancy Outcomes in Women after the Fontan Procedure

Women with single ventricle physiology after the Fontan procedure, despite numerous possible complications, can reach adulthood and give birth. Pregnancy poses a hemodynamic burden for distorted physiology of Fontan circulation, but according to the literature, it is usually well tolerated unless the patient is a "failing" Fontan. Our study aimed to assess maternal and fetal outcomes in patients after the Fontan procedure followed up in two tertiary Polish medical centers. We retrospectively evaluated all pregnancies in women after the Fontan procedure who were followed up between 1995-2022. During the study period, 15 women after the Fontan procedure had 26 pregnancies. Among 26 pregnancies, eleven ended with miscarriages, and 15 pregnancies resulted in 16 live births. Fetal complications were observed in 9 (56.3%) live births, with prematurity being the most common complication (n = 7, 43.8%). We recorded 3 (18.8%) neonatal deaths. Obstetrical complications were present in 6 (40%) out of 15 completed pregnancies-two (13.3%) cases of abruptio placentae, two (13.3%) pregnancies with premature rupture of membranes, and two (13.3%) patients with antepartum hemorrhage. There was neither maternal death nor heart failure decompensation during pregnancy. In two (13.3%) women, atrial arrhythmia developed. One (6.7%) patient in the second trimester developed ventricular arrhythmia. None of the patients suffered from systemic thromboembolism during pregnancy. Pregnancy in women after the Fontan procedure is well tolerated. However, it is burdened by a high risk of miscarriage and multiple obstetrical complications. These women require specialized care provided by both experienced cardiologists and obstetricians.

Functional hepatic deterioration determined by 13C-methacetin breath test is associated with impaired hemodynamics and late Fontan failure in adults

Background

Despite improved survival a substantial number of Fontan patients eventually develop late failure. Fontan-associated liver disease (FALD) is the most frequent end-organ dysfunction. Although impaired hemodynamics and Fontan failure correlate with FALD severity, no association between hepatic functional metabolic impairment and Fontan hemodynamics has been established.

Hypothesis

Metabolic liver function measured by liver maximum function capacity test (LiMAx®) correlates with Fontan hemodynamics and Fontan failure.

Methods

From 2020 to 2022, 58 adult Fontan patients [median age: 29.3 years, IQR (12.7), median follow-up time after Fontan operation: 23.2 years, IQR (8.7)] were analyzed in a cross-sectional study. Hemodynamic assessment included echocardiography, cardiopulmonary exercise testing and invasive hemodynamic evaluation. Fontan failure was defined based on commonly applied clinical criteria and our recently composed multimodal Fontan failure score.

Results

LiMAx® test revealed normal maximum liver function capacity in 40 patients (>315 μg/h^*kg). In 18 patients a mild to moderate impairment was detected (140–314 μg/h^*kg), no patient suffered from severe hepatic deterioration (≤ 139 μg/kg^*h). Fontan failure was present in 15 patients. Metabolic liver function was significantly reduced in patients with increased pulmonary artery pressure (p = 0.041. r = −0.269) and ventricular end-diastolic pressure (p = 0.033, r = −0.325), respectively. In addition, maximum liver function capacity was significantly impaired in patients with late Fontan failure (289.0 ± 99.6 μg/kg^*h vs. 384.5 ± 128.6 μg/kg^*h, p = 0.007).

Conclusion

Maximum liver function capacity as determined by LiMAx® was significantly reduced in patients with late Fontan failure. In addition, elevated pulmonary artery pressure and end-diastolic ventricular pressure were associated with hepatic functional metabolic impairment.