Usefulness of insulin like growth factor 1 as a marker of heart failure in children and young adults after the Fontan palliation procedure

Influence of growth and metabolic markers on hs-troponin T and NT-proBNP levels in healthy children

Background and objectives

As part of the LIFE Child study, we previously described the associations between N-terminal-pro-hormone brain natriuretic peptide (NT-proBNP) and hs-troponin T (hs-TnT) levels and an individual's sex, age and pubertal status, as well as with body mass index (BMI) and serum lipid levels. For NT-proBNP, we found inverse associations with advancing puberty, increasing BMI and serum lipid levels. These findings led us to further question the putative influences of the developing individual's metabolic and growth status as represented by levels of insulin-like growth factor-1 (IGF-1) and IGF-1-binding protein-3 (IGF-BP3) as well as hemoglobin A1c (HbA1c) and Cystatin C (CysC).

Material and methods

Serum values, medical history and anthropometric data provided by 2522 children aged 0.25-18 years were collected and analyzed as per study protocol.

Results

A strong negative association between NT-proBNP values and IGF-1, IGF-BP3 and HbA1c levels was identified. For IGF-BP3, this interaction was modulated by sex and age, for HbA1c only by age. For hs-TnT, a positive association was found with IGF-BP3, IGF-1 and CysC. The association between hs-TnT and IGF-1 was sex dependent. The association between CysC and hs-TnT was stronger in girls, but the interaction with age was only seen in boys. Between hs-TnT and HbA1c, the association was significantly negative and modulated by age.

Conclusion

Based on our large pediatric cohort, we could identify age- and sex-dependent interactions between the metabolic status represented by IGF-1, IGF-BP3, CysC and HbA1c levels and the cardiac markers NT-proBNP and hs-TnT.

Early growth trajectory is associated with psychological stress in parents of infants with congenital heart disease, but moderated by quality of partner relationship

PURPOSE

To explore the relationships between growth trajectory, parenting stress and parent post-traumatic stress (PTS), in infants with congenital heart disease, and the moderating role of parents' dyadic adjustment on those associations.

DESIGN AND METHODS

A secondary analysis of data from the REACH Telehalth home monitoring multi-site randomized clinical trial. Parents completed the Parenting Stress Index (PSI), Post-traumatic diagnostic scale, and the Dyadic Adjustment Scale. Multivariate logistic regression models were used to examine the associations of interest.

RESULTS

During 4-month follow-up after hospital discharge, parents of infants with 'Never recovered' and 'Partially recovered' growth trajectories had 2-5 times higher odds of experiencing higher stress on the Parent Domain (OR = 4.8, CI = 1.3-18.0; OR = 2.5, CI = 1.0-5.9, respectively) than those with stably grown infants. Parents of "Never recovered" infants had 4 times higher odds of PTS symptoms (OR = 3.9; CI = 1.6-9.9). Parental dyadic adjustment moderated the relationships. Parents of 'Partially recovered' infants and having low dyadic adjustment had 3-5 times higher odds of high stress on all PSI domains, while parents with high dyadic adjustment did not have increased stress due to poor infant growth. Parents of "Never recovered" infants had four times higher odds of PTS symptom, even with high dyadic adjustment.

CONCLUSIONS

Infant growth trajectory over the first four months is associated with parenting stress and PTS. Quality of partner relationship moderates some of these associations.

PRACTICE IMPLICATIONS

Infant growth should serve as a screening aid for identifying parents at psychological risk. Interventions targeting the quality of partner relationship may support parental coping and mitigate stress.

CLINICAL TRIAL REGISTRATION

NCT01941667.

Somatic growth in single ventricle patients: A systematic review and meta-analysis

AIM

To map somatic growth patterns throughout Fontan palliation and summarise evidence on its key modifiers.

METHODS

Databases were searched for relevant articles published from January 2000 to December 2021. Height and weight z scores at each time point (birth, Glenn procedure, Fontan procedure and >5 years after Fontan completion) were pooled using a random effects meta-analysis. A random effects meta-regression model was fitted to model the trend in z scores over time.

RESULTS

Nineteen studies fulfilled eligibility criteria, yielding a total of 2006 participants. The z scores for height and weight were markedly reduced from birth to the interstage period, but recovered by about 50% following the Glenn procedure. At >10 years after the Fontan procedure, the z scores for weight seemed to normalise despite persistent lower height, resulting in increased body mass index. The review revealed a number of modifiers of somatic growth, including aggressive nutritional management, timing of Glenn/Fontan, prompt resolution of complications and obesity prevention programmes in adolescence and adulthood.

CONCLUSION

This review mapped the somatic growth of single ventricle patients and summarised key modifiers that may be amendable to improvement. These data provide guidance on strategies to further optimise somatic growth in this population and may serve as a benchmark for clinical follow-up.

New insights on growth trajectory in infants with complex congenital heart disease

PURPOSE

We aimed to describe the weight-for-age Z-score growth trajectory (WAZ-GT) of infants with complex congenital heart disease (cCHD) after neonatal cardiac surgery in the first 4 months of life and assess potential risk factors.

METHODS

We utilized data from a previously reported trial of the REACH telehealth home monitoring (NCT01941667) program which evaluated 178 infants with cCHD from 2012 to 2017. Over the first 4 months of life, weekly infant weights were converted to WAZ. WAZ-GT classes were identified using latent class growth modeling. Multinomial logistic regression models were used to examine the associations between potential risk factors and WAZ-GT classes.

RESULTS

Four distinct classes of WAZ-GT were identified: maintaining WAZ > 0, 14%; stable around WAZ = 0, 35%; partially recovered, 28%; never recovered, 23%. Compared with reference group "stable around WAZ=0," we identified clinical and sociodemographic determinants of class membership for the three remaining groups. "Maintaining WAZ > 0" had greater odds of having biventricular physiology, borderline appetite, and a parent with at least a college education. "Partially recovered" had greater odds of hospital length of stay>14 days and being a single child in the household. "Never recovered" had greater odds hospital length of stay >14 and > 30 days, tube feeding at discharge, and low appetite.

CONCLUSIONS

This study described distinct classes of WAZ-GT for infants with cCHD early in infancy and identified associated determinants.

PRACTICE IMPLICATIONS

Findings from this study can be used in the identification of infants at risk of poor WAZ-GT and in the design of interventions to target growth in this vulnerable patient population.

Relationship Between Serum Brain-Type Natriuretic Peptide and Biomarkers of Growth in Infants With Shunt-Dependent Single Cardiac Ventricle

For infants with shunt-dependent or ductal-dependent single ventricle heart disease, poor growth is common and associated with morbidity and impaired neurodevelopmental outcomes. Although attention has focused on nutrition to promote weight gain, little is known about the relation between heart failure and growth factors. A prospective observational pilot study was performed to assess the relation between heart failure, assessed by brain natriuretic peptide (BNP), and growth factors (insulin-like growth factor 1 [IGF-1] and insulin-like growth factor-binding protein 3) at 3 visits: (1) before discharge from neonatal intervention with the establishment of stable pulmonary blood flow, (2) immediately before superior cavopulmonary connection, and (3) before discharge after superior cavopulmonary connection operation. The relation between BNP and growth factors was analyzed using Spearman pairwise correlations at each visit and modeled over time with a linear mixed-effects model. Correlations were considered worthy of further exploration using a p <0.10, given the exploratory nature of the study. The study included 38 infants (66% male, 68% hypoplastic left heart syndrome). Median BNP was elevated at visit 1 and decreased over time (287 pg/dl [interquartile range 147 to 794], 85 pg/dl [52 to 183], and 90 pg/dl [70 to 138]). Median IGF-1 Z score was <0 at each visit but increased over time (-0.9 [interquartile range -1.1 to 0.1], -0.7 [-1.2 to 0.1], and -0.5 [-1.2 to 0]). Inverse correlations were found between BNP and IGF-1 at visit 1 (r = -0.40, p = 0.097), BNP and IGF-1 and insulin-like growth factor-binding protein 3 at visit 2 (r = -0.33, p = 0.080 and r = -0.33, p = 0.085, respectively) and BNP and IGF-1 Z score at visit 3 (r = -0.42, p = 0.049). Significant relations were likewise found between the change in BNP and the change in IGF-1 between visits 1 and 3 (p = 0.046) and between visits 2 and 3 (p = 0.048). In conclusion, this pilot study demonstrates an inverse correlation between BNP and growth factors, suggesting that the heart failure state associated with this physiology may play a mechanistic role in impaired growth.

Body Composition and Exercise Performance in Youth With a Fontan Circulation: A Bio-Impedance Based Study

Background Adults with a Fontan circulation tend to have myopenia and elevated adiposity when measured by dual energy x-ray absorptiometry. Bioelectrical impedance analysis is an alternative validated approach to assess body composition. We used bioelectrical impedance analysis to compare body composition between pediatric patients with a Fontan circulation and control individuals without heart disease. Methods and Results A retrospective chart review identified all patients aged <22 years with a Fontan circulation who presented for cardiopulmonary exercise testing and bioelectrical impedance analysis from April 2019 to January 2020. Data were compared with control subjects tested during the same period. We studied 47 patients with a Fontan circulation (53% boys; 15±3.1 years) and 165 controls (48% boys; 14.4±2.5 years). Fontan status was associated with shorter height, but similar age, sex, and overall body mass. Patients with Fontan had lower lean body mass (-12.0±22%, Z-score -0.5±1, P=0.005), skeletal muscle mass (-13.6±1.4%; Z-score, -0.5±1; P=0.004), skeletal muscle indexed to height (-10.3±13.3%; Z-score, -0.5±1; P=0.005), and higher percent body fat (+13.8±18.6%; Z-score, 0.4±1.2; P=0.03). Greater skeletal muscle mass was associated with higher peak oxygen consumption (r2=0.52, P<0.0001) and oxygen pulse (r2=0.68, P<0.0001). Patients who had suffered a late complication (ie, heart transplant referral or evidence of extracardiac organ dysfunction) of the Fontan operation (13 of 47, 27.7%) had lower skeletal muscle mass (P=0.048) and higher body fat percentage (P=0.003). Conclusions The Fontan circulation is associated with marked myopenia and increased adiposity. Higher muscle mass was associated with better exercise capacity. Fontan complications are associated with lower muscle mass and increased adiposity.

Growth stunting in single ventricle patients after heart transplantation

BACKGROUND

Malnutrition is common among children with single ventricle (SV) congenital heart disease (CHD). The impact of heart transplantation (HT) on nutritional status in SV patients is understudied. Our aim was to evaluate anthropometric changes in SV patients after HT, compared with those transplanted for cardiomyopathy (CM).

METHODS

We performed a single-center retrospective chart review of SV and CM patients < 18 years who underwent HT from January 01, 2010 to December 05, 2017. Wasting and stunting were defined as z-scores for weight-for-age or height-for-age ≤-2, respectively. Changes in these indices between HT and 3 years post-HT were analyzed.

RESULTS

Of 86 eligible patients, 28 (33%) had SV CHD and 58 (67%) had CM. Data were available at 3 years post-HT for 57 patients. At transplant, wasting was equally present in SV versus CM patients (7/28, 25% vs. 9/58, 16%, P = .22), which remained true at 3 years post-HT (2/16, 13% vs. 3/41, 7%, P = .61). At transplant, stunting was more common in SV than CM patients (17/28, 61% vs. 8/58, 14%, P < .001). At 3 years post-HT, 6 of 16 (38%) SV patients and 3 of 41 (7%) CM patients remained stunted (P = .01). Among all patients, wasting decreased from transplant to end-point (19% vs. 9%, P = .05), but stunting did not (29% vs. 16%, P = .2), such that wasting and stunting were associated at transplant (P < .001) but not at end-point (P = .17).

CONCLUSIONS

Longitudinal growth remains impaired for several years after HT in SV patients, even when weight gain is achieved, suggesting that some factors contributing to growth impairment persist despite resolution of SV physiology.

Evaluation and Management of the Child and Adult With Fontan Circulation: A Scientific Statement From the American Heart Association

It has been 50 years since Francis Fontan pioneered the operation that today bears his name. Initially designed for patients with tricuspid atresia, this procedure is now offered for a vast array of congenital cardiac lesions when a circulation with 2 ventricles cannot be achieved. As a result of technical advances and improvements in patient selection and perioperative management, survival has steadily increased, and it is estimated that patients operated on today may hope for a 30-year survival of >80%. Up to 70 000 patients may be alive worldwide today with Fontan circulation, and this population is expected to double in the next 20 years. In the absence of a subpulmonary ventricle, Fontan circulation is characterized by chronically elevated systemic venous pressures and decreased cardiac output. The addition of this acquired abnormal circulation to innate abnormalities associated with single-ventricle congenital heart disease exposes these patients to a variety of complications. Circulatory failure, ventricular dysfunction, atrioventricular valve regurgitation, arrhythmia, protein-losing enteropathy, and plastic bronchitis are potential complications of the Fontan circulation. Abnormalities in body composition, bone structure, and growth have been detected. Liver fibrosis and renal dysfunction are common and may progress over time. Cognitive, neuropsychological, and behavioral deficits are highly prevalent. As a testimony to the success of the current strategy of care, the proportion of adults with Fontan circulation is increasing. Healthcare providers are ill-prepared to tackle these challenges, as well as specific needs such as contraception and pregnancy in female patients. The role of therapies such as cardiovascular drugs to prevent and treat complications, heart transplantation, and mechanical circulatory support remains undetermined. There is a clear need for consensus on how best to follow up patients with Fontan circulation and to treat their complications. This American Heart Association statement summarizes the current state of knowledge on the Fontan circulation and its consequences. A proposed surveillance testing toolkit provides recommendations for a range of acceptable approaches to follow-up care for the patient with Fontan circulation. Gaps in knowledge and areas for future focus of investigation are highlighted, with the objective of laying the groundwork for creating a normal quality and duration of life for these unique individuals.

The Prospective Association Between Plasma Concentrations of Cellular Growth Factors and Risk of Heart Failure Mortality in Japanese Population

Background

Limited evidence is available on the association of insulin-like growth factors (IGFs) and risk of heart failure in population-based samples. We investigated whether serum IGFs concentrations can predict mortality from heart failure.

Methods

We conducted a nested case-control study of 39,242 subjects aged 40–79 years who participated in the JACC study, a large Japanese prospective cohort study; participants provided serum samples and were followed up for 9 years. In heart failure cases and age-, sex-, community-, and year of blood withdrawal-matched controls, we measured serum concentrations of IGF-I, IGF-II, and IGF binding protein 3 (IGFBP3) and transforming growth factor (TGF-β1).

Results

During the follow-up, there were 88 heart failure deaths (44 men and 44 women). Each increment of 1 standard deviation [SD] of IGF-II (120.0 ng/mL in women and 143.7 ng/mL in men) was associated with a 47% reduced risk of mortality from heart failure; multivariable odds ratio was 0.53 (95% confidence interval [CI], 0.30–0.94, P-trend = 0.03). The multivariable odds ratio in the highest quartile of IGFBP3 serum concentrations (≥3.29 µg/mL in women and ≥3.31 µg/mL in men) compared with the lowest (<2.11 µg/mL in women and <2.56 µg/mL in men) was 0.24 (95% CI, 0.05–1.11; P-trend = 0.12). No association was found between serum concentrations of IGF-I or TGF-β1 and risk of heart failure.

Conclusions

Higher serum concentrations of IGF-II were associated with lower mortality from heart failure, which might suggest a possible role of IGF-II in the occurrence or prognosis of heart failure.

Leg lean mass correlates with exercise systemic output in young Fontan patients

OBJECTIVE

We previously described lower leg lean mass Z-scores (LLMZ) in Fontan patients associated with worse peak oxygen consumption on metabolic exercise testing. We hypothesised that LLMZ correlates with indexed systemic flow (Qsi) and cardiac index (CI) on exercise cardiac magnetic resonance (eCMR).

METHODS

Thirteen patients had LLM measured by dual-energy X-ray absorptiometry within mean 40 (range 0-258) days of eCMR. LLM was converted to sex and race-specific Z-scores based on healthy reference data. Ventricular volumes and flow measurements of the ascending and descending (DAO) aorta and superior vena cava (SVC) were obtained by CMR at rest and just after supine ergometer exercise to a heart rate associated with anaerobic threshold on prior exercise test. Baseline and peak exercise measures of Qsi (SVC+DAO/BSA) and CI, as well as change in Qsi and CI with exercise, were compared with LLMZ by linear regression.

RESULTS

LLMZ was not correlated with resting flows, stroke volume or CI. There was a strong linear correlation between LLMZ and change in both CI (r=0.77, p=0.002) and Qsi (r=0.73, p=0.005) from rest to exercise. There was also a significant correlation between LLMZ and Qsi at exercise (r=0.70, p=0.008). The correlation between LLMZ and CI at exercise did not reach significance (r=0.3, p=0.07).

CONCLUSIONS

In our cohort, there was a strong linear correlation between LLMZ and change in both CI and Qsi from rest to exercise, suggesting that Fontan patients with higher LLMZ may be better able to augment systemic output during exercise, improving performance.

Noncompliance to a Postoperative Algorithm Using Feeding Readiness Assessments Prolonged Length of Stay at a Pediatric Heart Institute

Introduction:

Variable compliance to postoperative feeding algorithms after pediatric cardiac surgery may be associated with suboptimal growth, decreased parental satisfaction, and prolonged hospital length of stay (LOS). Our heart center performed an audit of compliance to a previously introduced postoperative feeding algorithm to guide quality improvement efforts. We hypothesized that algorithm noncompliance would be associated with increased LOS.

Methods:

We retrospectively identified children ≤ 3 months admitted for their first cardiac surgery between January 1, 2015 and December 31, 2016. The algorithm uses objective oral feeding readiness assessments (FRA). At the end of a predefined evaluation period, a “sentinel” FRA score is assigned. The sentinel FRA and FRA trend guide decisions to pursue gastrostomy tube (GT) or oral-only feeds. Among those who reached the sentinel FRA, we defined compliance as ≤ 3 days before pursuing GT or oral-only feeds once indicated by the algorithm.

Results:

Sixty-nine patients were included. Forty-nine complied with the algorithm (71%), and 45 received GT (65.2%). Noncompliers had significantly longer LOS (34 versus 25 days; P = 0.01). Among GT recipients, noncompliers waited 6 additional days for a GT compared with compliers (P ≤ 0.001). Subjective decisions to extend oral feeding trials or await results of a swallow study were associated with algorithm noncompliance.

Conclusions:

This audit of compliance to a feeding algorithm after pediatric cardiac surgery highlighted variability of practice, including relying on subjective appraisals of feeding skills over objective FRAs. This variability was associated with increased LOS and can be hypothesis-generating for future quality improvement efforts.

Alkaline Phosphatase: A Biomarker of Cardiac Function in Pediatric Patients

Myocardial dysfunction and heart failure are common in pediatric patients with congenital and acquired heart disease. Alkaline phosphatase (AP) has been suggested as a biomarker for myocardial dysfunction after Fontan operation. We hypothesized that pediatric patients with myocardial dysfunction requiring orthotopic heart transplant (OHT) have diminished AP compared to normal. A retrospective review was performed in all patients who underwent OHT at Arkansas Children's Hospital between January 2007 and October 2012. Anatomic diagnoses, therapeutic interventions, and ventricular ejection fraction (EF) were recorded. Z scores for AP levels in the study group were determined by comparing the observed AP levels to age- and gender-matched normative values. T tests were performed to compare the mean AP Z score prior to and after OHT. p values <0.05 were considered statistically significant. During the study period, 124 OHTs were performed. Complete study data were available and analyzed from 71/124 patients (mean age at OHT 3.9 years; 51% female). The mean AP Z score was significantly lower in the study group prior to OHT compared to normal (p < 0.0001). The initiation of ACE inhibitor therapy prior to OHT was associated with a significant increase in AP and the ventricular EF (p < 0.001 for both). Treatment with milrinone was associated with an increase in EF. AP is significantly lower in pediatric patients with myocardial dysfunction prior to OHT compared to normal. AP increases significantly after the initiation of therapies to improve myocardial function. Diminished AP is an indicator of myocardial dysfunction in pediatric patients.

Intracoronary Cardiac Progenitor Cells in Single Ventricle Physiology: The PERSEUS (Cardiac Progenitor Cell Infusion to Treat Univentricular Heart Disease) Randomized Phase 2 Trial

RATIONALE

Patients with single ventricle physiology are at high risk of mortality resulting from ventricular dysfunction. The preliminary results of the phase 1 trial showed that cardiosphere-derived cells (CDCs) may be effective against congenital heart failure.

OBJECTIVE

To determine whether intracoronary delivery of autologous CDCs improves cardiac function in patients with single ventricle physiology.

METHODS AND RESULTS

We conducted a phase 2 randomized controlled study to assign in a 1:1 ratio 41 patients who had single ventricle physiology undergoing stage 2 or 3 palliation to receive intracoronary infusion of CDCs 4 to 9 weeks after surgery or staged reconstruction alone (study A). The primary outcome measure was to assess improvement in cardiac function at 3-month follow-up. Four months after palliation, controls had an alternative option to receive late CDC infusion on request (study B). Secondary outcomes included ventricular function, heart failure status, somatic growth, and health-related quality of life after a 12-month observation. At 3 months, the absolute changes in ventricular function were significantly greater in the CDC-treated group than in the controls (+6.4% [SD, 5.5] versus +1.3% [SD, 3.7]; P=0.003). In study B, a late CDC infusion in 17 controls increased the ventricular function at 3 months compared with that at baseline (38.8% [SD, 7.7] versus 34.8% [SD, 7.4]; P<0.0001). At 1 year, overall CDC infusion was associated with improved ventricular function (41.4% [SD, 6.6] versus 35.0% [SD, 8.2]; P<0.0001) and volumes (P<0.001), somatic growth (P<0.0001) with increased trophic factors production, such as insulin-like growth factor-1 and hepatocyte growth factor, and quality of life, along with a reduced heart failure status (P<0.0001) and cardiac fibrosis (P=0.014) relative to baseline.

CONCLUSIONS

Intracoronary infusion of CDCs after staged palliation favorably affected cardiac function by reverse remodeling in patients with single ventricle physiology. This impact may improve heart failure status, somatic growth, and quality of life in patients and reduce parenting stress for their families.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01829750.

Assessment of Growth 6 Years after the Norwood Procedure

At 6 years of age, patients with hypoplastic left heart syndrome had mean age-adjusted z-scores for weight and height below the normative population, and body mass index was similar to the normative population. Males had the greatest increase in z-scores for body mass index.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00115934.

Interstage somatic growth in children with hypoplastic left heart syndrome after initial palliation with the hybrid procedure

Introduction The hybrid procedure is one mode of initial palliation for hypoplastic left heart syndrome. Subsequently, patients proceed with either the "three-stage" pathway - comprehensive second stage followed by Fontan completion - or the "four-stage" pathway - Norwood procedure, hemi-Fontan, or Fontan completion. In this study, we describe somatic growth patterns observed in the hybrid groups and a comparison primary Norwood group.

METHODS

A retrospective analysis of patients who have undergone hybrid procedure and Fontan completion was performed. Weight-for-age and height-for-age z-scores were recorded at each operation.

RESULTS

We identified 13 hybrid patients - eight in the three-stage pathway and five in the four-stage pathway - and 49 Norwood patients. Weight: three stage: weight decreased from hybrid procedure to comprehensive second stage (-0.4±1.3 versus -2.3±1.4, p<0.01) and then increased to Fontan completion (-0.4±1.5 versus -0.6±1.4, p<0.01); four stage: weight decreased from hybrid procedure to Norwood (-2.0±1.4 versus -3.3±0.9, p=0.06), then stabilised to hemi-Fontan. Weight increased from hemi-Fontan to Fontan completion (-2.7±0.6 versus -1.0±0.7, p=0.01); primary Norwood group: weight decreased from Norwood to hemi-Fontan (p<0.001) and then increased to Fontan completion (p<0.001). Height: height declined from hybrid procedure to Fontan completion in the three-stage group. In the four-stage group, height decreased from hybrid to hemi-Fontan, and then increased to Fontan completion. The Norwood group decreased in height from Norwood to hemi-Fontan, followed by an increase to Fontan completion.

CONCLUSION

In this study, we show that patients undergoing the hybrid procedure have poor weight gain before superior cavopulmonary connection, before returning to baseline by Fontan completion. This study identifies key periods to target poor somatic growth, a risk factor of morbidity and worse neurodevelopmental outcomes.

The Fontan operation: the long-term outlook

PURPOSE OF REVIEW

As perioperative survival following the Fontan procedure has improved and more patients are reaping the benefits of physiologic palliation, the costs of longstanding systemic venous hypertension and the functional limitations of a single ventricle are becoming clearer. Arrhythmias, heart failure, protein-losing enteropathy, hepatic cirrhosis, pulmonary hypertension, and ventricular dysfunction are common in late survivors and result in significant morbidity and mortality. Current research is focused on characterizing late morbidities and developing risk-prediction models for worse outcomes in long-term survivors.

RECENT FINDINGS

Ten-year survival following the Fontan procedure is now 94-98%; however, estimated conditional survival in survivors aged above 18 years is 60% at 40 years of age. Atrial arrhythmias and heart failure are the leading causes of morbidity and mortality. Hypoplastic left heart syndrome, hepatic dysfunction, decreased exercise tolerance, lower quality of life, and markers of neurohormonal activation have been associated with worse outcome. Improvements in exercise tolerance are seen with selective pulmonary vasodilator therapy and exercise training. Heart transplant continues to be an effective therapy for end-stage Fontan failure, and reports of the use of traditional mechanical assist devices and the development of right heart assist devices in the setting of passive venous flow are ongoing.

SUMMARY

Over a generation has passed since the Fontan procedure revolutionized the care of patients with a single ventricle. Data generated from retrospective and prospective observational studies in long-term survivors are identifying patients at risk.