Patients with Single-Ventricle Physiology over the Age of 40 Years

Noninvasive Advanced Cardiovascular Magnetic Resonance-Derived Fontan Hemodynamics Are Associated With Reduced Kidney Function But Not Albuminuria

BACKGROUND

Kidney disease is the most important predictor of death in patients with a Fontan circulation, yet its clinical and hemodynamic correlates have not been well established.

METHODS AND RESULTS

A total of 53 ambulatory patients with a Fontan circulation (median age, 16.2 years, 52.8% male patients) underwent advanced cardiovascular magnetic resonance assessment, including 4-dimensional flow imaging and computational fluid dynamics. Estimated glomerular filtration rate (eGFR) <90 mL/min per 1.73 m2 was observed in 20.8% and albumin-to-creatinine ratio >3 mg/mmol in 39.6%. The average eGFR decline rate was -1.83 mL/min per 1.73 m2 per year (95% CI, -2.67 to -0.99; P<0.001). Lower eGFR was associated with older age, larger body surface area at examination, longer time since Fontan procedure, and lower systemic ventricular ejection fraction. Higher albumin-to-creatinine ratio was associated with absence of fenestration at the Fontan operation, and older age and lower systemic ventricular ejection fraction at the assessment. Lower cross-sectional area of the Fontan conduit indexed to flow (r=0.32, P=0.038), higher inferior vena cava-conduit velocity mismatch factor (r=-0.35, P=0.022), higher kinetic energy indexed to flow in the total cavopulmonary connection (r=-0.59, P=0.005), and higher total cavopulmonary connection resistance (r=-0.42, P=0.005 at rest; r=-0.43, P=0.004 during exercise) were all associated with lower eGFR but not with albuminuria.

CONCLUSIONS

Kidney dysfunction and albuminuria are common among clinically well adolescents and young adults with a Fontan circulation. Advanced cardiovascular magnetic resonance-derived metrics indicative of declining Fontan hemodynamics are associated with eGFR and might serve as targets to improve kidney health. Albuminuria might be driven by other factors that need further investigation.

Body plethysmography - additional information on exercise capacity in patients with congenital heart disease?

AIMS

In each cardiopulmonary exercise test (CPET), resting spirometry is performed in advance. In patients with a congenital heart defect (CHD), lung volumes are often impaired. This study investigates correlations between lung volumes and CPET parameters and determines, whether body plethysmography provides substantial additional information for these patients.

METHODS

Data from 102 patients (23.8 ± 10.4 years of age, 39 female) with various forms of CHD were examined from April 2018 to October 2022. All patients underwent spirometry (measuring forced vital capacity, FVC and forced expiratory volume in 1 s, FEV1), body plethysmography (measuring total lung capacity, TLC) and an exhausting CPET. Data is presented as the median and interquartile range (z-scores) and correlated with Spearman's rho.

RESULTS

Fifty-five% of all patients had normal results in lung function and 45% had normal peak oxygen uptake (≥ 80% predicted in peak VO2). Patients with impaired lung function were significantly more likely to have low exercise capacity (Fisher's exact test: p = 0.028). FVC z-values and %predicted peak VO2 (r = 0.365, p < 0.001) correlated significantly as well as FEV1_z and %predicted peak VO2 (r = 0.320, p = 0.001), and TLC z-values and %predicted peak VO2 (r = 0.249, p = 0.012). No correlation was found between FEV1/FVC z-values and %predicted peak VO2 (r = -0.043, p = 0.670).

CONCLUSION

Spirometry and exercise capacity positively correlate, also in CHD patients. However, body plethysmography does not provide additional or improved prediction and is therefore only recommended in noteworthy results in spirometry to exclude further lung co-morbidities.

Long-Term Renal Involvement in Association with Fontan Circulation

Multiorgan dysfunction is a concern of Fontan patients. To clarify the pathophysiology of Fontan nephropathy, we characterize renal disease in the long-term observational study. Medical records of 128 consecutive Fontan patients [median age: 22 (range 15-37) years old] treated between 2009 and 2018 were reviewed to investigate the incidence of nephropathy and its association with other clinical variables. Thirty-seven patients (29%) showed proteinuria (n = 34) or < 90 mL/min/1.73 m2 of estimated glomerular filtration rate (eGFR) (n = 7), including 4 overlapping cases. Ninety-six patients (75%) had liver dysfunction (Forns index > 4.21). Patients with proteinuria received the Fontan procedure at an older age [78 (26-194) vs. 56 (8-292) months old, p = 0.02] and had a higher cardiac index [3.11 (1.49-6.35) vs. 2.71 (1.40-4.95) L/min/m2, p = 0.02], central venous pressure [12 (7-19) vs. 9 (5-19) mmHg, p < 0.001], and proportion with > 4.21 of Forns index (88% vs. 70%, p = 0.04) than those without proteinuria. The mean renal perfusion pressure was lower in patients with a reduced eGFR than those without it [55 (44-65) vs. 65 (45-102) mmHg, p = 0.03], but no other variables differed significantly. A multivariable analysis revealed that proteinuria was associated with an increased cardiac index (unit odds ratio 2.02, 95% confidence interval 1.12-3.65, p = 0.02). Seven patients with severe proteinuria had a lower oxygen saturation than those with no or mild proteinuria (p = 0.01, 0.03). Proteinuria or a decreased eGFR differentially occurred in approximately 30% of Fontan patients. Suboptimal Fontan circulation may contribute to the development of proteinuria and reduced eGFR.

Impact of pulsatile pulmonary blood flow on cardiopulmonary exercise performance after the Fontan procedure

Objective

To evaluate the exercise capacity in patients following Fontan-Kreutzer, Fontan-Björk, and total cavopulmonary connection (TCPC).

Methods

Patients who performed exercise capacity tests at least once after the Fontan procedure between 1979 and 2007 were included. Patients after Fontan-Björk procedure were divided into 2 groups according to the pulmonary blood flow (PBF) pattern: patients with pulsatile PBF and those without. Peak oxygen uptake (VO2) was measured and percent-predicted VO2 was calculated.

Results

A total of 227 patients were nominated. The types of Fontan procedure included Fontan-Kreutzer in 48 (21.1%) patients, Fontan-Björk in 38 (16.7%); 11 (4.8%) with pulsatile PBF and 27 (11.9%) without pulsatile PBF; and TCPC in 141 (62.1%). Median age at the Fontan procedure was 4.5 years (interquartile range, 2.1-8.2 years). A total of 978 cardiopulmonary exercise tests were performed at median follow-up of 17.7 years (interquartile range, 11.3-23.4 years) postoperatively. Analysis using linear mixed-effects models demonstrated that percent-predicted VO2 was greater in patients with pulsatile PBF after Fontan-Björk compared with patients after other types of Fontan procedure (P < .001). The same results were obtained when the longitudinal percent predicted VO2 was performed using only patients with tricuspid atresia and double inlet left ventricle (P < .001).

Conclusions

Among long-term survivors after various types of Fontan procedures, patients with pulsatile PBF after the Fontan-Björk procedure demonstrated better exercise performance compared to those after TCPC, those after the Fontan-Kreutzer procedure, and those after the Fontan-Björk procedure with non-pulsatile PBF. The results implicate the importance of pulsatile PBF to maintain the Fontan circulation.

High Time to Consider the Role of Thyroid Function in Single Ventricle Heart Disease

Herein we respond to the controversial United States Food and Drug Administration (FDA) recommendation to perform thyroid function testing in children up to 3 years of age within 3 weeks of exposure to iodinated contrast media (ICM). Considering the many effects of thyroid hormone on the cardiovascular system, the increased risk of thyroid disease in patients with congenital heart disease, the hemodynamic consequences of the Fontan circulation on the thyroid gland, and the potential clinical significance of subclinical hypothyroidism, we share our perspective that the cardiovascular effects of thyroid hormone may carry more influence for patients with single ventricle heart disease. In our opinion, the FDA statement prompts us to consider routine thyroid hormone surveillance testing in the long-term management of patients with single ventricle heart disease.

Abnormalities in pulmonary function and volumes in patients with CHD: a systematic review

BACKGROUND

Lung function and cardiac function are naturally correlated by sharing the thoracic cage and handling the whole cardiac output sequentially. However, lung function studies are rare in patients with CHD, although results worthy of investigation could be expected. This review summarises existing studies with the lung function parameters (spirometry and body plethysmography) in CHD patients during the last decade.

METHODS

A systematic review was performed in the relevant database (PubMed, Cochrane, and Scopus) in studies including paediatric and adult patients with CHD where lung parameters (spirometry, body plethysmography) were investigated from January 2010 to December 2020. Two independent reviewers evaluated the studies according to the Study Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies of the National Heart, Lung, and Blood Institute.

RESULTS

Eight studies investigated patients with Fontan palliation including 704 patients (306 female). Four studies included patients after repaired tetralogy of Fallot examining 219 patients (103 female), with one study using double. Further six studies included 3208 (1324 female) children and adults with various CHDs. Overall, four studies were categorised as "good", ten as "fair", and four as "poor". While the measurements were consistently standardised, references to calculate %predicted differed substantially across all studies. All evaluated studies showed reduced forced vital capacity in the majority of CHD patients.

CONCLUSIONS

Many CHD patients have a reduced forced vital capacity independent of their underlying defect. Spirometry should not only follow a standardised measure according to ATS (update 2019) but also stick to the 2012 GLI reference values.

Prevalence and Treatment Outcomes of Arrhythmias in Patients with Single Ventricle Physiology over the Age of 40 Years

Background: Arrhythmias are a well known complication in patients with single ventricle physiology (SVP). However, there is still a lack of data regarding arrhythmias in older patients. The aim of this study was to analyze arrhythmia type and frequency, treatment and recurrence rates in patients with SVP over the age of 40 years. Methods: Data was obtained retrospectively from clinical records. All patients > 40 years with SVP with arrhythmias between 2005 and 2018 were included in the study. Treatment was classified as medical, interventional (electrophysiological studies (EPS) in combination with catheter ablation) or direct current cardioversion (DCCV). Results: Altogether, 29 patients (11 female; mean 47.5 ± 4.6 years) with 85 arrhythmia episodes were identified. The median follow-up time was 6.3 years. Cavo-tricuspid (CTI) and non-CTI related intra-atrial reentrant tachycardia (IART) and atrial fibrillation (AF) were most common (48.2% and 37.6%, respectively). In total, 18 EPS/ablations were performed in 9 patients and 52 DCCVs in 20 patients. Acute success was 98% for DCCV and 72.2% for EPS/ablation. Recurrence rate was high (70% for DCCV and 55% for EPS). AT recurrences occurred after a median of 8 and 2.5 months, respectively. On multivariate analyses, age was the only risk factor for arrhythmia recurrence (HR 0.58, 95% C.I. 0.43−0.78, p < 0.0001). Pacemaker implantation was necessary in seven patients (AV block n = 4, sinus node dysfunction n = 3) and one patient received an ICD for secondary prophylaxis. Sudden death occurred in three patients. Conclusions: The most common arrhythmias in patients with SVP > 40 years are IART and AF. Arrhythmia recurrence following EPS or DCCV is frequent. Older age is an independent risk factor for arrhythmia recurrence.

Fontan Circulation Associated Organ Abnormalities Beyond the Heart, Lungs, Liver, and Gut: A Systematic Review

Introduction

Patients with a Fontan circulation are at risk for sequelae of Fontan physiology during follow-up. Fontan physiology affects all organ systems and an overview of end-organ damage is needed.

Methods

We performed a systematic review of abnormalities in multiple organ systems for patients with a longstanding Fontan circulation. We searched online databases for articles describing abnormalities in multiple organ systems. Cardio-pulmonary abnormalities, protein losing enteropathy, and Fontan associated liver disease have already extensively been described and were excluded from this systematic review.

Results

Our search returned 5,704 unique articles. After screening, we found 111 articles relating to multiple organ systems. We found abnormalities in, among others, the nervous system, pituitary, kidneys, and musculoskeletal system. Pituitary edema—relating to the unique pituitary vasculature- may affect the thyroid axis. Renal dysfunction is common. Creatinine based renal function estimates may be inappropriate due to myopenia. Both lean muscle mass and bone mineral density are decreased. These abnormalities in multiple organ systems may be related to Fontan physiology, cyanosis, iatrogenic factors, or lifestyle.

Conclusions

Health care providers should be vigilant for hypothyroidism, visual or hearing deficits, and sleep disordered breathing in Fontan patients. We recommend including cystatin C for assessment of renal function. This review may aid health care providers and guide future research.

Systematic Review Registration:https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021232461, PROSPERO, identifier: CRD42021232461.

Complete Atrioventricular Septal Defects after the Age of 40 Years

Background: There is an increasing number of adults with complete atrioventricular septal defects (cAVSD). However, data regarding older adults are lacking. The aim of this study is to analyze the outcome of adults with cAVSD over the age of 40 years. Methods: Patients with cAVSD who were ≥40 years of age at any point between 2005 until 2018 were included retrospectively. Data were retrieved from hospital records. The primary endpoint was a combination of death from any cause and unplanned hospitalizations due to cardiac reasons. Results: 43 patients (60.5% female, mean age 43.7 ± 6.0 years, genetic syndrome 58.1%) were included. At begin of follow-up, the majority of patients (n = 41, 95.3%) was in New York Heart Association (NYHA) class I or II. Out of the whole cohort 26 (60.5%) had undergone cardiac surgery. At baseline, at least one extracardiac comorbidity was present in 40 patients (93.0%). Median follow-up was 1.7 years (IQR 0.3–4.6). On univariate Cox analysis, NYHA class at begin of follow-up (hazard ratio: 1.96, CI 95%: 1.04–3.72, p < 0.05) was the only predictor for the primary endpoint. Conclusions: Significant morbidity and mortality is present in cAVSD patients over the age of 40 years. NYHA class is predictive for a worse outcome.