Older age at Fontan completion is associated with reduced lung volumes and increased lung reactance

Lung Function in Fontan Patients Over a Ten-Year Period: Is the Fontan Circulation Impairing Lung Development?

Few studies have investigated how the Fontan circulation affects lung function, and no studies have investigated the development of lung function over longer time in these patients. We aimed to describe the development of lung function in Fontan patients over a 10-year period. Pulmonary function tests (PFT), including spirometry and diffusion capacity for Carbon Monoxide (DLCO) and Nitric Oxide (DLNO), were conducted in a Danish Fontan cohort in 2011 (PFT-I). In 2021, re-investigations were performed (PFT-II). We investigated changes in percent predicted (%pred) lung function from PFT-I to PFT-II. Patients were categorized into a pediatric group (age under 18 at PFT-I) and an adult group (age 18 or older at PFT-I). Out of the 81 patients completing PFT-I, 48 completed PFT-II. In the pediatric group (32 patients), there were significant declines in %pred forced expiratory volume in 1s (99.7 (92.4, 104.4)-89.3 (84.9, 97.2), p < 0,001), forced vital capacity (98.3 (87.8, 106.1)-96.7 (86.7, 100.6), p = 0.008), and alveolar volume (95.5 (89.5, 101.6)-89.5 (79.7, 93.2), p < 0.001). The corresponding measurements remained stable in the adult group. However, the median %pred DLNO significantly declined in the adult group (58.4 (53.3, 63.5)-53.7 (44.1, 57.3), p = 0.005). Over a 10-year period, several lung function parameters declined significantly in the younger Fontan patients, suggesting possible impairments in lung development during growth. The decline in %pred DLNO in the adult patient group indicates deterioration of the membrane component of diffusion capacity, implying that the Fontan circulation might negatively affect the alveolar membrane over time.

O2 pulse slope correlates with stroke volume during exercise in patients with a Fontan circulation

BACKGROUND

Peak oxygen pulse (O2pulse=oxygen consumption/heart rate) is calculated by the product of stroke volume (SV) and oxygen extraction. It has been shown to be reduced in patients with a Fontan circulation. However, in the Fontan population, it may be a poor marker of SV. We propose that the slope of the O2 pulse curve may be more reflective of SV during exercise.

METHODS

We analysed cardiopulmonary exercise test data in 22 subjects with a Fontan circulation (cohort A) and examined the association between peak SV during exercise (aortic flow measured on exercise cardiac MRI), and O2 pulse parameters (absolute O2 pulse and O2 pulse slopes up to anaerobic threshold (AT) and peak exercise). In a separate Fontan cohort (cohort B, n=131), associations between clinical characteristics and O2 pulse kinetics were examined.

RESULTS

In cohort A, peak aortic flow was moderately and significantly associated with O2pulseslopePEAK (r=0.47, p=0.02). However, neither absolute O2pulseAT nor O2pulsePEAK was significantly associated with peak aortic flow. In cohort B, O2pulseslopePEAK and O2pulseslopeAT were not significantly associated with clinical parameters, apart from a weak association with forced vital capacity.

CONCLUSION

The slope of the O2 pulse curve to peak exercise may be more reflective of peak SV in the Fontan population than a single peak O2 pulse value.

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.

Pleural and mediastinal effusions after the extracardiac total cavopulmonary connection: Risk factors and impact on outcome

Background

This study investigated the volume and duration of pleural and mediastinal effusions following extracardiac total cavopulmonary connection, as well as preoperative risk factors and their impact on outcome.

Materials and methods

A total of 210 patients who underwent extracardiac total cavopulmonary connection at our center between 2012 and 2020 were included in this study. Postoperative daily amount of pleural and mediastinal drainage were collected and factors influencing duration and amount of effusions were analyzed. The impact of effusions on adverse events was analyzed.

Results

Median age at extracardiac total cavopulmonary connection was 2.2 (interquartile range, 1.8–2.7) years with median weight of 11.6 (10.7–13.0) kg. Overall duration of drainage after extracardiac total cavopulmonary connection was 9 (6–17) days. The total volume of mediastinal, right pleural, and left pleural drainage was 18.8 (11.9–36.7), 64.4 (27.4–125.9), and 13.6 (0.0–53.5) mL/kg, respectively. Hypoplastic left heart syndrome (p = 0.004) and end-diastolic pressure (p = 0.044) were associated with high volume of drainages, and hypoplastic left heart syndrome (p = 0.007), presence of aortopulmonary collaterals (p = 0.002), and high end-diastolic pressure (p = 0.023) were associated with long duration of drainages. Dextrocardia was associated with higher volume (p &lt; 0.001) and longer duration (p = 0.006) of left pleural drainage. Duration of drainage was associated with adverse events following extracardiac total cavopulmonary connection (p = 0.015).

Conclusion

Volume and duration of pleural and mediastinal effusions following extracardiac total cavopulmonary connection were related with hypoplastic left heart syndrome, aortopulmonary collaterals, and end-diastolic pressure. The duration of drainage for effusions was a risk factor for adverse events after total cavopulmonary connection.