Abstract 4363984: The Andes Cardiac Magnetic Resonance Follow-up of a Fontan Cohort

Mechanical support for the failing single ventricle after Fontan

Management of the bad atrioventricular valve in Fontan…time for a change

Cardiac magnetic resonance (CMR) imaging is the gold standard non-invasive test for the diagnosis of acute myocarditis. Late gadolinium enhancement (LGE) on CMR imaging signifies myocardial fibrosis or scar but information on long-termfollow-up in pediatric patients is limited. The aim of this study is to evaluate the persistence of LGE in follow-up CMR imaging and highlight the need for serially following LGE after acute myocarditis in children. A retrospective review of the CMR images in pediatric patients less than 18years of age at Children's Memorial Hermann Hospital was performed from October 31, 2010, to December 31, 2017. The ages of the patients included in the study ranged from 10 to 17years. Out of 34 subjects, 12 subjects had a follow-up CMR imaging after the initial CMR imaging. Cardiac enzymes and inflammatory markers were elevated in all patients on initial presentation with normalization seen for all patients on follow-up testing. Baseline CMR imaging demonstrated depressed function in 50% of patients (6/12) with recovery of biventricular function seen in all except for one patient. LGE was detected in 10 out of 12 patients on baseline CMR and persisted in all on follow--up CMR imaging. Two patients did not have LGE at baseline CMR and had no evidence of LGE at follow-up CMR. Despite resolution of acute myocardial inflammation, LGE persisted in all of our study subjects. There is neither an agreement on time interval to perform follow-up CMR, nor on duration of follow-up. We recommend large-scale prospective CMR study for long-term follow-up evaluation of children after acute myocarditis.

Introduction: Data on the burden of clinically significant Fontan associated liver disease (FALD) and its relationship to mortality is scant. We performed a retrospective cohort study to assess the incidence of FALD and its association with mortality. Methods: Data source was the Quebec Congenital Heart Disease (CHD) Database, a population-based cohort of over 100,000 CHD patients followed from 1983-2017. Fontan patients surviving longer than 30 days post-Fontan were identified, each were matched to 20 VSD patients on age and sex. The Fontan-VSD cohort were used to assess the association between Fontan and the risk of developing FALD. The VSD cohort served as “Non-exposed to Fontan” group. FALD was defined as at least one hospitalization due to liver disease. Kaplan-Meier curves were used to estimate and compare the cumulative probability of 1) developing FALD between Fontan and VSD patients; and 2) mortality between Fontan patients w/o FALD. Results: A total of 512 Fontan patients and 10,232 VSD patients were included. The cumulative probability of developing FALD at 10 and 25 years of follow-up was higher in Fontan patients (13.0% and 37.1%, respectively), compared to 0.7% and 2.0% for VSD patients respectively (p-value <0.0001-Logrank test). In Fontan patients with FALD, the cumulative probability of mortality by 5 years after the diagnosis of FALD was 12.6%, 11 times higher than the risk in Fontan Patients without FALD (Figure) . Calendar year of Fontan operation was found to be an important predictor of developing FALD. Conclusions: This is the first study documenting the impact of FALD on mortality, using a large cohort with long-term follow up. The findings support the use of well-defined surveillance protocols to identify potential precipitants of FALD before liver disease becomes irreversible.

Background: A previously published randomized clinical trial of cardiac magnetic resonance (CMR) versus routine catheterization in patients with functional single ventricle (SV) prior to Glenn operation (BDG) demonstrated similar short-term post-operative outcomes. We sought to evaluate late outcomes in this cohort to ascertain any long-term effects of this management strategy. Methods: Retrospective review of enrolled patients through most recent follow-up. Results: Follow-up was available on all 82 patients in the original cohort, median age 6.5 years at most recent follow-up. Of these, 76 (93%) underwent Fontan operation; 2 died prior to Fontan. Baseline demographics, anatomic factors, and age at BDG did not differ between those randomized to CMR versus catheterization. Although CMR patients were slightly younger at Fontan operation (2.4 vs 2.7 years, p=0.02), baseline weight, body surface area, and oxygen saturation at time of Fontan were similar. Echocardiographic data prior to Fontan were similar, with 2 patients in each group having ≥ moderate ventricular dysfunction, and only 1 patient with ≥ moderate atrioventricular valve regurgitation. Catheterizations were performed in all patients prior to Fontan (n=76). Although age at catheterization was younger in the CMR group (2.3 vs 2.7 years, p=0.003), hemodynamic parameters were not significantly different, including pulmonary vascular resistance, mean pulmonary artery, atrial, and ventricular end-diastolic pressures. Prevalence of coarctation and pulmonary artery stenoses were similar. Patients in the CMR group had a similar rates of transcatheter interventions (71 vs. 79%, p=0.6) including similar rate of coil occlusion of aorto-pulmonary collaterals (66 vs. 61%, p=0.29). At time of Fontan, short-term complications, hospital length of stay, and the percent of patients meeting a 5-part definition of a successful Fontan operation were not significantly different (71 vs 55%, p=0.23). Conclusions: The CMR and catheterization groups had equivalent clinical and hemodynamic profiles prior to Fontan, and similar post-Fontan outcomes at a median follow-up of 6 years post BDG. For selected patients, a pre-BDG evaluation with CMR is an acceptable alternative to catheterization.

Funding Acknowledgements Type of funding sources: None. Background Multiparametric cardiac magnetic resonance (CMR) evaluation with modified Lake Louise criteria (mLLC) is the gold standard non-invasive test for the diagnosis of acute myocarditis. Although CMR in the follow-up may inform of edema resolution and myocardial fibrosis there is a lack of consensus on the optimal time interval to perform it and the clinical and prognostic differences between patients with complete resolution and those who present late gadolinium enhancement (LGE) persistence. Purpose To describe the clinical profile, CMR findings, early CMR follow-up and clinical events in patients with acute myocarditis focusing on the differences between patients who present complete LGE resolution versus patients with LGE persistence. Methods All patients who underwent a CMR for a suspected myocarditis during a period of 1 year from June 2021 to June 2022 were retrospectively evaluated. Those with a confirmed myocarditis by mLLC and a follow-up CMR were included. Electronic medical records were analyzed to collect data on baseline clinical variables, CMR features and follow-up events. Follow-up CMR was performed on follow-up based on clinician’s criteria. Results A total of 27 patients fulfilled mLLC for myocarditis during the period of study and had a follow-up CMR. The mean time to first CMR control was 186 +/- 95 days (6,2 months). Of those 23 (85.2%) presented persistent LGE enhancement and 4 of them presented a complete resolution of LGE. There were no statistically significant differences between groups although patients with complete LGE resolution tend to be younger. There were no differences between groups in terms of LVEF and RVEF. Patients with persistent LGE in the follow-up tend to have higher edema and LGE extension during the acute myocarditis episode, being the LGE difference statistically significant. In the follow up CMR almost all patients presented edema resolution and although the majority of patients (85.2%) presented LGE persistence they presented a trend to a decrease of affected segments (4.4 to 3.1 after mean time of 6 months). There were no differences in clinical events between groups in terms of death, admissions, ventricular arrhythmias and new episodes of myocarditis, patients with persistent LGE tend to have more visits for unresolved chest pain. Conclusions The majority of patients with a confirmed acute myocarditis had edema resolution and LGE persistence after 6 months. There were no differences in clinical events during follow-up. Follow up CMR before 6 months can prove resolving edema but LGE persistance is common. Further studies are needed to define the optimal interval to perform CMR after the index event.

Are we getting closer to identifying the best follow-up and management after Fontan completion?

Adult patients with univentricular physiology after Fontan palliation: prevalence and percutaneous closure of veno-venous collaterals

Anesthetic Management in Parturients With Fontan Physiology

Sinus rhythm restores ventricular function in patients with cardiomyopathy and no late gadolinium enhancement on cardiac magnetic resonance imaging who undergo catheter ablation for atrial fibrillation

Cardiac magnetic resonance (CMR) imaging is a main diagnostic tool in the follow-up of Fontan patients. However, the value of serial CMR for the evaluation of Fontan attrition is unknown. The aim of this prospective study of serial CMR is to describe the analysis of time-dependent evolution of blood flow distribution, ventricular volumes, and function in patients after Fontan completion. In this prospective single-centre study, between 2012 and 2022, 281 CMR examinations were performed in 88 Fontan patients with distribution of blood flows, measurements of ventricular volumes, and ejection fraction. Linear mixed model regression for repeated measurements was used to analyse changes of measurements across serial CMR examinations. During a time interval of 10 years, the median number of CMR per patient was 3 (range 1-5). Indexed flow of ascending aorta, caval veins, and pulmonary arteries decreased significantly across serial CMR examinations. Although a decrease of mean indexed aortic flow (3.03 ± 0.10 L/min/m2 at first CMR vs. 2.36 ± 0.14 L/min/m2 at fourth CMR, P < 0.001) was observed, ejection fraction did not decline (50 ± 1% at first CMR vs. 54 ± 2% at fourth CMR, P = 0.070). Indexed ventricular volumes did not differ significantly across serial CMR examinations. The decrease of indexed aortic and cavopulmonary flows reflects the attrition of univentricular circulation and can be detected by means of serial CMR. Ventricular systolic dysfunction does not contribute significantly to this attrition. In order to detect significant change of indexed aortic flow, we recommend performing serial CMR as routine practice in the Fontan population.

Background: In patients with Fontan palliation, ejection fraction (EF) and global longitudinal strain (GLS) are associated with exercise capacity and survival. We investigated the associations between EF and GLS on echo and 4-dimensional phase contrast (4DF) cardiac MRI (CMR) parameters, including percent collateral flow (%CF). Methods: Single-center, retrospective review of patients post-Fontan who underwent CMR in 2023 and echocardiogram within 1 year. GLS was measured on echo in the apical 4-chamber view. %CF and regurgitant fractions were measured using 4DF. Indexed ventricular end-diastolic (iEDV) and end-systolic (iESV) volumes and EF were also measured. Descriptive data are presented as median (Q1 – Q3). Spearman correlation was used to compare continuous variables. Linear regression analysis was performed to quantify the relationship between GLS and predictor variables. Results: Thirty-two patients met inclusion and exclusion criteria. Of the 32 patients in the study cohort, 40.6% were females and 75% had a systemic right ventricle. Median age at CMR was 16.6 (12.1 – 20.0) years, median duration between echo and CMR was 49.5 (2 – 95) days. There was moderate to high correlation between GLS and iEDV, GLS and iESV, and GLS and EF. There was no significant association between %CF and GLS, and %CF and EF (table). Moderate or severe valve regurgitation was present in 12 (38%) patients. When excluding these patients, GLS had a moderate correlation with %CF, EF, iEDV, and iESV (table). Multivariable linear regression analysis was performed to test if a combination of CMR parameters could best predict GLS. EF and %CF, remained associated with GLS. The overall regression was statistically significant (R2 = 0.5, F(2, 17) = 8.75, p = .002). Conclusion: In this pilot cohort of Fontan patients, worse (less negative) GLS% was associated with larger iEDV and iESV. There was also an association between GLS and higher %CF when excluding patients with more than mild valve regurgitation. This relationship may be mediated by volume load of collateral flow on the heart. These data may provide evidence of an early impact of %CF burden and resultant volume overload on ventricular contractility.

How Good Are Cardiologists at Predicting Major Adverse Events in Fontan Patients?

The effects of pregnancy in subjects with repaired tetralogy of Fallot

Background: The physiology of the Fontan circulation is consistent with chronic heart failure, characterized by elevated central venous pressure and reduced cardiac output. In adults with conventional heart failure, iron deficiency is common and is associated with increased morbidity and mortality. However, data is lacking on the prevalence of iron deficiency and its relationship with cardiovascular outcomes in pediatric patients with Fontan circulation. Aim: To characterize the relationship between iron profiles and measures of cardiovascular health in pediatric patients with Fontan circulation. Hypothesis: Iron deficiency is associated with worse measures of cardiovascular health. Methods: Cross-sectional study comprising patients with Fontan circulation who had iron labs measured from 2010 - 2024 at a single urban center. Exclusion criteria were hematologic disease other than iron deficiency, acute bleeding, and acute illness other than heart failure. Cardiovascular health was evaluated with NYHA or Ross class, echocardiogram, and cardiac MRI. Kruskal-Wallis tests and linear regression were used to analyze associations between iron labs and measures of cardiovascular health. Indexed oxygen delivery (iDO2) was calculated from cardiac index measured by cardiac MRI, pulse oximetry, and hemoglobin. Results: 100 patients (mean 12.5±4.7 years, 46% female) were included. Iron deficiency was present in 45% or 51% based on conventional criteria of transferrin saturation (TSAT) &lt;20% or ferritin &lt;30 ng/mL, and 94% based on suggested criteria for heart failure (ferritin &lt;100 ng/mL or ferritin 100-299 ng/mL and TSAT &lt;20%). TSAT was significantly lower in patients with NYHA or Ross class III/IV vs. I/II symptoms (median 14% [IQR 10-19%] vs. 20% [15-25.5%], p=0.014) and in those with history of ≥ moderate vs. &lt; moderate atrioventricular valve regurgitation (median 12.5% [10-21.8%] vs. 20.5% [15-24.5%], p=0.049). Ferritin trended toward being significantly lower in those with ≥ moderate vs. &lt; moderate ventricular dysfunction (median 19.5 [11-34] vs. 30.5 [18-56], p=0.095). Among patients with hemoglobin &lt;15 g/dL, TSAT strongly correlated with iDO2 (R2=0.495, p=0.034). Conclusion: Iron deficiency is common and is associated with both worse heart failure symptoms and objective measures of cardiovascular health in pediatric patients with Fontan circulation. Interventions to improve iron stores offer promising avenues for mitigating heart failure risk and improving outcomes.