The Fontan Udenafil Exercise Longitudinal Trial: Subgroup Analysis

The Pediatric Heart Network's Fontan Udenafil Exercise Longitudinal (FUEL) Trial (Mezzion Pharma Co. Ltd., NCT02741115) demonstrated improvements in some measures of exercise capacity and in the myocardial performance index following 6 months of treatment with udenafil (87.5 mg twice daily). In this post hoc analysis, we evaluate whether subgroups within the population experienced a differential effect on exercise performance in response to treatment. The effect of udenafil on exercise was evaluated within subgroups defined by baseline characteristics, including peak oxygen consumption (VO2), serum brain-type natriuretic peptide level, weight, race, gender, and ventricular morphology. Differences among subgroups were evaluated using ANCOVA modeling with fixed factors for treatment arm and subgroup and the interaction between treatment arm and subgroup. Within-subgroup analyses demonstrated trends toward quantitative improvements in peak VO2, work rate at the ventilatory anaerobic threshold (VAT), VO2 at VAT, and ventilatory efficiency (VE/VCO2) for those randomized to udenafil compared to placebo in nearly all subgroups. There was no identified differential response to udenafil based on baseline peak VO2, baseline BNP level, weight, race and ethnicity, gender, or ventricular morphology, although participants in the lowest tertile of baseline peak VO2 trended toward larger improvements. The absence of a differential response across subgroups in response to treatment with udenafil suggests that the treatment benefit may not be restricted to specific sub-populations. Further work is warranted to confirm the potential benefit of udenafil and to evaluate the long-term tolerability and safety of treatment and to determine the impact of udenafil on the development of other morbidities related to the Fontan circulation.Trial Registration NCT0274115.

Extracorporeal Life Support for Cardiogenic Shock in Adult Congenital Heart Disease-An ELSO Registry Analysis

There are minimal data on the use of venoarterial extracorporeal membrane life support (VA-ECLS) in adult congenital heart disease (ACHD) patients presenting with cardiogenic shock (CS). This study sought to describe the population of ACHD patients with CS who received VA-ECLS in the Extracorporeal Life Support Organization (ELSO) Registry. This was a retrospective analysis of adult patients with diagnoses of ACHD and CS in ELSO from 2009-2021. Anatomic complexity was categorized using the American College of Cardiology/American Heart Association 2018 guidelines. We described patient characteristics, complications, and outcomes, as well as trends in mortality and VA-ECLS utilization. Of 528 patients who met inclusion criteria, there were 32 patients with high-complexity anatomy, 196 with moderate-complexity anatomy, and 300 with low-complexity anatomy. The median age was 59.6 years (interquartile range, 45.8-68.2). The number of VA-ECLS implants increased from five implants in 2010 to 81 implants in 2021. Overall mortality was 58.3% and decreased year-by-year (β= -2.03 [95% confidence interval, -3.36 to -0.70], p = 0.007). Six patients (1.1%) were bridged to heart transplantation and 21 (4.0%) to durable ventricular assist device. Complications included cardiac arrhythmia/tamponade (21.6%), surgical site bleeding (17.6%), cannula site bleeding (11.4%), limb ischemia (7.4%), and stroke (8.7%). Utilization of VA-ECLS for CS in ACHD patients has increased over time with a trend toward improvement in survival to discharge.

A Multisite Retrospective Review of Direct Oral Anticoagulants Compared to Warfarin in Adult Fontan Patients

PURPOSE

Direct oral anticoagulants (DOACs) are not recommended in adult Fontan patients (Level of Evidence C). We hypothesized that DOACs are comparable to warfarin and do not increase thrombotic and embolic complications (TEs) or clinically significant bleeds.

METHODS

We reviewed the medical records of adult Fontan patients on DOACs or warfarin at three major medical centers. We identified 130 patients: 48 on DOACs and 107 on warfarin. In total, they were treated for 810 months on DOACs and 5637 months on warfarin.

RESULTS

The incidence of TEs in patients on DOACs compared to those on warfarin was not increased in a statistically significant way (hazard ratio [HR] 1.7 and p value 0.431). Similarly, the incidence of nonmajor and major bleeds in patients on DOACs compared to those on warfarin was also not increased in a statistically significant way (HR for nonmajor bleeds in DOAC patients was 2.8 with a p value of 0.167 and the HR for major bleeds was 2.0 with a p value 0.267). In multivariate analysis, congestive heart failure (CHF) was a risk factor for TEs across both groups (odds ratio [OR] = 4.8, 95% confidence interval [CI] = 1.3-17.6) and bleed history was a risk factor for clinically significant bleeds (OR = 6.8, 95% CI = 2.7-17.2).

CONCLUSION

In this small, retrospective multicenter study, the use of DOACs did not increase the risk of TEs or clinically significant bleeds compared to warfarin in a statistically significant way.

Society for Cardiovascular Magnetic Resonance 2020 Case of the Week series

The Society for Cardiovascular Magnetic Resonance (SCMR) is an international society focused on the research, education, and clinical application of cardiovascular magnetic resonance (CMR). Case of the week is a case series hosted on the SCMR website ( https://www.scmr.org ) that demonstrates the utility and importance of CMR in the clinical diagnosis and management of cardiovascular disease. Each case consists of the clinical presentation and a discussion of the condition and the role of CMR in diagnosis and guiding clinical management. The cases are all instructive and helpful in the approach to patient management. We present a digital archive of the 2020 Case of the Week series of 11 cases as a means of further enhancing the education of those interested in CMR and as a means of more readily identifying these cases using a PubMed or similar search engine.

Sizing Up Fontan Failure: Association with Increasing Weight in Adulthood

Obesity has become increasingly recognized in adults with Fontan palliation, yet the relationship between weight changes in adulthood and Fontan failure is not clearly defined. We hypothesize that increasing weight in adulthood among Fontan patients is associated with the development of Fontan failure. Single-center data from adults with Fontan palliation who were not in Fontan failure at their first clinic visit in adulthood and who received ongoing care were retrospectively collected. Fontan failure was defined as death, transplant, diagnosis of protein losing enteropathy, predicted peak VO₂ less than 50%, or new loop diuretic requirement. Anthropometric data including weight and BMI were collected. Change in weight was compared between those that developed Fontan failure, and those that remained failure-free. To estimate the association between weight change during adulthood and the risk of developing Fontan failure, a survival analysis using multiple Cox's proportional hazards regression model was performed. Overall, 104 patients were included in the analysis. Those that developed Fontan failure had a larger associated median weight gain than those who remained failure-free (7.8 kg vs. 4.9 kg, respectively; p = 0.011). In multivariable Cox regression analysis, increased weight during adulthood was associated with increased likelihood of developing Fontan failure (HR 1.36; CI 1.07-1.73; p = 0.011). Weight gain in adulthood is associated with the development of Fontan failure.

COVID-19 in Adults With Congenital Heart Disease

Background

Adults with congenital heart disease (CHD) have been considered potentially high risk for novel coronavirus disease-19 (COVID-19) mortality or other complications.

Objectives

This study sought to define the impact of COVID-19 in adults with CHD and to identify risk factors associated with adverse outcomes.

Methods

Adults (age 18 years or older) with CHD and with confirmed or clinically suspected COVID-19 were included from CHD centers worldwide. Data collection included anatomic diagnosis and subsequent interventions, comorbidities, medications, echocardiographic findings, presenting symptoms, course of illness, and outcomes. Predictors of death or severe infection were determined.

Results

From 58 adult CHD centers, the study included 1,044 infected patients (age: 35.1 ± 13.0 years; range 18 to 86 years; 51% women), 87% of whom had laboratory-confirmed coronavirus infection. The cohort included 118 (11%) patients with single ventricle and/or Fontan physiology, 87 (8%) patients with cyanosis, and 73 (7%) patients with pulmonary hypertension. There were 24 COVID-related deaths (case/fatality: 2.3%; 95% confidence interval: 1.4% to 3.2%). Factors associated with death included male sex, diabetes, cyanosis, pulmonary hypertension, renal insufficiency, and previous hospital admission for heart failure. Worse physiological stage was associated with mortality (p = 0.001), whereas anatomic complexity or defect group were not.

Conclusions

COVID-19 mortality in adults with CHD is commensurate with the general population. The most vulnerable patients are those with worse physiological stage, such as cyanosis and pulmonary hypertension, whereas anatomic complexity does not appear to predict infection severity.

No survival benefit associated with waiting for non-lung donor heart transplants for adult recipients with congenital heart disease

BACKGROUND

Adults with congenital heart disease (CHD) awaiting heart transplant (HT) have higher mortality and waitlist removal due to clinical deterioration than those without CHD. The selective use of non-lung donors (NLD) to recover donor pulmonary vasculature to assist in graft implantation may be a contributing factor and is supported by consensus statements despite the recent use of pericardium or graft material as an alternative in pulmonary vascular reconstruction. The impact of selecting NLD for CHD recipients on wait time and mortality has not been evaluated.

METHODS/RESULTS

In the United Network for Organ Sharing (UNOS) Registry, 1271 HT recipients age ≥ 18 with CHD were identified between 1987 and 2016, 68% of which had NLDs. Prior to HT, NLD recipients were significantly less likely to be listed UNOS Status 1A, require mechanical ventilation, or intra-aortic balloon pump support. There was no difference in mean waitlist time (254 vs. 278 days, p = .31), 1-year mortality (82% vs. 80%, p = .81; adjusted odds ratio 1.32, 95% confidence interval [CI] 0.96-1.83, p = .08), or overall mortality (adjusted hazard ratio 1.08, 95% CI 0.86-1.36, p = .48) between recipients from NLD and concomitant lung donors.

CONCLUSIONS

Adult CHD patients who are less critically ill or listed at a lower status are more likely to receive HT from NLD. There is no overall mortality benefit associated with this practice. While specific cases may necessitate waiting for NLD, programs need to re-evaluate whether this should remain a more widespread practice among CHD patients.

HeartMate 3 in a ccTGA patient

A 49-year-old female with congenitally corrected (or levo-) transposition of the great arteries complicated by nonischemic cardiomyopathy presented for worsening heart failure despite guideline-directed medical therapy and was found to be in cardiogenic shock. She successfully underwent ventricular assist device placement with a HeartMate III to her systemic right ventricle as a bridge to transplantation.

Results of the FUEL Trial

BACKGROUND

The Fontan operation creates a total cavopulmonary connection, a circulation in which the importance of pulmonary vascular resistance is magnified. Over time, this circulation leads to deterioration of cardiovascular efficiency associated with a decline in exercise performance. Rigorous clinical trials aimed at improving physiology and guiding pharmacotherapy are lacking.

METHODS

The FUEL trial (Fontan Udenafil Exercise Longitudinal) was a phase III clinical trial conducted at 30 centers. Participants were randomly assigned udenafil, 87.5 mg twice daily, or placebo in a 1:1 ratio. The primary outcome was the between-group difference in change in oxygen consumption at peak exercise. Secondary outcomes included between-group differences in changes in submaximal exercise at the ventilatory anaerobic threshold, the myocardial performance index, the natural log of the reactive hyperemia index, and serum brain-type natriuretic peptide.

RESULTS

Between 2017 and 2019, 30 clinical sites in North America and the Republic of Korea randomly assigned 400 participants with Fontan physiology. The mean age at randomization was 15.5±2 years; 60% of participants were male, and 81% were white. All 400 participants were included in the primary analysis with imputation of the 26-week end point for 21 participants with missing data (11 randomly assigned to udenafil and 10 to placebo). Among randomly assigned participants, peak oxygen consumption increased by 44±245 mL/min (2.8%) in the udenafil group and declined by 3.7±228 mL/min (-0.2%) in the placebo group (P=0.071). Analysis at ventilatory anaerobic threshold demonstrated improvements in the udenafil group versus the placebo group in oxygen consumption (+33±185 [3.2%] versus -9±193 [-0.9%] mL/min, P=0.012), ventilatory equivalents of carbon dioxide (-0.8 versus -0.06, P=0.014), and work rate (+3.8 versus +0.34 W, P=0.021). There was no difference in change of myocardial performance index, the natural log of the reactive hyperemia index, or serum brain-type natriuretic peptide level.

CONCLUSIONS

In the FUEL trial, treatment with udenafil (87.5 mg twice daily) was not associated with an improvement in oxygen consumption at peak exercise but was associated with improvements in multiple measures of exercise performance at the ventilatory anaerobic threshold.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT02741115.

More than the heart: Hepatic, renal, and cardiac dysfunction in adult Fontan patients

SETTING

Fontan-associated liver disease universally affects adults with single ventricle heart disease. Chronic kidney disease is also highly prevalent in adult Fontan patients. In this study, we evaluate the relationship of Fontan hemodynamics invasively and noninvasively with extra-cardiac dysfunction as measured by MELD and MELD-XI.

OBJECTIVE

We hypothesize that invasive and noninvasive measures of Fontan circuit congestion and ventricular dysfunction are associated with increased MELD and MELD-XI scores.

DESIGN

Single-center data from adults with Fontan palliation who had ongoing care, including cardiac catheterization, were retrospectively collected. Hemodynamic data from cardiac catheterization and echocardiographic assessment of ventricular and atrioventricular valve function were tested for association with serum creatinine, MELD, and MELD-XI. Linear regression was used to perform multivariable analysis in the echocardiogram cohort.

RESULTS

Fifty-seven patients had congruent lab and catheterization data for analysis. Sixty-three and sixty-nine patients had congruent lab and echocardiogram data for MELD and MELD-XI, respectively. Of the hemodynamic variables analyzed, only decreased systemic oxygen saturation had significant correlation with elevated MELD and MELD-XI (P = .045). Patients with moderately or severely reduced ejection fraction by echocardiogram had significantly higher MELD and MELD-XI scores compared to those with normal or mildly depressed systolic ventricular function (P = .008 and P < .001 for MELD and MELD-XI, respectively). Significant differences in creatinine were also found among the ventricular dysfunction groups (P = .02).

CONCLUSIONS

In adults following Fontan palliation, systolic ventricular dysfunction and decreased oxygen saturation were associated with hepatic and renal dysfunction as assessed by elevated serum creatinine, MELD, and MELD-XI scores.

Left main coronary artery stent placement in a 7.0 kg infant with Williams Syndrome

We report the case of a 9-month-old male with Williams syndrome who underwent patch augmentation of supravalvar aortic stenosis and pulmonary artery stenosis, and required emergent drug-eluting left coronary artery stenting on post-operative day 1 for severe left ventricular dysfunction related to myocardial ischemia.