Outcomes after initial heart failure consultation in Fontan patients

BACKGROUND

Patients with Fontan failure are high-risk candidates for heart transplantation and other advanced therapies. Understanding the outcomes following initial heart failure consultation can help define appropriate timing of referral for advanced heart failure care.

METHODS

This is a survey study of heart failure providers seeing any Fontan patient for initial heart failure care. Part 1 of the survey captured data on clinical characteristics at the time of heart failure consultation, and Part 2, completed 30 days later, captured outcomes (death, transplant evaluation outcome, and other interventions). Patients were classified as "too late" (death or declined for transplant due to being too sick) and/or "care escalation" (ventricular assist device implanted, inotrope initiated, and/or listed for transplant), within 30 days. "Late referral" was defined as those referred too late and/or had care escalation.

RESULTS

Between 7/2020 and 7/2022, 77 Fontan patients (52% inpatient) had an initial heart failure consultation. Ten per cent were referred too late (6 were too sick for heart transplantation with one subsequent death, and two others died without heart transplantation evaluation, within 30 days), and 36% had care escalation (21 listed ± 5 ventricular assist device implanted ± 6 inotrope initiated). Overall, 42% were late referrals. Heart failure consultation < 1 year after Fontan surgery was strongly associated with late referral (OR 6.2, 95% CI 1.8-21.5, p=0.004).

CONCLUSIONS

Over 40% of Fontan patients seen for an initial heart failure consultation were late referrals, with 10% dying or being declined for transplant within a month of consultation. Earlier referral, particularly for those with heart failure soon after Fontan surgery, should be encouraged.

Experience with SGLT2 Inhibitors in Patients with Single Ventricle Congenital Heart Disease and Fontan Circulatory Failure

Heart failure is the leading cause of morbidity and mortality in patients with Fontan circulation. Sodium-glucose-cotransporter 2 inhibitors (SGLT2i) have become a mainstay of heart failure therapy in adult patients, however, there remains a paucity of literature to describe its use in pediatric heart failure patients, especially those with single ventricle physiology. We describe our early experience using SGLT2i in patients with single ventricle congenital heart disease surgically palliated to the Fontan circulation. We conducted a single-center retrospective chart review of all patients with Fontan circulation who were initiated on an SGLT2i from January 1, 2022 to March 1, 2023. Patient demographics, diagnoses, clinical status, and other therapies were collected from the electronic medical record. During the study period, 14 patients (median age 14.5 years, range 2.0-26.4 years) with Fontan circulation were started on a SGLT2i. Mean weight was 54 kg (range 11.6-80.4 kg). Median follow-up since SGLT2i initiation was 4.1 months (range 13 days-7.7 months). Four patients had a systemic left ventricle and 10 had a systemic right ventricle. Half the patients had Fontan Circulatory Failure with reduced Ejection Fraction (FCFrEF) of the systemic ventricle and the other half had Fontan Circulatory Failure with preserved Ejection Fraction (FCFpEF) of the systemic ventricle. In addition, 3 patients experienced Protein Losing Enteropathy (PLE) and 2 patients had plastic bronchitis, one of whom also was diagnosed with chylothorax. There were no genitourinary infections, hypoglycemia, ketoacidosis, hypotension or other significant adverse effects noted in our patient population. One patient experienced significant diuresis and transient acute kidney injury. Patients with FCFrEF showed a decrease in natriuretic peptide levels. Given the lack of proven therapies, demonstrated benefits of SGLT2i in other populations, and some suggestion of efficacy in Fontan circulation, further study of SGTLT2i in patients with Fontan circulation is warranted.

Paediatric cardiology training: burnout, fulfilment, and fears

BACKGROUND

Burnout is well characterised in physicians and residents but not in paediatric cardiology fellows, and few studies follow burnout longitudinally. Training-specific fears have been described in paediatric cardiology fellows but also have not been studied at multiple time points. This study aimed to measure burnout, training-specific fears, and professional fulfilment in paediatric cardiology fellows with the attention to time of year and year-of-training.

METHODS

This survey-based study included the Professional Fulfillment Index and the Impact of Events Scale as well as an investigator-designed Fellow Fears Questionnaire. Surveys were distributed at three-time points during the academic year to paediatric cardiology fellows at a large Midwestern training programme. Fellow self-reported gender and year-of-training were collected. Descriptive analyses were performed.

RESULTS

10/17 (59%) of fellows completed all surveys; 60% were female, 40% in the first-year class, 40% in the second-year class, and 20% in the third-year class. At least half of the fellows reported burnout at each survey time point, with lower mean professional fulfilment scores. The second-year class, who rotate primarily in the cardiac ICU, had higher proportions of burnout than the other two classes. At least half of fellows reported that they "often" or "always" worried about not having enough clinical knowledge or skills and about work-life balance.

CONCLUSIONS

Paediatric cardiology fellows exhibit high proportions of burnout and training-specific fears. Interventions to mitigate burnout should be targeted specifically to training needs, including during high-acuity rotations.

Pediatric Heart Transplant Rejection After COVID-19 Infection

BACKGROUND

Infections have been associated with rejection episodes in solid organ transplant recipients. We report an association between COVID-19 infection and heart transplant (HT) rejection.

CASE DESCRIPTION

The patient was 14 years old and 6.5 years post-HT. He developed symptoms of rejection within 2 weeks of COVID exposure and presumed infection.

CONCLUSIONS

In this case, COVID-19 infection closely preceded significant rejection and graft dysfunction. Further study is needed to establish a correlation between COVID-19 infection and rejection in HT patients.

Representation of Women and Minority Faculty and Fellows in Academic Pediatric Cardiology Training Programs

BACKGROUND

Studies have shown that diverse care teams optimize patient outcomes. Describing the current representation of women and minorities has been a critical step in improving diversity across several fields.

OBJECTIVES

To address the lack of data specific to pediatric cardiology, the authors conducted a national survey.

METHODS

U.S. academic pediatric cardiology programs with fellowship training programs were surveyed. Division directors were invited (July 2021 to September 2021) to complete an e-survey of program composition. Underrepresented minorities in medicine (URMM) were characterized using standard definitions. Descriptive analyses at the hospital, faculty, and fellow level were performed.

RESULTS

Altogether, 52 of 61 programs (85%) completed the survey, representing 1,570 total faculty and 438 fellows, with a wide range in program size (7-109 faculty, 1-32 fellows). Although women comprise approximately 60% of faculty in pediatrics overall, they made up 55% of fellows and 45% of faculty in pediatric cardiology. Representation of women in leadership roles was notably less, including 39% of clinical subspecialty directors, 25% of endowed chairs, and 16% of division directors. URMM comprise approximately 35% of the U.S. population; however, they made up only 14% of pediatric cardiology fellows and 10% of faculty, with very few in leadership roles.

CONCLUSIONS

These national data suggest a "leaky pipeline" for women in pediatric cardiology and very limited presence of URRM overall. Our findings can inform efforts to elucidate underlying mechanisms for persistent disparity and reduce barriers to improving diversity in the field.

Predictors and clinical significance of pericardial effusions after pediatric heart transplantation

BACKGROUND

We aimed to describe the incidence, risk factors, and clinical outcomes of pericardial effusions within 6 months after pediatric heart transplantation (HT).

METHODS

A single-center retrospective cohort study was performed on all pediatric HT recipients from 2004 to 2018. Logistic regression was used to identify factors associated with pericardial effusions post-HT, and survival was compared using log-rank test.

RESULTS

During the study period, 97 HTs were performed in 93 patients. Fifty patients (52%) had a ≥small pericardial effusion within 6 months, 16 of which were, or became, ≥moderate in size. Pericardial drain was placed in 8 patients. In univariate analysis, larger recipient body surface area (p = .01) and non-congenital heart disease (p = .002) were associated with pericardial effusion development. Donor/recipient size ratios, post-HT hemodynamics, and rejection did not correlate with pericardial effusion development. In multivariable analysis, non-congenital heart disease (adjusted odds ratio 3.3, p = .01) remained independently associated with development of pericardial effusion. There were no significant differences in post-HT survival between patients with and without ≥small (p = .68) or ≥moderate pericardial effusions (p = .40).

CONCLUSIONS

Pericardial effusions are common after pediatric HT. Patients with cardiomyopathy, or non-congenital heart disease, were at higher risk for post-HT pericardial effusions. Pericardial effusions increased morbidity but had no effect on mortality in our cohort. The risk factors identified may be used for anticipatory guidance in pediatric HT.

Burnout, professional fulfillment, and post-traumatic stress among pediatric solid organ transplant teams

BACKGROUND

Adverse effects of clinician burnout have been studied across multiple specialties; however, there have been no studies examining rates of burnout among pediatric solid organ transplant teams. This study aimed to measure burnout, work exhaustion, professional fulfillment, and post-traumatic stress symptoms among clinicians and administrators practicing in this high-stress field.

METHODS

This cross-sectional study utilized a 50 item web-based survey that included the Personal Fulfillment Index and the IES-R. This survey was distributed across four pediatric solid organ transplant centers in North America. Basic demographics, clinician characteristics, and information regarding wellness and self-care activities were collected. Descriptive and correlational analyses were performed.

RESULTS

One hundred and thirty five participants completed the survey, 76% were female and 78% were Caucasian. One-third (34%) of participants endorsed burnout, while 43% reported professional fulfillment. Approximately 15% of respondents endorsed clinically significant levels of post-traumatic stress symptoms related to patient deaths, with female clinicians more likely to endorse symptoms (p = .01). Nearly 80% of participants reported engaging in self-care activities outside of work and only 10% of participants reported participation in hospital-sponsored wellness programs.

CONCLUSIONS

Pediatric solid organ transplant team members exhibited moderate levels of burnout, professional fulfillment, and post-traumatic stress. Female clinicians were the most likely to experience both work exhaustion and post-traumatic stress symptoms. Transplant centers are encouraged to consider interventions and programming to improve clinician wellness.

Generalized and specific anxiety in adolescents following heart transplant

Mental health concerns are associated with worse outcomes after adult heart transplant. Illness-specific anxiety is associated with worsened psychological well-being after other solid organ transplants but has never been characterized after pediatric heart transplant. This single-center cross-sectional study aimed to evaluate illness-specific and generalized anxiety after heart transplantation in adolescents. A novel 12-item PHTF, GAD-7, and the PedsQL were administered. Univariate associations of demographics, clinical features, and medication adherence as measured by immunosuppression standard deviation with the PHTF and GAD-7 scores were evaluated. Internal consistency and validity of the PHTF were examined. In total, 30 patients participated. The most common illness-specific fears were retransplantation, rejection, and more generally post-transplant complications. The PHTF had good internal consistency (Cronbach α = .88). Construct validity was demonstrated between PHTF and GAD-7 (r = .62) and PedsQL (r = -.54 to -.62). 23% endorsed moderate to severe generalized anxiety symptoms. More severe symptoms were associated with older age at survey (P = .03), older age at listing (P = .01) and having post-transplant complications (P = .004). Patients with moderate or severe symptoms were more likely to report late immunosuppression doses (P = .004). Illness-specific and generalized anxiety may be prevalent after pediatric heart transplant. Screening for anxiety in adolescents post-transplant may identify those at risk for adverse outcomes including non-adherence. The PHTF is a brief, valid, and reliable instrument identifying illness-specific anxiety in this population.

Transplantation of the failing Fontan

Half a century has passed since the original Fontan palliation. In the interim, surgical and medical advancements have allowed more single ventricle patients to reach Fontan and long-term survival for Fontan patients to improve significantly. However, the risk for Fontan failure and need for heart transplantation remains. In this article we discuss mechanisms of Fontan failure, risk factors and special considerations for Fontan patients in both medical and surgical management around heart transplantation and provide an updated review of survival for Fontan patients after heart transplantation.

Fulminant Influenza B Myocarditis in a Pediatric Patient

Influenza B is a common viral illness in childhood. We report a 5-year-old previously healthy girl admitted with facial edema that developed severe acute myocarditis from influenza B infection. As her clinical course progressed, she ultimately developed severe, acute heart failure requiring extracorporeal membrane oxygenation for support.

Cytochrome P450-dependent metabolism of gefitinib

The in vitro metabolism of [(14)C]-gefitinib (1-3 microM) was investigated using human liver microsomes and a range of expressed human cytochrome P450 enzymes, with particular focus on the formation of O-desmethyl-gefitinib (M523595), the major metabolite observed in human plasma. High-performance liquid chromatography with ultraviolet light, radiochemical and mass spectral analysis, together with the availability of authentic standards, enabled quantification and structural identification of metabolites. On incubation with pooled human liver microsomes, [(14)C]-gefitinib underwent rapid and extensive metabolism to a number of metabolites, although M523595 was only a minor microsomal product. Formation of most metabolites was markedly decreased by ketoconazole, but M523595 production was inhibited only by quinidine. Gefitinib was metabolized extensively by expressed CYP3A4, producing a similar range of metabolites to liver microsomes, but M523595 was not formed. CYP1A2, 2C9 and 2C19 produced no measurable metabolism of gefitinib, while CYP3A5 produced a range of metabolites similar to CYP3A4, but to a much lower degree. In contrast, CYP2D6 catalysed rapid and extensive metabolism of gefitinib to M523595. While formation of M523595 was CYP2D6 mediated, the overall metabolism of gefitinib was dependent primarily on CYP3A4, and this was not obviously diminished in liver microsomes from CYP2D6 poor metabolizers.

In vitrometabolism of gefitinib in human liver microsomes

The in vitro metabolism of gefitinib was investigated by incubating [14C]-gefitinib, as well as M537194, M387783 and M523595 (the main metabolites of gefitinib observed in man), at a concentration of 100 microM with human liver microsomes (4 mg ml(-1)) for 120 min. These relatively high substrate and microsomal protein concentrations were used in an effort to generate sufficient quantities of metabolites for identification. HPLC with ultraviolet light, radiochemical and mass spectral analysis, together with the availability of authentic standards, enabled quantification and structural identification of a large number of metabolites. Although 16 metabolites were identified, metabolism was restricted to three regions of the molecule. The major pathway involved morpholine ring-opening and step-wise removal of the morpholine ring and propoxy side chain. O-demethylation of the quinazoline methoxy group was a quantitatively less important pathway, in contrast to the clinical situation, where O-desmethyl gefitinib (M523595) is the predominant plasma metabolite. The third metabolic route, oxidative defluorination, was only a minor route of metabolism. Some metabolites were formed by a combination of these processes, but no metabolism was observed in other parts of the molecule. Incubation of gefitinib produced ten identified metabolites, but the use of the three main in vivo metabolites as additional substrates enabled a more comprehensive metabolic pathway to be constructed and this has been valuable in supporting the more limited data available from the human in vivo study.

In vitrometabolism of a triclyclic alkaloid (M445526) in human liver microsomes and hepatocytes

The in vitro metabolism of M445,526 (ZD6,126 phenol) was investigated by incubating [(14)C]-M445,526 at a concentration of 10 microg ml(-1) with human hepatic microsomes (4 mg ml(-1)) or human hepatocytes (2 x 10(6) cells ml(-1)) for up to 180 min. Following incubation with microsomes and hepatocytes, up to 78% and 40% of [(14)C]-M445,526 was metabolized after 180 and 120 min, respectively. High-performance liquid chromatography (HPLC) with radiochemical detection confirmed extensive metabolism of [(14)C]-M445,526 by microsomes and hepatocytes. Mass spectrometry and (1)H-NMR spectroscopy enabled structural identification of up to eight metabolites. Human liver microsomes formed one major (O-desmethyl) and three minor (a further O-desmethyl and two different hydroxylated) phase I metabolites. Human hepatocytes produced one major metabolite, a sulphate conjugate of the major O-desmethyl metabolite formed by microsomes. Four minor metabolites were also formed, primarily by O-demethylation with subsequent glucuronidation. Taken collectively, [(14)C]-M445,526 underwent extensive in vitro metabolism by human liver fractions. These data were confirmed by subsequent human in vivo studies.

HPLC–NMR with severe column overloading: Fast-track metabolite identification in urine and bile samples from rat and dog treated with [14C]-ZD6126

The subject of this study was the determination of the major urinary and biliary metabolites of [(14)C]-ZD6126 following i.v. administration to female and male bile duct cannulated rats at 10 mg/kg and 20 mg/kg, respectively, and male bile duct cannulated dogs at 6 mg/kg by HPLC-NMR spectroscopy. ZD6126 is a phosphorylated pro-drug, which is rapidly hydrolysed to the active metabolite, ZD6126 phenol. The results presented here demonstrate that [(14)C]-ZD6126 phenol is subsequently metabolised extensively by male dogs and both, male and female rats. Recovery of the dose in bile and urine was determined utilising the radiolabel, revealing biliary excretion as the major route of excretion (93%) in dog, with the majority of the radioactivity recovered in both biofluids in the first 6 h. In the rat, greater than 92% recovery was obtained within the first 24 h. The major route of excretion was via the bile 51-93% within the first 12 h. The administered phosphorylated pro-drug was not observed in any of the excreta samples. Metabolite profiles of bile and urine samples were determined by high performance liquid chromatography with radiochemical detection (HPLC-RAD), which revealed a number of radiolabelled components in each of the biofluids. The individual metabolites were subsequently identified by HPLC-NMR spectroscopy and HPLC-MS. In the male dog, the major component in urine and bile was the [(14)C]-ZD6126 phenol glucuronide, which accounted for 3% and 77% of the dose, respectively. [(14)C]-ZD6126 phenol was observed in urine at 1% of dose, but was not observed in bile. A sulphate conjugate of demethylated [(14)C]-ZD6126 phenol was identified in bile by HPLC-NMR and confirmed by HPLC-MS. In the rat, the bile contained two major radiolabelled components. One was identified as the [(14)C]-ZD6126 phenol glucuronide, the other as a glucuronide conjugate of demethylated [(14)C]-ZD6126 phenol. However, a marked difference in the proportions of these two components was observed between male and female rats, either due to a sex difference in metabolism or a difference in dose level. The glucuronide conjugate of the demethylated [(14)C]-ZD6126 phenol was present at higher concentration in the bile of male rats (4-34%), while the phenol glucuronide was present at higher concentration in the bile of female rats (8-70%) over a 0-6 h collection period. A third component was only observed in the bile samples (0-6 h and 6-12 h) of male rats. This was identified as being the same sulphate conjugate of demethylated [(14)C]-ZD6126 phenol as the one observed in dog bile. The rat urines contained two main metabolites in greatly varying concentrations, namely the demethylated [(14)C]-ZD6126 phenol glucuronide and the glucuronide of [(14)C]-ZD6126 phenol. Again, the differences in relative amounts between male and female rats were observed, the major metabolite in the urines from male rats being the demethylated [(14)C]-ZD6126 phenol (0-17% in 0-24 h), whilst the phenol glucuronide, accounting for 0.5-50% of the dose over 0-24 h, was the major metabolite in females. Methanolic extracts of the pooled biofluid samples were submitted for HPLC-NMR for the quick identification of the major metabolites. Following a single injection of the equivalent of 6-28 ml of the biofluids directly onto the HPLC-column with minimal sample preparation, the metabolites could be largely successfully isolated. Despite severe column overloading, the major metabolites of [(14)C]-ZD6126 could be positively identified, and the results are presented in this paper.

Preclinical and in vitro assessment of the potential of D0870, an antifungal agent, for producing clinical drug interactions

1. D0870, an azole antifungal agent, produced dose-related increases in total cytochrome P450 and aldrin epoxidase when administered as 14 daily oral doses (0, 0.5, 2.5 and 12.5 mg/kg/day) to the male rat. Administered as single doses, D0870 increased pentobarbitone-sleeping time in a dose-related manner. 2. In human hepatic microsomal incubations, D0870 produced pronounced inhibition of CYP2C9 (tolbutamide hydroxylase) and, to a lesser degree, CYP3A4 (testosterone 6beta-hydroxylase), but had more limited effects on CYP1A2, 2C19 and 2D6 activity. In comparison with ketoconazole, itraconazole and fluconazole, D0870 was the most potent inhibitor of CYP2C9 activity. It is predicted that D0870 may inhibit the in vivo clearance of CYP2C9 substrates by approximately 58%, thereby increasing their steady-state concentrations by 2.4 times, which would be of clinical significance for some compounds. 3. During incubation of [14C]-D0870 with cultured human hepatocytes for up to 72 h, two discrete metabolites (A and B) were formed. Formation of metabolite A was abolished by both quinidine and ketoconazole and is probably CYP3A4-mediated, whereas generation of metabolite B did not appear to be dependent on cytochrome P450. 4. D0870 has potential to produce both induction and inhibition of cytochrome P450 enzymes in man.

Metabolism of Casodex in laboratory animals

1. Casodex, a non-steroidal antiandrogen, was eliminated primarily in faeces by rat, mouse, rabbit and dog. Rat, mouse and rabbit eliminated 20-30% of a single oral dose (8-25 mg/kg) in urine; only 3-4% was excreted in urine by dog (2.5 mg/kg). Oral absorption was about 80% in rat, mouse, rabbit and dog. 2. Most of the dose was recovered in 48 h from rat, mouse and rabbit. In rat, < 1% of the dose was exhaled as 14CO2 and < 1% remained in the carcass after 7 days. Recovery from dog was incomplete in 4 days but consistent with the long plasma elimination half-life of 7-7.5 days. Casodex was eliminated from rat plasma with a half-life of 17-21 h. 3. Examination of urine indicated extensive metabolism of Casodex and showed a marked species difference. In rat, mouse and dog, Casodex was cleaved at the amide to yield a carboxylic acid and an aromatic amine which subsequently underwent ring hydroxylation with sulphate conjugation. In rabbit, the major urinary metabolite was Casodex glucuronide, conjugated on the tertiary hydroxyl. 4. The major component in faeces of all species was unchanged Casodex; some hydroxy-Casodex was also observed in rat faeces. Analysis of rat and dog bile indicated that Casodex and hydroxy-Casodex were eliminated in bile primarily as glucuronide conjugates.