Clinical course and follow-up of pediatric patients with COVID-19 vaccine-associated myocarditis compared to non-vaccine-associated myocarditis within the prospective multicenter registry-"MYKKE"

BACKGROUND

Since the onset of widespread COVID-19 vaccination, increased incidence of COVID-19 vaccine-associated myocarditis (VA-myocarditis) has been noted, particularly in male adolescents.

METHODS

Patients <18 years with suspected myocarditis following COVID-19 vaccination within 21 days were enrolled in the PedMYCVAC cohort, a substudy within the prospective multicenter registry for pediatric myocarditis "MYKKE." Clinical data at initial admission, 3- and 9-months follow-up were monitored and compared to pediatric patients with confirmed non-vaccine-associated myocarditis (NVA-myocarditis) adjusting for various baseline characteristics.

RESULTS

From July 2021 to December 2022, 56 patients with VA-myocarditis across 15 centers were enrolled (median age 16.3 years, 91% male). Initially, 11 patients (20%) had mildly reduced left ventricular ejection fraction (LVEF; 45%-54%). No incidents of severe heart failure, transplantation or death were observed. Of 49 patients at 3-months follow-up (median (IQR) 94 (63-118) days), residual symptoms were registered in 14 patients (29%), most commonly atypical intermittent chest pain and fatigue. Diagnostic abnormalities remained in 23 patients (47%). Of 21 patients at 9-months follow-up (259 (218-319) days), all were free of symptoms and diagnostic abnormalities remained in 9 patients (43%). These residuals were mostly residual late gadolinium enhancement in magnetic resonance imaging. Patients with NVA-myocarditis (n=108) more often had symptoms of heart failure (P = .003), arrhythmias (P = .031), left ventricular dilatation (P = .045), lower LVEF (P < .001) and major cardiac adverse events (P = .102).

CONCLUSIONS

Course of COVID-19 vaccine-associated myocarditis in pediatric patients seems to be mild and differs from non-vaccine-associated myocarditis. Due to a considerable number of residual symptoms and diagnostic abnormalities at follow-up, further studies are needed to define its long-term implications.

Clinical characteristics and outcome of biopsy-proven myocarditis in children - Results of the German prospective multicentre registry "MYKKE"

BACKGROUND

Heart failure (HF) due to myocarditis might not respond in the same way to standard therapy as HF due to other aetiologies. The aim of this study was to investigate the value of endomyocardial biopsies (EMB) for clinical decision-making and its relation to the outcome of paediatric patients with myocarditis.

METHODS

Clinical and EMB data of children with myocarditis collected for the MYKKE-registry between 2013 and 2020 from 23 centres were analysed. EMB studies included histology, immunohistology, and molecular pathology. The occurrence of major adverse cardiac events (MACE) including mechanical circulatory support (MCS), heart transplantation, and/or death was defined as a combined endpoint.

RESULTS

Myocarditis was diagnosed in 209/260 patients: 64% healing/chronic lymphocytic myocarditis, 23% acute lymphocytic myocarditis (AM), 14% healed myocarditis, no giant cell myocarditis. The median age was 12.8 (1.4-15.9) years. Time from symptom-onset to EMB was 11.0 (4.0-29.0) days. Children with AM and high amounts of mononuclear cell infiltrates were significantly younger with signs of HF compared to those with healing/chronic or healed myocarditis. Myocardial viral DNA/RNA detection had no significant effect on outcome. The worst event-free survival was seen in patients with healing/chronic myocarditis (24%), followed by acute (31%) and healed myocarditis (58%, p = 0.294). A weaning rate of 64% from MCS was found in AM.

CONCLUSIONS

EMB provides important information on the type and stage of myocardial inflammation and supports further decision-making. Children with fulminant clinical presentation, high amounts of mononuclear cell infiltrates or healing/chronic inflammation and young age have the highest risk for MACE.

Twelve Years of Complete Atrioventricular Septal Defect Repair

BACKGROUND

Surgical repair is the standard treatment for complete atrioventricular septal defect. At our institution, this repair is performed by single patch, modified single patch or two patch techniques, according to the surgeon preferences and the surgical anatomy of the defect. The goal of this study was to evaluate our results from the last twelve years.

METHODS

From June 2006 to June 2018, 81 children with complete atrioventricular septal defect (without tetralogy of Fallot or unbalanced ventricles) were submitted to surgical repair at our institution. Data from all patients was retrospectively collected and evaluated.

RESULTS

The average age was 6.9 ± 13.7 months and 84% had Down syndrome. Eighty percent were symptomatic and 6 patients were previously submitted to pulmonary artery banding. No more that mild left atrioventricular valve insufficiency was found in 84% and 89% of the patients, at discharge and follow-up, respectively. Small residual septal defects were present in 27% at discharge; during follow-up, 41% of these closed spontaneously. Pulmonary hypertension at discharge and follow-up appeared in 3.7% and 1.3%, respectively. Permanente pacemaker was implanted in 3 patients. Left ventricle outflow tract obstruction was found in 3 patients and 2 needed surgical correction. At follow-up (40 ± 38 months), 90% of the patients presented NYHA functional class I. No significant differences in the main repair outcomes were found between techniques, with the exception of small residual septal defects, although the groups were unmatched.

CONCLUSIONS

Overall and regardless of the technique used for the repair of complete AVSD, good early and midterm outcomes were achieved.

Functional Recovery of a Human Neonatal Heart After Severe Myocardial Infarction

RATIONALE

Cardiac remodeling and subsequent heart failure remain critical issues after myocardial infarction despite improved treatment and reperfusion strategies. Recently, cardiac regeneration has been demonstrated in fish and newborn mice after apex resection or cardiac infarctions. Two key issues remain to translate findings in model organisms to future therapies in humans: what is the mechanism and can cardiac regeneration indeed occur in newborn humans?

OBJECTIVE

To assess whether human neonatal hearts can functionally recover after myocardial infarction.

METHODS AND RESULTS

Here, we report the case of a newborn child having a severe myocardial infarction due to coronary artery occlusion. The child developed massive cardiac damage as defined by serum markers for cardiomyocyte cell death, electrocardiograms, echocardiography, and cardiac angiography. Remarkably, within weeks after the initial ischemic insult, we observed functional cardiac recovery, which translated into long-term normal heart function.

CONCLUSIONS

These data indicate that, similar to neonatal rodents, newborn humans might have the intrinsic capacity to repair myocardial damage and completely recover cardiac function.

Elevated heart rate triggers action potential alternans and sudden death. translational study of a homozygous KCNH2 mutation

BACKGROUND

Long QT syndrome (LQTS) leads to arrhythmic events and increased risk for sudden cardiac death (SCD). Homozygous KCNH2 mutations underlying LQTS-2 have previously been termed "human HERG knockout" and typically express severe phenotypes. We studied genotype-phenotype correlations of an LQTS type 2 mutation identified in the homozygous index patient from a consanguineous Turkish family after his brother died suddenly during febrile illness.

METHODS AND RESULTS

Clinical work-up, DNA sequencing, mutagenesis, cell culture, patch-clamp, in silico mathematical modelling, protein biochemistry, confocal microscopy were performed. Genetic analysis revealed a homozygous C-terminal KCNH2 mutation (p.R835Q) in the index patient (QTc ∼506 ms with notched T waves). Parents were I° cousins - both heterozygous for the mutation and clinically unremarkable (QTc ∼447 ms, father and ∼396 ms, mother). Heterologous expression of KCNH2-R835Q showed mildly reduced current amplitudes. Biophysical properties of ionic currents were also only nominally changed with slight acceleration of deactivation and more negative V50 in R835Q-currents. Protein biochemistry and confocal microscopy revealed similar expression patterns and trafficking of WT and R835Q, even at elevated temperature. In silico analysis demonstrated mildly prolonged ventricular action potential duration (APD) compared to WT at a cycle length of 1000 ms. At a cycle length of 350 ms M-cell APD remained stable in WT, but displayed APD alternans in R835Q.

CONCLUSION

Kv11.1 channels affected by the C-terminal R835Q mutation display mildly modified biophysical properties, but leads to M-cell APD alternans with elevated heart rate and could precipitate SCD under specific clinical circumstances associated with high heart rates.

Left ventricular function many years after recovery from pre-eclampsia

OBJECTIVE

Epidemiological observations have shown that women with pre-eclampsia are at increased risk for subsequent development of cardiovascular disease. We evaluated maternal haemodynamics in asymptomatic women many years after pre-eclampsia and HELLP (haemolysis, elevated liver enzymes and low platelets) syndrome.

DESIGN

Case-control study.

SETTING

University-based department of obstetrics.

POPULATION

Forty-eight women, 13-18 years after the affected pregnancy: 17 women with a history of HELLP syndrome, 14 women with a history of pre-eclampsia and 17 women following normal pregnancy (control group).

METHODS

Echocardiographic examination was performed in all groups, recording the isovolumetric contraction time and isovolumetric relaxation time (ICT + IVRT), ejection time (ET), myocardial performance index (MPI), transmitral early to atrial filling velocity ratio (MV-E/MV-A), stroke volume (SV) and cardiac output (CO).

MAIN OUTCOME MEASURES

Cardiac function.

RESULTS

Women with previous HELLP syndrome showed a significantly increased MPI (0.34 versus 0.26; P = 0.008) and ICT + IVRT (442.16 versus 415.03; P = 0.01); MV-E/A, SV, ET and CO were not significantly different. Women with a history of pre-eclampsia showed a significantly increased MPI (0.36 versus 0.26; P = 0.006) and decreased ET (317.3 versus 328.93; P = 0.04); ICT + IVRT, MV-E/A, SV and CO were not significantly different.

CONCLUSION

This study confirms epidemiological observations that women with pre-eclampsia are at increased risk for subsequent development of cardiovascular disease. Many years after HELLP syndrome or pre-eclampsia, asymptomatic women have an increased risk for impaired cardiac function as shown by an increased MPI.

Thymectomy in early childhood: significant alterations of the CD4(+)CD45RA(+)CD62L(+) T cell compartment in later life

The study was aimed to assess indicators of immunosenescence, such as the total counts of peripheral blood CD4(+)CD45RA(+)CD62L(+) (naive) T cells, the numbers of T cell receptor excision circles (TRECs), and Ki67-expression as marker of peripheral replication in thymectomized patients (TP) (n=101) compared to age-matched healthy donors (HD) (n=81). In TP, there was an inverse correlation between naive T cells and chronological age (p<0.001) or time post thymectomy (p<0.001). TP demonstrated lower TREC numbers in naive T cells compared to HD (p<0.001). TREC numbers negatively correlated with time post thymectomy (p<0.001). Percentages of Ki67-expresssing naive T cells were higher in TP compared to HD (p<0.05). The findings of the presented long-term follow up cohort of thymectomized patients indicate that changes of the peripheral naive T cell subset in TP may resemble the findings of an aging immune system in elderly persons after thymic involution. Our data provide evidence that peripheral T cell homeostasis in TP is maintained at minimal levels mainly by extrathymic expansion of existing naive T cells in the periphery to compensate the diminished thymic output.

Strategies for the treatment of acute heart failure in children

Acute heart failure is life threatening in adults and in the pediatric population. It represents the final pathway of complex physiological mechanisms that vary with age and underlying diseases. Strategies for treatment of heart failure should integrate to an concept of stepwise approach to heart failure. Evolving therapies, that are changing standard of care, are discussed. This paper gives an overview on principles for treatment of congestive heart failure, like diuretics, ss-beta-blockade, and angiotensin-converting enzyme blockers and discusses the approach to acute heart failure, including new and well known inotropic agents. Mechanical circulatory support and finally heart transplantation are focused as options in the last line.

NT-proBNP concentrations indicate cardiac disease in pediatric patients

OBJECTIVE

To test the performance of N-terminal pro B-type natriuretic peptide to distinguish from cardiac and non-cardiac disease in the pediatric patient population.

METHOD

NT-proBNP concentrations were retrospectively analysed in 102 pediatric patients (median age: 5.96 years; 0-18 years) with cardiac diseases comprising left-to-right-shunt lesions (n=42), left heart lesions (n=47) and right heart lesions (n=13) and in 65 pediatric patients (median age: 3.37 years; 0.03-18 years) with acute infection, minor trauma or neurological disorder.

RESULTS

NT-proBNP levels between patients without heart disease and patients with heart disease differed significantly with a median NT-proBNP value of 224.9 ng/l, 108.7 ng/l-945.6 ng/l (25th-75th percentile) versus 76.7 ng/l, 35.0 ng/l-122.4 ng/l, p<0.0001. The diagnostic performance of NT-proBNP to differentiate between patients with and without cardiac diseases was high with an area under curve of 0.81 (95% confidence intervals 0.75-0.87). At a cut-off value of 134 ng/l the specificity was 83% (95% CI: 74-92%). The presence of heart failure (p<0.0001) had a significant impact on NT-proBNP concentrations.

CONCLUSIONS

NT-proBNP measurement is a helpful addition to identify pediatric patients with heart disease.

Prolonged QTc intervals and decreased left ventricular contractility in patients with propionic acidemia

OBJECTIVE

To investigate electrophysiological and functional signs of myocardial damage in patients with propionic acidemia (PA), an inborn error of metabolism caused by deficiency of propionyl CoA carboxylase (PCC).

STUDY DESIGN

In an observational longitudinal study 10 patients with PA (6 boys and 4 girls) ranging between 2.5 and 20.2 (median 9.0) years of age at last follow-up were investigated over a period of up to 20 (mean 7.4) years using 12-lead electrocardiograms (ECGs), 24-hour continuous ECG recordings, bicycle exercise testings, and echocardiography with special focus on repolarization abnormalities such as corrected QT interval (QTc) prolongation, ventricular dysrhythmias, and left ventricular systolic function.

RESULTS

QTc interval was prolonged (>440 ms) in 70% of patients beyond infanthood. Continuous ECG recordings revealed rhythm disturbances in 20% of patients. M-mode echocardiographic left ventricular function was reduced (fractional shortening [FS] <30%) in 40%. One patient showed signs of dilated cardiomyopathy.

CONCLUSIONS

The majority of patients with PA (even in clinically stable situations) have disturbances in cardiac electrophysiology that can contribute to cardiac complications. Possible mechanisms include effects of toxic metabolites or deprivation of essential substrates. To avoid life-threatening complications, we recommend regular cardiological evaluations in this group of patients.

Interventional and Medical Treatment of Acute Heart Failure Due to Inflammation

Four patients (aged 15-41 years, mean age 26.7 years) with fulminant myocarditis undergoing mechanical circulatory support are reported. All patients suffered from acute low-output syndrome refractory to inotropic support. Diagnosis was confirmed by histology and immunohistochemistry. RT-PCR (reverse transcription-polymerase chain reaction) from endomyocardial biopsy specimens revealed parvovirus B19 in two patients and a coinfection with Chlamydia pneumoniae and parvovirus B19 in one patient. Midterm support with the biventricular Thoratec system was preceded by implantation of an extracorporeal membrane oxygenation (ECMO) device in two patients. Two patients regained full cardiac function and were successfully weaned from the ventricular assist device (VAD) after 12 and 40 days. Heart transplantation was performed in another patient without evidence of myocardial recovery after 53 days. One patient died of cerebral hemorrhage on day 12 after VAD implantation. In summary, patients with life-threatening fulminant myocarditis can be successfully bridged to recovery or transplantation with mechanical circulatory support.

Different patterns of aortic wall elasticity in patients with Marfan syndrome: A noninvasive follow-up study

OBJECTIVE

Aortic complications determine the life expectancy of most patients with Marfan syndrome. To find out whether there is heterogenous aortic involvement among patients and, if there is, to characterize aortic patterns and response to long-term beta-blocker therapy, we investigated aortic elastic properties before and during beta-blocker treatment.

METHODS

In 46 patients with Marfan syndrome (age, 17.4 +/- 11.1 years) and 46 healthy control subjects, ascending and descending aortic elastic parameters were determined noninvasively before and after 39 +/- 16 months of beta-blocker treatment with atenolol.

RESULTS

Aortic diameters and distensibility distinguished Marfan patients and controls with a sensitivity of 85% and a specificity of 87%. Cluster analysis revealed 4 patterns of aortic phenotypic expression: (1) reduced ascending aortic elasticity (46% of patients), (2) diminished ascending and descending aortic elasticity (17%), (3) minimal alterations of ascending and descending aortic elasticity (20%), and (4) reduced descending aortic elasticity (17%). During follow-up, aortic elastic properties improved in 21 (70%) of 30 patients and deteriorated in 9 (30%) irrespective of beta-blocker dosage. Improvement was observed in 100% of patients (n = 7; age, 5.3 +/- 4.2 years) with end-diastolic aortic root diameters between 20 and 30 mm and in 61% of patients (14/23; age, 20.5 +/- 10.0 years) with root diameters between 30 and 52 mm.

CONCLUSIONS

Aortic elastic parameters distinguish between patients with Marfan syndrome and healthy controls and show the pattern of regional aortic involvement. Improvement or deterioration during follow-up can influence therapeutic decisions to prevent aortic dissection and rupture. Young age, small root diameter, and high distensibility are favorable prognostic factors.

Diagnostic power of aortic elastic properties in young patients with Marfan syndrome

BACKGROUND

In patients with Marfan syndrome, progressive aortic dilation implicates a still-unpredictable risk of life-threatening aortic dissection and rupture. We sought to quantify aortic wall dysfunction noninvasively, determine the diagnostic power of various aortic parameters, and establish a diagnostic model for the early detection of aortic abnormalities associated with Marfan syndrome.

METHODS

In 19 patients with Marfan syndrome (age, 17.7 +/- 9.5 years) and 19 age- and sex-matched healthy control subjects, computerized ascending and abdominal aortic wall contour analysis with continuous determination of aortic diameters was performed out of transthoracic M-mode echocardiographic tracings. After simultaneous oscillometric blood pressure measurement, aortic elastic properties were determined automatically.

RESULTS

The following ascending aortic elastic parameters showed statistically significant differences between the Marfan group and the control group: (1) decreased aortic distensibility ( P < .001), (2) increased wall stiffness index ( P < .01), (3) decreased systolic diameter increase ( P < .01), and (4) decreased maximum systolic area increase ( P < .001). The diagnostic power of all investigated parameters was tested by single logistic regression models. A multiple logistic regression model including solely aortic parameters yielded a sensitivity of 95% and a specificity of 100%.

CONCLUSIONS

In young patients with Marfan syndrome, a computerized image-analyzing technique revealed decreased aortic elastic properties expressed by parameters showing high diagnostic power. A multiple logistic regression model including merely aortic parameters can serve as useful predictor for Marfan syndrome.

Prenatal diagnosis of intrauterine premature closure of the ductus arteriosus following maternal diclofenac application

We report a case of prenatal diagnosis of premature closure of the ductus arteriosus following maternal diclofenac therapy at 35 weeks of gestation. Fetal echocardiography at 37 weeks of gestation revealed a dilated right ventricle with moderate tricuspid regurgitation, pulmonary insufficiency and complete closure of the ductus arteriosus. Immediate Cesarean section resulted in an excellent neonatal outcome. Whereas the effect of indomethacin on prenatal ductal constriction is well known, widely prescribed non-steroidal anti-inflammatory drugs such as diclofenac can have an equally deleterious effect and are best avoided in the third trimester of pregnancy.

High prevalence and morbidity of Schistosoma mansoni along the Albert Nile in Uganda

An epidemiological cross sectional study of Schistosoma mansoni was conducted in two hyper endemic fishing villages of Rhino Camp and Obongi both in West Nile district in northern Uganda in 1991 and 1992. People with various water contacts were registered. A small group of civil servants and clergies with less water contact in the river Nile were studied for control of infection and morbidity. An overall prevalence of 81.5% of the 1367 people studied in both fishing villages of Rhino Camp and Obongi were excreting from 100 to > or = 500 Schistosoma mansoni eggs per gram (epg). 253 18.5% did not have Schistosoma mansoni eggs in their faeces. The influence of socioeconomic factors on infections in the study population was high among poorer illiterates who have frequent water contacts activities with River Nile. The sonomorphological abnormalities of periportal thickening (PT) due to Schistosoma mansoni were performed using ultrasound. 664 patients were found to have various stages of (PT stages 0, I, II and III). A total of 703 (51.4%) patients did not have any periportal thickening (PT 0) in their livers despite the fact that 450 (32.9%) of them had Schistosoma. mansoni eggs in their faeces. The gravities of schistosomiasis in the two villages were similar showing greater morbidity in the younger adults.

Evidence for a long-term effect of a single dose of praziquantel on Schistosoma mansoni-induced hepatosplenic lesions in northern Uganda

Treatment with praziquantel reduces the prevalence and intensity of Schistosoma mansoni infection. However, reversibility of periportal fibrosis of the liver, which potentially leads to fatal complications, is not unequivocally substantiated. In the Nile District of Uganda, 460 patients were parasitologically (Kato-Katz method) and ultrasonographically examined during October 1991, October 1992, and May 1994. Treatment with praziquantel at a dosage of 40 mg per kilogram of body weight was given in October 1991 and October 1992 to 460 individuals (group A). Another 192 patients were seen during the baseline study in October 1991 and missed the follow-up in October 1992 but took part in the second follow-up in May 1994. Thus, they received praziquantel only once in October 1991 (group B) and had an interval of 2.7 years until the next investigation in May 1994. Periportal thickening (PT) of the liver was assessed by ultrasound at each time point. Praziquantel therapy reduced the prevalence of S. mansoni in group A from 84% in 1991 to 31% in 1992 and 30% in 1994. The respective intensities of infection (geometric means of egg output) were 81 eggs per gram (epg) of stool in 1991, 31 epg in 1992, and 30 epg in 1994. Periportal thickening was found in 46% of patients in 1991, 32% of patients in 1992, and 35% of patients in 1994. Reversibility of PT was influenced by age (markedly lower reversibility in individuals older than 30 years) and sex (women and girls responded less favorably than did men and boys). Surprisingly, no significant difference was detected between group A and group B with respect to reversibility of PT The outcome between the 2 groups did not differ significantly. This may indicate that a single dose of praziquantel (as given to group B) may have a longer lasting effect than previously thought, that is, more than 2.5 years.

Urban Schistosoma mansoni near Enyau river in Arua town, Uganda

Using the Kato Katz method for quantification of parasitic eggs in faeces, 500 individuals aged between 4 and 50 years, living along River Enyau, half a kilometre from Arua town, were studied to assess the prevalence of Schistosoma mansoni in the population. The overall prevalence of Schistosoma mansoni infection was 62%. The infection was highest among school children (71.1%, i.e. 199 out of 280). Villagers who lived along the immediate vicinity of the river had a 62.8% prevalence of infection (98 out of 156). School teachers and the members of their families had the lowest infection rate (20.3% i.e. 13 out of 64). The geometric mean egg output for males and females in the community studied was 203 and 179 eggs per gram of stool, respectively. 206 (41%) out of 500 individuals had mixed infections of S. mansoni and hookworms. The rate of orally transmitted intestinal helminths like Trichuris trichiura was very low (0.8%). Ascaris lumbricoides eggs were not found.

Evidence for the occurrence of Schistosoma intercalatum at Albert Nile in northern Uganda

During a field investigation in Rhino Camp at Albert Nile in northern Uganda, 77.8% of 636 persons excreted Schistosoma mansoni ova that were detected by the Kato-Katz method. Six patients, 8-17 years of age, had terminally spined schistosome eggs in their stools. These findings were confirmed when preserved specimens were examined at the Institute of Medical Parasitology in Bonn using a concentration technique. The mean +/- SD length of 36 terminally spined eggs was 156 +/- 6 microns and the mean +/- SD width was 59 +/- 3.6 microns. Urine filtration in the study patients revealed no schistosome eggs in the urine. It is concluded that these findings provide evidence for the occurrence of S. intercalatum at Albert Nile in northern Uganda.

Transmission of Schistosoma mansoni in Rhino Camp, Uganda

Non-participant observations totalling 204 hours relevant to the transmission of Schistosoma mansoni infection were carried out in Rhino Camp at the shores of Albert Nile in North Uganda. A cross-sectional study of 636 individuals from Rhino Camp revealed a prevalence of S. mansoni infection of 77.8%. Occupational and domestic purposes were the most important reasons for water contact, whereas recreational purposes ranked lower and mainly concerned children. Both sexes were equally active in water contacts. A distinct preference of Nile water was noted despite availability of borehole water in the area. It is concluded that control measures against schistosomiasis have to take into consideration that water contact for recreational purposes might be minimized, whereas it is expected to be extremely difficult to reduce occupational and domestic water contacts.