Sudden cardiac death triggered by minimal alcohol consumption in the context of novel PPA2 mutations in 2 unrelated families

Biallelic variants in PPA2 gene cause a rare but lethal mitochondrial disorder. We describe the first four cases reported in Spain of PPA2 disease in two unrelated families. We have conducted a revision of the clinical history, necropsies, and postmortem genetic testing from probands, and clinical evaluation, genetic testing and blood transcript analysis in family members. All the cases harbored biallelic PPA2 variants in compound heterozygous status. Two brothers from family 1 suffered sudden death after a small first intake of alcohol in 2013 and 2022. The sister remains alive but affected with cardiomyopathy, extensive scar on cardiac imaging, and high sensitivity to alcohol intake. The three siblings carried PPA2 c.290A > G (p.Glu97Gly) novel missense variant and PPA2 c.513C > T (p.Cys171 = ) altering splicing site variant, both probably leading to mRNA degradation based on in-silico and transcript analyses. A teenager from family 2 suffered sudden death after a small intake of alcohol in 2018 and carried PPA2 c.683C > T (p.Pro228Leu) missense and PPA2 c.980_983del (p.Gln327fs) novel frameshift variant, both probably leading to abnormal protein structure. All cases were asymptomatic until adolescence. Furthermore, the sister in family 1 has survived as an asymptomatic adult. PPA2 disease can manifest as cardiac arrest in the young, especially after alcohol exposure. Our results show that PPA2 deficiency can be related to different pathogenicity mechanisms such as abnormal protein structure but also mRNA decay caused by synonymous or missense variants. Strict avoidance of alcohol consumption and early defibrillator implantation might prevent lethal arrhythmias in patients at risk.

Complications and inappropriate shocks in pediatric patients receiving a subcutaneous implantable cardioverter defibrilator

INTRODUCTION AND OBJECTIVES

There is limited evidence regarding the use of subcutaneous implantable cardioverter-defibrillators (S-ICD) in pediatric patients. The aim of this study was to determine the incidence of complications in these patients at our center, according to the type of ICD and patient size.

METHODS

We included all patients aged<18 years who received an S-ICD since 2016 at our center. As a control group, we also included contemporary patients (since 2014) who received a transvenous ICD (TV-ICD). The primary endpoint was a composite of complications and inappropriate shocks.

RESULTS

A total of 26 patients received an S-ICD (median age, 14 [5-17] years; body mass index [BMI], 20.2 kg/m2). Implantation was intermuscular in 23 patients (88%) and subserratus in the remainder. Two incisions were used in 24 patients (92%). In all patients, 2 zones were programmed: a conditional zone set at 230 (220-230) bpm, and a shock zone set at 250 bpm. Nineteen patients received a TV-ICD (median age, 11 [range, 5-16] years; BMI, 19.2 kg/m2, 79% single-chamber). Survival free from the primary endpoint at 5 years was 80% in the S-ICD group and 63% in the TV-ICD group (P=.54). Survival free from inappropriate shocks was similar (85% vs 89%, P=.86), while survival free from complications was higher in the S-ICD group (96% vs 57%, cloglog P=.016). There were no therapy failures in the S-ICD group, and no increased complication rates were observed in patients with BMI ≤20 kg/m2.

CONCLUSIONS

With contemporary implantation techniques and programming, S-ICD is a safe and effective therapy in pediatric patients. The number of inappropriate shocks is similar to TV-ICD, with fewer short- and mid-term complications.

Genotypic Findings in Noonan and Non-Noonan RASopathies and Patient Eligibility for Growth Hormone Treatment

Molecular study has become an invaluable tool in the field of RASopathies. Treatment with recombinant human growth hormone is approved in Noonan syndrome but not in the other RASopathies. The aim of this study was to learn about the molecular base of a large cohort of patients with RASopathies, with particular emphasis on patients with pathogenic variants in genes other than PTPN11, and its potential impact on rGH treatment indication. We reviewed the clinical diagnosis and molecular findings in 451 patients with a genetically confirmed RASopathy. HRAS alterations were detected in only 2 out of 19 patients referred with a Costello syndrome suspicion, whereas pathogenic variants in RAF1 and SHOC2 were detected in 3 and 2, respectively. In 22 patients referred with a generic suspicion of RASopathy, including cardiofaciocutaneous syndrome, pathogenic alterations in classic Noonan syndrome genes (PTPN11, SOS1, RAF1, LZTR1, and RIT1) were found in 7 patients and pathogenic variants in genes associated with other RASopathies (HRAS, SHOC2, and PPPCB1) in 4. The correct nosological classification of patients with RASopathies is critical to decide whether they are candidates for treatment with rhGH. Our data illustrate the complexity of differential diagnosis in RASopathies, as well as the importance of genetic testing to guide the diagnostic orientation in these patients.

A Neonatal ABO non-compatible heart transplant from a circulatory-determined death donor using NRP/Cold storage

BACKGROUND

Donation after Circulatory death is gaining worldwide acceptance. Most protocols regard their first cases to be performed with donor and recipient in the same institution. Few records of children or distant procurement have been published.

METHODS

Our institution was offered a heart from a 3-day-old, 3.4-kg child, blood group A, suffering irreversible encephalopathy. Parents accepted withdrawal of life-sustaining therapy and agreed to donation. The donor hospital was located 340 km away. Concomitantly, a 2-month-old, 3.1 kg, blood group type B and with non-compaction ventricles was awaiting for the heart transplant in our unit.

RESULTS

Thirty-seven minutes after withdrawal of life-sustaining therapy, the heart arrested. Five minutes afterwards, a sternotomy was performed. The supra-aortic vessels were clamped altogether. Aorta and right appendage were cannulated and connected to heart-lung machine. The innominate artery above the clamp was severed. The heart resumed spontaneous rhythm in less than 1 min. Ventilation was restored and extracorporeal circulation was maintained for 32 min. Upon cardiologic arrest, the graft was harvested as routinely. The heart was cold-stored and transported by plane to our Hospital. An orthotopic bicaval transplant was performed. Overall cold ischaemia was 245 min. Ten weeks later, the child was discharged home in good condition.

CONCLUSION

Donation in circulatory death could increase the pool in neonates. Extracorporeal circulation proves successful for procurement in neonates. Distant procurement plus cold storage for donation in circulatory death is feasible. Donation in circulatory death and ABO non-compatible strategies are complementary to each other.

Clinical Features and Natural History of Preadolescent Nonsyndromic Hypertrophic Cardiomyopathy

BACKGROUND

Up to one-half of childhood sarcomeric hypertrophic cardiomyopathy (HCM) presents before the age of 12 years, but this patient group has not been systematically characterized.

OBJECTIVES

The aim of this study was to describe the clinical presentation and natural history of patients presenting with nonsyndromic HCM before the age of 12 years.

METHODS

Data from the International Paediatric Hypertrophic Cardiomyopathy Consortium on 639 children diagnosed with HCM younger than 12 years were collected and compared with those from 568 children diagnosed between 12 and 16 years.

RESULTS

At baseline, 339 patients (53.6%) had family histories of HCM, 132 (20.9%) had heart failure symptoms, and 250 (39.2%) were prescribed cardiac medications. The median maximal left ventricular wall thickness z-score was 8.7 (IQR: 5.3-14.4), and 145 patients (27.2%) had left ventricular outflow tract obstruction. Over a median follow-up period of 5.6 years (IQR: 2.3-10.0 years), 42 patients (6.6%) died, 21 (3.3%) underwent cardiac transplantation, and 69 (10.8%) had life-threatening arrhythmic events. Compared with those presenting after 12 years, a higher proportion of younger patients underwent myectomy (10.5% vs 7.2%; P = 0.045), but fewer received primary prevention implantable cardioverter-defibrillators (18.9% vs 30.1%; P = 0.041). The incidence of mortality or life-threatening arrhythmic events did not differ, but events occurred at a younger age.

CONCLUSIONS

Early-onset childhood HCM is associated with a comparable symptom burden and cardiac phenotype as in patients presenting later in childhood. Long-term outcomes including mortality did not differ by age of presentation, but patients presenting at younger than 12 years experienced adverse events at younger ages.

Relationship Between Maximal Left Ventricular Wall Thickness and Sudden Cardiac Death in Childhood Onset Hypertrophic Cardiomyopathy

BACKGROUND

Maximal left ventricular wall thickness (MLVWT) is a risk factor for sudden cardiac death (SCD) in hypertrophic cardiomyopathy (HCM). In adults, the severity of left ventricular hypertrophy has a nonlinear relationship with SCD, but it is not known whether the same complex relationship is seen in childhood. The aim of this study was to describe the relationship between left ventricular hypertrophy and SCD risk in a large international pediatric HCM cohort.

METHODS

The study cohort comprised 1075 children (mean age, 10.2 years [±4.4]) diagnosed with HCM (1-16 years) from the International Paediatric Hypertrophic Cardiomyopathy Consortium. Anonymized, noninvasive clinical data were collected from baseline evaluation and follow-up, and 5-year estimated SCD risk was calculated (HCM Risk-Kids).

RESULTS

MLVWT Z score was <10 in 598 (58.1%), ≥10 to <20 in 334 (31.1%), and ≥20 in 143 (13.3%). Higher MLVWT Z scores were associated with heart failure symptoms, unexplained syncope, left ventricular outflow tract obstruction, left atrial dilatation, and nonsustained ventricular tachycardia. One hundred twenty-two patients (71.3%) with MLVWT Z score ≥20 had coexisting risk factors for SCD. Over a median follow-up of 4.9 years (interquartile range, 2.3-9.3), 115 (10.7%) had an SCD event. Freedom from SCD event at 5 years for those with MLVWT Z scores <10, ≥10 to <20, and ≥20 was 95.6%, 87.4%, and 86.0, respectively. The estimated SCD risk at 5 years had a nonlinear, inverted U-shaped relationship with MLVWT Z score, peaking at Z score +23. The presence of coexisting risk factors had a summative effect on risk.

CONCLUSIONS

In children with HCM, an inverted U-shaped relationship exists between left ventricular hypertrophy and estimated SCD risk. The presence of additional risk factors has a summative effect on risk. While MLVWT is important for risk stratification, it should not be used either as a binary variable or in isolation to guide implantable cardioverter defibrillator implantation decisions in children with HCM.

Association between common cardiovascular risk factors and clinical phenotype in patients with hypertrophic cardiomyopathy from the European Society of Cardiology (ESC) EurObservational Research Programme (EORP) Cardiomyopathy/Myocarditis registry

AIMS

The interaction between common cardiovascular risk factors (CVRF) and hypertrophic cardiomyopathy (HCM) is poorly studied. We sought to explore the relation between CVRF and the clinical characteristics of patients with HCM enrolled in the EURObservational Research Programme (EORP) Cardiomyopathy registry.

METHODS AND RESULTS

1739 patients with HCM were studied. The relation between hypertension (HT), diabetes (DM), body mass index (BMI), and clinical traits was analysed. Analyses were stratified according to the presence or absence of a pathogenic variant in a sarcomere gene. The prevalence of HT, DM, and obesity (Ob) was 37, 10, and 21%, respectively. HT, DM, and Ob were associated with older age (P<0.001), less family history of HCM (HT and DM P<0.001), higher New York Heart Association (NYHA) class (P<0.001), atrial fibrillation (HT and DM P<0.001; Ob p = 0.03) and LV (left ventricular) diastolic dysfunction (HT and Ob P<0.001; DM P = 0.003). Stroke was more frequent in HT (P<0.001) and mutation-positive patients with DM (P = 0.02). HT and Ob were associated with higher provocable LV outflow tract gradients (HT P<0.001, Ob P = 0.036). LV hypertrophy was more severe in Ob (P = 0.018). HT and Ob were independently associated with NYHA class (OR 1.419, P = 0.017 and OR 1.584, P = 0.004, respectively). Other associations, including a higher proportion of females in HT and of systolic dysfunction in HT and Ob, were observed only in mutation-positive patients.

CONCLUSION

Common CVRF are associated with a more severe HCM phenotype, suggesting a proactive management of CVRF should be promoted. An interaction between genotype and CVRF was observed for some traits.

Perioperative management of non-deferrable oncologic surgeries during COVID-19 pandemic in Madrid, Spain. Is it safe?

Introduction

Surgical treatment during Covid-19 pandemic is controversial. Currently, most clinical guidelines advise to defer surgical patients during the Covid-19 pandemic, although the supporting data is sparse. We assumed that a Covid-19-free hospital, on the back of strong isolation measures and targeted screening, could reduce complications and enable us to continue treating high-risk patients.

Methods

Prospective study with retrospective analysis of 355 patients who had undergone nondeferrable oncological surgery between March 16th, 2020, and April 14th, 2020, at our institution. The aim of the study was to assess the hospital restructuring and surgical protocols to be able to safely handle non-deferrable surgeries during the first wave of the Covid-19 pandemic. We implemented structural changes and an updated surgical-anesthetic protocol in order to isolate Covid-19 patients from other surgical patients. Comprehensive targeted screening for Covid-19 patients was made. PCR tests were requested for suspected Covid-19 patients. We analyzed mortality and complications related to both surgery and Covid-19 during hospital admission and also 15 and 30 days after surgery. We compared it with a sample of similar patients in the pre-pandemic period.

Results

Of the 355 patients enrolled in our study, 21 were removed due to Covid-19 infection, leaving a total of 334 patients in our final analysis. Post-operative complications were found in 37 patients (11.07%). Two patients died after surgery (0.6%). At the end of the study, Covid-19-related adverse outcomes were detected in six patients (1.79%). When comparing the complications of our original sample with the complications that occurred in the pre-covid era, we found no statistically significant differences.

Conclusions

Our results show that the surgical treatment of oncologic patients during the Covid-19 pandemic is safe, as long as the hospital performs surgeries under strict isolation measures and a robust screening method. It is necessary to select Covid-19 free hospitals for this matter in this and future pandemics.

Founder mutation in myosin-binding protein C with an early onset and a high penetrance in males

OBJECTIVE

One of the challenges in hypertrophic cardiomyopathy (HCM) is to determine the pathogenicity of genetic variants and to establish genotype/phenotype correlations. This study aimed to: (1) demonstrate that MYBPC3 c.2149-1G>A is a founder pathogenic variant, (2) describe the phenotype and clinical characteristics of mutation carriers and (3) compare these patients with those with the most frequent pathogenic HCM variants: MYBPC3 p.Arg502Trp/Gln.

METHODS

We reviewed genetic tests performed in HCM probands at our institution. We carried out transcript analyses to demonstrate the splicing effect, and haplotype analyses to support the founder effect of MYBPC3 c.2149-1G>A. Carriers with this mutation were compared with those from MYBPC3 p.Arg502Trp/Gln in terms of presentation features, imaging and outcomes.

RESULTS

MYBPC3 c.2149-1G>A was identified in 8 of 570 probands and 25 relatives. Penetrance was age and sex dependent, 50.0% of the carriers over age 36 years and 75.0% of the carriers over 40 years showing HCM. Penetrance was significantly higher in males: in carriers older than 30 years old, 100.0% of males vs 50.0% of females had a HCM phenotype (p=0.01). Males were also younger at diagnosis (32±13 vs 53±10 years old, p<0.001). MYBPC3 c.2149-1G>A resulted in an abnormal transcript that led to haploinsufficiency and was segregated in two haplotypes. However, both came from one founder haplotype. Affected carriers showed a better functional class and higher left ventricular ejection fraction (LVEF) than patients with MYBPC3 p.Arg502Trp/Gln (p<0.05 for both). Nevertheless, the rate of major adverse outcomes was similar between the two groups.

CONCLUSIONS

MYBPC3 c.2149-1G>A splicing variant is a founder mutation. Affected males show an early onset of HCM and with higher penetrance than women. Carriers show better functional class and higher LVEF than MYBPC3 p.Arg502Trp/Gln carriers, but a similar rate of major adverse outcomes.

Perioperative management of non-deferrable oncologic surgeries during COVID-19 pandemic in Madrid, Spain. Is it safe?

INTRODUCTION

Surgical treatment during COVID-19 pandemic is controversial. Currently, most clinical guidelines advise to defer surgical patients during the COVID-19 pandemic, although the supporting data is sparse. We assumed that a COVID-19-free hospital, on the back of strong isolation measures and targeted screening, could reduce complications and enable us to continue treating high-risk patients.

METHODS

Prospective study with retrospective analysis of 355 patients who had undergone nondeferrable oncological surgery between March 16th, 2020, and April 14th, 2020, at our institution. The aim of the study was to assess the hospital restructuring and surgical protocols to be able to safely handle non-deferrable surgeries during the first wave of the COVID-19 pandemic. We implemented structural changes and an updated surgical-anesthetic protocol in order to isolate COVID-19 patients from other surgical patients. Comprehensive targeted screening for COVID-19 patients was made. PCR tests were requested for suspected COVID-19 patients. We analyzed mortality and complications related to both surgery and COVID-19 during hospital admission and also 15 and 30 days after surgery. We compared it with a sample of similar patients in the pre-pandemic period.

RESULTS

Of the 355 patients enrolled in our study, 21 were removed due to COVID-19 infection, leaving a total of 334 patients in our final analysis. Post-operative complications were found in 37 patients (11.07%). Two patients died after surgery (0.6%). At the end of the study, COVID-19-related adverse outcomes were detected in six patients (1.79%). When comparing the complications of our original sample with the complications that occurred in the pre-COVID era, we found no statistically significant differences.

CONCLUSIONS

Our results show that the surgical treatment of oncologic patients during the COVID-19 pandemic is safe, as long as the hospital performs surgeries under strict isolation measures and a robust screening method. It is necessary to select COVID-19 free hospitals for this matter in this and future pandemics.

The role of the electrocardiographic phenotype in risk stratification for sudden cardiac death in childhood hypertrophic cardiomyopathy

AIMS

The 12-lead electrocardiogram (ECG) is routinely performed in children with hypertrophic cardiomyopathy (HCM). An ECG risk score has been suggested as a useful tool for risk stratification, but this has not been independently validated. This aim of this study was to describe the ECG phenotype of childhood HCM in a large, international, multi-centre cohort and investigate its role in risk prediction for arrhythmic events.

METHODS AND RESULTS

Data from 356 childhood HCM patients with a mean age of 10.1 years (±4.5) were collected from a retrospective, multi-centre international cohort. Three hundred and forty-seven (97.5%) patients had ECG abnormalities at baseline, most commonly repolarization abnormalities (n = 277, 77.8%); left ventricular hypertrophy (n = 240, 67.7%); abnormal QRS axis (n = 126, 35.4%); or QT prolongation (n = 131, 36.8%). Over a median follow-up of 3.9 years (interquartile range 2.0-7.7), 25 (7%) had an arrhythmic event, with an overall annual event rate of 1.38 (95% CI 0.93-2.04). No ECG variables were associated with 5-year arrhythmic event on univariable or multivariable analysis. The ECG risk score threshold of >5 had modest discriminatory ability [C-index 0.60 (95% CI 0.484-0.715)], with corresponding negative and positive predictive values of 96.7% and 6.7.

CONCLUSION

In a large, international, multi-centre cohort of childhood HCM, ECG abnormalities were common and varied. No ECG characteristic, either in isolation or combined in the previously described ECG risk score, was associated with 5-year sudden cardiac death risk. This suggests that the role of baseline ECG phenotype in improving risk stratification in childhood HCM is limited.

Hybrid Procedures. Opening Doors for Surgeon and Cardiologist Close Collaboration

Background: Collaboration between cardiac surgeons and cardiologists can offer interventions that each specialist may not be able to offer on their own. This type of collaboration has been demonstrated with the hybrid Stage I in patients with hypoplastic heart syndrome. Since that time, a hybrid approach to cardiac interventions has been expanded to an incredible variety of potential indications. Methods: Seventy-one patients were scheduled for a hybrid procedure along 8 years. This was defined as close collaboration between surgeon and cardiologist working together in the same room, either cath-lab (27 patients) or theater (44 patients). Results: Six groups were arbitrarily defined. A: vascular cut-down in the cath-lab (27 neonates); B: bilateral banding (plus ductal stent) in hypoplastic left heart syndrome or alike (15 children); C: perventricular closure of muscular ventricular septal defect (10 cases); D: balloon/stenting of pulmonary branches along with major surgical procedure (12 kids); E: surgical implantation of Melody valve (six patients) and others (F, one case). Two complications were recorded: left ventricular free wall puncture and previous conduit tearing. Both drawbacks were successfully sort out under cardiopulmonary by-pass. Conclusion: Surgeon and cardiologist partnership can succeed where their isolated endeavors are not enough. Hybrid procedures keep on spreading, overcoming initial expectations. As a bridge to biventricular repair or transplant, bilateral banding plus ductal stent sounds interesting. Novel indications can be classified into different groups. Hybrid procedures are not complication-free.

Development of a Novel Risk Prediction Model for Sudden Cardiac Death in Childhood Hypertrophic Cardiomyopathy (HCM Risk-Kids)

Importance

Sudden cardiac death (SCD) is the most common mode of death in childhood hypertrophic cardiomyopathy (HCM), but there is no validated algorithm to identify those at highest risk.

Objective

To develop and validate an SCD risk prediction model that provides individualized risk estimates.

Design, Setting, and Participants

A prognostic model was developed from a retrospective, multicenter, longitudinal cohort study of 1024 consecutively evaluated patients aged 16 years or younger with HCM. The study was conducted from January 1, 1970, to December 31, 2017.

Exposures

The model was developed using preselected predictor variables (unexplained syncope, maximal left-ventricular wall thickness, left atrial diameter, left-ventricular outflow tract gradient, and nonsustained ventricular tachycardia) identified from the literature and internally validated using bootstrapping.

Main Outcomes and Measures

A composite outcome of SCD or an equivalent event (aborted cardiac arrest, appropriate implantable cardioverter defibrillator therapy, or sustained ventricular tachycardia associated with hemodynamic compromise).

Results

Of the 1024 patients included in the study, 699 were boys (68.3%); mean (interquartile range [IQR]) age was 11 (7-14) years. Over a median follow-up of 5.3 years (IQR, 2.6-8.3; total patient years, 5984), 89 patients (8.7%) died suddenly or had an equivalent event (annual event rate, 1.49; 95% CI, 1.15-1.92). The pediatric model was developed using preselected variables to predict the risk of SCD. The model's ability to predict risk at 5 years was validated; the C statistic was 0.69 (95% CI, 0.66-0.72), and the calibration slope was 0.98 (95% CI, 0.59-1.38). For every 10 implantable cardioverter defibrillators implanted in patients with 6% or more of a 5-year SCD risk, 1 patient may potentially be saved from SCD at 5 years.

Conclusions and Relevance

This new, validated risk stratification model for SCD in childhood HCM may provide individualized estimates of risk at 5 years using readily obtained clinical risk factors. External validation studies are required to demonstrate the accuracy of this model's predictions in diverse patient populations.

Age-Dependence of Flow Homeostasis in the Left Ventricle

Background: Intracardiac flow homeostasis requires avoiding blood stasis and platelet activation during its transit through the cardiac chambers. However, the foundations of intraventricular blood washout and its exposure to shear stresses have been poorly addressed. We aimed to characterize and quantify these features in a wide population of healthy subjects and assess the relationships of these indices with age. Methods: We used color-Doppler echocardiography and custom post-processing methods to study 149 healthy volunteers from 26 days to 80 years old. From the intraventricular flow-velocity fields we obtained personalized maps of (1) the residence time of blood in the LV, and (2) the shear index, a metric accounting for the strongest occurrence of shear stresses inside the chamber. From these maps we derived quantitative indices of the overall intraventricular blood washout and shear exposure. We addressed the age-dependence of these indices and analyzed their relationship with age-related changes in filling-flow. Results: The entire intraventricular blood pool was replaced before 8 cycles. Average residence time of blood inside the LV was <3 cycles in all subjects and followed an inverse U-shape relationship with age, increasing from median (IQR) of 1.0 (0.7 to 1.2) cycles in the 1st year of life to 1.8 (1.4-2.2) cycles in young adults (17-30 years old), becoming shorter again thereafter. Shear index showed no relation with age and was bounded around 20 dyn·s/cm2. Regions with the longest residence time and highest shear index were identified near the apex. Differences in the degree of apical penetration of the filling waves and the duration of the late-filling phase explained the age-dependence of residence time (R adj 2 = 0.48, p < 0.001). Conclusions: In average, blood spends 1 to 3 beats inside the LV with very low shear stress rates. The apical region is the most prone to blood stasis, particularly in mid-aged adults. The washout of blood in the normal LV is age-dependent due to physiological changes in the degree of apical penetration of the filling waves.

Antithrombotic therapy in pediatric ventricular assist devices: Multicenter survey of the European EXCOR Pediatric Investigator Group

Objectives:

Mechanical circulatory support for pediatric heart failure patients with the Berlin Heart EXCOR ventricular assist system is the only approved and established bridging strategy for recovery or heart transplantation. In recent years, the burden of thromboembolic events has led to modifications of the recommended antithrombotic therapy. Therefore, we aimed to assess modifications of antithrombotic practice among the European EXCOR Pediatric Investigator Group members.

Methods:

We sent a questionnaire assessing seven aspects of antithrombotic therapy to 18 European hospitals using the EXCOR device for children. Returned questionnaires were analyzed and identified antithrombotic strategies were descriptively compared to “Edmonton protocol” recommendations developed for the US EXCOR pediatric approval study.

Results:

Analysis of 18 received surveys revealed substantial deviations from the Edmonton protocol, including earlier start of heparin therapy at 6–12 h postoperatively and in 50% of surveyed centers, monitoring of heparin effectiveness with aPTT assay, administering vitamin K antagonists before 12 months of age. About 39% of centers use higher international normalized ratio targets, and platelet inhibition is changed in 56% including the use of clopidogrel instead of dipyridamole. Significant inter-center variability with multiple deviations from the Edmonton protocol was discovered with only one center following the Edmonton protocol completely.

Conclusion:

Current antithrombotic practice among European EXCOR users representing the treatment of more than 600 pediatric patients has changed over time with a trend toward a more aggressive therapy. There is a need for systematic evidence-based evaluation and harmonization of developmentally adjusted antithrombotic management practices in prospective studies toward revised recommendations.

Pediatric Catheter Ablation: Characteristics and Results of a Series in a Tertiary Referral Hospital

INTRODUCTION AND OBJECTIVES

Catheter ablation has become the treatment of choice in an increasing number of arrhythmias in children and adolescents. There is still limited evidence of its use at a national level in Spain. The aim was to describe the characteristics and results of a modern monocentric series form a referral tertiary care centre.

METHODS

Retrospective register of invasive procedures between 2004 and 2016 performed in patients under 17 years and recorded clinical characteristic, ablation methodology and acute and chronic results of the procedure.

RESULTS

A total of 291 procedures in 224 patients were included. Median age was 12.2 years, 60% male. Overall, 46% patients were referred from other autonomous communities. The most frequent substrates were accessory pathways (AP) (70.2%,>50% septal AP localization) and atrioventricular nodal reentrant tachycardia (AVNRT) (15.8%). Congenital and acquired heart disease was frequent (16.8%). Cryoablation was used in 35.5% of the cases. Overall acute success of the primary procedure was 93.5% (AP 93.8%; AVNRT 100%). Redo procedures after recurrence were performed in 18.9% of all substrates, with a long-term cumulative efficacy of 98.4% (AP 99.3%; AVNRT 100%). One (0.37%) serious complication occurred, a case of complete atrioventricular block.

CONCLUSIONS

Our study replicated previous international reports of high success rates with scarce complications in a high complexity series, confirming the safety and efficacy of pediatric catheter ablation in our environment performed at highly experienced referral centers.

Down syndrome as risk factor for respiratory syncytial virus hospitalization: A prospective multicenter epidemiological study

BACKGROUND

Respiratory syncytial virus (RSV) infection in childhood, particularly in premature infants, is associated with significant morbidity and mortality.

OBJECTIVES

To compare the hospitalization rates due to RSV infection and severity of disease between infants with and without Down syndrome (DS) born at term and without other associated risk factors for severe RSV infection.

PATIENTS/METHODS

In a prospective multicentre epidemiological study, 93 infants were included in the DS cohort and 68 matched by sex and data of birth (±1 week) and were followed up to 1 year of age and during a complete RSV season.

RESULTS

The hospitalization rate for all acute respiratory infection was significantly higher in the DS cohort than in the non-DS cohort (44.1% vs 7.7%, P<.0001). Hospitalizations due to RSV were significantly more frequent in the DH cohort than in the non-DS cohort (9.7% vs 1.5%, P=.03). RSV prophylaxis was recorded in 33 (35.5%) infants with DS. The rate of hospitalization according to presence or absence of RSV immunoprophylaxis was 3.0% vs 15%, respectively.

CONCLUSIONS

Infants with DS showed a higher rate of hospitalization due to acute lower respiratory tract infection and RSV infection compared to non-DS infants. Including DS infants in recommendations for immunoprophylaxis of RSV disease should be considered.

Abstract P2-08-03: Targeting inflammatory pathways: A phase 2 trial of the JAK-inhibitor ruxolitinib in combination with exemestane for aromatase inhibitor-resistant, estrogen receptor-positive breast cancer

Background: In vitro mechanisms link IL-6 to poor outcome in breast cancer via inflammatory pathways, activated JAK/STAT tumor signaling and upregulation of aromatase, leading to an aggressive tumor phenotype. Epidemiological data from our group and others support these mechanisms in women with ER-positive (+) disease. We therefore hypothesized that the JAK inhibitor, ruxolitinib (RUX, INCB018424; Incyte), would enhance activity of exemestane (EXE) in women with ER+ breast cancer who relapsed after non-steroidal aromatase inhibitor therapy, particularly among carriers of a germ-line polymorphism in IL-6, conferring elevated levels of IL-6 in the tumor microenvironment.

Methods: The “JAKEE trial” is a phase II trial to determine the safety and efficacy of RUX + EXE in postmenopausal women with relapsed, ER+ advanced breast cancer. Eligible patients were required to have progressed on a non-steroidal AI and either measureable or bone-only disease. CRP, a putative biomarker of tumor microenvironment inflammation, was measured at baseline and serially during treatment. Using a Simon 2-stage design, we treated 15 patients with RUX at 25 mg BID and EXE at 25mg daily on a continuous 28-day schedule. First stage results were previously presented (AACR, 2014). Accrual proceeded to second stage after no patient met the pre-defined stopping rule of grade (G) 3/4 toxicity requiring discontinuation from the study within the first treatment cycle. Due to the substantial rate of anemia requiring dose reductions, however, RUX dose was reduced to 15 mg BID in second stage.

Results: A total of 25 patients were enrolled; 24/25 had progressed on AI in metastatic setting; 1 relapsed on adjuvant AI. RUX+EXE was well-tolerated overall, with only 2 G4 events (creatinine elevation, hepatic failure); both were due to disease progression. 16% had G3 fatigue, anemia or hypertension; 12% had G3 neutropenia or depression. Other lower grade toxicities in &gt;20% included musculoskeletal pain, increased ALT, and headache. Overall, patients stayed on therapy for a median of 3 cycles (range 2 – 21). There were no CR or PR, but 6/25 (24%) had prolonged disease control (SD&gt; 6 months). Median CRP at study entry was 6.4 (range 0.3-38.9), with 8/25 (32%) having CRP&gt;10. Achieving SD&gt;6 months was not associated with baseline CRP (CRP&gt;10 in 32% with vs. 33% without SD&gt;6 months, p(exact)=1.0). A novel pharmacodynamic assay to assess STAT3 phosphorylation in peripheral blood mononuclear cells after RUX exposure demonstrated differential effects in patients with response.

Conclusions: Targeting JAK/STAT signaling in AI-resistant breast cancer with RUX+EXE was safe and well-tolerated. 24% of patients had prolonged SD, but baseline CRP level did not predict response. Correlative studies to determine whether host and/or tumor biomarkers predict response to therapy, including germline IL-6 genotype, immune profiles, p-STAT3 and estradiol levels, are currently underway.

Citation Format: DeMichele AM, Clark AS, Holmes R, Volpe M, Medrano C, Troxel A, Fox K, Domchek S, Matro J, Bradbury A, Shih N, Feldman M, Hexner E, Bromberg J. Targeting inflammatory pathways: A phase 2 trial of the JAK-inhibitor ruxolitinib in combination with exemestane for aromatase inhibitor-resistant, estrogen receptor-positive breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-08-03.

Surgical Management of Vascular Stents in Pediatric Cardiac Surgery: Clues for a Staged Partnership

Complex cases undergo step surgical and percutaneous procedures, including stent deployment. Concerns arise on stent removal at latest surgery. Our initial experience is presented. Forty-six stents in 35 patients were partially or totally removed at surgery. Univentricular heart was diagnosed in 20 patients. Stents were previously deployed in: ductus (6), right ventricle outflow tract (12), atrial septal defect (4), right pulmonary artery (4), left pulmonary artery (16), inferior vena cava (2), superior vena cava (1) and ascending aorta (1). Surgical procedures performed: 9 transplants, 6 Fontan, 4 Glenn, 1 comprehensive repair (Norwood + Glenn), 1 Glenn takedown, 8 conduit replacement, 2 Fallot, 2 Rastelli, 1 ventricular septal defect closure and 1 iatrogenic aortopulmonary window. Five ductal stents were clipped. Eleven stents in right ventricle, four ones in atrial septal defect, two in right pulmonary artery, seven in the left pulmonary artery and two in inferior vena cava were completely removed. Two stents in right pulmonary artery, one in superior vena cava, one in ascending aorta and nine in the left pulmonary artery were partially retrieved. Handling the stents in ductus, right ventricle and atrial septal defect was straightforward. On the contrary, stent removal in the ductus (comprehensive case), pulmonary branches, both vena cavae or aorta required short periods of deep hypothermia with circulatory arrest. Surgery over stents is increasing in complex, step procedures. Univentricular hearts are most prevalent. Congenital transplant surgery faces new challenges. Stent removal at the time of surgery may require deep hypothermic circulatory arrest.

Antisense-mediated therapeutic pseudoexon skipping in TMEM165-CDG

Deficiencies in glycosyltransferases, glycosidases or nucleotide-sugar transporters involved in protein glycosylation lead to congenital disorders of glycosylation (CDG), a group of genetic diseases mostly showing multisystem phenotype. Despite recent advances in the biochemical and molecular knowledge of these diseases, no effective therapy exists for most. Efforts are now being directed toward therapies based on identifying new targets, which would allow to treat specific patients in a personalized way. This work presents proof-of concept for the antisense RNA rescue of the Golgi-resident protein TMEM165, a gene involved in a new type of CDG with a characteristic skeletal phenotype. Using a functional in vitro splicing assay based on minigenes, it was found that the deep intronic change c.792+182G>A is responsible for the insertion of an aberrant exon, corresponding to an intronic sequence. Antisense morpholino oligonucleotide therapy targeted toward TMEM165 mRNA recovered normal protein levels in the Golgi apparatus of patient-derived fibroblasts. This work expands the application of antisense oligonucleotide-mediated pseudoexon skipping to the treatment of a Golgi-resident protein, and opens up a promising treatment option for this specific TMEM165-CDG.

Comparison of bacterial results from conventional cultures of the periprosthetic membrane and the synovial or pseudocapsule during hip revision arthroplasty

INTRODUCTION

Bacterial identification is essential to diagnose and treat a revision for prosthetic loosening of an infected hip. The purpose of this study was to determine whether conventional cultures from the periprosthetic membrane are superior to synovial/pseudocapsule samples in the diagnosis of infection in hip revision arthroplasty.

MATERIALS AND METHODS

We performed a prospective study including all hip revisions from October 2009 to October of 2011. Once the implants were removed and prior to the administration of the antibiotic prophylaxis, six periprosthetic samples from different sites were sent to the laboratory for culturing: two periprosthetic fluid samples, two solid material (synovial/pseudocapsule) samples and two swabs. Once the six samples were taken, antibiotic prophylaxis was administered and just as the implant was removed, two more solid samples of the periprosthetic membrane were obtained.

RESULTS

Of a total of 86 hip revision surgeries, 22 were considered septic revisions postoperatively, of which 16 resulted in positive cultures. Of these 16 revisions, 14 obtained the same microbiologic diagnostic when considering either the synovial/pseudocapsule culture results or the solid membrane sample.

CONCLUSIONS

We conclude that the membrane sample for a conventional culture is not superior to the synovial/pseudocapsule sample in detecting microorganisms.

Mutations in the NOTCH pathway regulator MIB1 cause left ventricular noncompaction cardiomyopathy

Left ventricular noncompaction (LVNC) causes prominent ventricular trabeculations and reduces cardiac systolic function. The clinical presentation of LVNC ranges from asymptomatic to heart failure. We show that germline mutations in human MIB1 (mindbomb homolog 1), which encodes an E3 ubiquitin ligase that promotes endocytosis of the NOTCH ligands DELTA and JAGGED, cause LVNC in autosomal-dominant pedigrees, with affected individuals showing reduced NOTCH1 activity and reduced expression of target genes. Functional studies in cells and zebrafish embryos and in silico modeling indicate that MIB1 functions as a dimer, which is disrupted by the human mutations. Targeted inactivation of Mib1 in mouse myocardium causes LVNC, a phenotype mimicked by inactivation of myocardial Jagged1 or endocardial Notch1. Myocardial Mib1 mutants show reduced ventricular Notch1 activity, expansion of compact myocardium to proliferative, immature trabeculae and abnormal expression of cardiac development and disease genes. These results implicate NOTCH signaling in LVNC and indicate that MIB1 mutations arrest chamber myocardium development, preventing trabecular maturation and compaction.

Perventricular pulmonary valvuloplasty under echocardiographic guidance

We report the case of a small neonate with a complex congenital heart disease who successfully underwent a perventricular pulmonary valvuloplasty during the early postoperative period, using echocardiographic guidance alone without fluoroscopy. We describe the technique and the advantages of this novel procedure.

Respiratory infection in congenital cardiac disease. Hospitalizations in young children in Spain during 2004 and 2005: the CIVIC Epidemiologic Study

OBJECTIVES

To evaluate the rate of hospitalization for acute respiratory tract infection in children less than 24 months with haemodynamically significant congenital cardiac disease, and to describe associated risk factors, preventive measures, aetiology, and clinical course.

MATERIALS AND METHODS

We followed 760 subjects from October 2004 through April 2005 in an epidemiological, multicentric, observational, follow-up, prospective study involving 53 Spanish hospitals.

RESULTS

Of our cohort, 79 patients (10.4%, 95% CI: 8.2%-12.6%) required a total of 105 admissions to hospital related to respiratory infections. The incidence rate was 21.4 new admissions per 1000 patients-months. Significant associated risk factors for hospitalization included, with odds ratios and 95% confidence intervals shown in parentheses: 22q11 deletion (8.2, 2.5-26.3), weight below the 10th centile (5.2, 1.6-17.4), previous respiratory disease (4.5, 2.3-8.6), incomplete immunoprophylaxis against respiratory syncytial virus (2.2, 1.2-3.9), trisomy 21 (2.1, 1.1-4.2), cardiopulmonary bypass (2.0, 1.1-3.4), and siblings aged less than 11 years old (1.7, 1.1-2.9). Bronchiolitis (51.4%), upper respiratory tract infections (25.7%), and pneumonia (20%) were the main diagnoses. An infectious agent was found in 37 cases (35.2%): respiratory syncytial virus in 25, Streptococcus pneumoniae in 5, and Haemophilus influenzae in 4. The odds ratio for hospitalization due to infection by the respiratory syncytial virus increases by 3.05 (95% CI: 2.14 to 4.35) in patients with incomplete prophylaxis. The median length of hospitalization was 7 days. In 18 patients (17.1%), the clinical course of respiratory infection was complicated and 2 died.

CONCLUSIONS

Hospital admissions for respiratory infection in young children with haemodynamically significant congenital cardiac disease are mainly associated with non-cardiac conditions, which may be genetic, malnutrition, or respiratory, and to cardiopulmonary bypass. Respiratory syncytial virus was the most commonly identified infectious agent. Incomplete immunoprophylaxis against the virus increased the risk of hospitalization.

Myocardin mRNA is augmented in the failing myocardium: expression profiling in the porcine model and human dilated cardiomyopathy

The implication of myocardin and homeodomain only protein (HOP) in combinatorial molecular pathways that guide heart development and cardio-specific gene expression has recently been reported. However, expression of these genes in the failing heart has not yet been investigated. This study was designed to elaborate a molecular profile of myocardin and HOP expression in the failing ventricular myocardium through the use of both explanted human heart samples and heart biopsies from neonatal piglets with doxorubicin-induced cardiomyopathy (Dox-CM). Myocardin and HOP mRNA levels were estimated by both northern blot hybridization and semiquantitative RT-PCR in human ventricular preparations in end-stage failure due to dilated cardiomyopathy (DCM), as well as in nonfailing donor hearts. Similar experiments were performed with ventricular samples from normal and Dox-treated neonatal piglets. The gene expression of brain natriuretic peptide (BNP) was used as a molecular marker of myocardial damage and failure. The study revealed the following novel findings: (1) myocardin transcripts are detected in neonatal human and pig hearts at lower levels than in mature cardiac tissues, (2) the myocardin transcript pool is significantly augmented in the failing human and porcine myocardium as compared to that in nonfailing heart samples, (3) in the failing human myocardium, increased levels of myocardin mRNA are associated with a diminished HOP transcript content, and (4) the inverse proportion in cardiac myocardin/HOP mRNA pools observed in explanted human hearts is also traceable in normal human heart and aorta. A possible dual consequence of increased myocardin and decreased HOP expression levels on serum response factor-dependent cardiac-specific expression in the normal heart and at heart failure is discussed. Therefore, increased abundance of the myocardin mRNA pool is judged to be a novel CM-related feature which, alone or in association with decreased HOP transcript levels, can be responsible for dysregulation of myocardin-mediated gene expression in failing myocardium.

Vertebral osteomyelitis due to Pasteurella aerogenes

A case of C6-C7 vertebral osteomyelitis due to Pasteurella aerogenes in a previously healthy 62-y-old man in the absence of any history of animal exposure, debilitating disease or immunosuppression is reported. Culture testing of biopsy samples of the vertebral body using the panels and database of the BBL Crystal enteric/non-fermenter system revealed that the infecting bacterium was P. aerogenes. Treatment with cloxacillin and gentamicin was followed by resolution of bone infection on serial follow-up magnetic resonance imaging scans. Pasteurellae are primarily animal pathogens but are capable of producing a variety of local and systemic diseases in humans.

Thoracoscopic resection of ectopic parathyroid glands

BACKGROUND

The vast majority of parathyroid glands in hyperparathyroidism can be resected through a cervical approach. In approximately 2% of the cases, the ectopic gland is in the mediastinum in a location that requires a thoracic approach.

METHODS

We report 7 such cases that were resected using video-assisted thoracic surgery to avoid the need for an open surgical procedure.

RESULTS

All glands were successfully identified preoperatively and subsequently resected. Hospital stay averaged less than 3 days with only one minor complication.

CONCLUSIONS

Ectopic mediastinal parathyroid glands may be safely and accurately resected using video-assisted thoracic surgery to avoid open approaches.

[Hemodynamic changes during laparoscopic surgery. Preliminary study]

The haemodynamic changes produced by laparoscopic surgery in children have been evaluated. A transesophageal echocardiographic study on 13 patients (7 males and 6 females, 10.8 +/- 2.7 years old) has been performed before, during and after peritoneal CO2 gas insufflation. A change on the Doppler waves pattern of the infradiaphragmatic veins along with an increase in blood flow velocity were observed. Pulmonary veins suffered minimal changes showing an increase on either the systolic pressure and on atrial contraction. Diastolic retrograde flow in aorta reflected an increase in peripheral vascular resistance. Cardiac output increased minimally. All haemodynamic changes returned to basal after gas peritoneal desufflation. These data show that laparoscopic surgery could produce important cardiac derangements in children with ventricular dysfunction or in patients presenting left ventricular outlet obstruction. In these patients laparoscopic surgery might be precluded.

Two- and Three-Beam X-ray Diffraction Imaging of Domains in Magnetite

The X-ray diffraction topographic imaging process for ferrimagnetic domains in magnetite Fe3O4at room temperature is investigated, in two- and three-beam cases, for incident synchrotron radiation beams differing in angular divergence and energy spread. In the usual two-beam configuration, domain or wall contrast is obtained from the difference in Bragg conditions, or from the slight difference in the direction of the beams diffracted by neighbouring domains, revealed by the large crystal-to-film distance that can be used at a third-generation synchrotron radiation facility. A three-beamUmweganregungcase involving the weak 171 and the strong 131 reflections shows unusual domain contrast on the 171 topographs, even on images involving energy or angle integration; this contrast is particularly evident on white-beam topographs. The high angular sensitivity this implies is associated with the difference in dispersion relation between the two reflections.

Towards the physical map of the Trypanosoma cruzi nuclear genome: construction of YAC and BAC libraries of the reference clone T. cruzi CL-Brener

Strategies to construct the physical map of the Trypanosoma cruzi nuclear genome have to capitalize on three main advantages of the parasite genome, namely (a) its small size, (b) the fact that all chromosomes can be defined, and many of them can be isolated by pulse field gel electrophoresis, and (c) the fact that simple Southern blots of electrophoretic karyotypes can be used to map sequence tagged sites and expressed sequence tags to chromosomal bands. A major drawback to cope with is the complexity of T. cruzi genetics, that hinders the construction of a comprehensive genetic map. As a first step towards physical mapping, we report the construction and partial characterization of a T. cruzi CL-Brener genomic library in yeast artificial chromosomes (YACs) that consists of 2,770 individual YACs with a mean insert size of 365 kb encompassing around 10 genomic equivalents. Two libraries in bacterial artificial chromosomes (BACs) have been constructed, BACI and BACII. Both libraries represent about three genome equivalents. A third BAC library (BAC III) is being constructed. YACs and BACs are invaluable tools for physical mapping. More generally, they have to be considered as a common resource for research in Chagas disease.

High photorefractive sensitivity at 860 nm in reduced rhodium-doped KNbO(3)

We show that high-temperature reduction in a CO-CO(2) atmosphere increases the photorefractive sensitivity of KNbO(3):Rh at 860nm by 4 orders of magnitude compared with that of the as-grown crystal. The effective trap density is increased by a factor of 3, and the photoconductivity by a factor of 30, and the photorefractive response at a grating spacing of 0.15 mu;m is accelerated by a factor of 400. The grating buildup time at a grating spacing of 0.7 microm and an intensity of 1Wcm(-2) is 0.5 s, a value comparable with that of as-grown KNbO(3):Fe at visible wavelengths. The optical and photorefractive parameters of Rh-doped KNbO(3) subjected to reduction treatment are characterized for wavelengths of 0.48-1.064 microm .

Photorefractive properties of iron-doped stoichiometric lithium niobate

The photorefractive properties of stoichiometric LiNbO(3) crystals with a small number of defect densities grown by the double-crucible Czochralski method are investigated and compared with the defect densities of commercially available congruent Fe-doped LiNbO(3) crystals. Two-wave-mixing experiments show that novel stoichiometric crystals exhibit larger photorefractive gain and considerably faster response times than congruent ones. The results indicate that the nonstoichiometry defect control of photorefractive crystals is of key importance for the improvement of their properties.

Sequential granulocyte colony-stimulating factor increases cisplatin cytotoxicity in human epithelial ovarian cancer cell lines

BACKGROUND

To determine the effect of granulocyte colony-stimulating factor (G-CSF) on tumor growth and cisplatin cytotoxicity in human epithelial ovarian cancer.

METHODS

Six human epithelial ovarian cancer cell lines were treated with media (control) for 24 hr, G-CSF for 24 hr, cisplatin for 24 hr, simultaneous cisplatin and G-CSF for 24 hr, media (control) for 48 hr, cisplatin for 24 hr and sequential media for 24 hr, cisplatin for 24 hr, and sequential G-CSF for 24 hr. Following incubation, the percentage cell lysis was determined by particle concentration fluorescein immunoassay chemosensitivity assay.

RESULTS

G-CSF resulted in tumor cell growth (7-19%) in three cell lines. Simultaneous G-CSF decreased cisplatin cytotoxicity in five cell lines (7-45%). Sequential G-CSF increased cisplatin cytotoxicity in all six cell lines (5-108%).

CONCLUSIONS

G-CSF may result in ovarian cancer proliferation. Simultaneous G-CSF may decrease cisplatin cytotoxicity, while sequential G-CSF appears to increase cisplatin cytotoxicity.

Pulmonary alveolar proteinosis: prolonged spontaneous remission in two patients

Pulmonary alveolar proteinosis is a rare idiopathic diffuse airspace disease characterized by intra-alveolar accumulation of large quantities of lipoproteinaceous material, with preservation of the lung interstitium. The clinical course of pulmonary alveolar proteinosis is variable. Spontaneous resolution is known to occur in up to a quarter of the cases. We describe two patients with untreated pulmonary alveolar proteinosis who experienced complete clinical, functional and radiographic resolution. In follow-up periods of fourteen and six years, both patients have remained asymptomatic.