Rapidly progressive hypertrophic cardiomyopathy in an infant with Noonan syndrome with multiple lentigines: Palliative treatment with a rapamycin analog

Noonan syndrome with multiple lentigines (NSML) frequently manifests with hypertrophic cardiomyopathy (HCM). Recently, it was demonstrated that mTOR inhibition reverses HCM in NSML mice. We report for the first time on the effects of treatment with a rapamycin analog in an infant with LS and malignant HCM. In the boy, progressive HCM was diagnosed during the first week of life and a diagnosis of NSML was established at age 20 weeks by showing a heterozygous Q510E mutation in PTPN11. Immunoblotting with antibodies against pERK, pAkt, and pS6RP in fibroblasts demonstrated enhanced Akt/mTOR pathway activity. Because of the patient's critical condition, everolimus therapy was started at age 24 weeks and continued until heart transplantation at age 36 weeks. Prior to surgery, heart failure improved from NYHA stage IV to II and brain natriuretic peptide values decreased from 9,600 to <1,000 pg/ml, but no reversal of cardiac hypertrophy was observed. Examination of the explanted heart revealed severe hypertrophy and myofiber disarray with extensive perivascular fibrosis. These findings provide evidence that Akt/mTOR activity is enhanced in NSML with HCM and suggest that rapamycin treatment could principally be feasible for infantile NSML. The preliminary experiences made in this single patient indicate that therapy should start early to prevent irreversible cardiac remodelling

rFVIIa in the treatment of persistent hemorrhage in pediatric patients on ECMO following surgery for congenital heart disease

BACKGROUND: Patients who require extracorporeal membrane oxygenation (ECMO) postsurgery for congenital heart disease (CHD) frequently experience severe bleeding episodes. Whereas recombinant-activated factor VII (rFVIIa) has proven efficacy in counteracting intractable hemorrhage in various scenarios, its use in patients on ECMO is limited by the increased risk for thrombotic events. METHODS: Between December 2004 and January 2006, ECMO was used in 10 pediatric patients following cardiac surgery, of whom seven were treated with rFVIIa because of intractable hemorrhage. Their medical records were reviewed with respect to variations in chest tube output and transfusion requirements, occlusion of or thrombus formation in the ECMO circuit and the occurrence of thromboembolic events. Outcome and rate of ECMO circuit occlusion were compared with historic controls. RESULTS: Three patients died, and four survived (none of the deaths was attributable to thrombus formation or bleeding). All patients were treated with aprotinin prior to and during rFVIIa therapy. Two patients developed an occlusion of the oxygenator, one after receiving co-medication with a FXIII concentrate, another after RBC transfusion in the ECMO system. In two patients, thrombus formation was observed in the ECMO system on inspection after discontinuation. Thromboembolic events were not observed. CONCLUSIONS: Recombinant-activated factor VII in a median dosage of 90 microg.kg(-1) was used in seven pediatric patients on ECMO. Rates of ECMO system occlusions and mortality did not differ from historic controls. Neither the reduction of chest tube output nor the blood product transfusion requirements did reach statistical significance

Left Ventricular Physiology and Ventricular‐Vascular Interactions in Young Patients After Heart Transplantation

Background In patients after heart transplantation, systemic arterial hypertension and enhanced central aortic stiffness contribute to increased ventricular afterload, which might lead to graft dysfunction. The aim of our study was to characterize systemic arterial elastance and its impact on left ventricular function and ventriculo‐arterial coupling in a cohort of children, adolescents, and young adults after heart transplantation using invasive conductance catheter technique. Methods and Results Thirty patients who had heart transplants (age, 20.0±6.5 years, 7 female) underwent invasive cardiac catheterization including pressure‐volume loop analysis. Load‐independent parameters of systolic (ventricular elastance [Ees]) and diastolic (ventricular compliance) function as well as systemic arterial elastance (Ea, end‐systolic pressure/stroke volume) and ventriculo‐arterial coupling (Ea/Ees) were assessed at baseline level and during dobutamine infusion (10 μg/kg/min). Ees showed an appropriate increase under inotropic stimulation from 0.43 (0.11–2.52) to 1.00 (0.20–5.10) mm Hg/mL/m2 (P<0.0001), whereas ventricular compliance remained rather unchanged (0.16±0.10 mm Hg/mL/m2 to 0.12±0.07 mm Hg/mL/m2; P=0.10). Ventriculo‐arterial coupling Ea/Ees was abnormal at rest and did not improve significantly under dobutamine (1.7 [0.6–6.7] to 1.3 [0.5–4.9], P=0.70) due to a simultaneous rise in Ea from 0.71 (0.37–2.82) to 1.10 (0.52–4.03) mm Hg/mL/m2 (P<0.0001). Both Ees and ventricular compliance were significantly associated with Ea at baseline and under dobutamine infusion. Conclusions Patients who underwent heart transplantation show impaired ventriculo‐arterial coupling at rest and under inotropic stimulation despite preserved left ventricular contractile reserve. An abnormal response in vascular function resulting in increased afterload seems to represent an important factor that may play a role for the development of late graft failure

Pediatric heart allocation and transplantation in Eurotransplant

Pediatric heart allocation in Eurotransplant (ET) has evolved over the past decades to better serve patients and improve utilization. Pediatric heart transplants (HT) account for 6% of the annual transplant volume in ET. Death rates on the pediatric heart transplant waiting list have decreased over the years, from 25% in 1997 to 18% in 2011. Within the first year after listing, 32% of all infants (<12 months), 20% of all children aged 1-10 years, and 15% of all children aged 11-15 years died without having received a heart transplant. Survival after transplantation improved over the years, and in almost a decade, the 1-year survival went from 83% to 89%, and the 3-year rates increased from 81% to 85%. Improved medical management of heart failure patients and the availability of mechanical support for children have significantly improved the prospects for children on the heart transplant waiting list

Natural history of pulmonary atresia with intact ventricular septum (PAIVS) and critical pulmonary stenosis (CPS) and prediction of outcome

Objectives!#!To analyse prenatal parameters predicting biventricular (BV) outcome in pulmonary atresia with intact ventricular septum/critical pulmonary stenosis (PAIVS/CPS).!##!Methods!#!We evaluated 82 foetuses from 01/08 to 10/18 in 3 centres in intervals 1 (&amp;lt; 24 weeks), 2 (24-30 weeks) and 3 (&amp;gt; 30 weeks).!##!Results!#!61/82 (74.4%) were livebirths, 5 (8.2%) lost for follow-up, 3 (4.9%) had compassionate care leaving 53 (64.6% of the whole cohort and 86.9% of livebirths) with intention to treat. 9 died, 44/53 (83.0%) survived. 24/38 (63.2%) with information on postnatal outcome had BV outcome, 14 (36.8%) non-BV outcome (2 × 1.5 circulation). One with BV outcome had prenatal valvuloplasty. Best single parameter for BV outcome was tricuspid/mitral valve (TV/MV) ratio (AUC 0.93) in intervals 2 and 3 (AUC 0.92). Ventriculo-coronary-arterial communications (VCAC) were present in 11 (78.6%) in non-BV outcome group vs. 2 (8.3%) in BV outcome group (p &amp;lt; 0.001). Tricuspid insufficiency (TI)-Vmax &amp;gt; 2.5 m/s was present in BV outcome group in75.0% (18/24) vs. 14.3% (2/14) in non-BV outcome group. Including the most predictive markers (VCAC presence, TI- Vmax  &amp;lt; 2.5 m/s, TV/MV ratio &amp;lt; cutoff) to a score, non-BV outcome was correctly predicted when &amp;gt; 1 criterion was fulfilled in all cases. After recently published criteria for foetal intervention, only 4/9 (44.4%) and 5/14 (35.7%) in our interval 2 + 3 with predicted non-BV outcome would have been candidates for intervention. Two (1 × intrauterine intervention) in interval 2, two in interval 3 reached BV outcome and one 1.5 circulation without intervention.!##!Conclusion!#!TV/MV ratio as simple parameter has high predictive value. After our score, non-BV outcome was correctly predicted in all cases. Criteria for foetal intervention must further be evaluated

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