Evolving Solutions in the Surgical Treatment of Isolated Pulmonary Valve Stenosis

Background: Surgical treatment of isolated pulmonary valve stenosis in infants and children has evolved over the years, shifting from the original exclusive aim at lowering right ventricle pressure to the current concomitant focus on preserving pulmonary valve function. In our study, we sought to analyze the effect of such evolving philosophy on long-term results. Methods: All consecutive patients treated in our center between July 1983 and March 2019 were included. Patients were categorized into 2 groups based on the introduction into treatment practice of sparing valve techniques (1995). Actuarial survival, freedom from reintervention on the right outflow tract, transvalvular mean pressure gradient decrease, and pulmonary valve function at follow-up were analyzed. Results: One hundred twenty-three patients operated before (Group I, n=81) or since (Group II, n=42) 1995 were enrolled in the study. Mean age and weight were 3.0 ± 0.36 years and 16.6 ± 1.7kg, respectively. Early mortality occurred exclusively in 3 patients of Group 1. Transvalvular mean pressure gradient decreased in the entire patient population (from 63.28 ± 12.9mmHg to 16.46 ± 7.9mmHg). At a mean follow-up interval of 4.9 ± 33 years, freedom from death was comparable, but freedom from right ventricular outflow tract reintervention was significantly greater in Group II. Although the transvalvular gradient remained stable over time in non-reoperated survivors (mean value of 16.46 ± 7.9mmHg), pulmonary valve function on 2D-Echo showed severe incompetence in 2 patients of Group I and just mild to moderate incompetence in 20 patients of Group II, with a significantly negative effect of unsuccessful preoperative pulmonary balloon valvuloplasty (14/20 vs 6/20, p=0.025) in the latter. Conclusion: Current pulmonary valve sparing techniques are associated with better results, particularly in terms of freedom from re-interventions and pulmonary valve function at follow-up. Balloon valvuloplasty prior to surgery may worsen operative results, promoting pulmonary insufficiency and therefore should probably be avoided in all patients in whom anatomical characteristics predict failure of percutaneous therapy.

Cardiovascular safety of growth hormone treatment in Noonan syndrome: real-world evidence

Objective: To assess cardiovascular (CV) safety of growth hormone (GH) treatment in patients with Noonan syndrome (NS) in clinical practice. Design: Two observational, multicentre studies (NordiNet® IOS and the ANSWER Program) evaluating long-term effectiveness and safety of GH in >38,000 paediatric patients, of which 421 had NS. Methods: Serious adverse events, serious adverse reactions (SARs), and non-serious adverse reactions (NSARs) were reported by the treating physicians. CV comorbidities at baseline and throughout the studies were also recorded. Results: The safety analysis set comprised 412 children with NS (29.1% females), with a mean (standard deviation) baseline age of 9.29 (3.88) years, treated with an average GH dose of 0.047 (0.014) mg/kg/day during childhood. CV comorbidities at baseline were reported in 48 (11.7%), most commonly pulmonary valve stenosis and atrial septal defects. Overall, 22 (5.3%) patients experienced 34 safety events. The most common were the NSARs: headache (eight events in seven patients) and arthralgia (five events in three patients). Two SARs occurred in one patient (brain neoplasm and metastases to spine). No CV safety events were recorded in patients with NS. Five CV comorbidities in five patients were reported after initiation of GH treatment: three cases of unspecified CV disease, one ruptured abdominal aortic aneurysm and one pulmonary valve stenosis. Conclusions: GH treatment had a favourable safety profile in patients with NS, including those with CV comorbidities. Prospective studies are warranted to systematically assess the safety of GH treatment in patients with Noonan syndrome and CV disease.

336 Right ventricular mechanics in patients affected by pulmonary valve stenosis, before and after percutaneous pulmonary angioplasty

Aims Pulmonary valve stenosis accounts for 6–9% of all congenital heart diseases. The main effect of this obstructive lesion is a rise in right ventricular pressure; this overload leads to multiple changes in shape, dimensions, and volume of the ventricle. The diagnosis is based on transthoracic echocardiography and invasive heart catheterization. Usually the stenosis is classified into mild, moderate, and severe based on pressure gradient between right ventricle and pulmonary artery and on the ratio between right ventricle and left ventricle systolic pressure. Percutaneous balloon valvuloplasty is the treatment of choice in severe pulmonary valve stenosis in patients of all ages; alternatively surgical valvotomy is an option in selected cases. The aim of this study is to evaluate the mechanical changes of the right ventricle in patients undergoing balloon pulmonary valvuloplasty using transthoracic and speckle-tracking echocardiography (STE). Furthermore, we sought to investigate the correlation between haemodynamic and echocardiographic parameters to better evaluate the degree of pulmonary valve stenosis before and after treatment. Methods and results Forty-three pediatric patients (19 males), mean age 3.2 ± 4.9 years with severe pulmonary valve stenosis and indication for percutaneous balloon valvuloplasty were recruited at the University Hospital of Padua. All patients underwent standard transthoracic echocardiography (TTE), STE with analysis of right ventricle global longitudinal strain (RVGLS) one day before and one day after the procedure. For each patient were collected invasive parameters during the interventional procedure before and after balloon valvuloplasty. After the procedure, there was an immediate statistically significant reduction of both peak-to-peak transpulmonary gradient (Dp post) and ratio between the systolic pressure of right and left ventricle (RV/LV ratio) with a drop of 29.3 ± 14.67 mmHg and 0.43 ± 0.03, respectively. Post-procedural echocardiography showed peak and mean transvalvar pressure gradient drop (50 ± 32.23 and 31 ± 17.97, respectively). The degree of pulmonary valve regurgitation was mild in 8% of patients before the procedure, following the intervention it reached 29% with a statistically significant increase (P = 0.007). However, the incidence of pulmonary valve moderate and severe regurgitation remained stable after the procedure. The analysis of right ventricular function and mechanics showed a significant improvement of Fractional Area Change (FAC) immediately after the procedure (40.11% vs. 44.42%, P = 0,01). On the other hand, right ventricular longitudinal systolic function parameters, TAPSE (P = 0.60) and longitudinal strain (P = 0.31), did not improve significantly after intervention. Finally, pre-procedural invasive RV/LV ratio showed good correlation to echocardiographic transvalvular peak and mean pressure gradient (R = 0.375, P = 0.019 and R = 0.40, P = 0.012, respectively), as well as with FAC (R = 0.31, P = 0.05), TAPSE (R = 0.62, P < 0.001), and RVGLS (R = 0.46, P = 0.01). Conclusions Percutaneous balloon pulmonary valvuloplasty represents an efficient and safe procedure to relieve severe pulmonary valve stenosis. Interestingly, the analysis of right ventricular mechanics on echocardiography demonstrated an immediate global systolic function improvement following afterload reduction. Conversely, longitudinal systolic function did not show improvement immediately after intervention, possibly due to the necessity of longer time to recover. Finally, invasive preprocedural RV/LV ratio demonstrated better correlation with echocardiographic evaluation of stenosis degree and right ventricular function compared to invasive peak-to-peak pressure gradient. Therefore, RV/LV ratio should be preferred for the assessment of pulmonary valve stenosis.

Trametinib for Refractory Chylous Effusions in Children with Noonan Syndrome

BACKGROUND Noonan syndrome (NS) is one of several autosomal dominant multisystem disorders known as RASopathies. Common manifestations of NS include congenital heart defects and cardiomyopathy, lymphatic malformations, and predisposition to myeloproliferative disorders. Chylous fluid accumulation secondary to lymphatic malformations are seen in NS and are a major cause of morbidity and mortality often refractory to conventional medical management. There has been increasing interest in the use of pharmacologic MEK inhibition in the management of these patients given that activating RAS pathway mutations lead to downstream MEK activation that is causative of this pathology. DESIGN/METHODS Three patients with a confirmed diagnosis of NS are described. Each patient developed complications from chylous effusions refractory to conventional management and were subsequently enrolled on-study to treat with compassionate use oral trametinib from Novartis Pharmaceuticals on a single patient Investigational New Drug from the Food and Drug Administration (FDA). All patients were consented to be monitored for one year of therapy following a local protocol approved by the Colorado Institutional Review Board (COMIRB). Patient 1: a 4-year-old female with NS due to a pathogenic germline mutation of the RIT1 gene [c.246T>G, p.Phe82Leu] born with severe hypertrophic cardiomyopathy, mitral valve dysplasia, and pulmonary valve stenosis. She developed bilateral chylous pleural effusions that were refractory to dietary modification, diuretics, octreotide, and sirolimus. Patient 2: a 3-month-old female with NS due to a pathogenic germline mutation of the SOS1 gene [c.1322G>A; p.Cys441Tyr] born with esophageal atresia/tracheoesophageal fistula and moderate pulmonary valve stenosis. She developed bilateral chylous pleural effusions and ascites that were refractory to dietary modification and octreotide therapy. Patient 3: a 4-month-old male with NS due to a gain-of-function mutation of PTPN11 [c.854T>C; p.Phe285Ser] with hypertrophic cardiomyopathy, pulmonary valve stenosis, respiratory insufficiency with suspected pulmonary lymphangiectasia, and persistent chylous pleural effusions in addition to Noonan syndrome-associated myeloproliferative disorder (NS-MPD) that had been refractory to traditional management. RESULTS MEK inhibition with trametinib was used in three patients with NS and life-threatening complications with no medical or surgical treatment options. All three patients had dynamic contrast magnetic resonance lymphangiography (DCMRL) evidence of primary, central lymphatic dysplasia that manifested in lymphatic accumulation affecting cardiorespiratory function, nutrition, and the immune system. DCMRL imaging for patient 2 are highlighted in Figure 1 A and B. Within one month of initiating trametinib oral therapy, all three patients demonstrated response adequate to wean from mechanical ventilation and other supportive care modalities. Serum albumin levels improved as lymphatic leak resolved (Figure 1C). Patient 3 showed improvement in hypertrophic cardiomyopathy as evidenced by a decrease in both NT-proBNP and left ventricular mass by echocardiogram. Patients 1 and 2 demonstrated notable improvements in growth after one year of therapy, with increase in both weight and height percentiles. Patient 3 also presented with NS-MPD that responded with marked improvements in total WBC count as well as absolute monocyte count (Figure 1D). DISCUSSION Our experience adds to the growing body of evidence demonstrating the effectiveness of MEK inhibition on disease processes that are common in patients with NS and other RASopathies. None of the patients in our series experienced significant adverse effects from the medication aside from patient 2 who developed mild dermatitis. The efficacy of this therapy does not appear to be based on the underlying genotype, as each of the three patients we describe had different underlying molecular alterations (SOS1, RIT1, PTPN11). Substantial improvements in a variety of parameters including lymphatic malformations, cardiomyopathy, pulmonary valve stenosis, growth, and NS-MPD highlight the potential utility of trametinib in this patient population. Larger, prospective studies are necessary to confirm the efficacy of MEK inhibition and to assess the long-term safety of its use in this population. Figure 1 Figure 1. Disclosures Nakano: Novartis: Consultancy. OffLabel Disclosure: Trametinib is a MEK1/2 inhibitor that has been approved for the use in certain malignancies. Its off label use in children with Noonan Syndrome with significant lymphatic anomalies is based on the up regulation of the MAPK pathway in these patients.

Case Presentation - Biventricular Hypertrophy and Valvular Pulmonary Stenosis in Adult Patient with Noonan Syndrome: A Rare Case

Introduction: Noonan syndrome (NS) is a genetic disorder often accompanied by multiple congenital abnormalities. The prevalence of NS at live birth has been reported as one in 1000-2500 individuals. About 80% of patients with Noonan syndrome have abnormalities in the cardiovascular system.Case presentation:41-year-old Javanese male presented with chief complaint shortness of breath. His Body Mass Index (BMI) was 18,3. He had an oval-shaped face with a short neck, thin hair, and prominent nasolabial fold. Echocardiography showed biventricular hypertrophy alongside pulmonary valve stenosis, pulmonary regurgitation and minimal pericardial effusion. Discussion: In 1962, Jacqueline Noonan, a pediatric cardiologist, identified 9 patients whose faces were very similar, had short stature, significant chest deformities, and with pulmonary stenosis. Noonan syndrome is a relatively common non-chromosomal syndrome that is similar to the phenotype of Turner's syndrome and presents with cardiovascular malformations. Adult with NS has distinctive facial features such as ptosis, wide eyes, low posterior rotation of ears and helical thickening, and a wide neck.Pulmonary stenosis is the most common heartdefect found in NS, besides HCM isalsoquitecommon inabout20% of patients. We reported a case of a patient with typical characteristics of NS such as pulmonary valve stenosis accompanied by biventricular ventricular hypertrophyand its typical face who survived through adulthood.Conclusion: Syndrome Noonan in the adult is quite rare and difficult to diagnose. We reported a case of an adult man with facial appearance and echocardiographic findings identical with Noonan Syndrome.

Long-term survival in patients with isolated pulmonary valve stenosis: a not so benign disease?

Background and objectivesDuring the last decades, the survival rates in patients with congenital heart disease have increased dramatically, particularly in patients with complex heart malformations. However, the survival in patients with simple defects is still unknown. We aimed to determine the characteristics and the risk of mortality in patients with isolated pulmonary valve stenosis (PS).MethodsSwedish inpatient, outpatient and cause of death registries were used to identify patients born between 1970 and 2017 with a diagnosis of PS, without any other concomitant congenital heart lesion. For each patient with PS, 10 control individuals without congenital heart disease were matched by birth year and sex from the total population registry. We used median-unbiased method and Kaplan-Meier survival analysis to examine the risk of mortality.ResultsWe included 3910 patients with PS and 38 770 matched controls. The median age of diagnosis of PS was 0.7 years (IQR 0.3–7.0). During a median follow-up of 13.5 years (IQR 6.5–23.5), 88 patients with PS and 192 controls died; 500 patients with PS (12%) underwent at least one transcatheter or surgical valve intervention. The overall mortality rate was significantly higher in patients with PS compared with matched controls (HR 4.67, 95% CI 3.61 to 5.99, p=0.001). Patients with an early diagnosis of PS (0–1 year) had the highest risk of mortality (HR 10.99, 95% CI 7.84 to 15.45).ConclusionsIn this nationwide, register-based cohort study, we found that the risk of mortality in patients with PS is almost five times higher compared with matched controls. Patients with an early diagnosis of PS appears to be the most vulnerable group and the regular follow-up in tertiary congenital heart units may be the key to prevention.