Diala Khraiche

Mechanisms of coronary complications after the arterial switch for transposition of the great arteries

BACKGROUNDnThe arterial switch operation (ASO) for transposition of the great arteries requires transfer of the coronary arteries from the aorta to the proximal pulmonary artery (neoaorta). This is complicated by variable coronary anatomy before transfer. In 8% to 10% of cases, there is evidence of late coronary stenosis and/or occlusion, often with catastrophic clinical consequences. The mechanism of such complications has not been well studied.nnnMETHODS AND RESULTSnWe analyzed 190 consecutive high-resolution computed tomographic scans from the ASO procedure (patients aged 5-16 years) and found 17 patients with significant (>30% up to occlusion) coronary lesions (8.9%); all were later confirmed by conventional angiography. The left main coronary artery was abnormal in 9 patients (ostium in all), the left anterior descending artery in 3, the circumflex in 2, and the right coronary artery in 3 patients. Using multiplanar and 3-dimensional reconstructions of the coronary arteries, aorta, and pulmonary artery, we identified the commonest mechanisms of coronary abnormalities. For the left main and left anterior descending artery, anterior positioning of the transferred left coronary artery (between 12 and 1 oclock on the neoaorta) appeared to predispose to a tangential course of the proximal left coronary artery promoting stenosis. All circumflex lesions occurred in Yacoub type D coronaries where a long initially retroaortic artery was stretched by its new positioning behind an enlarged neoaorta. Right coronary artery lesions occurred only in cases in which the reimplantation site was very high above the right coronary sinus with potential compression from the main pulmonary artery bifurcation immediately above.nnnCONCLUSIONSnThus detailed multiplanar computed tomographic scanning can elucidate the mechanisms of late coronary complications after the ASO. Understanding these aspects could help to improve surgical technique to minimize the risk of late coronary obstructions.

Long-term results of the modified Konno procedure in high-risk children with obstructive hypertrophic cardiomyopathy

Objective: Transaortic septal myectomy is the gold standard surgery in obstructive hypertrophic cardiomyopathy, but it is not optimal for children aged less than 5 years and with right ventricular outflow tract obstruction. We evaluated outcomes with the modified Konno procedure in children with severe forms of obstructive hypertrophic cardiomyopathy. Methods: A total of 79 consecutive children who underwent the modified Konno procedure in our center between 1991 and 2016 were included. Results: Clinical features included age less than 5 years (38%), maximal septal thickness 25 mm or more (32%), extension to the left ventricular apex (29%), and right ventricular outflow tract obstruction (28%). In total, 25% of patients had Noonan syndrome. Five children (6%) aged less than 15 months with Noonan syndrome and biventricular obstruction died in the hospital. Mean follow‐up was 6 ± 5.7 years. Survival without death and heart transplantation was 82% at 20 years. Atrioventricular block occurred in 9 patients (11%) and was associated with right ventricular outflow tract obstruction and surgery before 2010. Death, resuscitated sudden cardiac death, and appropriate implantable defibrillator shock were associated with maximal septal thickness before surgery (adjusted odds ratio, 1.20; 95% confidence interval, 1.07–1.35; P = .002) and need for an associated procedure (adjusted odds ratio, 8.84; 95% confidence interval, 2.01–38.93; P = .004). There was no case of recurrent obstruction. Reoperation was required in 4 patients (5%) for other reasons. Conclusions: The modified Konno procedure provided durable obstruction relief and good long‐term survival in children with severe forms of obstructive hypertrophic cardiomyopathy. Children with Noonan syndrome undergoing surgery early in life were at higher risk of early mortality.

Educational needs of adolescents with congenital heart disease: Impact of a transition intervention programme

BACKGROUNDnAdolescents and young adults with congenital heart disease (CHD) have complex health needs and require lifelong follow-up. Interventions to facilitate the paediatric-to-adult healthcare transition are recommended, but outcomes remain largely under-investigated.nnnAIMSnTo identify the educational needs and the impact of a transition intervention on knowledge and self-management skills in adolescents and young adults with CHD.nnnMETHODSnFrom September 2014 to May 2015, 115 adolescents and young adults with CHD (mean age 17±2 years; 47 girls) were consecutively enrolled. Among these, 22 had participated in a structured educational programme in the previous 11±4 months (education group) and 93 had not (comparison group). Knowledge about their health status was assessed using a targeted CHD questionnaire.nnnRESULTSnThe mean overall health knowledge score (maximum of 20) in the education group was significantly higher than in the comparison group (11.7±3.5 vs. 8.6±3.2; P<0.001). We observed significant gaps in knowledge in the comparison group: e.g. 61.3% vs. 90.0% knew their condition name (P=0.01), 21.5% vs. 63.6% were aware of recommended follow-up (P=0.004), and 12.8% vs. 75.0% of girls knew to check their heart condition before pregnancy (P<0.01). In multivariable analysis, after adjustment for age, structured CHD education and higher academic attainment were significant determinants of health-related knowledge (P<0.01).nnnCONCLUSIONnEducation during adolescent-to-adult transition has a significant impact on health knowledge. Structured CHD educational programmes could improve understanding and prevent potential future complications.

0104 : Surrogate echocardiographic parameters to assess right ventricular global systolic function in children with congenital heart disease or pulmonary hypertension

In congenital heart diseases and pulmonary hypertension, right ventricle dysfunction is associated with prognosis. Surrogate parameters of RV systolic function are used in routine. However, their dependence to RV loading conditions has not been tested. Moreover, studies have suggested that these parameters are altered by cardiac surgery. The aim of our study was to assess the feasibility, reproducibility and relevance of surrogate echocardiographic parameters of RV systolic function in children with CHD involving the RV or pulmonary hypertension. We recruited 294 consecutive children with RV pathological loading conditions: 159 have barometric overload, 102 have volumetric overload, 33 have mixed overload. The median age was 9.2+/- 2.3. We assessed RV global systolic function by measuring the Fractional area change. We analyzed the feasibility, reproducibility and relevance of parameters of RV longitudinal systolic function: the Tricuspid Annular Peak Systole Excursion, RV 2 dimensional longitudinal strain and Tissue Doppler derived parameters: tricuspid systolic excursion velocity (Sa), myocardial acceleration during isovolumic contraction (IVA), and RV Tei index. TAPSE and Sa are the surrogate parameters with the best feasibility (>98%) and reproducibility (inter and intra observer variability

0241: Knowledge-based 3D reconstruction compared to MRI for evaluation of right ventricular volumes and function in congenital heart diseases affecting the right ventricle

Cardiac Magnetic resonance imaging (CMR) is considered the reference method for RV volumes and RVEF measurements. Three-dimensional knowledge- based reconstruction (3D-KR) derived from two-dimensional echocardiographic imaging is a novel technique. The aim of this study was to assess the feasibility and reliability of this novel echocardiographic technique in children with diverse CHD involving the right ventricle. 114 children (mean age 12.3 years, range 0,5 to 18) referred for cardiac MRI, were included. Among them, 27 patients had barometric overload, 63 patients had volumetric overload, and 24 patients had mixed overload. Echocardiographic image acquisition was performed using a standard ultrasound scanner linked to a Ventripoint Medical Systems unit. Parameters analysed were RV end-diastolic volume (EDV), RV end-systolic volume (ESV), and RVEF. The method of disks was used for CMR RV volumes. Feasibility of 3D-KR was 100%. Echocardiographic RV volumes correlated well with CMR (EDV, CC = 0.90; ESV, ICC = 0.87; RVEF, ICC = 0.64). For interobserver analyses, COV were 8% for EDV, 15% for ESV, and 17% for EF. For intra-observer analyses, COV were 4% for EDV, 7% for ESV, and 9% for EF. Characteristics of 3DKR as screening tool in detecting RV-EDV 40% in repaired conotruncal heart defects.

0458: Outcomes of pediatric hypertrophic cardiomyopathy associated with Rasopathy

Background The outcomes of pediatric hypertrophic cardiomyopathy (HCM) associated to RASopathies are scarcely known. Aim To describe outcomes of pediatric HCM associated with RASopathy. Methods and results 80 cases of children with a clinical phenotype of RASopathy and HCM were included. Age at diagnosis of HCM was 11.7 months (range 0 to 168). The HCM was diagnosed prenatally in 9 cases, and before one year of age in 58 cases. 67 had Noonan syndrome, 9 had Cardiofacio-cutaneous syndrome, 3 had Costello syndrome, and 1 had Noonan syndrome with multiples lentigines. The HCM was obstructive in 37 cases. Associated cardiac defects were right ventricular outflow tract obstruction in 40 children, polyvalvular dysplasia in 18, atrial septal defect (ASD) in 13, ventricular septal defect in 3, congenital mitral regurgitation in 2, persistent arterial duct in 2, left superior caval vein in 2, aortic arch anomaly in 2, coronary anomaly in 1, and systemic arteriovenous fistula in 1. Nineteen children underwent a Konno operation for obstructive HCM. Additional surgical procedures were 9 right ventricular outflow tract surgical reliefs, 9 percutaneous dilatations of pulmonary valve stenosis, 4 percutaneous closures of ASD, 1 tricuspid valve repair, 1 Brom procedure with aortic valve repair, 1 aortic valve replacement, and 1 coronary artery bypass. Overall mortality was 21%. Fourteen (82%) deaths occurred before 1 year of life. Causes of death were cardiac in 10 cases including two sudden deaths, related to respiratory diseases causes in 5, and in utero fœtal death in 1. Factors predicting mortality were diagnosis before 2 months of life (HR=4,33, p Conclusion Mortality of children with HCM due to RASopathy is high and occurs early in life. Main risk factors are early diagnosis of HCM including prenatal diagnosis, and need for surgery before one year of life.

0483: Cardiac magnetic resonance imaging and left ventricular diastolic function in children with hypertrophic cardiomyopathy

Background Hypertrophic cardiomyopathy (HCM) has a variety of causes in children. In adult, Cardiac Magnetic Resonance imaging (CMR) is emerging as a unique tool particularly suited to define myocardial anatomy and fibrosis. The purpose of the study is to define the feasibility and the role of CMR in children with HCM as well as the influence of myocardial fibrosis on left ventricular (LV) diastolic function in children. Methods CMR protocol included T2 weighted sequence in short axis view, TRIPLE IR FSE sequence, cine SSFP in short axis, two-chamber, three and four chamber view without contrast and perfusion analysis and late enhancement after injection of contrast agent. If left ventricular wall thickness seemed asymmetric, the size and location of relatively thickened segments were noted. Echocardiography analyzed LV diastolic function. Results A total of 60 patients were included in the study. Age at diagnosis was 3 years (range 1 day to 16 years). Mean age at CMR was 11 years (range 1-18 years). CMR was successfully performed in all patients, revealing a better performance in comparison to echocardiography to define precisely the anatomy of LV hypertrophy. Mean LV mass was estimated at 94±41gr/m 2 . LV hypertrophy was concentric in 32 patients, asymmetric in 28 patients, with evidence of LV non-compaction aspect in 7 patients. The right ventricle was affected in 7 cases. Presence of LV fibrosis was detected in 6 patients in LV septum. Perfusion defects were present in 5 patients in papillary muscles. LV function was reduced (LV ejection fraction Conclusion CMR in children with HCM is feasible and it contributes to anatomic definition and tissue analysis. LV diastolic function in pediatric HCM is common but is not related to fibrosis or perfusion defects. Prognostic value of fibrosis and perfusion defects have to be evaluated.

0449: Prognostic value of right ventricle echocardiographic parameters in children with idiopathic pulmonary hypertension

Background Echocardiography is the most common modality used for assessment and serial follow-up of right (RV) and left ventricle (LV) function in children with PAH. However, its role as predictors of outcome value has been poorly characterized. We aimed to characterize RV function in children with idiopathic PAH (iPAH) according their clinical status, and to assess the prognostic value of several echocardiographic indices of cardiac function. Methods and results Clinical, biological and echocardiographic variables were assessed in 39 children (28 girls) with iPAH (type 1, Dana Point classification). Patient’s median age at inclusion was 5.8 years old 95%CI [2.9 -10.4] and the median follow-up was 12.8 months. Forty-seven echocardiographic scans were performed in children at time of worsening defined by NYHA=III or IV and/ or history of syncope and/or RV failure, and 226 echocardiographic scans were performed in stable clinical status defined by NYHA≤II, without syncope and without RV failure. Outcome events were defined as changing from stable to worsening clinical status, death, transplantation, and Potts intervention. Patients in worsening status were significantly younger and had lower body mass index (median age 5.7 years old, BMI=15xa0kg/m2; p Conclusion Echocardiographic parameters of RV function and LV filling were impaired in children with iPAH. TAPSE can predict adverse cardiovascular events. These parameters could be used in the follow-up of children with iPAH, by comparing serially within a given patient.

0459: MRI evaluation of coronary anatomy and myocardial perfusion after arterial switch for transposition of great arteries

Background Coronary arteries obstruction is the main cause of mortality and morbidity in patients who underwent arterial switch for transposition of great arteries. Long-term outcome of coronary transfer and its consequences on myocardial perfusion is scarcely known. Objective: To evaluate feasibility of cardiac MRI to describe coronary anatomy, myocardial perfusion and fibrosis after arterial switch operation. Methods 110 patients (mean age 13.5 y) were included. Twenty-five/110 had had previously documented coronary artery obstruction. cMRI procotol included cine SSFP in short axis, two-chamber, three and four chamber view, and perfusion analysis before and after dipyridamole infusion. Anatomy was evaluated by 3D heart sequence in 78 patients. Finally, late enhancement was evaluated ten minutes after injection of contrast agent in 71 patients. Results Perfusion could be evaluated in all patients. One perfusion defect was identified. All patients with prior negative myocardial ischemia test had normal perfusion on MRI even those with mild to moderate coronary stenosis. Anatomical evaluation of proximal coronary arteries was possible in 71/78 patients. Finally, we found limited myocardial fibrosis in only two/78 patients who had left coronary artery obstruction that had been repaired. Conclusion cMRI is feasible and gives comprehensive information on coronary artery anatomy and physiology after the arterial switch operation. Use of cMRI as a screening tool for late coronary artery obstruction should be evaluated in larger series of patients to estimate its sensitivity and specificity.

0066 : Clinical outcomes of childhood hypertrophic cardiomyopathy associated with RASopathy: the Necker Sick Children Hospital experience

Background Because it represents few patients and a heterogeneous group of disorders, the natural outcomes for children with hypertrophic cardiomyopathy (HCM) are unclear; even more with regard to RASopathies. The aim of this study was to determinate outcomes of children with hypertrophic cardiomyopathy associated with RASopathy according to their therapeutic strategy. Methods and Results Patients in this study were identified between December 1980 and December 2012 in the Congenital and Pediatric Cardiology Unit of Necker Sick Children Hospital in Paris (France). The RASopathy cohort consisted of 81 children with clinical phenotypic diagnostic and echocardiographic hypertrophy cardiomyopathy. The median age at diagnosis of cardiomyopathy was 11,5 +/- 8 months without expecting 9 antenatal diag 46% and 75% of all RASopathy children were diagnosed with cardiomyopathy respectively before 1 months and 1 year. The duration of median follow-up was 8,2 +/- 7,7 years after date of birth. 35% of the study cohort required at least 1 surgical procedure. 82% of deaths occurred before 1 year of life in children with RASopathy and HCM. Risk factors for mortality in the first year of life were antenatal diagnosis (HR=3,38), surgery before 1 year of life (HR=3,38), HCM diagnosed before 2 months of life (HR=2,85), and male (HR=1,21). All deaths after 1 year of life were due to sudden death. 4 children had regressive hypertrophy. At the latest follow-up, 37% (n=11/28) children survived. Summary The outcome of children with hypertrophic cardiomyopathy due to RASopathy is frightful and early with 80% of survey at 1 year of life. Main risk factors seem to be antenatal diagnosis, surgery before 1 year of life, and HCM diagnosed before 2 months of life.