Lympho-hematopoietic malignancies risk after exposure to low dose ionizing radiation during cardiac catheterization in childhood.

Pediatric patients with congenital heart disease (CHD) often undergo low dose ionizing radiation (LDIR) from cardiac catheterization (CC) for the diagnosis and/or treatment of their disease. Although radiation doses from a single CC are usually low, less is known about the long-term radiation associated cancer risks. We aimed to assess the risk of lympho-hematopoietic malignancies in pediatric CHD patients diagnosed or treated with CC. A French cohort of 17,104 children free of cancer who had undergone a first CC from 01/01/2000 to 31/12/2013, before the age of 16 was set up. The follow-up started at the date of the first recorded CC until the exit date, i.e., the date of death, the date of first cancer diagnosis, the date of the 18th birthday, or the 31/12/2015, whichever occurred first. Poisson regression was used to estimate the LDIR associated cancer risk. The median follow-up was 5.9 years, with 110,335 person-years. There were 22,227 CC procedures, yielding an individual active bone marrow (ABM) mean cumulative dose of 3.0 milligray (mGy). Thirty-eight incident lympho-hematopoietic malignancies were observed. When adjusting for attained age, gender and predisposing factors to cancer status, no increased risk was observed for lympho-hematopoietic malignancies RR/mGy = 1.00 (95% CI: 0.88; 1.10). In summary, the risk of lympho-hematopoietic malignancies and lymphoma was not associated to LDIR in pediatric patients with CHD who undergo CC. Further epidemiological studies with greater statistical power are needed to improve the assessment of the dose-risk relationship.

Health-related quality of life and physical activity in children with inherited cardiac arrhythmia or inherited cardiomyopathy: the prospective multicentre controlled QUALIMYORYTHM study rationale, design and methods.

BACKGROUND: Advances in paediatric cardiology have improved the prognosis of children with inherited cardiac disorders. However, health-related quality of life (QoL) and physical activity have been scarcely analysed in children with inherited cardiac arrhythmia or inherited cardiomyopathy. Moreover, current guidelines on the eligibility of young athletes with inherited cardiac disorders for sports participation mainly rely on expert opinions and remain controversial. METHODS: The QUALIMYORYTHM trial is a multicentre observational controlled study. The main objective is to compare the QoL of children aged 6 to 17 years old with inherited cardiac arrhythmia (long QT syndrome, Brugada syndrome, catecholaminergic polymorphic ventricular tachycardia, or arrhythmogenic right ventricular dysplasia), or inherited cardiomyopathy (hypertrophic, dilated, or restrictive cardiomyopathy), to that of age and gender-matched healthy subjects. The secondary objective is to assess their QoL according to the disease's clinical and genetic characteristics, the level of physical activity and motivation for sports, the exercise capacity, and the socio-demographic data. Participants will wear a fitness tracker (ActiGraph GT3X accelerometer) for 2 weeks. A total of 214 children are required to observe a significant difference of 7 ± 15 points in the PedsQL, with a power of 90% and an alpha risk of 5%. DISCUSSION: After focusing on the survival in children with inherited cardiac disorders, current research is expanding to patient-reported outcomes and secondary prevention. The QUALIMYORYTHM trial intends to improve the level of evidence for future guidelines on sports eligibility in this population. Trial registration ClinicalTrials.gov Identifier: NCT04712136, registered on January 15th, 2021 ( https://clinicaltrials.gov/ct2/show/NCT04712136 ).

Diagnosis and treatment of anomalous aortic origin of coronary artery: A twenty-year retrospective study of experience and decision-making in children and young adults.

BACKGROUND: Anomalous aortic origin of a coronary artery, particularly in the presence of inter-arterial course between the great arteries, has been found to be associated with sudden death in young people. METHODS: This study reports a single-center experience in the management of anomalous aortic origin of a coronary artery, with or without inter-arterial course, by focusing specifically on presentation, diagnosis, and patient outcome. RESULTS: From March 1993 to February 2018, 100 patients (70 males) were diagnosed with anomalous aortic origin of a coronary artery, including 27 left coronary artery from the right sinus, 60 right coronary artery from the left sinus, and 13 other anomalies. Patients with inter-arterial course between the great arteries presented more frequently with syncope and/or sudden death compared to patients without (23.4% vs. 0%, p = 0.026). Diagnosis was reached using first-line transthoracic echocardiography in 65% of cases. Surgical repair was performed in 61 patients (61%). All operated patients (60 direct implantations, 1 unroofing) had been diagnosed with inter-arterial course between the great arteries, and were asymptomatic at a mean (±SD) postoperative follow-up of 4.9 ± 5.3 years. CONCLUSIONS: An inter-arterial course of the anomalous right or left coronary arteries arising from the opposite sinus is associated with life-threatening events. Direct reimplantation of coronary artery is reliable, and should be discussed even in asymptomatic patients.

Acute Cardiovascular Manifestations in 286 Children With Multisystem Inflammatory Syndrome Associated With COVID-19 Infection in Europe.

BACKGROUND: The aim of the study was to document cardiovascular clinical findings, cardiac imaging, and laboratory markers in children presenting with the novel multisystem inflammatory syndrome associated with coronavirus disease 2019 (COVID-19) infection. METHODS: This real-time internet-based survey has been endorsed by the Association for European Paediatric and Congenital Cardiologists Working Groups for Cardiac Imaging and Cardiovascular Intensive Care. Children 0 to 18 years of age admitted to a hospital between February 1 and June 6, 2020, with a diagnosis of an inflammatory syndrome and acute cardiovascular complications were included. RESULTS: A total of 286 children from 55 centers in 17 European countries were included. The median age was 8.4 years (interquartile range, 3.8-12.4 years) and 67% were boys. The most common cardiovascular complications were shock, cardiac arrhythmias, pericardial effusion, and coronary artery dilatation. Reduced left ventricular ejection fraction was present in over half of the patients, and a vast majority of children had raised cardiac troponin when checked. The biochemical markers of inflammation were raised in most patients on admission: elevated C-reactive protein, serum ferritin, procalcitonin, N-terminal pro B-type natriuretic peptide, interleukin-6 level, and D-dimers. There was a statistically significant correlation between degree of elevation in cardiac and biochemical parameters and the need for intensive care support (P<0.05). Polymerase chain reaction for severe acute respiratory syndrome coronavirus 2 was positive in 33.6%, whereas immunoglobulin M and immunoglobulin G antibodies were positive in 15.7% cases and immunoglobulin G in 43.6% cases, respectively, when checked. One child in the study cohort died. CONCLUSIONS: Cardiac involvement is common in children with multisystem inflammatory syndrome associated with the Covid-19 pandemic. The majority of children have significantly raised levels of N-terminal pro B-type natriuretic peptide, ferritin, D-dimers, and cardiac troponin in addition to high C-reactive protein and procalcitonin levels. In comparison with adults with COVID-19, mortality in children with multisystem inflammatory syndrome associated with COVID-19 is uncommon despite multisystem involvement, very elevated inflammatory markers, and the need for intensive care support.

Position paper concerning the competence, performance and environment required for the practice of ablation in children and in congenital heart disease.

The population of patients with congenital heart disease (CHD) is continuously increasing, and a significant proportion of these patients will experience arrhythmias because of the underlying congenital heart defect itself or as a consequence of interventional or surgical treatment. Arrhythmias are a leading cause of mortality, morbidity and impaired quality of life in adults with CHD. Arrhythmias may also occur in children with or without CHD. In light of the unique issues, challenges and considerations involved in managing arrhythmias in this growing, ageing and heterogeneous patient population and in children, it appears both timely and essential to critically appraise and synthesize optimal treatment strategies. The introduction of catheter ablation techniques has greatly improved the treatment of cardiac arrhythmias. However, catheter ablation in adults or children with CHD and in children without CHD is more technically demanding, potentially causing various complications, and thus requires a high level of expertise to maximize success rates and minimize complication rates. As French recommendations regarding required technical competence and equipment are lacking in this situation, the Working Group of Pacing and Electrophysiology of the French Society of Cardiology and the Affiliate Group of Paediatric and Adult Congenital Cardiology have decided to produce a common position paper compiled from expert opinions from cardiac electrophysiology and paediatric cardiology. The paper details the features of an interventional cardiac electrophysiology centre that are required for ablation procedures in adults with CHD and in children, the importance of being able to diagnose, monitor and manage complications associated with ablations in these patients and the supplemental hospital-based resources required, such as anaesthesia, surgical back-up, intensive care, haemodynamic assistance and imaging. Lastly, the need for quality evaluations and French registries of ablations in these populations is discussed. The purpose of this consensus statement is therefore to define optimal conditions for the delivery of invasive care regarding ablation of arrhythmias in adults with CHD and in children, and to provide expert and - when possible - evidence-based recommendations on best practice for catheter-based ablation procedures in these specific populations.

Outcomes of Newborns with Prenatal Ventricular Asymmetry not Requiring Neonatal Surgical Intervention: a 22-Year Retrospective Single-Center Study.

To assess the outcomes of neonates prenatally diagnosed with ventricular asymmetry and not operated on within the neonatal period and to determine the risk factors for left heart obstruction occurrence at follow-up. All neonates with prenatal asymmetry of the ventricles, diagnosed from August 1993 to July 2015, not operated on within the neonatal period, were retrospectively included in the study. Left heart echocardiographic measurements at birth and at last follow-up were collected and compared. Left heart anomaly included isthmus and/or aortic valve and/or mitral valve obstruction. There were a total of 34 newborns included in the study. The median follow-up was 2 years. There was no death. Eleven patients were operated on at a median age of three months; seven of them had an obstruction of the left heart (five coarctations of the aorta, one sub-aortic and aortic valve stenosis, and one mitral stenosis). Estimated freedom of left heart surgery was 80% at 6 months and 75% at 10 years. The main risk factor for progression to a left heart anomaly was a hypoplasia of the aortic isthmus (p = 0.0003), while the presence of a left superior vena cava was more frequent in these patients although the difference was not significant. Patients with an aortic isthmus z-score below - 2 at the closure of arterial duct are at risk of later coarctation and therefore follow-up should be extended to at least 3 months. Furthermore, the prenatal ventricular asymmetry does not only identify patients at risk of coarctation but also of other left heart anomalies. This last point should be a better approach with future parents to improve prenatal counseling on a more complex postnatal diagnostic than a simple isolated coarctation.

Surgical repair of a pseudocoarctation with cervical aortic arch complicated by multiple aneurysms of the aorta: a case report.

Aortic pseudocoarctation is a rare congenital anomaly characterized by elongation and deformity of the aortic arch and is known to be associated with aneurysmal formation. Several studies unite to say it leads to a surgical sanction as soon as symptomatic or associated with aneurysms of the aortic arch. Our patient is a 12 years old boy, followed since birth for a little tight pseudocoarctation with a cervical aortic arch and transverse aortic arch hypoplasia. Close clinical and paraclinical monitoring including angioscans, showed the gradual enlargement of the superior mediastinum, in relation with the appearance of three aneurysms of the aortic arch. The intervention, performed by sternotomy, has consisted of the resection of the aneurysmal area and the interposition of a Dacron tube to repair the aortic arch and the reimplantation of the left subclavian artery into the left carotid artery. The postoperative course was uneventful. Management of pseudocoarctation associated with cervical aortic arch and aneurysms remains surgical. Close monitoring of patients with pseudocorctation, seems to be essential to avoid fatal complications such as aneurysmal rupture.

Improving outcomes of acute myocarditis in children.

Acute viral myocarditis may impair prognosis in children of all ages. Its true incidence is underestimated because of heterogeneity of presentation and outcome. Patients may either recover or progress to chronic cardiomyopathy or death. Improving short-term and long-term prognosis is challenging but can probably be achieved by new diagnostic techniques and novel targeted therapies. The objectives of this review are: (1) to detail the current state of knowledge of the pathophysiological mechanisms of acute myocarditis; (2) to provide an update on diagnostic tools such as magnetic resonance imaging and endomyocardial biopsy; and (3) to present new insights in therapeutic strategies, targeted therapies and management of fulminant cases. Options for improving outcomes in acute myocarditis in the pediatric population are discussed.

Focus on echocardiographic and Doppler analysis of coronary artery abnormal origin from the pulmonary trunk with mild myocardial dysfunction.

BACKGROUND: Late presentation of abnormal origin of coronary artery from the pulmonary artery (ACAPA) is uncommon compared with early presentation, which usually induces extended myocardial necrosis and severe heart failure. The late presentation is characterized by abundant development of intercoronary collaterals resulting in mild and rare symptoms, but nevertheless can cause sudden cardiac death. Our objective was to describe presentation, cardiovascular imaging methods for diagnosis and outcomes of patients with late presentation of ACAP. METHODS: The study is a retrospective review of a single-center database to identify all patients diagnosed with ACAPA beyond the first year of life. RESULTS: From 1976 to 2011, 10 patients were identified with ACAPA at the age of 1.1-64 years: 6 with left coronary artery from the pulmonary artery (ALCAPA) and 4 with right coronary artery from the pulmonary artery (ARCAPA). Echocardiography and Doppler imaging evidenced: (1) direct signs: the abnormal coronary ostium arising from the pulmonary trunk with retrograde coronary artery flow and (2) indirect signs: abundant intercoronary septal collaterals with anterograde flow (ARCAPA) or retrograde flow (ALCAPA) and dilatation of the controlateral normally originated coronary artery. Nine patients underwent surgical implantation of the ACAPA into the ascending aorta. After 7.9 years mean follow-up, all were asymptomatic except one who required a second surgery. CONCLUSIONS: Noninvasive cardiovascular imaging, namely transthoracic echocardiography and Doppler specific parameters, can reach diagnosis of late presentation of ACAPA. Direct aortic implantation is a reliable and effective to establish dual coronary artery circulation and prevent risks due to myocardial ischemia.

Long-term outcome after annular mechanical mitral valve replacement in children aged less than five years.

BACKGROUND: When mitral valve repair in children is not possible, mitral valve replacement (MVR) is an alternative, which could result in better outcomes. We report the long-term outcome after replacement of systemic atrioventricular valve with bileaflet mechanical valves in annular position in patients less than 5 years of age. METHODS: Between 1983 and 2008, 29 MVRs were performed in children aged 1.82 ± 1.34 years (range, 95 days to 4.6 years); the average weight was 8.06 ± 2.92 kg (range, 4.7 to 15 kg). The main indication (86%) was severe regurgitation. Prosthesis size ranged between 17 mm and 25 mm. RESULTS: The follow-up was completed and totaled 373 patient-years (12.4 ± 8.6). Four children presented with permanent atrioventricular block. Freedom from thromboembolic and hemorrhage events at 1, 5, 15 years was 100%, 96.1%, and 91.3%, respectively. All deaths occurred within 2 months after MVR and were 5 children (17%). No late mortality was observed. Freedom of redo MVR at 5, 10, and 15 years was 95%, 86%, and 70%, respectively. At MVR, weight 7 kg or less and age 1 year or less (p = 0.03) were associated with redo MVR. During redo MVR, a larger mechanical valve was implanted (+2 sizes), with no postoperative death. Currently, 23 patients are in New York Heart Association class I, and 1 patient is in class II. CONCLUSIONS: The results of mechanical annular MVR are acceptable in children. Anticoagulants are well tolerated, with little thromboembolic complication. Long-term results for patients who survive the hospital period are excellent, and reinterventions show safe results.

Right ventricular recovery after cervical extra corporeal membrane oxygenation in a four-month-old male leading to left Berlin Heart Excor assistance.

A 4-month-old male with cardiogenic shock was implanted with cervical extracorporeal membrane oxygenation (ECMO). He had a biventricular heart failure associated to multiple organ failure (MOF). Right ventricular (RV) function and MOF recovered during five days ECMO leading to left ventricular assistance device (LVAD) implantation. This case shows the advantages of the double bridge strategy providing intervention time for complications refractory to VAD implantation and evaluation time of right and left ventricular function for potential mono- or bi-VAD implantation. Furthermore, there are no reports describing this strategy in young children leading to RV function recovery and its advantage.

Subtle bacterial endocarditis due to Kingella kingae in an infant: a case report.

A 9-month-old infant presented with fever, dyspnoea, and a murmur. Echocardiography showed a mitral vegetation with significant regurgitation. Mitral valve plasty was performed on day 6, and was polymerase chain reaction positive for Kingella kingae. The cardiac outcome was favourable. This case illustrates a subtle presentation of K. kingae mitral valve infective endocarditis in a normal-cardaic infant, treated with early surgery, and the agent belonged to the HACEK (Haemophilus spp Actinobacillus actinomycetemcomitans, Capnocytophaga spp, Cardiobacterium hominis, Eikenella corrodens, and Kingella kingae) group.

Simple repair of aortico-left ventricular tunnel in a newborn with early prenatal diagnosis.

We report a case with very early antenatal diagnosis of aortico-left ventricular tunnel (ALVT) at 22 weeks of pregnancy. Early recognition of ALVT by antenatal ultrasound allows prompt neonatal management and avoidance of harmful aortic valve regurgitation. The present case is unique because of the conjunction of very early antenatal diagnosis, prompt postnatal management, early surgical repair on the sixth day of life, direct closure from the aorta of the aortic orifice only, and optimal postoperative course with excellent mid-term result.

Coronary artery bypass in myocardial ischemia of the young due to hydatid cyst.

Cardiac hydatid cyst is an uncommon disease, especially in France. It is rarely responsible for myocardial ischemia, and even more rarely in the young. We report the clinical features and imaging of a 24-year-old Tunisian woman with hydatid cyst of the free wall of the left ventricle responsible for myocardial ischemia, associated with a hepatic hydatid cyst. Management consisted of a combination of surgery with cystopericystectomy and coronary artery bypass graft and prolonged medical treatment as for treatment of hepatic hydatid cyst. Three-year follow-up revealed no recurrence. This case illustrates two interesting points: the rare clinical presentation of cardiac hydatid cyst with a coronary syndrome in a young 24-year-old woman related to compression of the left anterior descending artery by the cyst with a need for coronary artery bypass graft after resection of the cyst, and the value of medical treatment of hydatid disease, even for cardiac localization.

Extubation after cardiothoracic surgery in neonates, children, and young adults: one year of institutional experience.

OBJECTIVE: Describe risk factors associated with successful and early extubation in the pediatric cardiac intensive care unit. DESIGN: Retrospective chart review. SETTING: University hospital, cardiac intensive care unit. MEASUREMENTS AND MAIN RESULTS: Review of 212 consecutive surgical admissions from January 2003 to January 2004, excluding deaths. Preoperative, intraoperative, and postoperative variables were studied. Successful extubation was defined as no reintubation at any time during the cardiac intensive care unit course and early extubation was defined as mechanical ventilation < or =24 hrs. Median subject age was 8 months (range, 1 day-25 yrs), with 57% <1 yr of age and 22% neonates. Fifty-eight (27%) were extubated in the operating room and 122 (58%) were extubated at <24 hrs (mean, 6.1 +/- 7.7 hrs). Only seven patients failed extubation: three in the operating room because of upper airway obstruction and four in the cardiac intensive care unit for acute respiratory failure associated with atelectasis (n = 2), ventricular dysfunction (n = 1), and arrhythmia (n = 1). There were no extubation failures in patients extubated >24 hrs after surgery. A history of prematurity (odds ratio [OR], 5.84, 2.29-14.9; p < .001), base excess (OR, 1.47, 1.27-1.70; p < .001), cardiopulmonary bypass time (OR, 1.01, 1.01 to -1.2; p < .05), and the need for surgical reintervention (OR, 18.29, 2.78 to -120.07; p < .05) were associated with intubation for >24 hrs. CONCLUSION: Extubation without the need for reintubation can be achieved in nearly all children following cardiothoracic surgery. The majority of successful extubations can be achieved within 24 hrs of surgery

Extubation after cardiothoracic surgery in neonates, children, and young adults: One year of institutional experience.

OBJECTIVE:: Describe risk factors associated with successful and early extubation in the pediatric cardiac intensive care unit. DESIGN:: Retrospective chart review. SETTING:: University hospital, cardiac intensive care unit. MEASUREMENTS AND MAIN RESULTS:: Review of 212 consecutive surgical admissions from January 2003 to January 2004, excluding deaths. Preoperative, intraoperative, and postoperative variables were studied. Successful extubation was defined as no reintubation at any time during the cardiac intensive care unit course and early extubation was defined as mechanical ventilation 24 hrs after surgery. A history of prematurity (odds ratio [OR], 5.84, 2.29-14.9; p < .001), base excess (OR, 1.47, 1.27-1.70; p < .001), cardiopulmonary bypass time (OR, 1.01, 1.01 to -1.2; p < .05), and the need for surgical reintervention (OR, 18.29, 2.78 to -120.07; p < .05) were associated with intubation for >24 hrs. CONCLUSION:: Extubation without the need for reintubation can be achieved in nearly all children following cardiothoracic surgery. The majority of successful extubations can be achieved within 24 hrs of surgery.

Time course and prognostic value of plasma B-type natriuretic peptide concentration in neonates undergoing the arterial switch operation.

BACKGROUND: Plasma B-type natriuretic peptide (BNP) can predict postoperative complications after cardiac surgery in adults. Our aim was to investigate BNP kinetics and prognostic value in neonates undergoing the arterial switch operation (ASO) for transposition of the great arteries (TGA). METHODS: We measured BNP concentrations in 30 neonates before, immediately after, and 6, 12, 24, and 48 h after ASO for TGA. Complicated postoperative evolution was defined as patients requiring mechanical ventilation or presenting low cardiac output syndrome for more than 72 h. We studied the ability of postoperative BNP concentrations to predict complicated evolution. RESULTS: Intubation duration, inotropic support duration, and intensive care unit stay were 68 (48-121) h, 78 (69-141) h, and 96 (76-149) h respectively. Patients with complicated evolution had higher 6 and 12-h BNP concentrations than patients with simple evolution (459 (210-897) vs 137 (67-248) ng/L and 547 (193-868) vs 185 (79-354) ng/L respectively; P < 0.05) and had longer intubation, inotropic support, and intensive care unit stay (96 (70-190) vs 50 (48-66) h, 100 (83-190) vs 70 (59-72) h, and 120 (90-240) vs 84 (72-96) h, P < 0.05). A 6-h BNP concentration >160 ng/L was able to predict complicated evolution with a sensitivity of 93% and a specificity of 67%. CONCLUSION: In neonates, BNP concentrations can predict adverse outcome in the postoperative period after ASO for TGA. This marker has potential clinical applications.

Use of dexmedetomidine in children after cardiac and thoracic surgery.

OBJECTIVE: In this report, we describe our experience with the use of dexmedetomidine in spontaneously breathing as well as in mechanically ventilated patients, after congenital cardiac and thoracic surgery. DESIGN: Retrospective case series. SETTING: University hospital, pediatric cardiac intensive care unit. PATIENTS: Thirty-three spontaneously breathing and five mechanically ventilated patients who received dexmedetomidine after cardiothoracic surgery. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Thirty-eight patients, age 8 +/- 1.1 yrs old and weight 29 +/- 3.8 kg, were included. Seven patients (18%) were <1 yr old. Dexmedetomidine was used as a primary sedative and analgesic agent, and when its effect was considered inadequate, despite incremental infusion doses, a rescue agent was administered. The initial dexmedetomidine infusion dose was 0.32 +/- 0.15 microg/kg/hr followed by an average infusion of 0.3 +/- 0.05 microg/kg/hr (range 0.1-0.75 microg/kg/hr). There was a trend toward higher dexmedetomidine infusion requirement in patients <1 yr old compared with older children, 0.4 +/- 0.13 vs. 0.29 +/- 0.17 microg/kg/hr (p = .06). Desired sedation and analgesia were achieved during 93% and 83% of the dexmedetomidine infusion, respectively. According to the intensive care unit sedation scale (score 0-3) and two pain scales (Numeric Visual Analog Scale and Face, Legs, Activity, Cry, and Consolability, score 0-10), the mean sedation score was 1.3 +/- 0.6 (mild sedation) and the mean pain score was 1.5 +/- 0.9 (mild pain). The most frequently rescue drugs administered were fentanyl, morphine, and midazolam. Overall, 49 rescue doses of sedatives/analgesics were given. Patients <1 yr old required more rescue boluses than older children, 22 boluses (3.19 +/- 0.8) vs. 27 boluses (0.8 +/- 0.2, p = .003). Throughout the dexmedetomidine infusion there was no significant change in the systolic and diastolic blood pressure trend. Six patients (15%) had documented hypotension. In three, hypotension resolved with decreasing the dexmedetomidine infusion dose whereas in the other three, hypotension resolved after discontinuing the infusion. Although there was a trend toward lower heart rates, this was not clinically significant. One patient had an episode of considerable bradycardia without hypotension, which resolved shortly after discontinuing the dexmedetomidine infusion. No significant changes in the arterial blood gases or respiratory rates were observed. There was no mortality, and the total intensive care unit length of stay was 19 +/- 2 hrs. CONCLUSIONS: Our data suggest that dexmedetomidine is a well-tolerated and effective agent for both spontaneously breathing and mechanically ventilated patients following congenital cardiac and thoracic surgery.

Rabbit antithymocyte globulin as induction immunotherapy in pediatric heart transplantation.

BACKGROUND: There is little published data on the use of antithymocyte globulins in children. This retrospective study describes the use of Thymoglobulin (Imtix, SangStat, Lyon, France) in pediatric cardiac transplantation over a 13-year period in a single center that adjusted the dose of Thymoglobulin according to platelet count monitoring and examines the short-term hematological effects as well as longer-term outcomes. METHODS: Data for all children who received a heart transplant at the Hôpital Cardiologique at Lyon from 1984 to 2001 and who were given Thymoglobulin as part of their immunosuppressive protocol were extracted. The dose of Thymoglobulin given depended on baseline platelet count and was 2, 1.5, or 1 mg/kg per day over 5 days for the following platelet count groups: greater than 150,000/mm (normal group), 100 to 150,000/mm (mild thrombocytopenia group), and 50 to 100,000/mm (moderate thrombocytopenia group). RESULTS: Thirty children of median age 14.2 years were given a median cumulative dose of Thymoglobulin of 8 mg/kg per patient; the moderate thrombocytopenia subgroup was given significantly less (6.4 mg/kg) ( P=0.032). Immediate tolerability of Thymoglobulin was good, with no cases of first-dose syndrome, anaphylaxis, or serum sickness. The platelet count decreased at the start of therapy, but recovered after discontinuation, and did not give rise to clinical concern. Patients were followed up for a median of 6.3 years (7 days-15.5 years); actuarial survival was 90%, 86%, and 74.5%, respectively, at 1, 5, and 10 years. In the first year, 50% of patients suffered an episode of rejection. The overall incidence of infection in the month following transplantation was 40%. One lymphoma occurred at 5 months. CONCLUSIONS: The use of Thymoglobulin in pediatric heart-transplant patients as part of an immunosuppressive protocol, with dose adjustment according to platelet levels, has been shown to be effective in terms of rejection rate and patient survival and safe in terms of the incidence of infections and malignancy.