Pharmacogenetics of warfarin in a paediatric population: time in therapeutic range, initial and stable dosing and adverse effects.

Warfarin is used in paediatric populations, but dosing algorithms incorporating pharmacogenetic data have not been developed for children. Previous studies have produced estimates of the effect of polymorphisms in Cytochrome P450 2C9 (CYP2C9) and vitamin K epoxide reductase complex subunit 1 (VKORC1) on stable warfarin dosing, but data on time in therapeutic range, initial dosing and adverse effects are limited. Participants (n=97) were recruited, and routine clinical data and salivary DNA samples were collected from all participants and analysed for CYP2C9*2, *3 and VKORC1-1639 polymorphisms.VKORC1 -1639 was associated with a greater proportion of the first 6 months' treatment time spent within the target International Normalised Ratio (INR) range, accounting for an additional 9.5% of the variance in the proportion of time. CYP2C9*2 was associated with a greater likelihood of INR values exceeding the target range during the initiation of treatment (odds ratio (OR; per additional copy) 4.18, 95% confidence interval (CI) 1.42, 12.34). CYP2C9*2 and VKORC1-1639 were associated with a lower dose requirement, and accounted for almost 12% of the variance in stable dose. VKORC1-1639 was associated with an increased likelihood of mild bleeding complications (OR (heterozygotes vs homozygotes) 4.53, 95% CI 1.59, 12.93). These data show novel associations between VKORC1-1639 and CYP2C9*2 and INR values in children taking warfarin, as well as replicating previous findings with regard to stable dose requirements. The development of pharmacogenomic dosing algorithms for children using warfarin has the potential to improve clinical care in this population.

Results of balloon pulmonary valvuloplasty as a palliative procedure in tetralogy of Fallot.

Balloon pulmonary valvuloplasty was attempted in 67 patients with tetralogy of Fallot at a median age of 5 months (range 0.03 to 52 months) for relief of cyanosis. In three patients, the valve could not be crossed and an aortopulmonary shunt was performed. In 35 patients, follow-up angiography was performed 3 to 30 months (average 12) after valvuloplasty. In 24 of these 35 patients (group A), the stenosis had been adequately palliated by valvuloplasty; the other 11 patients (group B) had required an aortopulmonary shunt 1 month (range 0 to 3 months) after valvuloplasty. The two groups were similar (p greater than 0.1) with respect to age at valvuloplasty, pulmonary anulus diameter, ratio of pulmonary artery to descending aorta diameter before valvuloplasty and interval to follow-up angiography. In contrast to patients in group B, patients in group A had a significant immediate improvement in systemic arterial oxygen saturation (p less than 0.01) and a significant increase in pulmonary anulus diameter at follow-up angiography (p less than 0.001). The growth of the branch pulmonary arteries was similar (p greater than 0.1) in the two groups. Among 42 patients who have had surgical correction, a transannular patch for right ventricular outflow tract reconstruction was used in 27 (64%); there was no difference between groups A and B with respect to its use. Eight patients died (three after repair) and death could not be directly attributed to valvuloplasty in any. Balloon valvuloplasty promotes growth of the pulmonary valve anulus and pulmonary arteries and is a useful alternative to an aortopulmonary shunt in patients with small pulmonary arteries or associated complex intracardiac defects.

Comparison of the Sideris and Amplatzer septal occlusion devices.

The results of transcatheter atrial septal defect (ASD) occlusion with 2 different devices (Sideris adjustable buttoned device vs Amplatzer Septal Occluder) were compared in 2 consecutive series of patients. Comparative outcomes were assessed by whether a device was implanted or not, by complications and fluoroscopy time of implantation, and by the incidence of residual shunting on transthoracic echocardiography at follow-up. The patient and defect characteristics were similar in both groups. Twenty-eight of 33 Sideris devices and 37 of 39 Amplatzer devices were implanted. The fluoroscopy time for the Amplatzer implants was 13.4 minutes (range 8 to 41) compared with 23.7 minutes (range 11 to 60.6) for the Sideris implants (p <0.001). The complete occlusion rate for the Amplatzer device was 93% compared with 44% for the Sideris device at 1 year (p <0.001). In conclusion, the Amplatzer device produces higher occlusion rates of ASDs with shorter fluoroscopy times.

Truncus arteriosus with interrupted aortic arch: successful correction in a neonate.

Truncus arteriosus (type II) with interrupted aortic arch (type B) was successfully repaired at 11 days of age using anterior translocation of the pulmonary arteries, resection of the ductus arteriosus, and direct anastomosis between the descending aorta and truncus. This technique permitted wide reconstruction of the aortic arch and minimized the number of suture lines. It also positioned the right ventricle-pulmonary artery conduit anteriorly, which may simplify its subsequent replacement.

Prognosis of supravalve aortic stenosis in 81 patients in Liverpool (1960-1993).

OBJECTIVE: To determine the prognosis of supravalve aortic stenosis into early adult life and the factors affecting this prognosis. DESIGN: 81 patients with supravalve aortic stenosis were followed for a median duration of 8.3 (range 1 to 29) years. PATIENTS: 40 patients (49.4%) had Williams' syndrome, 18 (22.2%) familial supravalve aortic stenosis, 18 (22.2%) sporadic supravalve aortic stenosis, and five (6.2%) other syndromes. Nineteen patients had additional levels of left ventricular outflow tract obstruction. RESULTS: 47 patients (58%) underwent operation; 20% within a year of presentation. Multivariable analysis predicted that 88% of patients would undergo intervention within 30 years of follow up. The chance of intervention was increased by more severe aortic stenosis at presentation and the presence of multilevel obstruction in patients with sporadic supravalve aortic stenosis. Three deaths occurred before operation and 13 within a month of operation. Ten (62.5%) of the postoperative deaths were in patients with multilevel obstruction. Predicted survival 30 years after presentation was 66%. Risk factors for survival were age and severity of aortic stenosis at presentation. Multilevel obstruction did not emerge as a significant risk factor for death because of the high association with the severity of stenosis at presentation. 74% of survivors had mild or insignificant stenosis at follow up. CONCLUSIONS: Long-term survival is related to age and the severity of aortic stenosis at presentation. Most patients will require intervention, and most survivors will have mild stenosis.

Balloon expandable stents for systemic venous pathway stenosis late after Mustard's operation.

OBJECTIVES: Description and evaluation of current experience with the use of balloon expandable stents for the relief of systemic venous pathway stenosis late after Mustard's operation. DESIGN: Retrospective observational study of technical procedures, angiographic, and haemodynamic findings. PATIENTS: Twenty long term survivors of Mustard's operation for transposition of the great arteries (TGA) with angiographic evidence of systemic venous pathway narrowing. INTERVENTION: Systemic venous pathway stenoses were stented using balloon expandable Palmaz stents. RESULTS: Twenty seven stents were deployed across 24 stenoses. Seventeen stents were placed in the inferior baffle (16 patients), with an increase in mean (range) minimum diameter from 9.6 (4.5-15.9) to 16.5 (11.9-22.2) mm (p = 0.007), and a reduction in mean pressure gradient from 3.1 (0-8) to 0.67 (0-3) mm Hg (p = 0.002). Eight stents were placed in the superior pathways of eight patients, with diameters widened from 9.1 (3.5-14.1) to 15.2 (8.7-19.2) mm (p = 0.018), and gradients reduced from 6.4 (2-11) to 0.9 (0-2) mm Hg (p = 0.02). Two badly deployed stents were safely withdrawn from their intracardiac positions and redeployed in the iliac vein. Transvenous pacemaker insertion was facilitated by prior stent insertion. CONCLUSIONS: The use of balloon expandable stents for late systemic pathway narrowing after Mustard's operation is safe and effective. The beneficial effects of stenting are likely to be more durable than those of balloon angioplasty alone, but longer term follow up is required.

Transcatheter occlusion of the patent ductus arteriosus with Cook detachable coils.

OBJECTIVE: To report initial experience with a new occlusion device for native and residual patent ductus arteriosus. DESIGN: Descriptive study of consecutive non-randomised patients undergoing a new method of patent ductus arteriosus closure with detachable coils. SETTING: Tertiary centres for paediatric cardiology. PATIENTS: 71 consecutive patients, aged 1.2-22 years, with a patent ductus arteriosus (PDA) underwent elective transcatheter closure. 45 had native PDAs (group A) with a minimum diameter of 1.0 mm-5.0 mm (median 2.0 mm). A further 26 had undergone one or more previous occlusion attempts (group B). INTERVENTIONS: A total of 133 detachable (Cook) spring coils were successfully implanted in 70 patients. The procedure was performed transvenously in 51 patients, retrograde arterially in 13, and by both routes in a further 6 patients. One 5 mm coil migrated but was successfully retrieved. MAIN OUTCOME MEASURES: In group A colour flow Doppler echocardiography showed that complete occlusion was achieved in 40/45 (89%) at 24 hours, 41/45 (91%) at 1 month, and 44/45 (98%) by 6 months post procedure. Occlusion rates in residual PDAs were 22/25 (88%) occluded at 24 hours, 23/25 (92%) at 1 month, and 24/25 (96%) at 6 months follow up. CONCLUSIONS: Transcatheter occlusion using detachable (Cook) spring coils is a safe and effective alternative to presently available devices. The delivery system allows full retrieval of the coil until a satisfactory position is obtained.

Tricuspid atresia with common arterial trunk: surgical palliation in a neonate.

A two-week-old asymptomatic baby was diagnosed by cross-sectional and Doppler ultrasound to have tricuspid atresia with a common arterial trunk. Successful surgical palliation was undertaken at 17 days of age, by disconnection of the pulmonary arteries from the trunk, and creation of an aortopulmonary shunt. There are no known previous reports of surgical palliation of this lesion.

Fallot's tetralogy with absent pulmonary valve and anomalous origin of the left pulmonary artery.

A 1-day-old asymptomatic neonate with a to and fro precordial murmur was diagnosed by cross sectional echocardiography to have Fallot's tetralogy with absent pulmonary valve, and origin of the left pulmonary artery from the ascending aorta. Moderate stenoses at the origin of the anomalous left pulmonary artery and of the right pulmonary artery were present, allowing definitive surgical correction to be deferred.

Congenital complete heart block and vasodepressor syncope.

An 18-year-old boy with congenital complete heart block presented with recurrent syncope following insertion of a rate-responsive dual-chamber pacemaker. Head-up tilt testing demonstrated a primary vasodepressor response with severe hypotension and reproduction of symptoms. Treatment with fludrocortisone and salt abolished symptoms, and repeat tilt testing was negative.

The progression of mild congenital aortic valve stenosis from childhood into adult life.

UNLABELLED: We studied 187 patients who presented with mild congenital aortic valve stenosis or a bicuspid aortic valve without stenosis at presentation; 63% were males. Information on all clinical events was obtained, and patients were traced to assess current clinical status. RESULTS: The median age at presentation was 2 years (range, 0-15). Additional cardiac lesions occurred in 51 patients, more commonly in patients presenting under 1 year of age (P < 0.0001). The median duration of follow-up was 10 years (range, 1-28); seven patients were lost to follow-up. Thirty-two patients progressed to require intervention (28 surgical, five balloon valvuloplasty) at a median age of 10.5 years. No patient who presented with a bicuspid aortic valve required intervention. Two patients developed endocarditis. There were eight deaths; four after surgery for aortic stenosis and four due to other cardiac lesions. There were no sudden deaths. Actuarial and hazard analysis showed that progression beyond mild stenosis was closely related to duration of follow-up. CONCLUSIONS: Congenital aortic valve stenosis is most frequently mild at presentation. Progression is related to duration of follow-up. Fewer than 20% of patients are likely to still have mild stenosis after 30 years. Follow-up into adult life is essential.

Valvar stenosis: a comparison of clinical assessment, echocardiography, Doppler ultrasound and catheterisation.

The relative merits of noninvasive techniques in the assessment of valve stenosis were examined by comparing the results of clinical assessment by two independent clinicians, the cross-sectional echocardiogram and Doppler ultrasound using the results of cardiac catheterisation as reference in 58 patients with a total of 60 stenotic valve lesions. Doppler ultrasound was the most reliable technique; it was correct in 57 (95%) of the 60 lesions. Clinical assessment and cross sectional echocardiography were correct in 48 (80%), and 46 (77%) of the 60 lesions, respectively. In 7 instances 2 noninvasive assessments were wrong in the same patient but on no occasion were all 3 techniques misleading in the same patient. In 17 patients with severe mitral stenosis, clinical assessment Doppler ultrasound and cross-sectional echocardiography were correct in 14 (82%), 16 (94%) and 17 (100%) patients, respectively, whilst in the 4 patients with moderate mitral stenosis the corresponding figures were 3 (75%), 4 (100%) and 2 (50%). In mild mitral stenosis (3 patients), the clinical assessment was correct in 2 (67%) patients, Doppler ultrasound in 3 (100%) patients and cross-sectional echocardiography in 2 (67%) patients. In 22 patients with severe aortic stenosis, the clinical assessment and Doppler ultrasound were correct in every patient (100%), whilst the cross-sectional echocardiogram was correct in 18 (82%) patients. In 11 patients with moderate aortic stenosis, the clinical assessment was correct in only 5 (45%) patients, the cross-sectional echocardiogram in 5 (45%) patients and Doppler assessment in 9 (82%) patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Absent left-sided atrioventricular connexion, with right atrium connected to left ventricle: prospective diagnosis in infancy, and outcome.

Prospective echocardiographic diagnosis of absence of the left atrioventricular connexion, with the right atrium connected to a morphologic left ventricle through a bileaflet morphologically mitral valve, was made in six infants. The rudimentary right ventricle was left-sided in all patients, and separated from the left atrium by sulcus tissue. The ventriculoarterial connexions were discordant. Associated defects included subpulmonary stenosis (2 patients), pulmonary atresia (1 patient), and a patent duct (4 patients). All patients developed early left atrial hypertension due to a restrictive interatrial septum, and required transcatheter septostomy (5 patients), or surgical septectomy (3 patients). One patient who had a severely restrictive ventricular septal defect died following cardiac catheterization. In three others the ventricular septal defect has become progressively restrictive on serial catheterization. Successful intermediate term palliation has been performed in two patients using a bidirectional Glenn anastomosis, together with enlargement of the ventricular septal defect and a Damus-Kay-Stansel procedure in one. It is possible to distinguish this malformation from "mitral atresia" using cross-sectional echocardiography. The long-term outlook is influenced by early relief of left atrial hypertension. Balloon atrial septostomy alone is usually inadequate, and either blade septostomy or surgical septectomy are required. Serial cardiac catheterization is mandatory for planning definitive palliation.

Diagnosis and assessment of disease activity in takayasu arteritis: a childhood case illustrating the challenge.

Takayasu Arteritis (TA) is a rare, debilitating large vessel vasculitis occurring in patients of all ages, including infants, but the disease most commonly presents in the third decade. Diagnosis is often delayed and consequently TA is associated with significant morbidity and mortality. Accurate methods of monitoring disease activity or damage are lacking and currently rely on a combination of clinical features, blood inflammatory markers, and imaging modalities. In this report we describe a case of a 14-year-old boy with childhood-onset TA who, despite extensive negative investigations, did indeed have on-going active large vessel vasculitis with fatal outcome. Postmortem analysis demonstrated more extensive and active disease than originally identified. This report illustrates and discusses the limitations of current modalities for the detection and monitoring of disease activity and damage in large vessel vasculitis. Clinicians must be aware of these limitations and challenges if we are to strive for better outcomes in TA.

Retained central venous lines (CVLs) after attempted removal: an 11-year series and literature review.

BACKGROUND: Central venous lines (CVLs) are frequently used in the management of many neonatal and pediatric conditions. Failure to remove the luminal part of the line (retained CVL) is rare. Consequently, there is lack of experience and consensus in its optimal management. AIM: To document the incidence and management of retained CVLs in a tertiary pediatric surgical centre with access to interventional cardiology services. To review the literature and report efficacy/morbidity of attempted extraction of retained CVLs. METHODS: Children with retained CVLs were identified from departmental morbidity and mortality records over an 11-year period. A literature search was performed in PubMed and Scopus to identify studies reporting retained CVLs (earliest date to 1 January 2012). This was supplemented by scanning bibliographies of retrieved articles. RESULTS: The 11-year incidence of retained CVL was 0.3% (n=10; median duration in-situ 66.5 {range 47-146} months). The underlying pathology in 8 was cystic fibrosis. Antegrade transfemoral snare retrieval was successful in 6 of 7 attempts. In the remaining 3, a conservative approach was adopted following consultation with the family. None of the 4 with retained CVL developed complications (median follow-up 7.5 {range 1-53} months). The literature describes 38 pediatric index cases (including 10 from the current series). Seventeen (49%) were managed conservatively either intentionally or by default after failed endovascular removal attempt (n=4). No complications directly attributed to retained CVLs have been reported (median follow-up 40 {range 1-120} months). Reported morbidity associated with endovascular retrieval includes: procedural failure 30%, line embolization 8%, and intra-operative thrombo-embolism 8%. CONCLUSION: Literature regarding management of retained CVLs is anecdotal. Although uncommon, the complication should feature in consent for removal of CVLs. Conservative management carries long-term risks of infection, thrombosis, and even migration, albeit unquantified over a child's lifetime. Endovascular retrieval is feasible with appropriate expertise.

Twiddler's syndrome in children: an unusual cause of pacemaker failure.

Mechanical causes of pacemaker failure are well recognised. Twiddler's syndrome leading to pacemaker failure has been previously recognised in adults, but there have been no published reports of its occurring in children. Two cases leading to failure of the pacing system are reported. In the first twiddling led to fracture of the lead and in the second it led to displacement of the lead from the heart. Children may be more susceptible to twiddler's syndrome because they have thinner subcutaneous tissues, making leads more accessible, and their comprehension of the consequences may be poor.

Recanalisation of an occluded modified Blalock-Taussig shunt by balloon dilatation.

A four year old boy with pulmonary atresia and ventricular septal defect had an acute cyanotic episode three years after undergoing a right-sided, 6 mm diameter, modified Blalock-Taussig shunt. On admission no continuous murmur could be heard from the shunt and the typical high velocity, continuous flow profile of the shunt could not be identified by Doppler echocardiography. At catheterisation a right subclavian artery angiogram confirmed shunt occlusion. From the subclavian artery, an 0.035 inch wire was used to enter the occluded shunt and then the pulmonary artery. Balloon angioplasty of the entire length of the shunt was performed with 6 mm diameter balloon. After angioplasty the arterial oxygen saturation increased from 63% to 83%. The patient was treated with intravenous heparin followed by warfarin. Repeat catheterisation and angiography eight days later confirmed wide patency of the shunt.

Unilateral cataplexy associated with systemic lupus erythematosus.

A patient with systemic lupus erythematosus (SLE) developed attacks of unilateral cataplexy precipitated by laughter. Unilateral cataplexy has not been described previously in detail and its association with SLE is unique. The clinical details, investigations, and diagnostic criteria are discussed and a causal relationship between cataplexy and SLE is suggested.

Balloon dilatation of unoperated aortic coarctation: immediate results and one year follow up.

Fifteen patients aged 1-19 years (mean 10.9) with previously unoperated aortic coarctation underwent percutaneous balloon angioplasty between January 1985 and February 1986. Nine (60%) were hypertensive at presentation. Under general anaesthetic the systolic coarctation gradient was 24-50 mm Hg (mean 29) and the coarctation diameter was 4-9 mm (mean 5.5). Meditech balloon catheters 8-18 mm in diameter were inflated 1-4 times at 410-760 kPa. After dilatation the systolic coarctation gradient decreased to 0-20 mm Hg (mean 6) and the coarctation diameter increased to 7-20 mm (mean 12). One patient developed a fusiform aneurysm of the aorta at the coarctation site immediately after the procedure. At reinvestigation 6-16 months (mean 12.5) after dilatation 14 of the 15 patients were normotensive. In 13 patients the residual coarctation gradient was 0-10 mm Hg (mean 3). Two patients had recoarctation with residual gradients of 20 and 24 mm Hg and underwent successful repeat dilatation. One patient had developed a small discrete aneurysm at the coarctation site. Balloon angioplasty is thus a safe and effective method of relieving unoperated aortic coarctation. The frequency of aortic aneurysm and recoarctation is small and probably related to balloon size. This early experience is encouraging, but long term results and further experience are required before this approach is used to treat coarctation generally.