Current state of interventional cardiology in congenital heart disease.

Congenital interventional cardiology seeks to provide alternative percutaneous solutions to congenital cardiac problems in preference to more traditional surgical approaches. Simpler procedures have been refined and are now achievable in smaller children and infants. More complex procedures are increasingly recognised as superior to surgical alternatives, though most patients with complex disease inevitably undergo combinations of interventional, surgical and joint or hybrid procedures. This review seeks to highlight recent advances in these techniques of most interest to the readership of this journal.

Device closure of secundum atrial septal defect's and the risk of cardiac erosion.

Cardiac erosion related to transcatheter atrial septal defect closure devices is of increasing concern. Erosion is reported to have occurred with most of currently available occluder devices. Perhaps due to the very large number of implants worldwide, the Amplatzer (St Jude) occluder is associated with the majority of cardiac erosion events reported in the literature. Best current estimates of the incidence of erosion with the St Jude device are between one and three cases per 1000 implants. Most events occur early after implantation and it is rare, although not unheard of, for events to occur after a year following device insertion. It is important that those involved with closure programmes are vigilant for the problem, because device-related erosion is associated with a significant mortality risk. Despite considerable debate, the risk factors (either patient or device) for erosion remain unclear and require further investigation. Currently available data sets have focussed largely on erosion cohorts and are unable to place these cases in appropriate context with non-erosion closure cases. What is certain is that programmes implanting these devices must take care to implant appropriately sized devices and have in place plans to ensure that patients are both well informed and can access help and advice in the event of developing symptoms.

The early and mid-term fate of the axillary artery following axillary artery cut-down and cardiac catheterization in infants and young children.

OBJECTIVES: To study the early and mid-term vascular complications of axillary artery catheterization in children <2 years by clinical and ultrasound examination. BACKGROUND: Femoral arterial access for cardiac catheterization in young children is associated with significant morbidity. Early complications of axillary artery catheterization have been reported but no long-term vascular follow-up data are available. METHODS: Prospective case-control study using standard vascular ultrasound techniques to examine the upper limbs in study participants (n = 10). RESULTS: In total, 23% of axillary artery catheterizarions (56 procedures in 54 patients) resulted in acute arterial insufficiency requiring heparin. Of the survivors under follow-up (n = 33), none had symptoms of chronic arterial insufficiency. At a median follow-up of 8 years postprocedure, three out of the ten study participants had a weak brachial pulse in the test arm but no significant difference in arm measurements. Color Doppler revealed occlusion of the axillary artery in the test arm with collateralization in three patients. The brachial peak systolic velocity (V(max)) was significantly lower in the test arm than the control arm of all the patients with a mean difference of 30 cm/sec (P = 0.007). CONCLUSION: Our study is the first to examine the long-term vascular sequelae of axillary artery catheterization using ultrasound examination and highlights the importance of careful surveillance of vascular access sites. Although axillary artery cut-down for cardiac catheterization in infants and young children does not appear to result in clinical signs of chronic arterial insufficiency, we demonstrate clear evidence of flow abnormalities on vascular ultrasound which are of uncertain long-term significance.

Outcome after extended arch repair for aortic coarctation.

OBJECTIVES: To assess survival and long term arch patency rates in a consecutive group of children after extended arch repair for coarctation of the aorta. METHODS: Review of 191 consecutive children (154 (81%) under 1 year of age) operated on between 1990 and 2002 by a single surgeon using extended arch reconstructive techniques. For assessment of survival patients were divided into three groups: 1, coarctation alone, n = 104; 2, coarctation and ventricular septal defect, n = 38; and 3, coarctation in association with complex intracardiac anomalies, n = 49. A prospective and systematic clinical and echocardiographic evaluation of the aortic arch was undertaken. RESULTS: Median time to follow up was 4.2 years (range 1-10.6 years). Overall actuarial survival was 92%, 88%, and 88% at two, five, and 10 years. Mortality was significantly higher in those patients with complex intracardiac anatomy. Arch obstruction recurred in seven of 165 (4.2%) patients: four of 139 (2.9%) term and three of 10 (30%) premature infants (p < 0.001). CONCLUSIONS: Survival after extended arch reconstruction for coarctation is excellent. At long follow up recurrent arch obstruction is rare, with prematurity the only risk factor.

Poor sensitivity of routine fetal anomaly ultrasound screening for antenatal detection of atrioventricular septal defect.

OBJECTIVE: To report the antenatal detection rate in a consecutive series of liveborn infants with atrioventricular septal defect (AVSD). DESIGN: Review and analysis of referrals for detailed fetal echocardiography and postnatal diagnosis of AVSD. SETTING: Tertiary referral centre for congenital heart disease centre with data prospectively collected between 1996 to 2001. RESULTS: 92 consecutively liveborn infants with AVSDs were identified of which 27 (29%) were detected by routine obstetric antenatal ultrasound. The antenatal diagnosis rate was worse for liveborn infants with trisomy 21 (12 of 49 (25%) v 15 of 43 (35%) chromosomally normal children) and for infants with AVSD without other structural heart disease (18 of 74 (24%) v 9 of 18 (50%) infants with associated structural heart disease). CONCLUSION: Despite the potential ability of fetal ultrasound to detect AVSDs, the antenatal diagnosis rate is poor. This is particularly true for infants with trisomy 21 and is of importance when counselling parents with an apparently normal fetal ultrasound scan.

Successful treatment of left atrial disk thrombus on an Amplatzer atrial septal defect occluder with abciximab and heparin.

Acute device thrombosis is a rare but important complication after transcatheter atrial septal defect closure. In this case a mobile thrombus was noted on the left side of an Amplatzer atrial septal occluder after device release in a 12 year old boy with an uncomplicated atrial septal defect. The thrombus was successfully treated with an infusion of heparin and the glycoprotein IIa/IIIb receptor antagonist abciximab. Transoesophageal ultrasound performed the following day showed complete resolution of the clot. There are no reports to guide treatment of acute thrombosis in this setting. This combination of treatments was effective without complication in this case.

Management of valvar aortic stenosis in children.

What is the best treatment for the child with valvar aortic stenosis-balloon or surgical valvotomy?

Troponin for acute coronary syndromes: has NICE got it right?

The guidelines on the use of glycoprotein IIb/IIIa inhibitors for acute coronary syndromes issued by the National Institute for Clinical Excellence (NICE) recommend that blood troponin is used to identify patients who might benefit from therapy. There are, however, a number of circumstances in which troponin results may be misleading. Firstly, the trials which comprise the evidence base for the therapeutic effect were only based on patients with documented coronary artery disease. Secondly, troponin is elevated in patients with heart failure and concentrations fall with appropriate treatment. Thirdly, there is no internationally accepted standard for troponin, and there are therefore important differences at the 'cut-off' values between the methods of different manufacturers. Fourthly, immunoassays suffer from interfering antibodies and at least 17 case reports have been published outlining false positive tests. It is important that the shortfalls of troponin tests in the diagnosis of acute coronary syndromes are widely recognized.

Surgical and transcatheter (Amplatzer) closure of atrial septal defects: a prospective comparison of results and cost.

OBJECTIVE: To compare effectiveness, complications, and cost of Amplatzer with surgical atrial septal defect (ASD) closure. DESIGN: Prospective study. SETTING: Tertiary cardiac referral centre. PATIENTS: 43 consecutive patients (excluding non-UK residents) aged between 2.1 and 56.8 years (median 7) undergoing ASD closure. MAIN OUTCOME MEASURES: Procedural success, complications, regression of right ventricular dilatation (up to one year postprocedure), cost, inpatient stay, and home convalescent time. RESULTS: Amplatzer ASD closure was successful in 24 of 27 (89%) patients. Surgical closure was successful in all 19 cases. Cardiac complications affecting management occurred in three (11%) of the Amplatzer group (two procedural failures, one device embolisation) and 4 of 19 (21%) surgical patients (one pericardial pain, one global pericardial effusion requiring drainage, and one patient with anaemia requiring haematinics in addition to an incidental pericardial effusion and one further incidental pericardial effusion) (p = NS). There were complications that did not affect management in a further 5 of 19 surgical patients. There was no significant difference in regression of right ventricular dilatation by six months postprocedure (median right ventricular end diastolic diameter decrease: Amplatzer group 17.5%, surgical group 15.1%; median cardiothoracic ratio decrease: Amplatzer 7.9%, surgical 7.5%). Both hospital stay and home convalescent times were significantly shorter after Amplatzer closure (median hospital stay: Amplatzer one day, surgery six days; median convalescent time: Amplatzer two weeks, surgery 5.5 weeks). Median cost was similar for both groups (Amplatzer pound5375, surgical pound5412). CONCLUSIONS: Amplatzer ASD closure has a lower chance of success with a single procedure than surgery. Overall, there were more complications in the surgical group but the majority of these were minor and did not require any change in management. Resolution of right ventricular dilatation over the study period was similar for both techniques. Time spent in hospital and away from work or school was shorter for the Amplatzer group. The cost of both techniques was similar.