Long-Term Outcomes After Melody Transcatheter Pulmonary Valve Replacement in the US Investigational Device Exemption Trial

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Background:

The Melody valve was developed to extend the useful life of previously implanted right ventricular outflow tract (RVOT) conduits or bioprosthetic pulmonary valves, while preserving RV function and reducing the lifetime burden of surgery for patients with complex congenital heart disease.

Methods:

Enrollment for the US Investigational Device Exemption study of the Melody valve began in 2007. Extended follow-up was completed in 2020. The primary outcome was freedom from transcatheter pulmonary valve (TPV) dysfunction (freedom from reoperation, reintervention, moderate or severe pulmonary regurgitation, and/or mean RVOT gradient >40 mm Hg). Secondary end points included stent fracture, catheter reintervention, surgical conduit replacement, and death.

Results:

One hundred seventy-one subjects with RVOT conduit or bioprosthetic pulmonary valve dysfunction were enrolled. One hundred fifty underwent Melody TPV replacement. Median age was 19 years (Q1–Q3: 15–26). Median discharge mean RVOT Doppler gradient was 17 mm Hg (Q1–Q3: 12–22). The 149 patients implanted >24 hours were followed for a median of 8.4 years (Q1–Q3: 5.4–10.1). At 10 years, estimated freedom from mortality was 90%, from reoperation 79%, and from any reintervention 60%. Ten-year freedom from TPV dysfunction was 53% and was significantly shorter in children than in adults. Estimated freedom from TPV-related endocarditis was 81% at 10 years (95% CI, 69%–89%), with an annualized rate of 2.0% per patient-year.

Conclusions:

Ten-year outcomes from the Melody Investigational Device Exemption trial affirm the benefits of Melody TPV replacement in the lifetime management of patients with RVOT conduits and bioprosthetic pulmonary valves by providing sustained symptomatic and hemodynamic improvement in the majority of patients.

Registration:

URL: https://www.clinicaltrials.gov; Unique identifier: NCT00740870.

Comparison of the investigational device exemption and post-approval trials of the Melody transcatheter pulmonary valve

OBJECTIVE

We compared 5-year outcomes of transcatheter pulmonary valve (TPV) replacement with the Melody TPV in the post-approval study (PAS) and the investigational device exemption (IDE) trial.

BACKGROUND

As a condition of approval of the Melody TPV after the IDE trial, the Food and Drug Administration required that a PAS be conducted to evaluate outcomes of TPV replacement in a "real-world" environment. The 5-year outcomes of the PAS have not been published, and the IDE and PAS trials have not been compared.

METHODS

The cohorts comprised all patients catheterized and implanted at 5 IDE sites and 10 PAS sites. Differences in trial protocols were detailed. Time-related outcomes and valve-related adverse events were compared between the two trials with Kaplan-Meier curves and log-rank testing.

RESULTS

167 patients (median age, 19 years) were catheterized and 150 underwent TPV replacement in the IDE trial; 121 were catheterized (median age, 17 years) and 100 implanted in the PAS. Freedom from hemodynamic dysfunction (p = .61) or any reintervention (p = .74) over time did not differ between trials. Freedom from stent fracture (p = .003) and transcatheter reintervention (p = .010) were longer in PAS, whereas freedom from explant (p = .020) and TPV endocarditis (p = .007) were shorter. Clinically important adverse events (AEs) were reported in 14% of PAS and 7.2% of IDE patients (p = .056); the incidence of any particular event was low in both.

CONCLUSIONS

Hemodynamic and time-related outcomes in the PAS and IDE trials were generally similar, confirming the effectiveness of the Melody TPV with real-world providers. There were few significant complications and limited power to identify important differences in AEs. The lack of major differences in outcomes between the two studies questions the usefulness of mandated costly post-approval studies as part of the regulatory process for Class III medical devices.

Endocarditis After Transcatheter Pulmonary Valve Replacement

BACKGROUND

Endocarditis has emerged as one of the most concerning adverse outcomes in patients with congenital anomalies involving the right ventricular outflow tract (RVOT) and prosthetic valves.

OBJECTIVES

The aim of this study was to evaluate rates and potential risk factors for endocarditis after transcatheter pulmonary valve replacement in the prospective Melody valve trials.

METHODS

All patients in whom a transcatheter pulmonary valve (TPV) was implanted in the RVOT as part of 3 prospective multicenter studies comprised the analytic cohort. The diagnosis of endocarditis and involvement of the TPV were determined by the implanting investigator.

RESULTS

A total of 309 patients underwent transcatheter pulmonary valve replacement (TPVR) and were discharged with a valve in place. The median follow-up duration was 5.1 years, and total observation until study exit was 1,660.3 patient-years. Endocarditis was diagnosed in 46 patients (median 3.1 years after TPVR), and a total of 35 patients were reported to have TPV-related endocarditis (34 at the initial diagnosis, 1 with a second episode). The annualized incidence rate of endocarditis was 3.1% per patient-year and of TPV-related endocarditis was 2.4% per patient-year. At 5 years post-TPVR, freedom from a diagnosis of endocarditis was 89% and freedom from TPV-related endocarditis was 92%. By multivariable analysis, age ≤12 years at implant (hazard ratio: 2.3; 95% confidence interval: 1.2 to 4.4; p = 0.011) and immediate post-implant peak gradient ≥15 mm Hg (2.7; 95% confidence interval: 1.4 to 4.9; p = 0.002) were associated with development of endocarditis and with development of TPV-related endocarditis (age ≤12 years: 2.8; 95% confidence interval: 1.3 to 5.7; p = 0.006; gradient ≥15 mm Hg: 2.6; 95% confidence interval: 1.3 to 5.2; p = 0.008).

CONCLUSIONS

Endocarditis is an important adverse outcome following TVPR in children and adults with post-operative congenital heart disease involving the RVOT. Ongoing efforts to understand, prevent, and optimize management of this complication are paramount in making the best use of TPV therapy. (Melody Transcatheter Pulmonary Valve [TPV] Study: Post Approval Study of the Original Investigational Device Exemption [IDE] Cohort; NCT00740870; Melody Transcatheter Pulmonary Valve Post-Approval Study; NCT01186692; and Melody Transcatheter Pulmonary Valve [TPV] Post-Market Surveillance Study; NCT00688571).

Comparison of valvar and right ventricular function following transcatheter and surgical pulmonary valve replacement

OBJECTIVE

Trans-catheter (TC) pulmonary valve replacement (PVR) has become common practice for patients with right ventricular outflow tract obstruction (RVOTO) and/or pulmonic insufficiency (PI). Our aim was to compare PVR and right ventricular (RV) function of patients who received TC vs surgical PVR.

DESIGN

Retrospective review of echocardiograms obtained at three time points: before, immediately after PVR, and most recent.

PATIENTS

Sixty-two patients (median age 19 years, median follow-up 25 months) following TC (N = 32) or surgical (N = 30) PVR at Yale-New Haven Hospital were included.

OUTCOME MEASURES

Pulmonary valve and right ventricular function before, immediately after, and most recently after PVR.

RESULTS

At baseline, the TC group had predominant RVOTO (74% vs 10%, P < .001), and moderate-severe PI was less common (61% vs 100%, P < .001). Immediate post-procedural PVR function was good throughout. At last follow-up, the TC group had preserved valve function, but the surgical group did not (moderate RVOTO: 6% vs 41%, P < .001; >mild PI: 0% vs 24%, P = .003). Patients younger than 17 years at surgical PVR had the highest risk of developing PVR dysfunction, while PVR function in follow-up was similar in adults. Looking at RV size and function, both groups had a decline in RV size following PVR. However, while RV function remained stable in the TC group, there was a transient postoperative decline in the surgical group.

CONCLUSIONS

TC PVR in patients age <17 years is associated with better PVR function in follow-up compared to surgical valves. There was a transient decline in RV function following surgical but not TC PVR. TC PVR should therefore be the first choice in children who are considered for PVR, whenever possible.

Clinical and hemodynamic outcomes up to 7 years after transcatheter pulmonary valve replacement in the US melody valve investigational device exemption trial

BACKGROUND

Studies of transcatheter pulmonary valve (TPV) replacement with the Melody valve have demonstrated good short-term outcomes, but there are no published long-term follow-up data.

METHODS AND RESULTS

The US Investigational Device Exemption trial prospectively enrolled 171 pediatric and adult patients (median age, 19 years) with right ventricular outflow tract conduit obstruction or regurgitation. The 148 patients who received and were discharged with a TPV were followed up annually according to a standardized protocol. During a median follow-up of 4.5 years (range, 0.4-7 years), 32 patients underwent right ventricular outflow tract reintervention for obstruction (n=27, with stent fracture in 22), endocarditis (n=3, 2 with stenosis and 1 with pulmonary regurgitation), or right ventricular dysfunction (n=2). Eleven patients had the TPV explanted as an initial or second reintervention. Five-year freedom from reintervention and explantation was 76±4% and 92±3%, respectively. A conduit prestent and lower discharge right ventricular outflow tract gradient were associated with longer freedom from reintervention. In the 113 patients who were alive and reintervention free, the follow-up gradient (median, 4.5 years after implantation) was unchanged from early post-TPV replacement, and all but 1 patient had mild or less pulmonary regurgitation. Almost all patients were in New York Heart Association class I or II. More severely impaired baseline spirometry was associated with a lower likelihood of improvement in exercise function after TPV replacement.

CONCLUSIONS

TPV replacement with the Melody valve provided good hemodynamic and clinical outcomes up to 7 years after implantation. Primary valve failure was rare. The main cause of TPV dysfunction was stenosis related to stent fracture, which was uncommon once prestenting became more widely adopted.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00740870.

Iatrogenic left pulmonary artery to left atrium fistula

Trans-catheter balloon angioplasty is a well-established treatment modality for pulmonary artery (PA) stenosis in children with congenital heart disease. We report a case of an unusual complication where a fistula developed between the left PA and the left atrium during balloon angioplasty in a patient with history of tetralogy of Fallot. This was successfully treated with placement of a covered stent.

Melody valve implant within failed bioprosthetic valves in the pulmonary position: a multicenter experience

BACKGROUND

Transcatheter pulmonary valve implantation using the Melody valve has emerged as an important therapy for the treatment of postoperative right ventricular outflow tract dysfunction. Melody-in-bioprosthetic valves (BPV) is currently considered an off-label indication. We review the combined experience with transcatheter pulmonary valve implantation within BPVs from 8 centers in the United States and discuss technical aspects of the Melody-in-BPV procedure.

METHODS AND RESULTS

A total of 104 patients underwent Melody-in-BPV in the pulmonary position at 8 US centers from April 2007 to January 2012. Ten different types of BPVs were intervened on, with Melody valve implantation at the intended site in all patients. Following Melody valve implant, the peak right ventricle-to-pulmonary artery gradient decreased from 38.7 ± 16.3 to 10.9 ± 6.7 mm Hg (P<0.001), and the right ventricular systolic pressure fell from 71.6 ± 21.7 to 46.7 ± 15.9 mm Hg (P<0.001). There was no serious procedural morbidity, and no deaths related to the catheterization or implant. At a median follow-up of 12 months (1-46 months), no patients had more than mild regurgitation, and 4 had a mean right ventricular outflow tract gradient ≥30 mm Hg. During follow-up, there were 2 stent fractures, 3 cases of endocarditis (2 managed with surgical explant), and 2 deaths that were unrelated to the Melody valve.

CONCLUSIONS

Transcatheter pulmonary valve implantation using the Melody valve within BPVs can be accomplished with a high rate of success, low procedure-related morbidity and mortality, and excellent short-term results. The findings of this preliminary multicenter experience suggest that the Melody valve is an effective transcatheter treatment option for failed BPVs.

Catheterization for Congenital Heart Disease Adjustment for Risk Method (CHARM)

OBJECTIVES

This study sought to develop a method to adjust for case mix complexity in catheterization for congenital heart disease to allow equitable comparisons of adverse event (AE) rates.

BACKGROUND

The C3PO (Congenital Cardiac Catheterization Project on Outcomes) has been prospectively collecting data using a Web-based data entry tool on all catheterization cases at 8 pediatric institutions since 2007.

METHODS

A multivariable logistic regression model with high-severity AE outcome was built using a random sample of 75% of cases in the multicenter cohort; the models were assessed in the remaining 25%. Model discrimination was assessed by the C-statistic and calibration with Hosmer-Lemeshow test. The final models were used to calculate standardized AE ratios.

RESULTS

Between August 2007 and December 2009, 9,362 cases were recorded at 8 pediatric institutions of which high-severity events occurred in 454 cases (5%). Assessment of empirical data yielded 4 independent indicators of hemodynamic vulnerability. Final multivariable models included procedure type risk category (odds ratios [OR] for category: 2 = 2.4, 3 = 4.9, 4 = 7.6, all p < 0.001), number of hemodynamic indicators (OR for 1 indicator = 1.5, ≥2 = 1.8, p = 0.005 and p < 0.001), and age <1 year (OR: 1.3, p = 0.04), C-statistic 0.737, and Hosmer-Lemeshow test p = 0.74. Models performed well in the validation dataset, C-statistic 0.734. Institutional event rates ranged from 1.91% to 7.37% and standardized AE ratios ranged from 0.61 to 1.41.

CONCLUSIONS

Using CHARM (Catheterization for Congenital Heart Disease Adjustment for Risk Method) to adjust for case mix complexity should allow comparisons of AE among institutions performing catheterization for congenital heart disease.

Stent Fracture, Valve Dysfunction, and Right Ventricular Outflow Tract Reintervention After Transcatheter Pulmonary Valve Implantation

Background—

Among patients undergoing transcatheter pulmonary valve (TPV) replacement with the Melody valve, risk factors for Melody stent fracture (MSF) and right ventricular outflow tract (RVOT) reintervention have not been well defined.

Methods and Results—

From January 2007 to January 2010, 150 patients (median age, 19 years) underwent TPV implantation in the Melody valve Investigational Device Exemption trial. Existing conduit stents from a prior catheterization were present in 37 patients (25%, fractured in 12); 1 or more new prestents were placed at the TPV implant catheterization in 51 patients. During follow-up (median, 30 months), MSF was diagnosed in 39 patients. Freedom from a diagnosis of MSF was 77±4% at 14 months (after the 1-year evaluation window) and 60±9% at 39 months (3-year window). On multivariable analysis, implant within an existing stent, new prestent, or bioprosthetic valve (combined variable) was associated with longer freedom from MSF ( P <0.001), whereas TPV compression ( P =0.01) and apposition to the anterior chest wall ( P =0.02) were associated with shorter freedom from MSF. Freedom from RVOT reintervention was 86±4% at 27 months. Among patients with a MSF, freedom from RVOT reintervention after MSF diagnosis was 49±10% at 2 years. Factors associated with reintervention were similar to those for MSF.

Conclusions—

MSF was common after TPV implant in this multicenter experience and was more likely in patients with severely obstructed RVOT conduits and when the TPV was directly behind the anterior chest wall and/or clearly compressed. A TPV implant site protected by a prestent or bioprosthetic valve was associated with lower risk of MSF and reintervention.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT00740870.

Short-Term Performance of the Transcatheter Melody Valve in High-Pressure Hemodynamic Environments in the Pulmonary and Systemic Circulations

Background—

The Melody valve is approved for percutaneous pulmonary valve replacement in dysfunctional right ventricular outflow tracts. The function of this valve when subjected to high-pressure loads in humans is unknown. The aim of this study was to describe the immediate and short-term results of Melody valves implanted in a high-pressure environment.

Methods and Results—

Definitions of a high-pressure system were established for Melody valves implanted in the systemic (ie, aortic or mitral position) and pulmonary (ie, right ventricular outflow tract conduit or tricuspid valve annulus) circulations. Implants in these environments were ascertained from databases of the 5 centers that participated in the US Investigational Device Exemption trial. Thirty implants met the inclusion criteria: 23 pulmonary circulation implants (all in the pulmonary position) systemic circulation implants (5 in the native aortic position, 1 in a left ventricle-to-descending aorta conduit, and 1 in the mitral annulus). All pulmonary circulation implants were performed percutaneously in the catheterization laboratory. A hybrid approach (surgical exposure for transcatheter implant) was used for 4 of the aortic implants. There were no procedure-related deaths. Three patients died of nonprocedure- and nonvalve-related causes. At 1 year, freedom from moderate to severe regurgitation was 100%, and freedom from mild regurgitation was 90%. Freedom from moderate to severe stenosis was 86% at 1 year.

Conclusions—

Short-term performance of the Melody valve in high-pressure environments is encouraging, with good valve function in all patients.

Short- and medium-term outcomes after transcatheter pulmonary valve placement in the expanded multicenter US melody valve trial

BACKGROUND

Transcatheter pulmonary valve placement is an emerging therapy for pulmonary regurgitation and right ventricular outflow tract obstruction in selected patients. The Melody valve was recently approved in the United States for placement in dysfunctional right ventricular outflow tract conduits.

METHODS AND RESULTS

From January 2007 to August 2009, 136 patients (median age, 19 years) underwent catheterization for intended Melody valve implantation at 5 centers. Implantation was attempted in 124 patients; in the other 12, transcatheter pulmonary valve placement was not attempted because of the risk of coronary artery compression (n=6) or other clinical or protocol contraindications. There was 1 death from intracranial hemorrhage after coronary artery dissection, and 1 valve was explanted after conduit rupture. The median peak right ventricular outflow tract gradient was 37 mm Hg before implantation and 12 mm Hg immediately after implantation. Before implantation, pulmonary regurgitation was moderate or severe in 92 patients (81% with data); no patient had more than mild pulmonary regurgitation early after implantation or during follow-up (>or=1 year in 65 patients). Freedom from diagnosis of stent fracture was 77.8+/-4.3% at 14 months. Freedom from Melody valve dysfunction or reintervention was 93.5+/-2.4% at 1 year. A higher right ventricular outflow tract gradient at discharge (P=0.003) and younger age (P=0.01) were associated with shorter freedom from dysfunction.

CONCLUSIONS

In this updated report from the multicenter US Melody valve trial, we demonstrated an ongoing high rate of procedural success and encouraging short-term valve function. All reinterventions in this series were for right ventricular outflow tract obstruction, highlighting the importance of patient selection, adequate relief of obstruction, and measures to prevent and manage stent fracture. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT00740870.

Coronary artery fistulas: a review of the literature and presentation of two cases of coronary fistulas with drainage into the left atrium

We report 2 cases of infants presenting with a murmur shortly after birth and diagnosed with coronary artery fistulas with drainage into the left atrium. The first infant had a fistulous communication between the left main coronary artery and the left atrial appendage and presented with signs and symptoms of heart failure. The infant was repaired surgically in the first week of life. The second infant was asymptomatic and had a fistulous communication between the right coronary artery and the left atrium. The infant will have the fistula closed in the cardiac catheterization laboratory when the child is older. The literature on coronary artery fistulas is reviewed, and the diagnosis and management of coronary artery fistulas is discussed.

Intermediate follow-up following intravascular stenting for treatment of coarctation of the aorta

BACKGROUND

We report a multiinstitutional study on intermediate-term outcome of intravascular stenting for treatment of coarctation of the aorta using integrated arch imaging (IAI) techniques.

METHODS AND RESULTS

Medical records of 578 patients from 17 institutions were reviewed. A total of 588 procedures were performed between May 1989 and Aug 2005. About 27% (160/588) procedures were followed up by further IAI of their aorta (MRI/CT/repeat cardiac catheterization) after initial stent procedures. Abnormal imaging studies included: the presence of dissection or aneurysm formation, stent fracture, or the presence of reobstruction within the stent (instent restenosis or significant intimal build-up within the stent). Forty-one abnormal imaging studies were reported in the intermediate follow-up at median 12 months (0.5-92 months). Smaller postintervention of the aorta (CoA) diameter and an increased persistent systolic pressure gradient were associated with encountering abnormal follow-up imaging studies. Aortic wall abnormalities included dissections (n = 5) and aneurysm (n = 13). The risk of encountering aortic wall abnormalities increased with larger percent increase in CoA diameter poststent implant, increasing balloon/coarc ratio, and performing prestent angioplasty. Stent restenosis was observed in 5/6 parts encountering stent fracture and neointimal buildup (n = 16). Small CoA diameter poststent implant and increased poststent residual pressure gradient increased the likelihood of encountering instent restenosis at intermediate follow-up.

CONCLUSIONS

Abnormalities were observed at intermediate follow-up following IS placement for treatment of native and recurrent coarctation of the aorta. Not exceeding a balloon:coarctation ratio of 3.5 and avoidance of prestent angioplasty decreased the likelihood of encountering an abnormal follow-up imaging study in patients undergoing intravascular stent placement for the treatment of coarctation of the aorta. We recommend IAI for all patients undergoing IS placement for treatment of CoA.

Procedural results and acute complications in stenting native and recurrent coarctation of the aorta in patients over 4 years of age: a multi-institutional study

BACKGROUND

We report a multi-institutional experience with intravascular stenting (IS) for treatment of coarctation of the aorta.

METHODS AND RESULTS

Data was collected retrospectively by review of medical records from 17 institutions. The data was broken down to prior to 2002 and after 2002 for further analysis. A total of 565 procedures were performed with a median age of 15 years (mean=18.1 years). Successful reduction in the post stent gradient (<20 mm Hg) or increase in post stent coarctation to descending aorta (DAo) ratio of >0.8 was achieved in 97.9% of procedures. There was significant improvement (P<0.01) in pre versus post stent coarctation dimensions (7.4 mm+/-3.0 mm vs. 14.3+/-3.2 mm), systolic gradient (31.6 mm Hg+/-16.0 mm Hg vs. 2.7 mm Hg+/-4.2 mm Hg) and ratio of the coarctation segment to the DAo (0.43+/-0.17 vs. 0.85+/-0.15). Acute complications were encountered in 81/565 (14.3%) procedures. There were two procedure related deaths. Aortic wall complications included: aneurysm formation (n=6), intimal tears (n=8), and dissections (n=9). The risk of aortic dissection increased significantly in patients over the age of 40 years. Technical complications included stent migration (n=28), and balloon rupture (n=13). Peripheral vascular complications included cerebral vascular accidents (CVA) (n=4), peripheral emboli (n=1), and significant access arterial injury (n=13). Older age was significantly associated with occurrence of CVAs. A significant decrease in the technical complication rate from 16.3% to 6.1% (P<0.001) was observed in procedures performed after January 2002.

CONCLUSIONS

Stent placement for coarctation of aorta is an effective treatment option, though it remains a technically challenging procedure. Technical and aortic complications have decreased over the past 3 years due to, in part, improvement in balloon and stent design. Improvement in our ability to assess aortic wall compliance is essential prior to placement of ISs in older patients with coarctation of the aorta.

Pulmonary Atresia With Intact Ventricular Septum: Limitations of Catheter-Based Intervention

BACKGROUND

Pulmonary atresia with intact ventricular septum (PAIVS) has a wide spectrum of anatomic heterogeneity and invokes a wide variety of treatment strategies. We reviewed the outcome of our patients with PAIVS in order to delineate strategies for the optimal management of PAIVS. In particular, the possibility of avoiding neonatal surgical intervention with catheter-based technology was assessed.

METHODS

The study cohort was composed of all patients presented with PAIVS from January 1999 through December 2005. Demographic and anatomic variables were analyzed to determine association with in-hospital mortality.

RESULTS

Forty-four infants with PAIVS underwent catheter valvuloplasty (n = 17) and (or) surgical intervention (n = 42). The mean age and weight of the infants was six days and 3.1 kg, and the average follow-up was 40 +/- 29.5 months. Five (11%) had right ventricle dependent coronary circulation (RVDCC) and six (14%) had Ebstein's anomaly. Five (11%) patients died. Of those who underwent catheter valvotomy, three (18%) underwent shunt placement, 12 (71%) underwent right ventricular outflow tract reconstruction with shunt placement, and only two (12%) did not require a further surgical intervention in the newborn period. Multivariable analyses demonstrated RVDCC (odds ratio 21.3, p = 0.025) and Ebstein's anomaly (odds ratio 16.0, p = 0.038) to be risk factors for in-hospital mortality. Of those patients with Ebstein's anomaly, a single ventricle approach had a better outcome.

CONCLUSIONS

We demonstrated excellent recent outcomes for patients with PAIVS. Catheter-based interventions rarely avoid surgical repair. The RVDCC and Ebstein's anomaly were associated with high mortality. In patients with Ebstein's anomaly, single ventricular pathway may be the better strategy for this specific patient population.

Coarctation of the aorta: stenting in children and adults

Coarctation of the aorta may present in infants, children, or adults, and it requires treatment to prevent serious morbidity and mortality. Recent advances in equipment and a growing collective experience have made placement of balloon-expandable stents a safe and effective alternative to surgery or angioplasty in a growing range of patients. This review seeks to provide a working aid for stenting of coarctation of the aorta, based on the techniques and technical considerations in practice at our institution. Between 1989 and 2005, the Congenital Cardiovascular Interventional Study Consortium (CCISC), a consortium of 17 centers, of which our institution is the largest contributor, performed 588 stent placements for coarctation of the aorta. Of the 588 procedures, 580 (98.6%) were successful, as defined by reduction of the gradient to less than 20 mm Hg or increase of the ratio of the diameter of the coarctation area (CoA) to the diameter of the descending aorta (DAo) to at least 0.8. There were a total of 84 complications occurring in 69/588 (11.7%) cases. The most common significant complications were femoral access vessel related 15/588 (2.6%), aneurysm formation 13/588 (2.2%), aortic dissection 9/588 (1.5%), and cerebrovascular accident 6/588 (1.0%). There were two procedure-related deaths (0.3%) recorded in the 16-year period. Many of these significant complications occurred in the same patients. Balloon-expandable stents should be considered a safe and very effective treatment modality in a significant subset of patients with coarctation of the aorta.

Anomalous right coronary artery arising from the pulmonary artery: a report of 7 cases and a review of the literature

OBJECTIVE

To determine the experience with anomalous right coronary artery arising from the pulmonary artery (ARCAPA) at our institution.

BACKGROUND

Anomalous right coronary artery from the pulmonary artery is a rare congenital defect affecting 0.002% of the population. Unlike anomalous left coronary artery from the pulmonary artery (ALCAPA), ARCAPA generally has not been considered to be a lethal defect in infancy or childhood, although case reports of sudden death exist. The natural history of ARCAPA is difficult to describe because of the relatively small number of cases reported. Medical knowledge of this defect has been collected from case reports alone. No pediatric series of ARCAPA has been published.

METHODS

Hospital databases were retrospectively searched for cases of ARCAPA diagnosed at the New York Presbyterian Hospital over the past 25 years. A comprehensive literature search for case reports of ARCAPA was performed.

RESULTS

Seven pediatric cases are described. The cases range in clinical presentation from a young infant with tetralogy of Fallot to an adolescent with chest pain on exertion. Only 1 patient came to medical attention because of chest pain; 6 patients were asymptomatic. In these 6, ARCAPA was diagnosed upon evaluation of either a murmur (3) or associated congenital heart disease (3). All 7 patients have undergone repair. One patient died after repair of complex tetralogy of Fallot/pulmonary atresia. One patient developed a thrombus in the dilated right coronary artery years after repair. The thrombus resolved with anticoagulation.

CONCLUSIONS

Anomalous right coronary artery from the pulmonary artery is an uncommon coronary anomaly that, unlike ALCAPA, rarely leads to sudden death. Surgical correction is low risk and should be considered for all patients.

Superior outcomes for repair in infants and neonates with tetralogy of Fallot with absent pulmonary valve syndrome

OBJECTIVE

Primary repair of tetralogy of Fallot with absent pulmonary valve syndrome has been associated with significant mortality, particularly for neonates in respiratory distress. Controversy persists regarding the method of establishing right ventricle-pulmonary artery continuity.

METHODS

Anatomic and demographic parameters were evaluated for patients undergoing repair of tetralogy of Fallot with absent pulmonary valve syndrome from 1990 to 2005, as were perioperative and late postoperative parameters (airway complications, reoperation or catheter-based intervention, and mortality).

RESULTS

Twenty-three patients underwent repair. Median age was 15 days (range 2-1154 days). Patients were followed up for 5.3 +/- 3.9 years. Seventeen (85%) required preoperative ventilatory assistance. One patient died within 24 hours; 1 patient died 8 months postoperatively. Four patients received valved homografts, and the remainder had valveless connections. All patients underwent reduction pulmonary arterioplasty and mobilization, unifocalization (in 3), and ventricular septal defect closure. Valveless connection recipients had a transannular hood. No patient underwent a Lecompte maneuver. Four patients underwent reoperation for conversion to valveless connection (n = 1), reduction arterioplasty (n = 1), and repair of pulmonary stenosis (n = 2). Three patients required catheter-based intervention, with balloon angioplasty (n = 3) and stent placement (n = 1); 2 now demonstrate equal quantitative lung perfusion. No patient has had significant debility from airway compromise. All patients demonstrate free pulmonary insufficiency and good biventricular function.

CONCLUSIONS

We report excellent overall survival (89%) and low postoperative morbidity for neonates and infants undergoing primary repair of tetralogy of Fallot with absent pulmonary valve syndrome. Our recent experience supports the use of a valveless right ventricle-pulmonary artery connection, which, combined with catheter-based intervention, reduces the likelihood of reoperation necessitated by homograft placement.

Non-surgical Alternatives in the Treatment of Congenital Heart Defects

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Transcatheter closure of perimembranous ventricular septal defects using the new Amplatzer membranous VSD occluder: results of the U.S. phase I trial

OBJECTIVES

This phase I study attempted to report the initial safety and efficacy results of transcatheter closure of perimembranous ventricular septal defects (PmVSDs) using the new Amplatzer Membranous VSD Occluder (AGA Medical Corp., Golden Valley, Minnesota) in the U.S.

BACKGROUND

The most common congenital heart disease is PmVSD. Surgical repair is widely accepted, but still carries a small but definite risk of morbidity and mortality.

METHODS

Between October 2003 and August 2004, a total of 35 patients with PmVSD underwent an attempt of transcatheter closure under transesophageal and/or intracardiac echocardiographic guidance. The median age was 7.7 years (range, 1.2 to 54.4 years) and median weight was 25 kg (range, 8.3 to 110 kg). The median Qp/Qs ratio was 1.8 (range, 1 to 4), and the median VSD size as assessed by echocardiography was 7 mm (range, 4 to 15 mm).

RESULTS

The attempt to place a device was successful in 32 patients (91%). The median device size used was 10 mm (range, 6 to 16 mm). The complete closure rates by echocardiography at 10 min (transesophageal/intracardiac), 24 h, 1 month, and 6 months (transthoracic) were 47% (15/32), 63% (20/32), 78% (25/32), and 96% (27/28), respectively. The median fluoroscopy time was 36 min (range, 14 to 191 min), and the median total procedure time was 121 min (range, 67 to 276 min). Three patients (8.6%) had serious adverse events of complete heart block, peri-hepatic bleeding, and rupture of tricuspid valve chordae tendineae. No other patient encountered serious adverse events during the follow-up.

CONCLUSIONS

Transcatheter closure of a PmVSD is technically feasible and seems safe enough in children over 8 kg in weight to warrant continuation of clinical trials to assess the long-term safety and efficacy.

The effect of repair technique on postoperative right-sided obstruction in patients with truncus arteriosus

OBJECTIVES

We reviewed our experience with repair of truncus arteriosus to assess the effect of type of right ventricular outflow tract reconstruction on perioperative morbidity, survival, and freedom from catheter-based interventions and reoperation.

METHODS

Patients undergoing repair of truncus arteriosus from June 1990 through February 2004 were evaluated on the basis of operative procedure regarding preoperative and postoperative variables, the need for postoperative catheter-based intervention or reoperation, and survival on the basis of univariate, multivariable, and actuarial analyses.

RESULTS

Of 54 study patients, 15 (28%) received a valved homograft, and 39 (72%) received a direct connection with a variety of hood materials. Five (9.1%) patients died. Valved homograft recipients were more likely to require reoperation than patients receiving direct connections (40% vs 15%, P = .046); however, valved homograft and direct connection recipients had a similar incidence of the combined end point of reoperation or catheter-based intervention (40.0% vs 37.5%, P = .865). Univariate and multivariable modeling demonstrated use of valved homografts or direct connections with an autologous pericardial hood to be predictive of the need for later catheter-based intervention or reoperation. Actuarial analysis demonstrated a trend toward improved outcomes in the direct connection group and within the direct connection cohort, a statistically significant difference on the basis of hood type.

CONCLUSIONS

Although the direct connection technique might not prevent later catheter-based intervention, it does reduce the need for reoperation. Outcomes among direct connection recipients were associated with hood type: polytetrafluoroethylene hoods (W. L. Gore & Associates, Inc, Tempe, Ariz) had the lowest rate of reintervention, and untreated autologous pericardial hoods had the highest rate of reintervention. We report excellent outcomes with primary repair of truncus arteriosus. Where anatomically appropriate, we advocate the direct connection technique.

"Taking in the Waist": Adjusting the Size of a Stented Fontan Fenestration

Early spontaneous closure of a fenestration following Fontan palliation may complicate the postoperative management of such patients. The creation of a fenestration in the catheterization laboratory with an intravascular stent may improve these patients' hemodynamic status. The aim of this study is to present a new technique to reduce the diameter of stented Fontan fenestrations in those patients in whom the stent diameter is functionally made too large.

Recent advances in non-interventional pediatric cardiac catheterization

PURPOSE OF REVIEW

The role of cardiac catheterization in pediatric cardiology has changed significantly in the past 10-15 years. As interventional procedures dominate the field, it is important to examine the recent advances in non-interventional pediatric cardiac catheterization.

RECENT FINDINGS

Meaningful and accurate data must be acquired for the presurgical evaluation of patients with congenital heart disease to better guide clinical decisions. In particular, all patients with single- ventricle physiology currently undergo diagnostic catheterization before bidirectional Glenn and Fontan surgeries. Recent studies are beginning to identify a subset of these patients who may not need to undergo presurgical catheterization. As surgical techniques evolve, diagnostic catheterization has a role in the analysis of hemodynamic variables and clinical outcomes. This can be seen in recent papers that examine the Sano modification to the Norwood procedure.Recent papers demonstrate the continued development of new techniques, new technology, and a progression towards smaller equipment. The use of conductance catheters, Doppler flow wires, and smaller traditional catheters will allow the pediatric cardiologist to more accurately and safely evaluate hemodynamic parameters.

SUMMARY

Non-interventional pediatric cardiac catheterization continues to have an important role in the assessment and treatment of patients with congenital heart disease.

Evaluation of the AMPLATZER vascular plug for embolization of peripheral vascular malformations associated with congenital heart disease

OBJECTIVE

The purpose of this study is to evaluate the recently FDA-approved AMPLATZER Vascular Plug in the embolization of vascular lesions associated with congenital heart disease (CHD).

BACKGROUND

Fistulas and arteriovenous malformations have been occluded using various devices. The AMPLATZER Vascular Plug is a self-expandable, cylindrical device, used for embolization in the peripheral vasculature.

METHODS

A total of 84 vessels in 52 patients with CHD from 11 centers were occluded with 89 AMPLATZER Vascular Plugs, delivered through a coronary guide catheter in various vascular sites, including collaterals, pulmonary arterio-venous and coronary artery fistulas, transhepatic tracts, central shunts, patent ductus arteriosus (PDA), and excluded hepatic vein. Complete vessel occlusion was demonstrated within 10 min in 94% of patients.

RESULTS

There was no device embolization, vascular disruption, or procedure-related complication. One vascular plug implanted in a large type C PDA required surgical removal followed by PDA ligation, after 5 weeks from successful implant because of significant residual flow through the device.

CONCLUSIONS

The AMPLATZER Vascular Plug is an effective transcatheter occlusion device in the embolization of a wide variety of vascular lesions associated with CHD. Based on our early experience, caution should be used when considering the Vascular Plug as a closure device for large PDA.

Transcatheter Device Closure of Congenital and Postoperative Residual Ventricular Septal Defects

Background— Our purpose was to describe a 13-year experience with patients undergoing transcatheter device closure of unrepaired congenital or postoperative residual ventricular septal defects (VSDs).

Methods and Results— Since 1989, 170 patients (median age, 3.9 years) have undergone catheterization for closure of 1 or more congenital (n=92) or postoperative (n=78) residual VSDs using successive generations of STARFlex-type devices. Outcomes included echocardiographic assessment of residual flow and device position, assessment of VSD shunt/severity, and adverse events. Among 168 patients in whom device implantation was performed, between 1 and 7 devices were placed per patient (median, 1), with multiple devices placed in 40%. There was a significant decrease in left-to-right shunting after device implantation ( P <0.001) and significant improvement in VSD size/severity, and device position proved stable. Of 332 adverse events, 39 were related to the device and 261 were related to the catheterization; all but 5 occurred in the periprocedural period. At a median follow-up of 24 months (0 to 154 months), 14 patients had died and 18 had device(s) explanted.

Conclusions— Congenital and postoperative VSD closure using STARFlex-type devices resulted in stable improvement in clinical status and decreased interventricular shunting. Although periprocedural events occurred frequently, late events caused by the device were rare. Transcatheter device closure is an effective management option for patients with complex muscular VSDs that are difficult to approach surgically and for postoperative residual VSDs.

Multicenter USA Amplatzer Patent Ductus Arteriosus Occlusion Device Trial

OBJECTIVES

We sought to review and report initial and one-year efficacy and safety results of the multicenter USA Amplatzer ductal occluder (ADO) device trial.

BACKGROUND

Transcatheter closure of a moderate to large patent ductus arteriosus (PDA) using conventional techniques is challenging. The ADO can close a PDA up to 12 mm in diameter.

METHODS

From September 1999 to June 2002, 484 patients were enrolled in 25 U.S. centers. Forty-five (9%) of 484 patients did not have ADO implantation, because the PDA was too small or because of elevated pulmonary resistance. The median age of the patients at catheterization was 1.8 years (range 0.2 to 70.7 years), and weight was 11 kg (range 4.5 to 164.5 kg).

RESULTS

The median PDA minimal diameter was 2.6 mm (range 0.9 to 11.2 mm); 76 (17%) of 439 were larger than 4.0 mm. Median pulmonary artery mean pressure was 20 mm Hg (range 7 to 80 mm Hg). The ADO was implanted successfully in 435 (99%) of 439 patients, with a median fluoroscopy time of 7.1 min (range 2.9 to 138.4 min). Angiographic demonstration of occlusion was seen in 329 (76%) of 435. This increased to 384 (89%) of 433 on post-catheterization day 1, with occlusion documented in 359 (99.7%) of 360 at one year. At the last evaluation in all patients at any time, PDA closure was documented in 428 (98%) of 435 patients. There have been two cases of partial left pulmonary artery occlusion after ADO implantation and no cases of significant aortic obstruction.

CONCLUSIONS

Moderate to large PDAs can be effectively and safely closed using the ADO device, with excellent initial and one-year results. This device should obviate the need for multiple coils or surgical intervention for these defects.

Erosion of Amplatzer septal occluder device after closure of secundum atrial septal defects: Review of registry of complications and recommendations to minimize future risk

The objectives of this study were to identify possible risk factors that may lead to erosion of the Amplatzer septal occluder (ASO) and recommend ways to minimize future risk. There have been rare occurrences of adverse events with development of pericardial effusion after ASO placement. Identification of high-risk cases, early recognition, and prompt intervention may minimize the future risks of adverse events. In all patients who developed hemodynamic compromise after ASO placement, echocardiograms (pre-, intra-, and postprocedure), atrial septal defect (ASD) size (nonstretched, stretched), size of the device used, cineangiograms, and operative records were reviewed by a panel selected by AGA Medical Corporation. The findings were compared to the premarket approval data obtained from FDA-approved clinical trials that were conducted in the United States, before the device was approved. A total of 28 cases (14 in United States) of adverse events were reported to AGA Medical. All erosions occurred at the dome of the atria, near the aortic root. Deficient aortic rim was seen in 89% and the defect described as high ASD, suggesting deficient superior rim. The device to unstretched ASD ratio was significantly larger in the adverse event group when compared to the FDA trial group. The incidence of device erosion in the United States was 0.1%. The risk of device erosion with ASO is low and complications can be decreased by identifying high-risk patients and following them closely. Patients with deficient aortic rim and/or superior rim may be at higher risk for device erosion. Oversized ASO may increase the risk of erosion. The defect should not be overstretched during balloon sizing. Patients with small pericardial effusion at 24 hr should have closer follow-up.

The Genesis stent: A new low-profile stent for use in infants, children, and adults with congenital heart disease

Placement of intravascular stents that can reach adult size in infants and smaller children has been limited by the large profile and poor flexibility of currently available stents. In vitro and in vivo testing of the Genesis stent was performed to evaluate crimpability, predeployment flexibility, and radial strength. Comparisons were made to the Palmaz iliac and IntraStent (IS) LD stents. Nine physicians placed 30 Genesis stents in swine pulmonary and systemic arteries to evaluate stent deliverability/crimpability. Two swine were recovered and underwent a second catheterization 8 weeks later, where the stents (n = 8) were reexpanded to maximal size. Angiographic and intravascular ultrasound (IVUS) assessments were performed. In vitro testing revealed the Genesis stent to have superior crimpability, flexibility, and comparable radial strength to the Palmaz iliac stent, and superior crimpability and radial strength and comparable flexibility to the IS LD series. During in vivo testing, the physicians graded the Genesis stent superior to the Palmaz stent regarding crimpability and deliverability, and superior to the IS LD stent in regard to crimpability, and comparable to or superior in deliverability. In the chronic animals, the Genesis stent was expanded up to maximal diameter 8 weeks following implantation. Angiographic and IVUS revealed no fractures no in-stent restenosis. The Genesis stent can be easily delivered through smaller sheaths, which will facilitate their use in infants and smaller children with vascular stenosis.

Transcatheter closure of a very large patent ductus arteriosus in a pregnant woman at 22 weeks of gestation

Successful transcatheter closure of a large PDA in a pregnant patient is reported using the Amplatzer ductal occluder device. This procedure was safe and uncomplicated, obviating the need for surgery in this high risk patient.

Coronary artery fistula embolization in an infant with pulmonary atresia intact ventricular septum: a case report

This report presents a case of pulmonary atresia/intact ventricular septum with right ventricular-dependent coronary circulation. At 7 months of age, the infant underwent coil embolization of the connection between the right ventricle and the coronary circulation. The child is currently well following surgical decompression of the right ventricle.

Transcatheter closure of patent ductus arteriosus in adults using the Amplatzer duct occluder: initial results and follow-up

BACKGROUND

Surgical closure of patent ductus arteriosus in adult patients may be problematic. Transcatheter closure of patent ductus arteriosus is an established procedure. Recently, transcatheter closure of patent ductus arteriosus using the Amplatzer duct occluder has been shown to be safe and efficacious. We present our experience with this device in adults.

METHODS AND RESULTS

Between January 2000 and January 2002,41 adult patients (31 females and 10 males) with a patent ductus arteriosus were referred for closure with the Amplatzer duct occluder. The median age was 35.6 years (range 18-70.7 years) and the median weight was 65.8 kg (range 32.7-164.5 kg). Of these 41 patients, 37 underwent attempted closure of the patent ductus arteriosus using the Amplatzer duct occluder. The device was successfully deployed in all patients except 1. Complete angiographic closure was seen Immediately after device deployment in 29 out of 36 patients (81%). Complete echocardiographic closure was demonstrated within 24 hours post-procedure in 34 out of 36 patients (94%), and at 6-month follow-up in 35 out of 36 patients (97%). No complications related to device implantation occurred in any patient.

CONCLUSIONS

Closure of patent ductus arteriosus using the Amplatzer duct occluder is safe and effective in adults.

Endovascular stent placement for venous obstruction after cardiac transplantation in children and young adults

Survival following cardiac transplantation in children and adults, including the group with complex congenital heart disease, has improved over the last decade secondary to medical and surgical advances in management. There have been rare reports of superior vena cava obstruction at anastomotic sites following transplantation. In patients following heart transplantation, venous stenosis can limit the ability to perform endomyocardial biopsies. We reviewed our experience in three patients who underwent cardiac transplantation and developed significant venous stenosis requiring intervention. All three were successfully treated by transcatheter implantation of endovascular stents. Endovascular stent implantation for venous obstruction in patients following cardiac transplantation was safe and effective, allowing improved ease of catheterization for future posttransplantation monitoring and surveillance.

Endovascular stent implantation in the pulmonary arteries of infants and children without the use of a long vascular sheath

Endovascular stent implantation for pulmonary artery stenosis requires the use of a long, large-bore vascular sheath to insure precise implantation without embolization or malposition. A long vascular sheath may be difficult to position and usage may be associated with vascular compromise and/or hemodynamic embarrassment, especially in infants and small children. We report a new technique for pulmonary artery endovascular stent implantation without the use of a long sheath. From December 2000 to May 2001, 10 patients underwent implantation of 13 Palmaz Corinthian premounted biliary transhepatic stents for pulmonary artery stenosis. Median age was 0.8 years (range, 0.5-18.5) and median weight was 11.8 kg (range, 4.6-65). Patient diagnoses were tetralogy of Fallot (five), double outlet right ventricle (three), branch peripheral pulmonary artery stenosis (two), single ventricle s/p cavopulmonary shunt (one), and truncus arteriosus (one). All Palmaz Corinthian stents were delivered uncovered on Cordis Opta LP balloon catheters via short sheaths (6-7 Fr); super-stiff guidewires were not always necessary. These stents, with a maximal expanded diameter of 12 mm, were placed for peripheral pulmonary artery stenosis as a definitive procedure or at the pulmonary artery bifurcation in patients who were expected to undergo future open heart surgery. The stents were initially implanted on 4, 6, or 8 mm balloon catheters and further expanded if needed. Stents were placed in the right pulmonary artery alone in three patients, left pulmonary artery alone in four patients, and side-by-side stents were implanted simultaneously in three patients. All thirteen stents were implanted successfully in the desired location without stent malposition or embolization. Mean angiographic diameter increased from 2.5 +/- 1.5 to 5.7 +/- 1.4 mm (P < 0.01) and peak systolic ejection gradients decreased from 44 +/- 22 to 14 +/- 11.6 mm Hg (P < 0.01). The uncovered delivery of the premounted Palmaz Corinthian stent allowed for precise and safe endovascular stent implantation without the hemodynamic and technical problems associated with long vascular sheath usage. This technique is useful for the palliation of proximal pulmonary artery stenosis and is effective definitive treatment for peripheral pulmonary artery stenosis in small infants and children.