• Congential Heart Disease Clinical Interest Section

    Winter 2015 Journal Scan

    Presented by Nathaniel W. Taggart, MD and Todd M. Gudausky, MD, FSCAI

    One-Year Follow-Up of the Melody Transcatheter Pulmonary Valve Multicenter Post-Approval Study

    Armstrong AK, Balzer DT, Cabalka AK, Gray RG, Javois AJ, Moore JW, Rome JJ, Turner DR, Zellers TM, Kreutzer J. JACC Cardiovasc Interv. 2014 Nov;7(11):1254-62.

    • Summary:

    Prospective, nonrandomized study of 1-year outcomes of Melody valve placement in dysfunctional RVOT conduits after initial HDE approval by the FDA.  Hemodynamic inclusion criteria mirrored those of the IDE (≥35 mmHg RVOT mean Doppler gradient and/or moderate or greater PR), but age and weight limitations were not factors were not considered.  A total of 120 patients underwent catheterization; implantation was attempted in 101 patients.  One patient did not undergo transcatheter pulmonary valve (TPV) placement due to pulmonary hemorrhage that resolved spontaneously.  One other developed coronary artery compression with Melody valve placement (after balloon testing and pre-stenting) and underwent immediate placement of a left ventricular assist device and emergent surgical RVOT conduit removal.  The remaining 99 patients all had a peak gradient <35 mmHg and less than moderate PR immediately after TPV.  The most common procedural serious adverse event (SAE) was contained conduit tear in 6 patents, all of which were managed successfully with covered stent.  Among those with evaluable data at 1 year, 96.9% were free of TPV dysfunction at 1 year.  Within the first year, two patients had undergone surgical RVOT revision; none underwent additional transcatheter intervention.  The most common device related SAE was endocarditis (n=3).

    • Authors’ Conclusions:

    “Real world” experience with Melody valve placement largely confirms the conclusions from the initial IDE trial—TPV can be performed safely with excellent clinical and hemodynamic results in the short- to medium-term.  Patients from this study had a lower rate of stent fracture and valve dysfunction likely due to the option of pre-stenting prior to TPV placement.  There was a higher rate of procedural SAE than in the IDE trial, probably due to interventions (e.g. angioplasty and stent placement) before TPV placement.

    • Interpretation:

    This study largely confirms the data from the initial Melody valve IDE study and other non-US series.  The one-year durability of the Melody valve after successful implantation is excellent.  Screening for the risk of coronary artery compression is vital.  Conduit disruption during preparation for Melody valve implantation remains a significant risk, but can almost always be managed from a transcatheter approach using covered stents.  Endocarditis remains an important concern during follow up (3% risk in the first year after TPV in this study), although it can often be managed medically.

    Transcatheter Closure of Large Atrial Septal Defects:  Feasibility and Safety in a Large Adult and Pediatric Population

    Baruteau AE, Petit J, Lambert V, Gouton M, Piot D, Brenot P, Angel CY, Houyel L, Le Bret E, Roussin R, Ly M, Capderou A, Belli E. Circ Cardiovasc Interv. 2014;7(6):837-843.

    • Summary:

    In this single-center prospective study from 1998-2013, 336 patients with large ASDs (≥34 mm balloon-stretched diameter for adults or >15 mm/m2 for children) underwent attempted device closure using Amplatzer Septal Occluder (ASO) devices.  Mean stretched diameter of ASD was 37.6±3.3 mm for adults and 26.3±6.3 mm/m2 for children.  Closure was successful for 311 patients (92.6%).  Four patients experienced device embolization; for the remaining 21 patients, the closure device was positioned but not released.  Deficiency of the posterior or superior rims was associated with unsuccessful device closure.  Median duration of follow-up was 10 years (2.5-17 years) with no late complications.

    • Authors’ Conclusions:

    This is the largest series of patients with large ASDs undergoing device closure.  While successful closure is guaranteed, the vast majority of patients are able to undergo device closure.  Successful closure may be less likely in patients with large ASDs and posterior or superior rim deficiency.  Device embolization is a risk, but almost always occurs within the first 24-48 hours after device placement and is not associated with a significant risk of mortality.  Long-term follow-up of this cohort suggests a low risk of late complications, even erosion.

    • Interpretation:

    This single-center study reports an extensive experience managing patients with large ASDs using Amplatzer septal occluder devices.  The authors report a very high success rate and very low complication rate relative to previous, smaller studies.  While these results are encouraging, one wonders how easily they could be duplicated elsewhere.   

    Results of the Combined U.S. Multicenter Pivotal Study and the Continuing Access Study of the Nit-Occlud PDA Device for Percutaneous Closure of Patent Ductus Arteriosus

    Moore JW, Greene J, Palomares S, Javois A, Owada CY, Cheatham JP, Hoyer MH, Jones TK, Levi DS. JACC Cardiovasc Interv. 2014 Dec;7(12):1430-6.

    • Summary:

    A multi-center prospective pre-market study of the safety and efficacy of the Nit-Occlud PDA device (PFM Medical, Cologne, Germany) for closure of small to moderate PDAs (minimum diameter ≤4 mm) over one year of follow-up.  A total of 357 patients (median age 3 years; range 6 months-21.9 years) were enrolled across 15 sites.  Device implantation was successful in 347 patients (97.2%).  Six month echocardiography was performed, but results were not reported.  Definitive echocardiographic closure was documented in 96.8% at 1 year, murmur was absent in 98.1% of patients.  Six patients experienced a device-related adverse event (AE), including three device embolizations requiring catheter retrieval (as late as 215 days after device placement).   No patients experienced a serious AE (including cerebral or pulmonary embolism, bacterial endocarditis, device embolization requiring surgery or arrhythmia requiring pacemaker). 

    • Authors’ Conclusions:

    The Nit-Occlud PDA device is the first coil system designed specifically for PDA closure.  This study demonstrates that it is a safe and effective option for closure of small-to-moderate PDAs. 

    • Interpretation:

    Nit-Occlud PDA offers an alternative option for closing small-to-moderate PDAs to the Amplatzer Duct Occluder (ADO) devices.  The advantage of the Nit-Occlud system is the smaller system profile, which can be deployed through a 4 Fr or 5 Fr catheter.   While direct comparison of the ADO devices and the Nit-Occlud PDA device is not presented, the Nit-Occlud coil may have a higher rate of incomplete closure at 1 year.  The authors did not report 6-month closure rates, although that data was collected, which raises the question of whether effective PDA closure is not as immediate as seen with the ADO devices.

    Cardiac Catheterization in the Early Post-Operative Period after Congenital Cardiac Surgery

    Nicholson GT, Kim DW, Vincent RN, Kogon BE, Miller BE, Petit CJ. JACC Cardiovasc Interv. 2014 Dec;7(12):1437-43.

    • Summary:

    This is a large, single-center review of diagnostic and interventional cardiac catheterization in the early post-operative period over the course of almost 10 years.  The authors report a total of 219 procedures performed on 193 patients (median age 0.3 years).  Ninety-one interventions were performed on 65 patients; the most common interventions were stent or balloon dilation of stenotic vessels (71.4%), occlusion of collateral vessels (15.4%), and thrombectomy (9.9%).  About half of dilations were performed across fresh anastomotic sites.  While there was no significant difference in rate of major or minor complications between interventional and diagnostic caths, the only procedure-related death was due to avulsion of a pulmonary artery after aggressive (6:1 balloon-to-vessel diameter) dilation.  Early post-operative cardiac catheterization was followed by repeat surgical operation in 43% of patients; for 60% of these patients, repeat operation was prompted by findings on catheterization.   Overall one-year survival was poor—around 70%—with no difference between those undergoing diagnostic vs. interventional caths.  One-year mortality was associated with younger age at time of operations, ECMO support at time of catheterization, and single-ventricle heart disease.

    • Authors’ Conclusions:

    Early post-operative cardiac catheterization can be helpful in delineating residual lesions that require interventional or surgical treatment.  Vessel dilation should be approached cautiously, but can be performed safely in the early post-operative period particularly along anastomotic sites of continuous suturing.  High overall mortality in this cohort reflects the severity of underlying disease, poor hemodynamics at the time of catheterization and small patient size.

    • Interpretation:

    This study presents a rather large experience with early post-operative cardiac catheterization in a very young and very ill cohort.  Catheterization in the early post-operative period can be a useful tool for identifying and potentially treating residual lesions, most commonly obstructive lesions.  Interventional procedures may not present a significant increased risk over diagnostic catheterization, although the heterogeneity of this cohort limits how much we can conclude in this regard.

    Procedural results and Safety of Common Interventional Procedures in Congenital Heart Disease:  Initial Report from the National Cardiovascular Data Registry

    Moore JW, Vincent RN, Beekman RH, Benson L, Bergersen L, Holzer R, Jayaram N, Jenkins K, Li Y, Ringel R, Rome J, Martin GR. J Am Coll Cardiol. 2014 Dec 16;64(23):2439-51.

    • Summary:

    This is a large, multi-center database report of outcomes of six common congenital interventions (ASD closure, PDA closure, pulmonary valvuloplasty, aortic valvuloplasty, coarctation angioplasty or stenting, pulmonary artery stenting).  From January 2011-March 2013, a total of 81 institutions provided data for 4,152 qualifying interventions (1,286 single ASD closures, 1,375 PDA closures, 270 “typical” pulmonary valvuloplasties, 305 aortic valvuloplasties, 671 aortic coarctation interventions, and 245 pulmonary artery stents).  ASD and PDA closure both had a success rate of >98% with low complication rate.  The least successful procedure was coarctation angioplasty (51%).  Major adverse event rates were low (<4% for each procedure), but varied significantly by patient age and size.  Overall adverse event rates ranged from 5.3% (PDA closure) to 24.3% (aortic valvuloplasty).  Descriptive statistics are presented, but statistical comparisons between procedures, age groups or institutions are not presented.

    • Authors’ Conclusions:

    This report provides valuable, real world data regarding the success and safety of six common congenital interventions.  The data presented provide a “benchmark” against which individual institutions can compare their own experience. 

    • Interpretation:

    This database report provides substantial descriptive data regarding common interventions.  This data may be useful for counseling patients regarding the risk of these procedures and likelihood of success.  However, it lacks the granular data to further identify predictors of success or complication.

    Percutaneous Treatment of Adult Isthmic Aortic Coarctation: Acute and Long-Term Clinical and Imaging Outcome with a Self-Expandable Uncovered Nitinol Stent

    Kische S, D’Ancona G, Stoeckicht Y, Ortak J, Elsasser A, Ince H. Circ Cardiovasc Interv. 2015 Jan;8(1):837-43.

    • Summary:

    In this single-center study, 52 consecutive adults with severe native coarctation of the aorta underwent stent repair using Sinus-XL (Optimed, Esslingen, Germany) self-expanding stents.  Pre-procedural CT imaging was performed in all patients and scrutinized for selecting the optimal stent diameter and length.   Patients were excluded if they had a tubular coarctation that was felt to be better served by covered stent placement.  Stent diameter was selected to be 10-15% wider than the proximal landing zone (usually just beyond the left subclavian artery).  Eight patients (15.4%) with severe lesions underwent pre-dilation prior to stent placement.  All patients underwent post-dilation using non-compliant balloons.  The mean stent diameter was 24.2 cm, and stent lengths ranged from 40-80 mm.  On average the peak systolic gradient decreased from 54.7±9.9 mmHg to 3.3±2.5 mmHg; minimum aortic diameter increased from 4.6±1.9 mm to 18.6±2.5 mm.  Major complications included:   one patient who was found to have an aortic rupture a few hours after the procedure requiring placement of a covered endoprothesis, and one patient with a femoral artery dissection that was treated with interposition graft.  Overall adverse event rate was 6.8%.  Over a mean follow-up duration of about 48 months, no patients underwent late intervention or reoperation related to the procedure.  Blood pressure improvement seen immediately after stent placement was sustained throughout the duration of follow-up.

    • Authors’ Conclusions:

    Sinus XL self-expanding stent placement and post-dilation can provide immediate and ongoing relief of severe native coarctation of the aorta.  The novel stent design provides continuous moderate outward radial pressure, which may help maintain patency over time.  The 10 Fr stent delivery system is lower profile than comparable balloon-expandable stents.  Some complications reported in this study may be related to a learning curve; overall complication rates are similar to previously published data.

    • Interpretation:

    Though generally avoided for treatment of coarctation of the aorta in favor of balloon-expandable covered and bare-metal stents, self-expanding stents may have value in this regard.  The Sinus XL stent appears to have favorable properties related to size of the delivery system and radial strength of the stent but is not available for use in the U.S.  It is unlikely that other self-expanding stents would function similarly in the treatment of coarctation of the aorta.

    Incidence of Acute Kidney Injury Following Cardiac Catheterization prior to Cardiopulmonary bypass in Children.

    Huggins N, Nugent A, Moden V, Rodriguez JS, Forbess J, Scott W, Dimas VV. Catheter Cardiovasc Interv. 2014 Oct 1; 84(4): 615-19.

    • Summary:

    The aim of this study was to determine if contrast administration was a risk factor for developing acute kidney injury (AKI) in cyanotic congenital heart disease patients undergoing cardiopulmonary bypass surgery (CPB).   A total of 113 patients undergoing either a bidirectional Glenn procedure (55 pts) or Fontan procedure (58 pts) from 2007-2010 were identified retrospectively and divided into 2 groups based on the timing of their preoperative cardiac catheterization (PCC).  A total of 36 patients (17 BDG and 19 Fontan) underwent PCC ≤ 48 hours prior to CPB and 77 patients (38 BDG and 39 Fontan) underwent PCC > 5 days prior to CPB.  No patients received prophylaxis for contrast related kidney injury with hydration, alkalinization or administration of n-acetylcysteine.  Median contrast dose for all groups was < 6 ml/kg.  AKI developed in 2/17 BDG and 7/19 Fontan patients undergoing PCC ≤ 48 hours prior to CPB and in 15/38 BDG and 22/39 Fontan patients undergoing PCC > 5 days prior to CBP.  AKI developed more commonly in the patients undergoing PCC > 5 days prior to CPB 37/78 (47%) vs. patients undergoing PCC ≤ 48 hours prior CPB 9/36 (25%).  No patient required dialysis as a result of AKI. 

    • Author’s Conclusions:

    AKI is common following BDG and Fontan procedures (30% and 50% of cohort respectively).   Contrast administration from PCC ≤ 48 hours prior to CBP did not increase the risk of developing AKI.        

    • Interpretation:

    This single center study provides additional evidence for the safety of contrast administration immediately prior to CPB in children with cyanotic CHD.  Although AKI remains common following CPB, the timing of contrast administration during preoperative PCC does not seem to be associated with the development of AKI.  Larger, multi-intuitional studies confirming this finding are needed.

    Outcome Following Cardiac Catheterization after Congenital Heart Surgery.

    Siehr SL, Martin MH, Axelrod D, Efron B, Peng L, Roth SJ, Perry S, Shin AY. Catheter Cardiovasc Interv. 2014 Oct 1; 84(4): 622-28.

    • Summary:

    This is a large, single center retrospective study of the utility of unplanned cardiac catheterization following congenital heart surgery.  Over a 7 year period 120 patients underwent 150 unplanned cardiac catheterizations.  The median day of catheterization was postoperative day 20.  A total of 103 of 150 (69%) catheterizations resulted in a change in clinical management.  Trans-catheter interventions were performed in 59 procedures, 31 catheterizations lead to early re-operation, 11 patients were started on a new pharmacological agent, 6 patients had a new operative plan or elective re-operation in the future and 5 patients were transitioned to palliative care.   Nine patients who underwent trans-catheter intervention also underwent early re-operation.  There was no associated change in clinical management in 47/150 (31%) of catheterizations. Complications were rare in this patient cohort and included pulmonary hemorrhage (1 pt), peritoneal hemorrhage (1 pt), SVT requiring cardioversion (2 pts), transient complete heart block requiring CPR (1 pt) and acute kidney injury (2 pts).  Post catheterization 30 day survival was 85% and overall survival to hospital discharge was 72%.    

    • Author’s Conclusions:

    Unplanned cardiac catheterization in the early post operative period was frequently associated with changes in medical and surgical management.  Trans-catheter intervention is frequently performed during these procedures.  Although significant complications can occur during cardiac catheterization during the postoperative period they are rare. 

    • Interpretation:

    Evidence is accumulating that cardiac catheterization during the postoperative, vulnerable period is safer than previously recognized and often results in significant changes in medical and surgical management. 

    Standardizing Radiation Dose Reporting in the Pediatric Cardiac Catheterization Laboratory—A Multicenter Study by the CCISC

    Kobayashi D, Meadows J, Forbes TJ, Moore P, Javois AJ, Pedra CA, Du W, Gruenstein DH, Wax DF, Hill JA, Graziano JN, Fagan TE, Alvarez WM, Nykanen DG, Divekar AA.  Catheter Cardiovasc Interv. 2014 Nov 1; 84(5): 785-93.

    • Summary:

    This report was the result of a large multi-institutional prospective registry from 16 pediatric cardiac catheterization laboratories reporting radiation data collected on over 8,000 diagnostic and interventional catheterizations performed between 2008-2013.  The aim of the study was to determine the best unit to report radiation dose for pediatric cardiac catheterizations in order to standardize radiation dose reporting so accurate comparisons of dose could be made both within and between institutions.  Radiation dose data including fluoroscopic time, total air Kerma and air Kerma area product (PKA) along with age and weight were collected for each procedure.  Analysis of radiation data stratified by age and weight groups showed wide variation; however when PKA was indexed to body weight and expressed as PKA/BW (µGy m2/kg) a strong correlation for all procedure types across the pediatric age range was noted.    

    • Author’s Conclusions:

    PKA/BW appears to be the most reliable standard to report radiation dose for pediatric cardiac catheterization across all procedure types and patient age.  PKA/BW should become the standard unit when documenting radiation usage in pediatric catheterization laboratories.

    • Interpretation:

    This large, international multi-institutional study has confirmed the utility of PKA indexed to body weight (PKA/BW) as the preferred measure for documenting radiation dose in the pediatric cardiac catheterization lab.  Use of this standard measure will facilitate future quality efforts to reduce radiation dose within pediatric laboratories and allow for comparison of performance between institutions.

    Pulmonary Artery Stents in the Recent Era:  Immediate and Intermediate Follow-up

    Ing FF, Khan A, Kobayashi D, Hagler DJ, Forbes TJ.  Catheter Cardiovasc Interv. 2014 Dec 1; 84(7): 1123-30.

    • Summary:

    This article summarizes the recent experience of 3 congenital heart centers who performed unilateral stenting of a proximal pulmonary artery from 2006-2011.  The aim of this study was to describe the immediate and intermediate results of proximal pulmonary artery stenting using modern stent technology.  A total of 58 patients received 60 stents over the study period.  The Palmaz Genesis XD stent was used in 47/60 (78%) procedures.  The majority of patients treated had a diagnosis of tetralogy of Fallot or pulmonary atresia-VSD (36/58 pts).  The mean age of patients was 10.4 ± 10.3 years.  Overall stent implantation was successful in 57 of 58 patients (98%).  The single patient experiencing stent failure had stent embolization requiring surgical removal and repair of the pulmonary artery.  There were 10 procedure related complications (17%) including 7 major and 3 minor with no acute mortality.  The stent implantation procedure was considered an immediate success in 57 of 58 patients with average vessel diameter increasing from 5.1 ± 1.9 mm to 10.6 ± 2.9 mm which represents an average increase in luminal diameter of 234 ± 84%. One year follow up echocardiograms were available in 48 patients and showed mild increase in the stent gradient from 5.7 ± 6.7 mmHg to 17.1 ± 11.7 mmHg.  Follow up catheterization in 16 patients showed no significant decrease in stent diameter or significant increase in stent gradient or RV pressure over a median of 14 months. 

    • Author’s Conclusions:

    With the recent improvements in stent design, lower profile delivery systems and greater range of sizes, stenting has become the preferred treatment for proximal branch pulmonary artery stenosis.  This retrospective study shows excellent immediate and 1 year follow-up results with maintenance of improved caliber of the stented vessel and lower right ventricular systolic pressures.

    • Interpretation:

    This study demonstrates the immediate and 1 year effectiveness of proximal pulmonary artery stenting using modern stent technology.  The results would seem to be generalizable to the pediatric interventional community at large. 

    Early Clinical Experience with a Novel Self-Expanding Percutaneous Stent-Valve in the Native Right Ventricular Outflow Tract

    Cau Q, Kenny D, Zhou D, Pan W, Guan L, Ge J, Hijazi Z.   Catheter Cardiovasc Interv. 2014 Dec 1; 84(7): 1131-37.

    • Summary:

    This report summarizes the early results of the Venus Pulmonary Valve, a self expandable nitinol frame with a tri-leaflet porcine pericardial tissue valve secured to the frame.  This valve ranges in size from 20-32 mm in diameter and is available in 20 and 30 mm lengths.  The self expandable valve is delivered via a 14-22 Fr delivery system depending on valve size.  Five patients ages 20-45 years with surgically repaired tetralogy of Fallot with RVOT patching and severe pulmonary regurgitation (PR) underwent trans-catheter Venous  P Valve implantation.  Valve sizes used were 26 (n=3), 30 (n=1) and 32 (n=1) and were all 30 mm in length.  Mean procedural time was 136 ± 26.8 min and mean fluoroscopy time was 22.8 ± 8.8 min.  All valves were delivered successfully and no paravalvar leak was identified.  At follow up 3.4 ± 2.5 months 3 patients have no PR and 2 patients have trivial PR.  No patient has developed significant pulmonary valve stenosis. 

    • Author’s Conclusions:

    The Venus P Valve can be safely deployed within the native pulmonary outflow of patients with chronic severe PR following repair of tetralogy of Fallot with transannular patching.  The valve restores pulmonary valve function immediately and appears to have excellent short term durability. 

    • Interpretation:

    The Venus P Valve is a promising development for the trans-catheter treatment of chronic severe PR following repair of tetralogy of Fallot with transannular patching.  Additional clinical trials are necessary to determine the utility and longer term durability of this valve. 

    Outcomes Using a Clinical Practice Pathway for the Management of Pulse Loss Following Pediatric Cardiac Catheterization

    Glatz AC, Keashen R, Chang J, Balsama L, Dori Y, Gillespie MJ, Giglia TM, Raffini L, Rome JJ.   Catheter Cardiovasc Interv. 2015 Jan 1; 85(1): 111-17.

    • Summary:

    This is a single center report summarizing the results of using a standardized clinical practice pathway (CPP) to diagnose and manage femoral artery pulse loss following pediatric cardiac catheterization.  A total of 93 cases (5.6%) of pulse loss were identified from 1672 catheterizations performed from 2010-2012.  Of these 93 patients, 85 had documented thrombus by US and the remaining 8 had vessel spasm which resolved within 24 hours. The median age and weight of the patients with arterial thrombosis was 73 days and 4.8 kg; with 80 of 85 patients being less than 1 year of age.  Overall, 19% of the patients less than 1 year of age developed arterial thrombosis, and represented the highest risk group.  A primary goal of the CPP was to initiate treatment with a first line anticoagulant (unfractionated heparin or enoxaparin) within 4 hours of pulse loss detection, and the median time to anticoagulant administration was 2 hours during the CPP.  A total of 66 of 74 patients (89%) completing up to 12 weeks of therapy with enoxaparin had complete resolution of their arterial thrombus.  Eight patients continued to have persistent thrombus at 12 weeks post catheterization, 4 patients were lost to follow up and 7 patients died prior to completing the treatment course.  No patient developed a bleeding complication while being treated on the CPP.  Of the patients experiencing thrombus resolution while completing treatment on the CPP, 35/66 (53%) had documented arterial thrombus resolution by 2 weeks and 57/66 (86%) had thrombus resolution by 6 weeks.

    • Author’s Conclusions:

    A standardized approach to the diagnosis and treatment of femoral artery thrombosis following cardiac catheterization allowed for rapid diagnosis and treatment initiation with thrombus resolution in nearly 90% of patients who completed treatment on the CPP.  Children under 1 year of age represent the highest risk group for arterial thrombosis, with nearly 20% having detectable thrombus following cardiac catheterization. 

    • Interpretation:

    This study demonstrates that by utilizing a robust CPP with the goal of detecting and treating pulse loss following cardiac catheterization within 4 hours, nearly 90% of arterial thromboses can be successfully treated.  Although older data suggest that untreated arterial thromboses in children often persist, the lack of an untreated control group in this study leaves open the possibility of spontaneous resolution of some of these arterial thromboses.