Right ventricular outflow tract obstruction associated with neointimal tissue accumulation and distortion of the Harmony TPV25 stent frame: Potential mechanisms and treatment.

BACKGROUND: The Harmony TPV25 transcatheter pulmonary valve (Medtronic Inc.) is constructed with a self-expanding stent frame comprising six zigged nitinol wires sewn together and covered with knitted polyester fabric, with flared inflow and outflow ends and a porcine pericardial valve sutured to the central portion of the device. It was approved for treatment of pulmonary regurgitation after prior right ventricular outflow tract repair in 2021. Early outcomes of this procedure have been excellent, but little is known about valve durability or ultimate mechanisms of dysfunction. METHODS: We collected data on patients who underwent reintervention for TPV25 dysfunction and described findings related to distortion of the stent frame and tissue accumulation. RESULTS: We describe six patients who underwent valve-in-valve implant for TPV25 obstruction (peak catheterization gradient peak 28-73 mmHg) 10-28 months after implant. In all cases, there was tissue accumulation within the inflow and valve-housing segments of the device and deformation of the self-expanding valve frame characterized by variable circumferential narrowing at the junction between the valve housing and the inflow and outflow portions of the device, with additional geometric changes in all segments. All six patients underwent valve-in-valve implant that results in a final peak gradient ≤10 mmHg and no regurgitation. DISCUSSION: The occurrence of short-term Harmony TPV25 dysfunction in multiple patients with a similar appearance of frame distortion and tissue accumulation within the inflow and valve housing portions of the device suggests that this may be an important failure mechanism for this valve. Potential causes of the observed findings are discussed. It is possible to treat this mechanism of TPV25 dysfunction with valve-in-valve implant using balloon expandable transcatheter valves.

Initial results from the off-label use of the SAPIEN S3 valve for percutaneous transcatheter pulmonary valve replacement: A multi-institutional experience.

OBJECTIVES: To describe a multi-center experience of percutaneous transcatheter pulmonary valve replacement (TPVR) using the Edwards Sapien S3 Valve. BACKGROUND: Off-label use of the Sapien S3 valve can allow for TPVR in patients with congenital heart disease (CHD) and large diameter dysfunctional right ventricular outflow tract (RVOT). The initial experience at five centers with the SAPIEN S3 valve for TPVR is presented with a focus on procedural techniques, success, complications, and efficacy. METHODS: A retrospective review was performed of all patients with CHD and dysfunctional RVOT who underwent TPVR using Sapien S3 valve. Imaging data, procedural elements, and clinical follow-up data were collected to evaluate acute and short-term results. RESULTS: A total of 50 patients underwent percutaneous placement of the Sapien S3 in the pulmonary position. Of these, 38 were placed into "native RVOTs", measuring 24-32 mm in diameter, as assessed by compliant balloon sizing. In all cases, the valve was implanted after introduction and there were no cases of valve embolization. On follow up (range 1-9 months, median 3 months), no patients had significant obstruction or regurgitation through or around the valve requiring intervention. There were no procedural deaths. Major complications included severe aortic compression (n = 1) and tricuspid valve (TV) injury related to valve placement (n = 2) and prestenting (n = 1). CONCLUSIONS: TPVR in patients with large diameter dysfunctional RVOTs can be effectively performed with the Sapien S3. All procedures were technically successful with no embolizations, no perivalvular leaks, and excellent short-term valve function. Tricuspid valve injury from implantation of an uncovered valve was a serious procedural complication.

Reducing Radiation Exposure in Cardiac Catheterizations for Congenital Heart Disease.

Ionizing radiation exposure is a necessary risk entailed during congenital cardiac catheterizations. The congenital catheterization lab at Yale New Haven Children's Hospital employed quality improvement strategies to minimize radiation exposure in this vulnerable population. In two phases, we implemented six interventions, which included adding and utilizing lower fluoroscopy and digital angiography (DA) doses, increasing staff and physician radiation awareness, focusing on tighter collimation, and changing the default fluoroscopy and DA doses to lower settings. Post-intervention data were collected prospectively for all procedures in the congenital catheterization lab and compared to pre-intervention radiation data collected retrospectively. Radiation exposure was measured in total air kerma (mGy), dose area product per body weight (DAP/kg) (µGy m2/kg), and fluoroscopy time (min). Data were collected for a total of 312 cases. In considering all procedures, the DAP/kg decreased by 67.6% and air kerma decreased by 63%. Fluoroscopy time did not change over the study period. Significant decreases in radiation exposure (DAP/kg) by procedure type were seen for atrial septal defect, patent ductus arteriosus, and transcatheter pulmonary valve procedures with a 45%, 42% and 83% decrease, respectively. Air kerma decreased significantly for ASD and PDA procedures with an 80% and 72% decrease, respectively. When compared to national benchmarks, the median DAP/kg and air kerma for these procedures are lower at our institution. The decreases continue to be sustained 2 years post-interventions. Systems-based interventions can be readily implemented in the congenital cardiac catheterization lab with dramatic and sustainable radiation dose reduction for patients.

Ventricular arrhythmias immediately following transcatheter pulmonary valve implantation: A cause for concern?

BACKGROUND: Transcatheter pulmonary valve implantation (TPVI) has revolutionized the care of patients with congenital disorders of the right ventricular outflow tract (RVOT) and is increasingly being used in patients with native outflow tracts. This is the first study to specifically report the occurrence of ventricular arrhythmias in the immediate post-TPVI period. METHODS AND RESULTS: Medical records of all adult and pediatric patients who underwent TPVI at our institution between May 1, 2011 and March 1, 2016, were reviewed for the presence of clinically significant ventricular arrhythmias occurring within 30 days of TPVI. We defined a clinically significant arrhythmia as any ventricular arrhythmia that led to hemodynamic instability, resulted in a change of dose or addition of a new anti-arrhythmic medication, caused a delay in discharge, or was the primary reason for readmission. Seventy-five patients, with a median age of 19 years (range 4-65 years), underwent TPVI. In total, 12 (16%) patients had a clinically significant ventricular arrhythmia within 30 days following TPVI. Patients with native outflow tracts were at higher risk of post-TPVI arrhythmias than non-native outflow tract (29% vs. 9%, P = 0.02, adjusted OR 4.8, 95%CI 1.2-20.2). There were no cases of hemodynamic compromise or sudden cardiac death. The arrhythmias were well controlled with beta-blocker therapy. CONCLUSION: In this single center study, ventricular arrhythmias were common following TPVI, particularly in native outflow tract patients. However, the arrhythmias were generally benign and responded well to medical therapy when indicated. Long term therapy was often not needed.

Percutaneous transcatheter pulmonary valve replacement in children weighing less than 20 kg.

BACKGROUND: Since FDA approval of the Melody valve, transcatheter pulmonary valve replacement (TPVR) has been offered to an expanding population. Limited data exist regarding the safety and feasibility of TPVR in smaller patients. METHODS: All patients weighing <20 kg who underwent catheterization for percutaneous TPVR at four centers were reviewed. RESULTS: Of the 51 patients reviewed, 43 (84%) had successful valve implantation and 8 (16%) were found not to be candidates due to access veins too small (n = 3), coronary artery/aortic root compression (n = 3), and RVOT too large (n = 2). The 43 patients who underwent successful percutaneous TPVR had a median age and weight of 5.8 years (3.3-10) and 17.7 kg (13.5-19.8), and most had tetralogy of Fallot (TOF). TPVR was performed via femoral vein (FV) access in 24 patients and internal jugular vein (IJV) access in 19 patients. Median weight in patients with IJV implant was 1.1 kg lower than those who underwent transfemoral implant (17.0 vs. 18.1 kg, P = 0.05). There were four adverse events: one iliac vein injury, one contained MPA tear, and two patients with post-procedure femoral vein bleeding. All patients were alive at recent follow-up, a median of 2.0 years (0.1-6.0) after TPVR. There was excellent valve function with mean Doppler gradients of 3-20 mm Hg, and trivial or mild pulmonary regurgitation in all but one patient. There were no RVOT reinterventions and no cases of endocarditis. CONCLUSIONS: Percutaneous TPVR can be safely performed in patients <20 kg. The procedure frequently requires IJV access, and access site/bleeding complications may be more common in this cohort.

Transcatheter Tricuspid Valve-in-Valve Implantation for the Treatment of Dysfunctional Surgical Bioprosthetic Valves: An International, Multicenter Registry Study.

BACKGROUND: Off-label use of transcatheter aortic and pulmonary valve prostheses for tricuspid valve-in-valve implantation (TVIV) within dysfunctional surgical tricuspid valve (TV) bioprostheses has been described in small reports. METHODS AND RESULTS: An international, multicenter registry was developed to collect data on TVIV cases. Patient-related factors, procedural details and outcomes, and follow-up data were analyzed. Valve-in-ring or heterotopic TV implantation procedures were not included. Data were collected on 156 patients with bioprosthetic TV dysfunction who underwent catheterization with planned TVIV. The median age was 40 years, and 71% of patients were in New York Heart Association class III or IV. Among 152 patients in whom TVIV was attempted with a Melody (n=94) or Sapien (n=58) valve, implantation was successful in 150, with few serious complications. After TVIV, both the TV inflow gradient and tricuspid regurgitation grade improved significantly. During follow-up (median, 13.3 months), 22 patients died, 5 within 30 days; all 22 patients were in New York Heart Association class III or IV, and 9 were hospitalized before TVIV. There were 10 TV reinterventions, and 3 other patients had significant recurrent TV dysfunction. At follow-up, 77% of patients were in New York Heart Association class I or II (P<0.001 versus before TVIV). Outcomes did not differ according to surgical valve size or TVIV valve type. CONCLUSIONS: TVIV with commercially available transcatheter prostheses is technically and clinically successful in patients of various ages across a wide range of valve size. Although preimplantation clinical status was associated with outcome, many patients in New York Heart Association class III or IV at baseline improved. TVIV should be considered a viable option for treatment of failing TV bioprostheses.

Transcatheter valve implantation for right atrium-to-right ventricle conduit obstruction or regurgitation after modified Björk-fontan procedure.

BACKGROUND: The most common reason for reintervention after a Björk modification of the Fontan procedure, in which the right ventricle (RV) is incorporated into the pulmonary circulation by connecting the right atrial (RA) appendage to the RV directly or with an extra-anatomic graft, is obstruction or regurgitation of the RA-RV connection. Transcatheter implantation of a valved stent is an appealing option for the treatment of RA-RV conduit dysfunction in these patients. In the present study, we assessed early and intermediate results after transcatheter valve implantation within an obstructed or regurgitant RA-RV modified Fontan pathway. METHODS: Through a retrospective multicenter registry, we collected data from 16 patients with a modified Fontan circulation who were treated with percutaneous Melody or Sapien valve implantation for dysfunction of an extra-anatomic RA-RV conduit or valve. RESULTS: All patients had successful and uncomplicated implantation of a Melody (n = 15) or Sapien 3 (n = 1) valve with hemodynamic and, in most cases, clinical improvement. During a median follow-up of 3.3 years, 3 patients died of cardiovascular causes unrelated to the procedure or the valve, and no major valve dysfunction was observed. CONCLUSION: Percutaneous transcatheter valve deployment to treat a dysfunctional RA-RV connection after a Björk modification of the Fontan procedure is a viable alternative to surgery, with low procedural risk, and appears to offer good early and intermediate results.© 2016 Wiley Periodicals, Inc.

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.

Thoracic aortic aneurysm in an adolescent with intraoperative discovery of contained rupture: a case report.

Background: As surgical recommendations in adults based on size criteria of ascending aortic aneurysms become more refined, criteria for childhood/adolescence remains less clear. Multiple pathologic factors may predispose younger patients to thoracic aortic aortopathy and increase the risk of rupture. An evolving field of research is how to identify thoracic aortic dilation earlier in patients, risk stratify, and to obtain objective measures beyond size for proceeding with surgical intervention in order to prevent catastrophic thoracic aortic dissection. Case Description: We report an adolescent case of dilated ascending aortic aneurysm with a functionally unicuspid/bicuspid aortic valve. This patient was taken to surgery electively, given the gradual increasing size of the ascending aorta. Intraoperatively, there was an unexpected intraoperative finding of a contained aortic rupture. The patient underwent an aortic root replacement with mechanical valve composite graft and coronary artery reimplantation (modified Bentall) with ascending hemiarch replacement. The patient did well with no post-operative complications. Aortic pathology and genetic analysis were performed. The patient was discovered to have a heterozygous variant in PTPN11 which is typically associated with Noonan syndrome; however, this is not known to be associated with aortopathy. Conclusions: As criteria for surgical intervention in adult thoracic ascending aortic aneurysms continues to evolve, this case illustrates challenges when determining the optimal criteria for surgical intervention in adolescent patients.

Use of intracardiac echocardiography during atrial fibrillation ablation.

As the volume and complexity of catheter ablation of atrial fibrillation (AF) continue to rise, there is increasing attention directed at reducing exposure to ionizing radiation. This has led to the emergence of intracardiac echocardiography (ICE) as a stand-alone imaging modality guiding AF ablation. In addition to directing transseptal puncture, ICE may be used to identify left atrial structures and to guide the manipulation of catheters. ICE may also be used to visualize the esophagus in real-time and to assist with early identification of procedural complications. This review provides detailed step-by-step directions for identification of relevant structures and summarizes the use of ICE during AF ablation.

1-Year Outcomes in a Pooled Cohort of Harmony Transcatheter Pulmonary Valve Clinical Trial Participants.

BACKGROUND: The Harmony transcatheter pulmonary valve (TPV) is the first U.S. Food and Drug Administration-approved device for severe pulmonary regurgitation (PR) in the native or surgically repaired right ventricular outflow tract (RVOT). OBJECTIVES: One-year safety and effectiveness of the Harmony TPV were evaluated in patients from the Harmony Native Outflow Tract Early Feasibility Study, Harmony TPV Pivotal Study, and Continued Access Study, representing the largest cohort to date of Harmony TPV recipients. METHODS: Eligible patients had severe PR by echocardiography or PR fraction ≥ 30% by cardiac magnetic resonance imaging and clinical indications for pulmonary valve replacement. The primary analysis included 87 patients who received a commercially available TPV22 (n = 42) or TPV25 (n = 45) device; 19 patients who received an early device iteration prior to its discontinuation were evaluated separately. RESULTS: In the primary analysis, median patient age at treatment was 26 years (IQR: 18-37 years) in the TPV22 group and 29 years (IQR: 19-42 years) in the TPV25 group. At 1 year, there were no deaths; 98% of TPV22 and 91% of TPV25 patients were free from the composite of PR, stenosis, and reintervention (moderate or worse PR, mean RVOT gradient >40 mmHg, device-related RVOT reoperation, and catheter reintervention). Nonsustained ventricular tachycardia occurred in 16% of patients. Most patients had none/trace or mild PR (98% of TPV22 patients, 97% of TPV25 patients). Outcomes with the discontinued device are reported separately. CONCLUSIONS: The Harmony TPV device demonstrated favorable clinical and hemodynamic outcomes across studies and valve types through 1 year. Further follow-up will continue to assess long-term valve performance and durability.

Anatomical Classification and Posttreatment Remodeling Characteristics to Guide Management and Follow-Up of Neonates and Infants With Coronary Artery Fistula: A Multicenter Study From the Coronary Artery Fistula Registry.

BACKGROUND: Coronary artery fistulas (CAFs) presenting in infancy are rare, and data regarding postclosure sequelae and follow-up are limited. METHODS: A retrospective review of all the neonates and infants (<1 year) was conducted from the CAF registry for CAF treatment. The CAF type (proximal or distal), size, treatment method, and follow-up angiography were reviewed to assess outcomes and coronary remodeling. RESULTS: Forty-eight patients were included from 20 centers. Of these, 30 were proximal and 18 had distal CAF; 39 were large, 7 medium, and 2 had small CAF. The median age and weight was 0.16 years (0.01-1) and 4.2 kg (1.7-10.6). Heart failure was noted in 28 of 48 (58%) patients. Transcatheter closure was performed in 24, surgical closure in 18, and 6 were observed medically. Procedural success was 92% and 94 % for transcatheter closure and surgical closure, respectively. Follow-up data were obtained in 34 of 48 (70%) at a median of 2.9 (0.1-18) years. Angiography to assess remodeling was available in 20 of 48 (41%). I. Optimal remodeling (n=10, 7 proximal and 3 distal CAF). II. Suboptimal remodeling (n=7) included (A) symptomatic coronary thrombosis (n=2, distal CAF), (B) asymptomatic coronary thrombosis (n=3, 1 proximal and 2 distal CAF), and (C) partial thrombosis with residual cul-de-sac (n=1, proximal CAF) and vessel irregularity with stenosis (n=1, distal CAF). Finally, (III) persistent coronary artery dilation (n=4). Antiplatelets and anticoagulation were used in 31 and 7 patients post-closure, respectively. Overall, 7 of 10 (70%) with proximal CAF had optimal remodeling, but 5 of 11 (45%) with distal CAF had suboptimal remodeling. Only 1 of 7 patients with suboptimal remodeling were on anticoagulation. CONCLUSIONS: Neonates/infants with hemodynamically significant CAF can be treated by transcatheter or surgical closure with excellent procedural success. Patients with distal CAF are at higher risk for suboptimal remodeling. Postclosure anticoagulation and follow-up coronary anatomic evaluation are warranted.

Transcatheter Pulmonary Valve Replacement With the Sapien Prosthesis.

BACKGROUND: There are limited published data focused on outcomes of transcatheter pulmonary valve replacement (TPVR) with either a Sapien XT or Sapien 3 (S3) valve. OBJECTIVES: This study sought to report short-term outcomes in a large cohort of patients who underwent TPVR with either a Sapien XT or S3 valve. METHODS: Data were entered retrospectively into a multicenter registry for patients who underwent attempted TPVR with a Sapien XT or S3 valve. Patient-related, procedural, and short-term outcomes data were characterized overall and according to type of right ventricular outflow tract (RVOT) anatomy. RESULTS: Twenty-three centers enrolled a total of 774 patients: 397 (51%) with a native/patched RVOT; 183 (24%) with a conduit; and 194 (25%) with a bioprosthetic valve. The S3 was used in 78% of patients, and the XT was used in 22%, with most patients receiving a 29-mm (39%) or 26-mm (34%) valve. The implant was technically successful in 754 (97.4%) patients. Serious adverse events were reported in 67 patients (10%), with no difference between RVOT anatomy groups. Fourteen patients underwent urgent surgery. Nine patients had a second valve implanted. Among patients with available data, tricuspid valve injury was documented in 11 (1.7%), and 9 others (1.3%) had new moderate or severe regurgitation 2 grades higher than pre-implantation, for 20 (3.0%) total patients with tricuspid valve complications. Valve function at discharge was excellent in most patients, but 58 (8.5%) had moderate or greater pulmonary regurgitation or maximum Doppler gradients >40 mm Hg. During limited follow-up (n = 349; median: 12 months), 9 patients were diagnosed with endocarditis, and 17 additional patients underwent surgical valve replacement or valve-in-valve TPVR. CONCLUSIONS: Acute outcomes after TPVR with balloon-expandable valves were generally excellent in all types of RVOT. Additional data and longer follow-up will be necessary to gain insight into these issues.

Spontaneous reversal of stenosis in tissue-engineered vascular grafts.

We developed a tissue-engineered vascular graft (TEVG) for use in children and present results of a U.S. Food and Drug Administration (FDA)-approved clinical trial evaluating this graft in patients with single-ventricle cardiac anomalies. The TEVG was used as a Fontan conduit to connect the inferior vena cava and pulmonary artery, but a high incidence of graft narrowing manifested within the first 6 months, which was treated successfully with angioplasty. To elucidate mechanisms underlying this early stenosis, we used a data-informed, computational model to perform in silico parametric studies of TEVG development. The simulations predicted early stenosis as observed in our clinical trial but suggested further that such narrowing could reverse spontaneously through an inflammation-driven, mechano-mediated mechanism. We tested this unexpected, model-generated hypothesis by implanting TEVGs in an ovine inferior vena cava interposition graft model, which confirmed the prediction that TEVG stenosis resolved spontaneously and was typically well tolerated. These findings have important implications for our translational research because they suggest that angioplasty may be safely avoided in patients with asymptomatic early stenosis, although there will remain a need for appropriate medical monitoring. The simulations further predicted that the degree of reversible narrowing can be mitigated by altering the scaffold design to attenuate early inflammation and increase mechano-sensing by the synthetic cells, thus suggesting a new paradigm for optimizing next-generation TEVGs. We submit that there is considerable translational advantage to combined computational-experimental studies when designing cutting-edge technologies and their clinical management.

Causes of recurrent focal neurologic events after transcatheter closure of patent foramen ovale with the CardioSEAL septal occluder.

Transcatheter patent foramen ovale (PFO) closure has been undertaken to eliminate paradoxical emboli as a cause for recurrent strokes/transient ischemic attacks (TIAs). We report the results of investigations to determine causes of all significant focal neurologic events (FNEs) after PFO closure reported to our center. Records of 216 consecutive patients who underwent PFO closure were reviewed. Patients had to have had > or =1 preceding clinical event consistent with stroke/TIA considered by a neurologist to be consistent with an embolic episode. Follow-up was recommended at 24 hours, 1 month, 6 months, 1 year, and every 1 to 2 years thereafter. All patients were requested to report any new FNE possibly suggestive of stroke/TIA to our center. Reports of evaluations were reviewed in detail. Twenty patients had an FNE 0.1 month to 40.2 months after PFO closure over 438 person-years of follow-up (mean 2.1 years, range 1 month to 7.1 years). There were 4 recurrent strokes, 2 likely directly device related. Ten patients had TIA and 6 patients had clear evidence of pathology unrelated to the device. Event rate for recurrent strokes was 0.9% per year (95% confidence interval for difference 0.3 to 2.4) and combined event rate for stroke/TIA was 3.4% per year (95% confidence interval for difference 2 to 5.6). In conclusion, transcatheter PFO occlusion can be accomplished as an outpatient procedure with minimal immediate morbidity. Patients may have multiple possible causes of recurrent FNE. Recurrence rate of cryptogenic FNE compares favorably with reports of medical management. Analysis of results from ongoing randomized trials of transcatheter PFO closure versus medical management may improve our ability to select the best treatment for individual patients.

Novel catheter positioning technique for atretic pulmonary valve perforation.

Percutaneous pulmonary valve perforation in selected neonates with pulmonary valve atresia and intact ventricular septum has been well established as a therapeutic option. Pulmonary valve perforation is associated with significant risks including perforation of the right ventricle. Optimal catheter positioning is crucial to the success of the procedure. This report describes a novel technique for accurate positioning of a guiding catheter during perforation of an atretic pulmonary valve.

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.

Transcatheter pulmonary valve replacement using the melody valve for treatment of dysfunctional surgical bioprostheses: A multicenter study.

BACKGROUND: Stented bioprosthetic valves (BPVs) are commonly used for surgical pulmonary valve (PV) replacement in postoperative congenital heart disease, but develop structural failure in a time-related fashion. The Melody transcatheter PV (TPV) (Medtronic, Minneapolis, Minn) has been used to treat BPV dysfunction, but there have been few studies in this population. METHODS: We performed a retrospective, multicenter study to evaluate Melody valve function in patients who underwent TPV replacement (TPVR) into a dysfunctional pulmonary BPV. RESULTS: One hundred patients who underwent TPVR at 10 centers between January 2010 and June 2015 were enrolled. The median patient age was 22 years (range, 5-79 years), and 32 patients were age <18 years. The underlying diagnosis was tetralogy of Fallot in 80 patients, and moderate or severe pulmonary regurgitation (PR) was present in 84%. The TPV was implanted into various types of BPVs, with a median size of 23 mm (range, 19-33 mm). At hospital discharge, PR was mild or less in all but 1 patient, and the mean Doppler right ventricular outflow tract (RVOT) gradient was reduced from a mean of 29.3 ± 12.0 mm Hg to 16.2 ± 6.9 mm Hg (median, 29 mm Hg to 16 mm Hg; P < .001). During follow-up (median, 12.4 months), no patients underwent reintervention on the TPV. Endocarditis was diagnosed in 1 patient who was managed medically without intervention. The mean RVOT gradient at the most recent follow-up was ≤35 mm Hg in all patients, and was similar to that at early postimplantation. PR was more than mild in only 1 patient. Hemodynamic outcomes did not differ between patients with small BPVs (≤23 mm) and those with large BPVs (≥25 mm). CONCLUSIONS: TPVR restores competence and relieves the obstruction of dysfunctional surgical BPVs, with excellent early results in both small and large BPVs, highlighting the potential for TPVR to extend the life of existing BPVs in adults and children. Collaboration between surgeons and cardiologists is important to determine the optimal lifetime management, combining surgical PV replacement and TPVR in this population.

Intentional Fracture of Bioprosthetic Valve Frames in Patients Undergoing Valve-in-Valve Transcatheter Pulmonary Valve Replacement.

BACKGROUND: Percutaneous transcatheter pulmonary valve replacement (TPVR) has good clinical and hemodynamic outcomes in treating dysfunctional bioprosthetic valves (BPV) in the pulmonary position. Valve-in-valve therapy can further decrease the inner diameter (ID), potentially resulting in patient-prosthesis mismatch in patients with smaller BPVs. METHODS AND RESULTS: To evaluate feasibility and outcomes of intentional BPV fracture to enlarge the pulmonary valve orifice with TPVR, 37 patients from 13 centers who underwent TPVR with intended BPV fracture were evaluated. A control cohort (n=70) who underwent valve-in-valve TPVR without attempted fracture was evaluated. BPV was successfully fractured in 28 patients and stretched in 5 while fracture was unsuccessful in 4. A Melody valve was implanted in 25 patients with fractured/stretched frame and a Sapien (XT 3) valve in 8. Among patients whose BPV was fractured/stretched, the final ID was a median of 2 mm larger (0-6.5 mm) than the valve's true ID. The narrowest diameter after TPVR in controls was a median of 2 mm smaller ( P<0.001) than true ID. Right ventricular outflow tract gradient decreased from median 40 to 8 mm Hg in the fracture group. Cases with fracture/stretching were matched 1:1 (weight, true ID) to controls. Post-TPVR peak gradient was lower but not significant (8.3±5.2 versus 11.8±9.2 mm Hg; P=0.070). There were no fracture-related adverse events. CONCLUSIONS: Preliminary experience shows intentional fracture of BPV frame can be useful for achieving larger ID and better hemodynamics after valve-in-valve TPVR.

Transcatheter Pulmonary Valve Replacement With the Melody Valve in Small Diameter Expandable Right Ventricular Outflow Tract Conduits.

OBJECTIVES: This study sought to evaluate the safety, feasibility, and outcomes of transcatheter pulmonary valve replacement (TPVR) in conduits ≤16 mm in diameter. BACKGROUND: The Melody valve (Medtronic, Minneapolis, Minnesota) is approved for the treatment of dysfunctional right ventricular outflow tract (RVOT) conduits ≥16 mm in diameter at the time of implant. Limited data are available regarding the use of this device in smaller conduits. METHODS: The study retrospectively evaluated patients from 9 centers who underwent percutaneous TPVR into a conduit that was ≤16 mm in diameter at the time of implant, and reported procedural characteristics and outcomes. RESULTS: A total of 140 patients were included and 117 patients (78%; median age and weight 11 years of age and 35 kg, respectively) underwent successful TPVR. The median original conduit diameter was 15 (range: 9 to 16) mm, and the median narrowest conduit diameter was 11 (range: 4 to 23) mm. Conduits were enlarged to a median diameter of 19 mm (29% larger than the implanted diameter), with no difference between conduits. There was significant hemodynamic improvement post-implant, with a residual peak RVOT pressure gradient of 7 mm Hg (p < 0.001) and no significant pulmonary regurgitation. During a median follow-up of 2.0 years, freedom from RVOT reintervention was 97% and 89% at 2 and 4 years, respectively, and there were no deaths and 5 cases of endocarditis (incidence rate 2.0% per patient-year). CONCLUSIONS: In this preliminary experience, TPVR with the Melody valve into expandable small diameter conduits was feasible and safe, with favorable early and long-term procedural and hemodynamic outcomes.