Evan M. Zahn

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 (≥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.

Implantation of the Melody Transcatheter Pulmonary Valve in Patients With a Dysfunctional Right Ventricular Outflow Tract Conduit: Early Results From the U.S. Clinical Trial

OBJECTIVES This study was designed to evaluate the safety, procedural success, and short-term effectiveness of the Melody transcatheter pulmonary valve (Medtronic, Inc., Minneapolis, Minnesota) in patients with dysfunctional right ventricular outflow tract conduits. BACKGROUND Conduit dysfunction has recently been treated with transcatheter pulmonary valve placement. There have been no prospective, multicenter trials evaluating this technology. METHODS Standardized entry criteria, implantation, and follow-up protocols were used. Nonimplanting core laboratories were used to evaluate results. RESULTS Between January 2007 and September 2007, 34 patients underwent catheterization for intended Melody valve implantation at 3 centers. Mean age was 19.4 +/- 7.7 years. Initial conduit Doppler mean gradient was 28.8 +/- 10.1 mm Hg, and 94% of patients had moderate or severe pulmonary regurgitation (PR). Implantation was successful in 29 of 30 attempts and not attempted in 4 patients. Procedural complications included conduit rupture requiring urgent surgery and device removal (n = 1), wide-complex tachycardia (n = 1), and distal pulmonary artery guidewire perforation (n = 1). Peak systolic conduit gradient fell acutely from 37.2 +/- 16.3 mm Hg to 17.3 +/- 7.3 mm Hg, and no patient had more than mild PR. There were no deaths or further device explants. At 6-month follow-up, conduit Doppler mean gradient was 22.4 +/- 8.1 mm Hg, and PR fraction by magnetic resonance imaging was significantly improved (3.3 +/- 3.6% vs. 27.6 +/- 13.3%, p < 0.0001). Stent fracture occurred in 8 of 29 implants; 3 of these were treated with a second Melody valve for recurrent stenosis later in follow-up. CONCLUSIONS Implantation of the Melody valve for right ventricular outflow tract conduit dysfunction can be performed by experienced operators at multiple centers, appears safe, and has encouraging acute and short-term outcomes.

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 ± 3.2mm), 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.

Outcome of cardiopulmonary resuscitation in a pediatric cardiac intensive care unit.

ObjectiveTo determine the eventual outcome of children with heart disease who had cardiopulmonary resuscitation (CPR) in a specialized pediatric cardiac intensive care unit (CICU), and to define the influence of any prearrest variables on the outcome. DesignA retrospective review of patients’ medical records. SettingA pediatric CICU of a tertiary pediatric teaching hospital. Patients and MethodsPatients were all children who presented with cardiopulmonary arrest and who were administered CPR in the pediatric CICU between June 1995 and June 1997. Prearrest variables such as age, diagnosis, prior cardiac surgery, and inotropic support with epinephrine, as well as cause of arrest, were evaluated. Measurements and Main ResultsThirty-two patients, ranging in age from 1 day to 21 yrs (median, 1 month), satisfied criteria for inclusion in the study group. These 32 patients had a total of 38 episodes of cardiopulmonary arrest. Twenty-five of these patients (78%) had cardiac surgery before arrest. Inotropic support with continuous infusion of epinephrine was being administered at the time of arrest in 18 of 38 (47%) arrests. These prearrest variables did not influence outcome of CPR.Of the 38 episodes of CPR, 24 episodes (63%) were successful, with 20 episodes resulting in return of spontaneous circulation and four patients being successfully placed on mechanical cardiopulmonary support. Fourteen children, including all four patients who were rescued with mechanical cardiopulmonary support, survived to discharge. At 6-month follow-up, 11 patients were still alive, with three having neurologic impairment. ConclusionsAfter cardiopulmonary resuscitation in this pediatric CICU, the rate of success was 63% and the rate of survival was 42%. Prior cardiac surgery and use of epinephrine before arrest did not influence the outcome of CPR. The availability of effective mechanical cardiopulmonary support can improve the outcome of CPR.

Percutaneous Tricuspid Valve Replacement in Congenital and Acquired Heart Disease

OBJECTIVES This study sought to describe the first human series of percutaneous tricuspid valve replacements in patients with congenital or acquired tricuspid valve (TV) disease. BACKGROUND Percutaneous transcatheter heart valve replacement of the ventriculoarterial (aortic, pulmonary) valves is established. Although there are isolated reports of transcatheter atrioventricular heart valve replacement (hybrid and percutaneous), this procedure has been less frequently described; we are aware of no series describing this procedure for TV disease. METHODS We approached institutions with significant experience with the Melody percutaneous pulmonary valve (Medtronic, Inc., Minneapolis, Minnesota) to collect data where this valve had been implanted in the tricuspid position. Clinical and procedural data were gathered for 15 patients. Indications for intervention included severe hemodynamic compromise and perceived high surgical risk; all had prior TV surgery and significant stenosis and/or regurgitation of a bioprosthetic TV or a right atrium-to-right ventricle conduit. RESULTS Procedural success was achieved in all 15 patients. In patients with predominantly stenosis, mean tricuspid gradient was reduced from 12.9 to 3.9 mm Hg (p < 0.01). In all patients, tricuspid regurgitation was reduced to mild or none. New York Heart Association functional class improved in 12 patients. The only major procedural complication was of third-degree heart block requiring pacemaker insertion in 1 patient. One patient developed endocarditis 2 months after implant, and 1 patient with pre-procedural multiorgan failure did not improve and died 20 days after the procedure. The remaining patients have well-functioning Melody valves in the TV position a median of 4 months after implantation. CONCLUSIONS In selected cases, patients with prior TV surgery may be candidates for percutaneous TV replacement.

Stent Fracture, Valve Dysfunction, and Right Ventricular Outflow Tract Reintervention After Transcatheter Pulmonary Valve Implantation Patient-Related and Procedural Risk Factors in the US Melody Valve Trial

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.

Comparison of surgical, stent, and balloon angioplasty treatment of native coarctation of the aorta: an observational study by the CCISC (Congenital Cardiovascular Interventional Study Consortium).

OBJECTIVES The purpose of this study was to compare the safety and efficacy of surgical, stent, and balloon angioplasty (BA) treatment of native coarctation acutely and at follow-up. BACKGROUND Controversy surrounds the optimal treatment for native coarctation of the aorta. This is the first multicenter study evaluating acute and follow-up outcomes of these 3 treatment options in children weighing >10 kg. METHODS This is a multicenter observational study. Baseline, acute, short-term (3 to 18 months), and intermediate (>18 months) follow-up hemodynamic, imaging data, and complications were recorded. RESULTS Between June 2002 and July 2009, 350 patients from 36 institutions were enrolled: 217 underwent stent, 61 underwent BA, and 72 underwent surgery. All 3 arms showed significant improvement acutely and at follow-up in resting systolic blood pressure and upper to lower extremity systolic blood pressure gradient (ULG). Stent was superior to BA in achieving lower ULG acutely. Surgery and stent were superior to BA at short-term follow-up in achieving lower ULG. Stent patients had shorter hospitalization than surgical patients (2.4 vs. 6.4 days; p < 0.001) and fewer complications than surgical and BA patients (2.3%, 8.1%, and 9.8%; p < 0.001). The BA patients were more likely to encounter aortic wall injury, both acutely and at follow-up (p < 0.001). CONCLUSIONS Stent patients had significantly lower acute complications compared with surgery patients or BA patients, although they were more likely to require a planned reintervention. At short-term and intermediate follow-up, stent and surgical patients achieved superior hemodynamic and integrated aortic arch imaging outcomes compared with BA patients. Because of the nonrandomized nature of this study, these results should be interpreted with caution.

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.

Infective Endocarditis After Transcatheter Pulmonary Valve Replacement Using the Melody Valve Combined Results of 3 Prospective North American and European Studies

Background—Transcatheter (percutaneous) pulmonary valve (TPV) replacement has emerged as a viable therapy for right ventricular outflow tract conduit dysfunction. Little is known about the incidence, clinical course, and outcome of infective endocarditis (IE) after TPV implant. We reviewed combined data from 3 ongoing prospective multicenter trials to evaluate the experience with IE among patients undergoing TPV replacement using the Melody valve. Methods and Results—Any clinical episode reported by investigators as IE with documented positive blood cultures and fever, regardless of TPV involvement, was considered IE. Cases were classified as TPV-related if there was evidence of vegetations on or new dysfunction of the TPV. The 3 trials included 311 patients followed for 687.1 patient-years (median, 2.5 years). Sixteen patients were diagnosed with IE 50 days to 4.7 years after TPV implant (median, 1.3 years), including 6 who met criteria for TPV-related IE: 3 with vegetations, 2 with TPV dysfunction, and 1 with both. The annualized rate of a first episode of IE was 2.4% per patient-year and of TPV-related IE was 0.88% per patient-year. Freedom from TPV-related IE was 97±1% 4 years after implant. All patients were treated with intravenous antibiotics, 4 had the valve explanted, and 2 received a second TPV. There was 1 sepsis-related death, 1 patient died of sudden hemoptysis, and 2 patients developed recurrent IE. Conclusions—Bacterial endocarditis has occurred in all 3 prospective multicenter studies of the Melody valve in North America and Europe. Most cases did not involve the TPV and responded to antibiotics. More data are necessary to understand risk factors in this population. Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique identifiers: NCT00740870, NCT01186692, and NCT00688571.

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.