Infective endocarditis after transcatheter pulmonary valve replacement using the Melody valve: combined results of 3 prospective North American and European studies

[The successful saga of percutaneous pulmonary valvulation in congenital heart diseases]

With new surgical techniques, more and more complex congenital heart defects are treated requiring sometimes right ventricle to pulmonary artery conduit implantation. In order to extend RV to PA conduit lifespan, 15 years ago a valved stent was developed. The implantation technique was progressively standardized to decrease risks of procedural complications. Medium and long-term hemodynamic results of the stent were so good that indications were broadened to native or complex right ventricular outflow tracts. Currently, 2 types of stents are implanted routinely: the Melody valve^® (Medtronic, Minneapolis, USA) and the Sapien^® valve (Edwards, Lifesciences, Irvine, USA). Other devices are evaluated in trials: thanks to their diabolo shape, implantation is feasible in large outflows tracts. The main source of worries is infective endocarditis. Numerous studies are conducted in order to identify risks factors, prevention and optimal treatment of this complication. In the near future, new devices and new implantation strategies will make this technology available for a larger number of patients.

Percutaneous pulmonary valve implantation - state of the art and Polish experience

Percutaneous pulmonary valve implantation (PPVI) is a relatively new method of treating patients with right ventricular outflow tract (RVOT) dysfunction after surgical repair of congenital heart disease. Since its introduction in 2000 by Bonhoeffer, more than ten thousand PPVI procedures have been performed worldwide. Indications for PPVI have been adapted from those accepted for surgical intervention. Two types of valves are being used: Melody Medtronic available in diameters 16 mm and 18 mm and the family of Edwards SAPIEN valves 23, 26 and 29. The procedure has been shown to be feasible and safe when performed in patients with full pulmonary conduit dysfunction and in selected cases of patched RVOT. The low complication rate and the reduced number of open-chest re-interventions over a patient’s lifetime are among the main advantages of the procedure. The most important problem responsible for late mortality and reinterventions is infective endocarditis. Size restrictions of the currently available valves limit deployment in the majority of patients with a wide RVOT. Newer devices are being developed to make these patients suitable for PPVI. A literature review, Polish experience and results of PPVI performed in 66 patients in the Institute of Cardiology in Warsaw are briefly reported.

Infective endocarditis following Melody valve implantation: comparison with a surgical cohort

BACKGROUND

Infective endocarditis has been reported post Melody percutaneous pulmonary valve implant; the incidence and risk factors, however, remain poorly defined. We identified four cases of endocarditis from our first 25 Melody implants. Our aim was to examine these cases in the context of postulated risk factors and directly compare endocarditis rates with local surgical valves.

METHODS

We conducted a retrospective review of patients post Melody percutaneous pulmonary valve implant in New Zealand (October, 2009-May, 2015) and also reviewed the incidence of endocarditis in New Zealand among patients who have undergone surgical pulmonary valve implants.

RESULTS

In total, 25 patients underwent Melody implantation at a median age of 18 years. At a median follow-up of 2.9 years, most were well with low valve gradient (median 27 mmHg) and only mild regurgitation. Two patients presented with life-threatening endocarditis and obstructive vegetations at 14 and 26 months post implant, respectively. Two additional patients presented with subacute endocarditis at 5.5 years post implant. From 2009 to May, 2015, 178 surgical pulmonic bioprostheses, largely Hancock valves and homografts, were used at our institution. At a median follow-up of 2.9 years, four patients (2%) had developed endocarditis in this group compared with 4/25 (16%) in the Melody group (p=0.0089). Three surgical valves have been replaced.

CONCLUSIONS

The Melody valve offers a good alternative to surgical conduit replacement in selected patients. Many patients have excellent outcomes in the medium term. Endocarditis, however, can occur and if associated with obstruction can be life threatening. The risk for endocarditis in the Melody group was higher in comparison with that in a contemporaneous surgical pulmonary implant cohort.

Patient outcomes after transcatheter and surgical pulmonary valve replacement for pulmonary regurgitation in patients with repaired tetralogy of Fallot: A quasi-meta-analysis

BACKGROUND

Individuals with repaired tetralogy of Fallot develop pulmonary regurgitation that may cause symptoms (dyspnea, chest pain, palpitations, fatigue, presyncope, and syncope), impair functional capacity, and may affect health-related quality of life. Surgical pulmonary valve replacement is the gold standard of treatment although transcatheter pulmonary valve replacement is becoming more common. Patients want to know whether less invasive options are as good.

AIMS

This analysis aimed to examine the differences in surgical versus transcatheter pulmonary valve replacement effects in terms of physiological/biological variables, symptoms, functional status and health-related quality of life.

METHODS

This quasi-meta-analysis included 85 surgical and 47 transcatheter pulmonary valve replacement studies published between 1995-2016.

RESULTS

In terms of physiological/biological variables, both surgical and transcatheter pulmonary valve replacement improved pulmonary regurgitation and systolic and diastolic right ventricular volume indices but not heart function. In the left heart, only surgical pulmonary valve replacement improved heart function. Only transcatheter pulmonary valve replacement improved left ventricular end-diastolic indices and neither improved endsystolic indices. Only surgery has been demonstrated to decrease QRS duration but there is little evidence of arrhythmia reduction. Symptom change is poorly documented. Functional class improves but exercise capacity generally does not. Some aspects of health-related quality of life improve with surgery and in one small transcatheter pulmonary valve replacement study.

CONCLUSION

Transcatheter and surgical pulmonary valve replacement compare favorably for heart remodeling. Exercise capacity does not change with either technique. Health-related quality of life improves after surgical pulmonary valve replacement. There are numerous gaps in documentation of changes in arrhythmias and symptoms.

Mechanism of valve failure and efficacy of reintervention through catheterization in patients with bioprosthetic valves in the pulmonary position

BACKGROUND

Surgical and transcatheter bioprosthetic valves (BPVs) in the pulmonary position in patients with congenital heart disease may ultimately fail and undergo transcatheter reintervention. Angiographic assessment of the mechanism of BPV failure has not been previously described.

AIMS

The aim of this study was to determine the mode of BPV failure (stenosis/regurgitation) requiring transcatheter reintervention and to describe the angiographic characteristics of the failed BPVs and report the types and efficacy of reinterventions.

MATERIALS AND METHODS

This is a retrospective single-center review of consecutive patients who previously underwent pulmonary BPV placement (surgical or transcatheter) and subsequently underwent percutaneous reintervention from 2005 to 2014.

RESULTS

Fifty-five patients with surgical (41) and transcutaneous pulmonary valve (TPV) (14) implantation of BPVs underwent 66 catheter reinterventions. The surgically implanted valves underwent fifty reinterventions for indications including 16 for stenosis, seven for regurgitation, and 27 for both, predominantly associated with leaflet immobility, calcification, and thickening. Among TPVs, pulmonary stenosis (PS) was the exclusive failure mode, mainly due to loss of stent integrity (10) and endocarditis (4). Following reintervention, there was a reduction of right ventricular outflow tract gradient from 43 ± 16 mmHg to 16 ± 10 mmHg (P < 0.001) and RVp/AO ratio from 0.8 ± 0.2 to 0.5 ± 0.2 (P < 0.001). Reintervention with TPV placement was performed in 45 (82%) patients (34 surgical, 11 transcatheter) with no significant postintervention regurgitation or paravalvular leak.

CONCLUSION

Failing surgically implanted BPVs demonstrate leaflet calcification, thickness, and immobility leading to PS and/or regurgitation while the mechanism of TPV failure in the short- to mid-term is stenosis, mainly from loss of stent integrity. This can be effectively treated with a catheter-based approach, predominantly with the valve-in-valve technique.

Recent advances in transcatheter pulmonary valve delivery

PURPOSE OF REVIEW

Transcatheter pulmonary valve replacement has only been both approved and widely available for most congenital heart disease centers for a few years; its use and familiarity for interventionalists have greatly expanded our knowledge of its applicability to a multitude of clinical situations. Expanded worldwide use and longer time from implant have both served to better understand procedural limits and uncommon late adverse events.

RECENT FINDINGS

Although currently approved for implantation in the USA only in dysfunctional and circumferential right ventricle to pulmonary artery conduits, with expanded experience operators have been able to adapt the delivery of this valve in a large number of additional clinical scenarios. Rare technical limitations of the procedure, most importantly coronary compression, are now being better defined. Although not frequent, a significant number of infective endocarditis episodes have been reported, but more recently several studies have deepened our understanding of this late adverse event for the most commonly implanted transcatheter pulmonary valve prosthesis.

SUMMARY

Expanded and widened use has extended our understanding of who may benefit from transcatheter pulmonary valve implantation (TPVI), the current limits of TPVI, and uncommon but important late issues following TPVI.

Diagnostic Value of Contrast-Enhanced Multiphase Computed Tomography for Assessment of Percutaneous Pulmonary Valve Obstruction

Percutaneous pulmonary valve replacement has emerged as an alternative to operation for some patients with congenital heart disease requiring intervention. Endocarditis is increasingly described as an adverse event during follow-up [1-4]. Diagnosis is difficult because of the poor visualization of the prosthetic valve in the pulmonary position by transthoracic and transesophageal echocardiogram and by the metallic artifact that degrades the image quality of magnetic resonance imaging (MRI). Two cases of percutaneous pulmonary valve obstruction diagnosed by cardiac computed tomographic angiography are presented. These cases demonstrate the utility of cardiac computed tomography for noninvasive imaging of suspected thrombus or endocarditis in a percutaneously placed pulmonary valve.

Infective endocarditis prophylaxis: current practice trend among paediatric cardiologists: are we following the 2007 guidelines?

BACKGROUND

In 2007, the American Heart Association modified the infective endocarditis prophylaxis guidelines by limiting the use of antibiotics in patients with cardiac conditions associated with the highest risk of adverse outcomes after infective endocarditis. Our objective was to evaluate current practice for infective endocarditis prophylaxis among paediatric cardiologists.

METHODS

A web-based survey focussing on current practice, describing the use of antibiotics for infective endocarditis prophylaxis in various congenital and acquired heart diseases, was distributed via e-mail to paediatric cardiologists. The survey was kept anonymous and was distributed twice.

RESULTS

Data from 253 participants were analysed. Most paediatric cardiologists discontinued infective endocarditis prophylaxis in patients with simple lesions such as small ventricular septal defect, patent ductus arteriosus, and bicuspid aortic valve without stenosis or regurgitation; however, significant disagreement persists in prescribing infective endocarditis prophylaxis in certain conditions such as rheumatic heart disease, Fontan palliation without fenestration, and the Ross procedure. Use of antibiotic prophylaxis in certain selected conditions for which infective endocarditis prophylaxis has been indicated as per the current guidelines varies from 44 to 83%. Only 44% follow the current guidelines exclusively, and 34% regularly discuss the importance of oral hygiene with their patients at risk for infective endocarditis.

CONCLUSION

Significant heterogeneity still persists in recommending infective endocarditis prophylaxis for several cardiac lesions among paediatric cardiologists. More than half of the participants (56%) do not follow the current guidelines exclusively in their practice. Counselling for optimal oral health in patients at risk for infective endocarditis needs to be optimised in the current practice.

Impact of percutaneous pulmonary valve implantation procedural steps on leaflets histology and mechanical behaviour: An in vitro study

BACKGROUND

Percutaneous pulmonary valve implantation (PPVI) using the bovine jugular vein Melody(®) valve (Medtronic Inc., Minneapolis, MN, USA) is safe and effective. However, post-procedural complications have been reported, the reasons for which are unclear.

OBJECTIVE

To assess the impact of PPVI procedural steps on valvular histology and leaflet mechanical behaviour.

METHODS

Three different valved stents (the Melody(®) valve and two homemade stents with bovine and porcine pericardium) were tested in vitro under four conditions: (1) control group; (2) crimping; (3) crimping plus inflation of low-pressure balloon; (4) condition III plus post-dilatation (high-pressure balloon). For each condition, valvular leaflets (and a venous wall sample for Melody(®) stents) were taken for histological analysis and mechanical uniaxial testing of the valve leaflets.

RESULTS

Among the Melody(®) valves, the incidence of transverse fractures was significantly higher in traumatized samples compared with the control group (P<0.05), whereas the incidence and depth of transverse fractures were not statistically different between the four conditions for bovine and porcine pericardial leaflets. No significant modification of the mechanical behaviour of in vitro traumatized Melody(®) valvular leaflets was observed. Bovine and porcine pericardia became more elastic and less resilient after balloon expansion and post-dilatation (conditions III and IV), with a significant decrease in elastic modulus and stress at rupture.

CONCLUSION

Valved stent implantation procedural steps induced histological lesions on Melody(®) valve leaflets. Conversely, bovine and porcine pericardial valved stents were not histologically altered by in vitro manipulations, although their mechanical properties were significantly modified. These data could explain some of the long-term complications observed with these substitutes.

Transcatheter Tricuspid Valve-in-Valve Implantation for the Treatment of Dysfunctional Surgical Bioprosthetic Valves

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.

Impact of Right-Sided-Catheter-Based Valve Implantation on Decision-Making in Congenital Heart Disease

There is a growing appreciation for the adverse long-term impact of right-sided valvular dysfunction in patients with congenital heart disease. Although right-sided valvular stenosis and/or regurgitation is often better tolerated than left-sided valvular dysfunction in the short and intermediate term, the long-term consequences are numerous and include, but are not limited to, arrhythmias, heart failure, and multi-organ dysfunction. Surgical right-sided valve interventions have been performed for many decades, but the comorbidities associated with multiple surgeries are a concern. Transcatheter right-sided valve replacement is safe and effective and is being performed at an increasing number of centers around the world. It offers an alternative to traditional surgical techniques and may potentially alter the decision making process whereby valvular replacement is performed prior to the development of long-term sequelae of right-sided valvular dysfunction.

[Infective endocarditis in adult patients with congenital heart disease. Experience from a reference centre]

INTRODUCTION

A growing number of patients with congenital heart disease (CHD) will reach adulthood. Infective endocarditis (IE) is a major complication in this population. The aim of this study was to describe the features of IE in adults with CHD treated in a reference centre.

METHODS

A retrospective review was performed on a cohort of patients over 16 years of age with CHD who presented with IE (defined by the modified Duke criteria) between 1996 and 2014. Only the first episode from each patient was considered for the descriptive analysis.

RESULTS

IE was observed in 27 patients. The median age at diagnosis of IE was 27.7 years, and 63% were male. Comorbidity was low (median Charlson index was 0). IE was mostly community-acquired (78%). The most frequent CHD were ventricular septal defect (33%). A repair was performed in 48% of patients, and 19% received palliative treatment. Forty-one percent of patients had some type of prosthesis. A residual defect was observed in 81%. The IE was detected in the right side of 44% of the patients. The most frequent aetiological agents were viridans group streptococci (41%) and Staphylococcus epidermidis (30%). Surgery was required to treat IE in 37% of patients. There were five re-infections and three relapses. Two patients died, both as a result of recurrence.

CONCLUSIONS

IE in adults with CHD occurred in young patients, and almost all of them carried some prosthetic material or a residual defect. The IE is frequently right-sided. Although surgical treatment was required in many cases, mortality was low, except in the case of relapses.

Common long-term complications of adult congenital heart disease: avoid falling in a H.E.A.P

Advances in cardiology and cardiac surgery have transformed the outlook for patients with congenital heart disease (CHD) so that currently 85% of neonates with CHD survive into adult life. Although early surgery has transformed the outcome of these patients, it has not been curative. Heart failure, endocarditis, arrhythmias and pulmonary hypertension are the most common long term complications of adults with CHD. Adults with CHD benefit from tertiary expert care and early recognition of long-term complications and timely management are essential. However, it is as important that primary care physicians and general adult cardiologists are able to recognise the signs and symptoms of such complications, raise the alarm, referring patients early to specialist adult congenital heart disease (ACHD) care, and provide initial care. In this paper, we provide an overview of the most commonly encountered long-term complications in ACHD and describe current state of the art management as provided in tertiary specialist centres.

Melody Valve Bartonella henselae Endocarditis in an Afebrile Teen: A Case Report

Significant advancements in the care of children with cardiac valve disease over the past 15 years have led to the increasingly common use of percutaneous transcatheter valve implantation as an alternative to surgical replacement in selected patient populations. Although the transcatheter approach has several advantages, this approach and the valves used are not without complications. Bacterial endocarditis is a known and concerning complication after transcatheter pulmonary valve replacement (TPVR). Most reported cases have involved organisms that are common etiologic agents of bacterial endocarditis and are readily identified via blood culture. However, culture-negative endocarditis in the setting of TPVR has not been well described. We present our experience with one afebrile teenager with culture-negative, serology-positive Bartonella henselae endocarditis of a Melody valve 18 months after TPVR for management of tetralogy of Fallot. The teen was successfully managed with long-term antibiotic therapy followed by surgical replacement of the valve. To our knowledge, this is the first reported case of culture-negative endocarditis of a Melody TPVR in the absence of fever. This report discusses the importance of considering culture-negative endocarditis in the differential diagnosis of an afebrile patient with TPVR presenting with constitutional symptoms and valve dysfunction, particularly in the primary care setting. It is anticipated that with an increase in the successfully aging population of children who have undergone cardiac repair, the evaluation of these patients will become an increasingly important and common task for the community pediatrician.

Cost comparison of Transcatheter and Operative Pulmonary Valve Replacement (from the Pediatric Health Information Systems Database)

Outcomes for transcatheter pulmonary valve replacement (TC-PVR) and operative pulmonary valve replacement (S-PVR) are excellent. Thus, their respective cost is a relevant clinical outcome. We performed a retrospective cohort study of children and adults who underwent PVR at age ≥ 8 years from January 1, 2011, to December 31, 2013, at 35 centers contributing data to the Pediatric Health Information Systems database to address this question. A propensity score-adjusted multivariable analysis was performed to adjust for known confounders. Secondary analyses of department-level charges, risk of re-admission, and associated costs were performed. A total of 2,108 PVR procedures were performed in 2,096 subjects (14% transcatheter and 86% operative). The observed cost of S-PVR and TC-PVR was not significantly different (2013US $50,030 vs 2013US $51,297; p = 0.85). In multivariate analysis, total costs of S-PVR and TC-PVR were not significantly different (p = 0.52). Length of stay was shorter after TC-PVR (p <0.0001). Clinical and supply charges were greater for TC-PVR (p <0.0001), whereas laboratory, pharmacy, and other charges (all p <0.0001) were greater for S-PVR. Risks of both 7- and 30-day readmission were not significantly different. In conclusion, short-term costs of TC-PVR and S-PVR are not significantly different after adjustment.

Acute endocarditis of a percutaneously placed pulmonary valve

Endocarditis of percutaneously placed pulmonary valve is increasingly being recognized and reported as a potentially life-threatening complication. In this report, we discuss a 17-year-old male who presented with septic shock secondary to staphylococcal endocarditis of a percutaneously placed pulmonary valve.

Recent Development in Pulmonary Valve Replacement after Tetralogy of Fallot Repair: The Emergence of Hybrid Approaches

An increasing number of patients with tetralogy of Fallot require repeat surgical intervention for pulmonary valve replacement secondary to pulmonary regurgitation. Catheter-based interventions have emerged as an attractive alternative to surgery in this patient population but it is limited by patient size or the anatomy of the right ventricular outflow tract. Hybrid approaches involving both cardiac interventionists and surgeons are being developed to overcome these limitations. The purpose of this review is to highlight the recent advances in the hybrid field of pulmonary valve replacement, summarizing the advantages and disadvantages of the “traditional” surgical and the new catheter-based techniques and discuss the direction future research should take to determine the optimal management for individual patients.

Late postoperative prosthetic pulmonary valve endocarditis in a 13-year-old girl with repaired tetralogy of fallot

Prosthetic pulmonary valve endocarditis has infrequently been described outside large cohort reviews, which have typically focused on infections of the left-sided heart valves. Hence, the pathogenesis, clinical presentation, and management principles of prosthetic pulmonary valve endocarditis have not been well differentiated from those of infected aortic and mitral valves. More patients with repaired tetralogy of Fallot are reaching adulthood and will need pulmonary valve implantation. Consequently, a focus on this infrequent but serious cardiac infection is needed, to learn what characteristics might distinguish it from infections of left-sided heart valves. We report the case of a 13-year-old girl with repaired tetralogy of Fallot who presented with fever and nonspecific symptoms. The patient initially failed to meet the Duke criteria for endocarditis but was then found to have endocarditis of her prosthetic pulmonary valve. We explanted the valve and replaced it with a pulmonary homograft, after which the patient had no infectious sequelae. In addition to presenting the patient's case, we review the literature on surgically inserted prosthetic pulmonary valves and discuss the primary management concerns when those valves become infected with endocarditis.

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.

Percutaneous pulmonary and tricuspid valve implantations: An update

The field of percutaneous valvular interventions is one of the most exciting and rapidly developing within interventional cardiology. Percutaneous procedures focusing on aortic and mitral valve replacement or interventional treatment as well as techniques of percutaneous pulmonary valve implantation have already reached worldwide clinical acceptance and routine interventional procedure status. Although techniques of percutaneous pulmonary valve implantation have been described just a decade ago, two stent-mounted complementary devices were successfully introduced and more than 3000 of these procedures have been performed worldwide. In contrast, percutaneous treatment of tricuspid valve dysfunction is still evolving on a much earlier level and has so far not reached routine interventional procedure status. Taking into account that an “interdisciplinary challenging”, heterogeneous population of patients previously treated by corrective, semi-corrective or palliative surgical procedures is growing inexorably, there is a rapidly increasing need of treatment options besides redo-surgery. Therefore, the review intends to reflect on clinical expansion of percutaneous pulmonary and tricuspid valve procedures, to update on current devices, to discuss indications and patient selection criteria, to report on clinical results and finally to consider future directions.

Melody transcatheter valve: Histopathology and clinical implications of nine explanted devices

OBJECTIVES

We examined interventionally implanted valved Melody conduits after surgical explantation by means of histology and immunohistochemistry and matched these findings with clinical data in order to assess in vivo biocompatibility and to identify risk factors for graft failure.

METHODS

9 Melody valves had been implanted in 8 patients (pulmonary n = 7, tricuspid position n = 1). Indication for explantation included significant obstruction in 7 patients and valve insufficiency in 1 patient. 4 of 8 patients had suffered from endocarditis. Mean interval between implantation and explantation was 3.2 (1.8-5.2) years. All explants were worked up using a uniform protocol with fixation in formalin and embedding in methylmethacrylate.

RESULTS

All but one valve of the explanted Melody grafts were thin and histologically intact without any pathological findings. Complete neo-endothelialization could be demonstrated by means of immunohistochemistry. All 4 Melody valves from patients with endocarditis showed dense granulocytic infiltrations, 3 of these showed thrombotic material within the valves.

CONCLUSION

This report covers the first series of explanted Melody valves from humans applying a uniform protocol for histopathological examination. Good biocompatibility of the Melody valves could be demonstrated after a mid-term follow-up. Factors for graft failure included endocarditis, outgrowth, and residual stenosis. These findings may have significant implications for the implant procedure as well as care of the patients during long-term follow-up.

Prosthetic Valve Endocarditis After Transcatheter Aortic Valve Implantation

Background—

Transcatheter aortic valve implantation (TAVI) is an advancing mode of treatment for inoperable or high-risk patients with aortic stenosis. Prosthetic valve endocarditis (PVE) after TAVI is a serious complication, but only limited data exist on its incidence, outcome, and procedural risk factors.

Methods and Results—

Observational single-center study of 509 consecutive patients treated with a transcatheter implanted self-expandable aortic valve prosthesis (Medtronic CoreValve). We identified 18 patients diagnosed with TAVI-PVE during a median follow-up period of 1.4 years (interquartile range, 0.5–2.5 years; longest follow-up was 6.3 years). TAVI-PVE was most frequent in the first year after implantation (first-year incidence, 3.1% [confidence interval, 1.4%–4.8%]); the overall annualized rate was 2.1% per patient-year (confidence interval, 1.2%–3.3%). Seventeen patients (94%) were treated conservatively and 1 with surgery. Four patients (22%) died from endocarditis or complications to treatment, 2 of those (11%) during initial hospitalization for PVE. An increased risk of TAVI-PVE was seen in patients with low implanted valve position (hazard ratio, 2.8 [1.1–7.2]), moderate or worse postprocedural paravalvular regurgitation (hazard ratio, 4.0 [1.5–11]), implantation of >1 prosthesis (hazard ratio, 5.2 [1.5–18]), and any vascular complication (hazard ratio, 3.8 [1.5–9.8]).

Conclusions—

TAVI-PVE occurred at a slightly higher rate than reported for surgically implanted valves. Conservative treatment was associated with an acceptable outcome. Suboptimal valve deployment and vascular complications were associated with an increased risk of TAVI-PVE.

SCAI/AATS/ACC/STS operator and institutional requirements for transcatheter valve repair and replacement, Part III: Pulmonic valve

With the evolution of transcatheter valve replacement, an important opportunity has arisen for cardiologists and surgeons to collaborate in identifying the criteria for performing these procedures. Therefore, The Society for Cardiovascular Angiography and Interventions (SCAI), American Association for Thoracic Surgery (AATS), American College of Cardiology (ACC), and The Society of Thoracic Surgeons (STS) have partnered to provide recommendations for institutions to assess their potential for instituting and/or maintaining a transcatheter valve program. This article concerns transcatheter pulmonic valve replacement (tPVR). tPVR procedures are in their infancy with few reports available on which to base an expert consensus statement. Therefore, many of these recommendations are based on expert consensus and the few reports available. As the procedures evolve, technology advances, experience grows, and more data accumulate, there will certainly be a need to update this consensus statement. The writing committee and participating societies believe that the recommendations in this report serve as appropriate requisites. In some ways, these recommendations apply to institutions more than to individuals. There is a strong consensus that these new valve therapies are best performed using a Heart Team approach; thus, these credentialing criteria should be applied at the institutional level. Partnering societies used the ACC's policy on relationships with industry (RWI) and other entities to author this document (http://www.acc.org/guidelines/about-guidelines-and-clinical-documents). To avoid actual, potential, or perceived conflicts of interest due to industry relationships or personal interests, all members of the writing committee, as well as peer reviewers of the document, were asked to disclose all current healthcare-related relationships including those existing 12 months before the initiation of the writing effort. A committee of interventional cardiologists and surgeons was formed to include a majority of members with no relevant RWI and to be led by an interventional cardiology cochair and a surgical cochair with no relevant RWI. Authors with relevant RWI were not permitted to draft or vote on text or recommendations pertaining to their RWI. RWI were reviewed on all conference calls and updated as changes occurred. Author and peer reviewer RWI pertinent to this document are disclosed in the Appendices. In addition, to ensure complete transparency, authors' comprehensive disclosure information (including RWI not pertinent to this document) is available in Appendix AII. The work of the writing committee was supported exclusively by the partnering societies without commercial support. SCAI, AATS, ACC, and STS believe that adherence to these recommendations will maximize the chances that these therapies will become a successful part of the armamentarium for treating valvular heart disease in the United States. In addition, these recommendations will hopefully facilitate optimum quality during the delivery of this therapy, which will be important to the development and successful implementation of future, less invasive approaches to structural heart disease.