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

Medium term follow-up after percutaneous pulmonary valve replacement with the Melody® valve

INTRODUCTION

Data on long term function of the Melody valve are scarce. Patients and methods: single institution; results of percutaneous pulmonary valve implantation (PPVI) from 2006 to 2014. The function of the valved conduit was analyzed by Doppler echocardiography. Annual Chest X-ray after implant and permanent screening for events (e.g. Endocarditis).

RESULTS

112 Melody valves were implanted in 111 patients; mean age 19.3 years (4.5-81.6). No pre-stenting of the RVOT was performed (n = 4) at first. In the next 107 patients pre-stenting was always performed. In 82 patients 1 pre-stent, 18 patients 2, in 6 patients 3 stents and 1 patient 4 stents were used. The Melody stent was dilated up to 24 mm (n = 4), 22 mm (n = 72), 20 mm (n = 28) and 18 mm (n = 6). When stenotic, the Doppler gradient reduced from 67.0 mm Hg (SD 13.9) to 18.9 mm Hg (SD 10.4) (p < 0.001); pulmonary regurgitation (PR) was reduced from median 3.5/4 (range 0-4/4) to none or trivial (p < 0.001). There was no significant change in RVOT peak velocity at 5 years (p = 0.122) nor PR (p = 0.835). Type 1 stent fractures were observed in 1/4 non-pre-stented patients and in 5/107 pre-stented (p < 0.05). Endocarditis occurred in 8/112 valves; freedom of endocarditis was 85% at 5 years. In 2 patients early surgical replacement was necessary. Six were sterilized with antibiotic treatment; 2 patients required re-stenting and re-PPVI due to residual gradient.

CONCLUSION

Adequate pre-stenting of the RVOT before PPVI nearly abolishes or delays stent fracture. Cusp function is well preserved in mid-term follow-up; endocarditis is a threat.

Infective endocarditis of a transcatheter pulmonary valve in comparison with surgical implants

BACKGROUND

Melody valved stents (Medtronic Inc, Minneapolis, Minnesota, USA) have become a very competitive therapeutic option for pulmonary valve replacement in patients with congenital heart disease. After adequate prestenting of the right ventricular outflow tract (RVOT) Melody valved stents have a good medium term functional result but are exposed to infective endocarditis (IE).

PATIENTS AND METHODS

Retrospective study of tertiary centre Congenital Heart Disease database; to compare incidence of IE in three different types of valved conduits in RVOT: Melody valved stent, cryopreserved homograft (European Homograft Bank) and Contegra graft (Medtronic Inc).

RESULTS

Between 1989 and 2013, 738 conduits were implanted in 677 patients. 107 Melody valved stents were implanted in 107 patients; IE occurred in 8 (7.5%) patients during a follow-up of 2.0 years (IQR 2.4 years, range 0.3-7.8 years). 577 Homografts were implanted in 517 patients; IE occurred in 14 patients (2.4%) during a median follow-up of 6.5 years (IQR 9.2 years; range 0.1-23.7 years). Finally, 54 Contegra grafts were implanted in 53 patients; 11 patients (20.4%) had IE during a follow-up of 8.8 years (IQR 7.7 years; range 0.2-3.5 years). Survival free of IE by Kaplan-Meier for homografts was 98.7% at 5 years and 97.3% at 10 years; for Contegra 87.8% at 5 years and 77.3% at 10 years and for Melody 84.9% at 5 years (log-rank test; p<0.001).

CONCLUSIONS

The Contegra conduit and Melody valved stents have a significantly higher incidence of IE than homografts. IE is a significant threat for long-term conduit function.

Transcatheter pulmonary valve insertion, expanded use (beyond large conduits from the right ventricle to pulmonary artery), and future directions

Transcatheter pulmonary valve insertion is the most important advance in congenital interventional cardiology since atrial septal defect devices became commonly available 15 years ago. It has changed the way we look at a number of diverse diagnoses and changes how we plan, diagnose, operate, and follow-up patients. It has changed how we counsel families expecting a child that may benefit from it. Expanded use of the Melody® valve, outside its United States Food and Drug Administration approved indications, has helped numerous additional patients. The use of transcatheter pulmonary valve insertion in selected patients following surgical Gore-tex® bileaflet in valve right ventricular outflow tract reconstruction and those with a history of prior small homograft conduits will be discussed.

One-year follow-up of the Melody transcatheter pulmonary valve multicenter post-approval study

OBJECTIVES

This study sought to confirm that the short-term hemodynamic effectiveness of the Melody transcatheter pulmonary valve (TPV) (Medtronic, Inc., Minneapolis, Minnesota) achieved by real-world providers is equivalent to the historical results established in the initial 5-center Investigational Device Exemption trial.

BACKGROUND

TPV replacement has been used to treat right ventricular outflow tract (RVOT) conduit dysfunction for >10 years. The Melody TPV received U.S. Food and Drug Administration approval in 2010 as a Humanitarian Use Device.

METHODS

Patients with dysfunctional RVOT conduits were entered in this prospective, nonrandomized study at 10 centers. The primary endpoint was acceptable hemodynamic function at 6 months post-implantation, defined as a composite of RVOT echocardiographic mean gradient ≤30 mm Hg, pulmonary regurgitation less than moderate as measured by echocardiography, and freedom from conduit reintervention and reoperation.

RESULTS

Cardiac catheterization was performed in 120 patients for potential implantation of the Melody TPV; of these, 100 patients were implanted, with a 98.0% procedural success rate. There were no procedure-related deaths. Acceptable hemodynamic function at 6 months was achieved in 96.7% of patients with evaluable data (87.9% of the entire implanted cohort), with results maintained through 1 year. No patient had moderate or severe pulmonary regurgitation after implantation. No patient required catheter reintervention in the first year after implantation, and 2 patients required reoperation for conduit replacement. The rate of freedom from TPV dysfunction was 96.9% at 1 year.

CONCLUSIONS

This first prospective, real-world experience with the Melody TPV in the United States demonstrates continued high procedural success, excellent short-term TPV function, and low reintervention and reoperation rates at 1 year. (Melody Transcatheter Pulmonary Valve Post-Approval Study; NCT01186692).

Incidence and predictors of Melody® valve endocarditis: a prospective study

BACKGROUND

Percutaneous pulmonary valve replacement (PPVR) has achieved standard of care for the management of dysfunctional right ventricular outflow tract.

AIM

Because of increasing reports of Melody(®) valve (Medtronic, Inc., Minneapolis, MN, USA) infective endocarditis (IE), we aimed to evaluate its incidence and predictors of occurrence.

METHODS

We collected data on all patients who received a Melody valve in the pulmonary position from 2009 to 2012.

RESULTS

A total of 86 consecutive patients underwent PPVR from 2009 to 2012; of these, five developed IE (5.8%). Freedom from IE was 91% at 50 months. Baseline demographics, type of conduit, PPVR procedural success, residual gradients and in situ duration of Melody valve were similar in IE and non-IE patients. A significant number of IE patients had additional unprotected invasive procedures during follow-up and abruptly discontinued antiplatelet therapy (P=0.0139 and P=0.002, respectively). The cumulative probability of survival without cardiovascular events for IE patients was 20% at 20 months, compared with 98.1% for non-IE patients (P<0.0001). Death was statistically associated with IE.

CONCLUSION

Early- and late-onset IE of the Melody valve is emerging as a catastrophic complication of PPVR. Abrupt aspirin discontinuation and additional unprotected invasive procedures during follow-up are significant predictors of Melody valve IE. Owing to its rapidly progressive nature, aggressive invasive management should not be delayed.

Corynebacterium endocarditis of a percutaneously placed transcatheter pulmonary valve

We report a case of endocarditis of a transcatheter pulmonary valve-in-valve in a 14-year-old boy with tetralogy of Fallot. He presented with recurrent low-grade fevers, lethargy, and anorexia. Multiple blood cultures grew a gram-positive rod, Corynebacterium pseudodiphtheriticum. He was taken to the operating room for removal of the vegetative endocarditis and pulmonary valve replacement.

Stents in paediatric and adult congenital interventional cardiac catheterization

A 'stent' is a tubular meshed endoprosthesis that has contributed to the development of interventional catheterization over the past 30 years. In congenital heart diseases, stents have offered new solutions to the treatment of congenital vessel stenosis or postsurgical lesions, to maintain or close shunt patency, and to allow transcatheter valve replacement. First, stents were made of bare metal. Then, stent frameworks evolved to achieve a better compromise between radial strength and flexibility. However, almost all stents used currently in children have not been approved for vascular lesions in children and are therefore used 'off-label'. Furthermore, the inability of stents to follow natural vessel growth still limits their use in low-weight children and infants. Recently, bioresorbable stents have been manufactured and may overcome this issue; they are made from materials that may dissolve or be absorbed in the body. In this review, we aim to describe the history of stent development, the technical characteristics of stents used currently, the clinical applications and results, and the latest technological developments and perspectives in paediatric and adult congenital cardiac catheterization.

Will catheter interventions replace surgery for valve abnormalities?

PURPOSE OF REVIEW

Catheter-based valve technologies have evolved rapidly over the last decade. Transcatheter aortic valve replacement (TAVR) has become a routine procedure in high-risk adult patients with calcific aortic stenosis. In patients with congenital heart disease (CHD), transcatheter pulmonary valve replacement represents a transformative technology for right ventricular outflow tract dysfunction with the potential to expand to other indications. This review aims to summarize the current state-of-the-art for transcatheter valve replacement (TVR) in CHD; the expanding indications for TVR; and the technological obstacles to optimizing TVR.

RECENT FINDINGS

Multiple case series have demonstrated that TVR with the Melody transcatheter pulmonary valve in properly selected patients is safe, effective, and durable in short-term follow-up. The Sapien transcatheter heart valve represents an alternative device with similar safety and efficacy in limited studies. Innovative use of current valves has demonstrated the flexibility of TVR, while highlighting the need for devices to address the broad range of postoperative anatomies either with a single device or with strategies to prepare the outflow tract for subsequent device deployment.

SUMMARY

The potential of TVR has not been fully realized, but holds promise in treatment of CHD.

Bartonella henselae endocarditis and glomerulonephritis with dominant C3 deposition in a 21-year-old male with a Melody transcatheter pulmonary valve: case report and review of the literature

We report a case of a 21-year-old young man with underlying congenital heart disease who developed Bartonella henselae endocarditis of the right ventricular outflow tract (RVOT) conduit of his Melody transcatheter (percutaneous) pulmonary valve (TPV), with an initial presentation of glomerulonephritis with a dominant C3 pattern, with renal failure and circulating cryoglobulins. There are few reports of a glomerulonephritis with a dominant C3 pattern presenting as a manifestation of B. henselae endocarditis. While most cases of B. henselae endocarditis affect the aortic valve, in this case the valve damage was to the RVOT of the Melody TPV, a percutaneous transcatheter valve delivery system that had previously replaced his pulmonary homograft, which had become dysfunctional as a result of prior Streptococcus viridans endocarditis. The pulmonary homograft had been in place since childhood as a result of a Ross procedure to repair his congenital aortic stenosis. The patient's renal failure significantly improved after surgical resection of the infected RVOT and institution of appropriate antibiotic therapy.

Pulmonic regurgitation and management challenges in the adult with tetralogy of fallot

OPINION STATEMENT

Patients with tetralogy of Fallot (TOF) are living longer than ever because of advances in surgery in childhood since the 1950s. However, surgery in childhood is not a cure and remains only a palliative procedure because almost all patients will require further intervention throughout life. The most common intervention required in adulthood is pulmonary valve replacement (PVR) because of residual pulmonary regurgitation leading to right ventricular dilation and eventual dysfunction. The most appropriate timing for PVR remains difficult to determine and is based on many factors. Our practice is to weigh not only objective factors such as right ventricular size and function but also careful objective assessment of the patient's current quality of life and functional status.

Infective endocarditis following percutaneous pulmonary valve replacement: diagnostic challenges and application of intra-cardiac echocardiography

BACKGROUND

Infective endocarditis (IE) following percutaneous pulmonary valve replacement (PPVR) with the Melody valve is rarely reported. Furthermore, there are challenges in this diagnosis; especially echocardiographic evidence of vegetation within the prosthesis may be difficult.

METHOD AND RESULT

This study is a retrospective review of all patients with Melody valve implantation in a tertiary centre. Between November 2006 and November 2012, 43 procedures were performed in 42 patients (mean age 25 years, 6-67 years). At a median follow-up of 27 months (2-66 months), six patients were suspected for IE. However, repeated transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) showed no evidence of IE and the patients were diagnosed as possible cases according to the modified Duke's criteria. Two patients did not respond to antibiotic treatment and underwent intra-cardiac echocardiography (ICE), which clearly demonstrated vegetations. These two cases required surgical explantation, while the other four patients were treated medically without complications.

CONCLUSION

IE after Melody valve implantation is uncommon, but difficult to verify since TTE and TEE often cannot demonstrate vegetations inside the stent. ICE should be considered in suspected cases of IE following PPVR with negative TTE and TEE examinations in order to early tailor the best treatment for the individual patient suspected for IE.