Reflection and Rationalization

Advanced imaging for pre- and post-operative evaluation of tetralogy of Fallot

Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart disease and imaging plays a key role in diagnosis, pre-operative planning and follow up, with MRI as the gold standard for imaging in these patients despite echocardiography being more widely available. While static MRI sequences are suitable for evaluation of anatomical structures, dynamic imaging is required for volume and flow measurements through valves, chambers, and surgical conduits. Newer techniques with 4D data acquisitions allow for feasible 2D cine reconstruction in desired planes. Ferumoxytol, a blood pool contrast agent with long intravascular half-life, facilitates acquisition of 4D flow and 4D MUSIC (multiphase, steady-state imaging with contrast) sequences, eliminating need for repeated contrast administrations. In this article we review conglomerate of TOF anomalies, their historical and current surgical managements with respective devices, as well as cutting-edge MRI techniques for their evaluation.

Early-term results of percutaneous pulmonary valve implantation (valve-in-valve) in dysfunctional bioprosthetic valves in pulmonary position

Background

This study aimed to assess the outcomes of valve-in-valve implantation within previously placed bioprosthetic valves.

Methods

This single-center retrospective study included patients who underwent percutaneous valve-in-valve procedures between July 2014 and September 2023. These patients had previously received pulmonary bioprosthetic valves via surgical or transcatheter methods.

Results

The study included 20 patients (13 males, 7 females; mean age: 20.4±7.1 years; range, 10.8 to 35.8 years). Preprocedural assessment revealed stenotic dysfunction in 12 patients, regurgitant dysfunction in two patients, and a combination of both in six patients. Following implantation, there was a notable improvement in invasive measurements; systolic right ventricular pressure decreased from 64.0±24.5 mmHg to 31.3±6.7 mmHg (p<0.001), right ventricular outflow tract gradient from 44.0±23.2 mmHg to 7.6±5.8 mmHg (p<0.001), and echocardiographic pulmonary regurgitation grade from 2.1±1.2 to 0.2±0.4 (p<0.001). The median time between initial bioprosthetic pulmonary valve placement and valve-in-valve procedure was 8.2 years (IQR, 6.2 to 9.9 years). The median follow-up duration was 24.8 months (IQR, 8.3 to 40.2 months). Only one patient required a repeat PPVI procedure 10 years after the valve-in-valve procedure, while no other patients required reintervention during the follow-up period.

Conclusion

Valve-in-valve implantation within previously placed bioprosthetic valves is a feasible and safe approach, offering symptom relief and eliminating the need for further surgical interventions.

Melody transcatheter pulmonary valve replacement: a single-center case series in Southeast Asia

BACKGROUND

Studies of transcatheter pulmonary valve replacement (TPVR) with the Melody valve have demonstrated good clinical and hemodynamic outcomes. Our study analyzes the midterm clinical and hemodynamic outcomes for patients who underwent Melody valve implantation in Southeast Asia.

METHODS

Patients with circumferential conduits or bioprosthetic valves and experiencing post-operative right ventricular outflow tract (RVOT) dysfunction were recruited for Melody TPVR.

RESULTS

Our cohort (n = 14) was evenly divided between pediatric and adult patients. The median age was 19 years (8-38 years), a male-to-female ratio of 6:1 with a median follow-up period of 48 months (16-79 months), and the smallest patient was an 8-year-old boy weighing 18 kg. All TPVR procedures were uneventful and successful with no immediate mortality or conduit rupture. The primary implant indication was combined stenosis and regurgitation. The average conduit diameter was 21 ± 2.3 mm. Concomitant pre-stenting was done in 71.4% of the patients without Melody valve stent fractures (MSFs). Implanted valve size included 22-mm (64.3%), 20-mm (14.3%), and 18-mm (21.4%). After TPVR, the mean gradient across the RVOT was significantly reduced from 41 mmHg (10-48 mmHg) to 16 mmHg (6-35 mmHg) at discharge, p < 0.01. Late follow-up infective endocarditis (IE) was diagnosed in 2 patients (14.3%). Overall freedom from IE was 86% at 79 months follow-up. Three patients (21.4%) developed progressive RVOT gradients.

CONCLUSION

For patients in Southeast Asia with RVOT dysfunction, Melody TPVR outcomes are similar to those reported for patients in the US in terms of hemodynamic and clinical improvements. A pre-stenting strategy was adopted and no MSFs were observed. Post-implantation residual stenosis and progressive stenosis of the RVOT require long term monitoring and reintervention. Lastly, IE remained a concern despite vigorous prevention and peri-procedural bacterial endocarditis prophylaxis.

Infective endocarditis after transcatheter pulmonary valve implantation in patients with congenital heart disease: Distinctive features

The introduction of transcatheter pulmonary valve implantation (TPVI) has greatly benefited the management of right ventricular outflow tract dysfunction. Infective endocarditis (IE) is a feared complication of TPVI that affects valve durability and patient outcomes. Current recommendations provide only limited guidance on the management of IE after TPVI (TPVI-IE). This article, by a group of experts in congenital heart disease in children and adults, interventional cardiology, infectious diseases including IE, and microbiology, provides a comprehensive review of the current evidence on TPVI-IE, including its incidence, risk factors, causative organisms, diagnosis, and treatment. The incidence of TPVI-IE varies from 13-91/1000 person-years for Melody valves to 8-17/1000 person-years for SAPIEN valves. Risk factors include history of IE, DiGeorge syndrome, immunosuppression, male sex, high residual transpulmonary gradient and portal of bacteria entry. Staphylococci and streptococci are the most common culprits, whereas Staphylococcus aureus is associated with the most severe disease. In addition to the modified Duke criteria, a high residual gradient warrants a strong suspicion. Imaging studies are helpful for the diagnosis. Intravenous antibiotics guided by blood culture results are the mainstay of treatment. Invasive re-intervention may be required. TPVI-IE in patients with congenital heart disease exhibits several distinctive features. Whether specific valve types are associated with a higher risk of TPVI-IE requires further investigation. Patient and parent education regarding IE prevention may have a role to play and should be offered to all patients.

Infective endocarditis after transcatheter approach versus surgical pulmonary valve replacement: A meta-analysis

BACKGROUND

In this meta-analysis, we aimed to assess the risk of infective endocarditis in transcatheter versus surgical pulmonary valve replacement patients.

METHODS

We systematically searched PubMed, Cochrane, EMBASE, Scopus, and Web of Science for the studies that reported the event rate of infective endocarditis in both transcatheter and surgical pulmonary valve replacement between December 2012 and December 2021. Random-effects model was used in the meta-analysis.

RESULTS

Fifteen comparison groups with 4,706 patients were included. The mean follow-up was 38.5±3.7 months. Patients with transcatheter pulmonary valve replacement had a higher risk of infective endocarditis than patients receiving surgically replaced valves (OR 2.68, 95% CI: 1.83-3.93, p<0.00001). The calculated absolute risk difference was 0.03 (95% CI: 0.01-0.05), indicating that if 1,000 patients received a surgical valve replacement, 30 cases of infective endocarditis would be prevented. A meta-regression of follow-up time on the incidence of infective endocarditis was not statistically significant (p=0.753).

CONCLUSION

Although transcatheter pulmonary valve replacement is a feasible alternative to surgical replacement in severe right ventricular outflow tract dysfunction, the higher incidence of infective endocarditis in transcatheter replacement remains a significant concern. Regarding this analysis, surgical treatment of right ventricular outflow tract dysfunction is still a viable option in patients with prohibitive risk.

Multicenter Study of Endocarditis After Transcatheter Pulmonary Valve Replacement

BACKGROUND

Endocarditis has emerged as one of the most impactful adverse events after transcatheter pulmonary valve replacement (TPVR), but there is limited information about risk factors for and outcomes of this complication.

OBJECTIVES

The purpose of this study was to evaluate risk factors for and outcomes of endocarditis in a large multicenter cohort.

METHODS

The authors established an international registry focused on characterizing endocarditis after TPVR, including the incidence, risk factors, characteristics, and outcomes.

RESULTS

Investigators submitted data for 2,476 patients who underwent TPVR between July 2005 and March 2020 and were followed for 8,475 patient-years. In total, 182 patients were diagnosed with endocarditis a median of 2.7 years after TPVR, for a cumulative incidence of 9.5% (95% CI: 7.9%-11.1%) at 5 years and 16.9% (95% CI: 14.2%-19.8%) at 8 years (accounting for competing risks: death, heart transplant, and explant) and an annualized incidence of 2.2 per 100 patient-years. Staphylococcus aureus and Viridans group Streptococcus species together accounted for 56% of cases. Multivariable analysis confirmed that younger age, a previous history of endocarditis, and a higher residual gradient were risk factors for endocarditis, but transcatheter pulmonary valve type was not. Overall, right ventricular outflow tract (RVOT) reintervention was less often to treat endocarditis than for other reasons, but valve explant was more often caused by endocarditis. Endocarditis was severe in 44% of patients, and 12 patients (6.6%) died, nearly all of whom were infected with Staphylococcus aureus.

CONCLUSIONS

The incidence of endocarditis in this multicenter registry was constant over time and consistent with prior smaller studies. The findings of this study, along with ongoing efforts to understand and mitigate risk, will be critical to improve the lifetime management of patients with heart disease involving the RVOT. Although endocarditis can be a serious adverse outcome, TPVR remains an important tool in the management of RVOT dysfunction.

Mid-Term Outcomes Following Percutaneous Pulmonary Valve Implantation Using the "Folded Melody Valve" Technique

Background:

The folded valve is a manual shortening of the Melody device, which has been validated as a valuable therapeutic option for the management of dysfunctional right ventricular outflow tracts needing a short valved stent. In this article, we aimed to evaluate, in a multicenter cohort, the mid-term outcomes of patients in whom a percutaneous pulmonary valve implantation was performed using the folded valve technique.

Methods:

A 2012 to 2018 retrospective multicenter study was performed in 7 European institutions. All patients who benefit from percutaneous pulmonary valve implantation with a folded Melody valve were included.

Results:

A total of 49 patients (median age, 19 years [range 4–56], 63% male) were included. The primary percutaneous pulmonary valve implantation indication was right ventricular outflow tract stenosis (n=19; 39%), patched native right ventricular outflow tracts were the most common substrate (n=15; 31%). The folded technique was mostly used in short right ventricular outflow tracts (n=28; 57%). Procedural success was 100%. After a median follow-up of 28 months (range, 4–80), folded Melody valve function was comparable to the immediate postimplantation period (mean transvalvular peak velocity=2.6±0.6 versus 2.4±0.6 m/s, P>0.1; only 2 patients had mild pulmonary regurgitation). Incidence rate of valve-related reinterventions was 2.1% per person per year (95% CI, 0.1%–3.9%). The probability of survival without valve-related reinterventions at 36 months was 90% (95% CI, 76%–100%).

Conclusions:

The folded Melody valve is a safe technique with favorable mid-term outcomes up to 6.5 years after implantation, comparable with the usual Melody valve implantation procedure. Complications and reinterventions rates were low, making this technique relevant in selected patients.

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.

Prevention and management of endocarditis after transcatheter pulmonary valve replacement: current status and future prospects

Introduction: Transcatheter pulmonary valve replacement (TPVR) has become an important tool in the management of congenital heart disease with abnormalities of the right ventricular outflow tract. Endocarditis is one of the most serious adverse long-term outcomes and among the leading causes of death in patients with congenital heart disease and after (TPVR).Areas covered: This review discusses the current state knowledge about the risk factors for and outcomes of endocarditis after transcatheter pulmonary valve replacement in patients with congenital and acquired heart disease. It also addresses practical measures for mitigating endocarditis risk, as well as diagnosing and managing endocarditis when it does occur.Expert opinion: With increasing understanding of the risk factors for and management and outcomes of endocarditis in patients who have undergone TPVR, we continue to learn how to utilize TPVR most effectively in this complex population of patients.

Acute and midterm outcomes of the post-approval MELODY Registry: a multicentre registry of transcatheter pulmonary valve implantation

AIMS

The post-approval MELODY Registry aimed to obtain multicentre registry data after transcatheter pulmonary valve implantation (TPVI) with the Melody™ valve (Medtronic plc.) in a large-scale cohort of patients with congenital heart disease (CHD).

METHODS AND RESULTS

Retrospective analysis of multicentre registry data after TPVI with the Melody™ valve. Eight hundred and forty-five patients (mean age: 21.0 ± 11.1 years) underwent TPVI in 42 centres between December 2006 and September 2013 and were followed-up for a median of 5.9 years (range: 0-11.0 years). The composite endpoint of TPVI-related events during follow-up (i.e. death, reoperation, or reintervention >48 h after TPVI) showed an incidence rate of 4.2% per person per year [95% confidence interval (CI) 3.7-4.9]. Transcatheter pulmonary valve implantation infective endocarditis (I.E.) showed an incidence rate of 2.3% per person per year (95% CI 1.9-2.8) and resulted in significant morbidity and in nine deaths. In multivariable Cox proportional hazard models, the invasively measured residual right ventricle (RV)-to-pulmonary artery (PA) pressure gradient (per 5 mmHg) was associated with the risk of the composite endpoint (adjusted hazard ratio: 1.21, 95% CI 1.12-1.30; P < 0.0001) and the risk of TPVI I.E. (adjusted hazard ratio: 1.19, 95% CI 1.07-1.32; P = 0.002). Major procedural complications (death, surgical, or interventional treatment requirement) occurred in 0.5%, 1.2%, and 2.0%, respectively. Acutely, the RV-to-PA pressure gradient and the percentage of patients with pulmonary regurgitation grade >2 improved significantly from 36 [interquartile range (IQR) 24-47] to 12 (IQR 7-17) mmHg and 47 to 1%, respectively (P < 0.001 for each).

CONCLUSION

The post-approval MELODY Registry confirms the efficacy of TPVI with the Melody™ valve in a large-scale cohort of CHD patients. The residual invasively measured RV-to-PA pressure gradient may serve as a target for further improvement in the composite endpoint and TPVI I.E. However, TPVI I.E. remains a significant concern causing significant morbidity and mortality.

Infective endocarditis in patients after percutaneous pulmonary valve implantation with the stent-mounted bovine jugular vein valve: Clinical experience and evaluation of the modified Duke criteria

AIMS

Percutaneous pulmonary valve implantation (PPVI) has proven good hemodynamic results. As infective endocarditis (IE) remains a potential complication with limited available clinical data, we reviewed our patient records to improve future strategies of IE prevention, diagnosis and treatment.

METHODS

Medical records of all patients diagnosed with Melody® valve IE according to the modified Duke criteria were retrospectively analyzed in three Belgian tertiary centers.

RESULTS

23 IE episodes in 22 out of 240 patients were identified (incidence 2.4% / patient year) with a clear male predominance (86%). Median age at IE was 17.9 years (range 8.2-45.9 years) and median time from PPVI to IE was 2.4 years (range 0.7-8 years). Streptococcal species caused 10 infections (43%), followed by Staphylococcus aureus (n = 5, 22%). In 13/23 IE episodes a possible entry-point was identified (57%). IE was classified as definite in 15 (65%) and as possible in 8 (35%) cases due to limitations of imaging. Echocardiography visualized vegetations in only 10 patients. PET-CT showed positive FDG signals in 5/7 patients (71%) and intracardiac echocardiography a vegetation in 1/1 patient (100%). Eleven cases (48%) had a hemodynamically relevant pulmonary stenosis at IE presentation. Nine early and 6 late percutaneous or surgical re-interventions were performed. No IE related deaths occurred.

CONCLUSIONS

IE after Melody® valve PPVI is associated with a relevant need of re-interventions. Communication to patients and physicians about risk factors is essential in prevention. The modified Duke criteria underperformed in diagnosing definite IE, but inclusion of new imaging modalities might improve diagnostic performance.

Endocarditis After Transcatheter Pulmonary Valve Replacement

BACKGROUND

Endocarditis has emerged as one of the most concerning adverse outcomes in patients with congenital anomalies involving the right ventricular outflow tract (RVOT) and prosthetic valves.

OBJECTIVES

The aim of this study was to evaluate rates and potential risk factors for endocarditis after transcatheter pulmonary valve replacement in the prospective Melody valve trials.

METHODS

All patients in whom a transcatheter pulmonary valve (TPV) was implanted in the RVOT as part of 3 prospective multicenter studies comprised the analytic cohort. The diagnosis of endocarditis and involvement of the TPV were determined by the implanting investigator.

RESULTS

A total of 309 patients underwent transcatheter pulmonary valve replacement (TPVR) and were discharged with a valve in place. The median follow-up duration was 5.1 years, and total observation until study exit was 1,660.3 patient-years. Endocarditis was diagnosed in 46 patients (median 3.1 years after TPVR), and a total of 35 patients were reported to have TPV-related endocarditis (34 at the initial diagnosis, 1 with a second episode). The annualized incidence rate of endocarditis was 3.1% per patient-year and of TPV-related endocarditis was 2.4% per patient-year. At 5 years post-TPVR, freedom from a diagnosis of endocarditis was 89% and freedom from TPV-related endocarditis was 92%. By multivariable analysis, age ≤12 years at implant (hazard ratio: 2.3; 95% confidence interval: 1.2 to 4.4; p = 0.011) and immediate post-implant peak gradient ≥15 mm Hg (2.7; 95% confidence interval: 1.4 to 4.9; p = 0.002) were associated with development of endocarditis and with development of TPV-related endocarditis (age ≤12 years: 2.8; 95% confidence interval: 1.3 to 5.7; p = 0.006; gradient ≥15 mm Hg: 2.6; 95% confidence interval: 1.3 to 5.2; p = 0.008).

CONCLUSIONS

Endocarditis is an important adverse outcome following TVPR in children and adults with post-operative congenital heart disease involving the RVOT. Ongoing efforts to understand, prevent, and optimize management of this complication are paramount in making the best use of TPV therapy. (Melody Transcatheter Pulmonary Valve [TPV] Study: Post Approval Study of the Original Investigational Device Exemption [IDE] Cohort; NCT00740870; Melody Transcatheter Pulmonary Valve Post-Approval Study; NCT01186692; and Melody Transcatheter Pulmonary Valve [TPV] Post-Market Surveillance Study; NCT00688571).

Current outcomes and treatment of tetralogy of Fallot

Tetralogy of Fallot (ToF) is the most common type of cyanotic congenital heart disease. Since the first surgical repair in 1954, treatment has continuously improved. The treatment strategies currently used in the treatment of ToF result in excellent long-term survival (30 year survival ranges from 68.5% to 90.5%). However, residual problems such as right ventricular outflow tract obstruction, pulmonary regurgitation, and (ventricular) arrhythmia are common and often require re-interventions. Right ventricular dysfunction can be seen following longstanding pulmonary regurgitation and/or stenosis. Performing pulmonary valve replacement or relief of pulmonary stenosis before irreversible right ventricular dysfunction occurs is important, but determining the optimal timing of pulmonary valve replacement is challenging for several reasons. The biological mechanisms underlying dysfunction of the right ventricle as seen in longstanding pulmonary regurgitation are poorly understood. Different methods of assessing the right ventricle are used to predict impending dysfunction. The atrioventricular, ventriculo-arterial and interventricular interactions of the right ventricle play an important role in right ventricle performance, but are not fully elucidated. In this review we present a brief overview of the history of ToF, describe the treatment strategies currently used, and outline the long-term survival, residual lesions, and re-interventions following repair. We discuss important remaining challenges and present the current state of the art regarding these challenges.

Pulmonary Valve Replacement for Tetralogy of Fallot

Right ventricular outflow tract (RVOT) dysfunction is common following surgical repair of tetralogy of Fallot and other forms of complex congenital heart disease. This results in pulmonary stenosis or regurgitation and may ultimately lead to RV failure and dysrhythmias. Transcatheter valve technologies are now available to treat certain patients with RVOT dysfunction. Current devices include the Medtronic Melody valve and the Edwards Lifesciences SAPIEN XT. Although these valves are approved for use in dysfunctional circumferential RVOT conduits, they are increasingly being used off label for nonconduit outflow tracts. Procedural complications include but are not limited to conduit rupture and coronary compression. Longer-term complications include stent fracture and endocarditis. Outcomes with these valves have demonstrated durable relief of stenosis and regurgitation. The Medtronic Harmony valve and the Alterra Prestent from Edwards Lifesciences are investigational devices that are intended to treat the patulous RVOT that is too large to accommodate currently available valves. This review will focus on current indications to treat RVOT dysfunction, existing transcatheter valve technologies, and investigational devices undergoing clinical trials. Hopefully, within the not-too-distant future, transcatheter pulmonary valve implantation will be feasible in the vast majority of patients with RVOT dysfunction following surgical repair of congenital heart disease.