Assessment of the Melody valve in the mitral position in young children by echocardiography

National In-Hospital Outcomes of Mechanical Mitral Valve Replacement in the Pediatric Population

Background: National data about the outcomes of children undergoing mechanical mitral valve replacement (m-MVR) are scarce. Methods: A retrospective review of hospitalizations from the Kids' Inpatient Database was performed for patients ≤18 years of age in the United States. A total of 500 patients underwent m-MVR in 2009, 2012, 2016, and 2019. Patients with single ventricle physiology were excluded (n  =  13). These patients were categorized into three groups according to age: neonates (<1 month, n  =  20), infants (1-12 months, n  =  76 patients), and children (1-18 years, n  =  404). Outcomes were compared between the three groups. Results: The proportion of m-MVR involving children undergoing MV procedures (repair and replacement) has increased from 17.3% in 2009 to 30.8% in 2019 (Ptrend < .01). History of cardiac surgery was present in 256 patients (51.2%). Concomitant procedures were performed in 119 patients (23.8%). Intra- or postoperative extracorporeal membrane oxygenation was required in 19 patients (3.8%). The overall in-hospital mortality was 4.8% and was significantly higher in neonates and infants compared with older children (10% vs 11.8% vs 3.2%, P = .003). The length of hospital stay was longer in the neonatal group (median, 57 days, interquartile range, [24.8-90] vs 29.5 days [15.5-61] vs 10 days [7-18], P < .01). Nonhome discharges were more common in neonates and infants (40% vs 36.8% vs 13.1%, P < .01). Conclusion: Mechanical mitral valve replacement is increasingly performed over time with acceptable in-hospital morbidity and mortality, especially in older children and adolescents. Neonates and infants are associated with worse hospital survival, prolonged hospitalization, and significant rates of nonhome discharges.

Infant Mitral Valve Replacement: Current State of the Art

Mitral valve replacement (MVR) in the very young is an imposing clinical challenge. Early and late mortality risk is substantial, severe adverse events are common, and redo mitral valve replacement is inevitable. Therapeutic options are limited. In the older infant with an annulus of 17mm or larger, mechanical MVR is associated with low risk of mortality and predictable durability. For the very young with annular hypoplasia, bovine jugular vein conduit MVR appears to offer equivalent or better early outcomes with the possibility of subsequent valve expansion, potentially prolonging the interval to redo MVR. Experience with cylinder MVR and other forms of surgeon-manufactured MVR is quite limited, and there is currently no information on late outcomes or durability.

Transcatheter Mitral Valve-in-Valve Implantation in Pediatric Patients

BACKGROUND

Transcatheter implantation of the Edwards Sapien 3 valve (Edwards Lifesciences, Irvine CA) within the bioprosthetic mitral valve (MV) is an established method of treatment in adults. However, it has not been well studied in the pediatric age group.

METHODS

Transcatheter mitral valve-in-valve implantation was attempted in 4 symptomatic pediatric patients with a dysfunctional MV bioprosthesis implanted at an earlier stage due to severe MV stenosis or regurgitation. We reviewed our experience with MV implantation in this cohort.

RESULTS

The mean age and weight of the patients at the time of the procedure were 11.4 years (range: 10-14 years) and 36 kg (range: 31-44 kg), respectively. The transmitral mean gradient dropped from a mean of 19.75 mm Hg (range: 15-22 mm Hg) to a mean of 1 mm Hg (range: 0-3 mm Hg) after the procedure. The mean fluoroscopy time was 55.25 minutes (range: 40-72 minutes), and the mean hospital length of stay was 4 days (range: 3-7 days). The patients' functional class improved from New York Heart Association class IV to class I during the follow-up period.

CONCLUSIONS

Transcatheter mitral valve-in-valve implantation can be performed safely for dysfunctional bioprosthetic MVs in the pediatric age group with favorable early and midterm outcomes. This procedure offers a viable alternative in patients who have high surgical risk or are deemed unfit for conventional surgery. However, we still recommend a long-term study of this approach in a large cohort, multicentre study.

Echocardiographic changes in patients with a cylinder mitral valve replacement: Preliminary analysis

AIMS

Cylinder mitral valve construct (cMVC) is new technique for replacing the mitral valve compared to more traditional mitral valve replacement (MVR) procedures. Goal of this study was to describe echocardiographic changes over time in patients undergoing a cMVC. Secondary goal was to compare echocardiographic changes in patients that underwent a cMVC to a group of patients that underwent a MVR.

METHODS

Retrospective analysis of patients undergoing a cMVC was performed. Demographics, discharge echocardiogram, and recent echocardiogram vales were evaluated. Age matched patients undergoing a MVR were assessed. Discharge and recent echocardiographic parameters were compared within the cMVC group. cMVC and MVR values were compared between groups.

RESULTS

Five cMVC patients were studied. Age at surgery for the cMVC was 4.3 ± 4.2 years (median 2.2, .8-10.3 years). Time interval from hospital discharge echocardiogram to the most recent echocardiogram was 1.2 ± .7 years (median 1.0, .6-2.0 years). Mean mitral valve gradient significantly increased over time (3.6 ± 3.0 mm Hg vs 7.6 ± 2.9 mm Hg). There were significant improvements in left ventricular diameters, systolic sphericity index, shortening fraction, and ejection fraction over time. There were no significant differences in demographics, discharge echocardiogram values, and follow up echocardiogram values between the cMVC and MVR groups.

CONCLUSION

In conclusion, echocardiographic indices of left ventricular function improved over time in patients undergoing cMVC. In addition, there were no significant differences between cMVC and MVR patients in echocardiographic values. Studies with a larger patient sample with longer follow up are needed to determine if cMVC continues to have comparable echocardiographic results to MVR.

Acute and Short-Term Outcomes of Percutaneous Transcatheter Mitral Valve Replacement in Children

[Figure: see text].

Surgical Atrioventricular Valve Replacement With Melody Valve in Infants and Children

Background Pediatric patients with atrioventricular valve disease have limited options for prosthetic valve replacement in sizes <15 mm. Based on successful experience with the stented bovine jugular vein graft (Melody valve) in the right ventricular outflow tract, the prosthesis has been modified for surgical valve replacement in pediatric patients with atrioventricular dysfunction with the intention of subsequent valve expansion in the catheterization laboratory as the child grows. Methods and Results A multicenter, retrospective cohort study was performed among patients who underwent atrioventricular valve replacement with Melody valve at 17 participating sites from North America and Europe, including 68 patients with either mitral (n=59) or tricuspid (n=9) replacement at a median age of 8 months (range, 3 days to 13 years). The median size at implantation was 14 mm (range, 9-24 mm). Immediately postoperatively, the valve was competent with low gradients in all patients. Fifteen patients died; 3 patients underwent transplantation. Nineteen patients required reoperation for adverse outcomes, including valve explantation (n=16), left ventricular outflow tract obstruction (n=1), permanent pacemaker implantation (n=1), and paravalvular leak repair (n=1). Twenty-five patients underwent 41 episodes of catheter-based balloon expansion, exhibiting a significant decrease in median gradient ( P<0.001) with no significant increase in grade of regurgitation. Twelve months after implantation, cumulative incidence analysis indicated that 55% of the patients would be expected to be free from death, heart transplantation, structural valve deterioration, or valve replacement. Conclusions The Melody valve is a feasible option for surgical atrioventricular valve replacement in patients with hypoplastic annuli. The prosthesis shows acceptable short-term function and is amenable to catheter-based enlargement as the child grows. However, patients remain at risk for mortality and structural valve deterioration, despite adequate early valvular function. Device design and implantation techniques must be refined to reduce complications and extend durability. Clinical Trial Registration URL: https://www.clinicaltrials.gov. Unique identifier: NCT02505074.

Gradient over Melody valve in left AV valve position reduces with beta blockade

The Melody valve, designed for implantation into the pulmonary outflow tract, can also be used to treat the pathology of atrioventricular (AV) valves. Increasing gradients are seen as an indication for re-dilating the valve. Our case demonstrates the heart rate dependency of the gradient across a Melody implanted in the left AV valve position in an infant. Beta blockers were used to lower both heart rate and gradient.

Supra-Annular Mitral Implantation of Melody Valve: Minimizing Left Ventricular Outflow Tract Obstruction

Utilization of the Melody valve for mitral valve replacement has been previously reported; however, left ventricular outflow tract obstruction is a frequent concern. In this report, a technique for supra-annular placement of the Melody valve in the mitral position is described which will minimize the risk of left ventricular outflow tract obstruction.

Pulmonary Autograft Mitral Valve Replacement (Ross II): Long-Term Follow-Up of a US Center

BACKGROUND

Mitral valve replacement (MVR) with a pulmonary autograft (Ross II) may be a useful technique for pediatric and young adult patients who wish to avoid anticoagulation. Our aim was to evaluate the long-term outcomes of the Ross II procedure at our institution.

METHODS

Patients undergoing the Ross II procedure between June 2002 and April 2008 were included. Preoperative diagnoses included rheumatic disease (n = 5), congenital mitral valve (MV) pathology (partial atrioventricular canal defect [n = 2], complete atrioventricular canal defect [n = 1], Shone's complex [n = 1]), and myocarditis (n = 1).

RESULTS

Ten patients (eight females and two males) between 7 months and 46 years were included. Mean age at surgery was 25.2 ± 15.7 years. There were no in-hospital deaths. Mean follow-up was 11.7 ± 5.2 years. There were three late deaths at 11 months, 5 years, and 11 years, respectively. Causes of death included right heart failure, sepsis, and sudden cardiac arrest. Three patients required subsequent mechanical MVR a median of two years after the Ross II procedure (range: 1-4 years). There was no mortality with reoperation. Echocardiographic follow-up demonstrated mean MV gradients ranging from 2.2 to 9.6 mm Hg. Two patients had greater than mild MV regurgitation postoperatively, and all others had minimal mitral regurgitation or less. Two patients developed moderate MV stenosis.

CONCLUSIONS

The Ross II procedure is an option for select older children and young adults desiring a durable tissue MVR to avoid long-term anticoagulation.

Transcatheter pulmonary valve replacement: evolving indications and application

The introduction of transcatheter therapy for valvular heart disease has changed the spectrum of care of patients with a variety of cardiovascular conditions. Transcatheter valve placement has become established as a method of treating pathologic regurgitation or stenosis of the pulmonary valve, right ventricular outflow tract or a right ventricle to pulmonary artery conduit. In this review, we examine the pathophysiology of and indications for transcatheter pulmonary valve replacement along with procedural complications. Advancements in clinical application and valve technology will also be covered.

Edwards Sapien 3 Valve for Mitral Replacement in a Child After Melody Valve Endocarditis

We present the surgical implantation in mitral position of the Edwards Sapien 3 valve for prosthetic valve endocarditis in a severely ill child after multiple valve replacements. The procedure was safely performed and provided adequate hemodynamic results in the short term. This report highlights the excellent potential of Sapien 3 valve for the treatment of mitral valve disease in children with a mitral valve annulus of appropriate size. Of note, the use of the Sapien 3 valve should be considered when a bioprosthesis is required at the time of valve re-replacement.

Impact of AHA's 2007 guideline change on incidence of infective endocarditis in infants and children

Use a nationally representative sample to assess impacts of new clinical guidelines issued by the American Heart Association (AHA) in 2007 for many types of invasive procedures, with recommendations for significant decreases in antimicrobial prophylaxis use.

STUDY DESIGN

Interrupted time series analyses of pediatric hospitalizations for Infective Endocarditis (IE), using the Nationwide Inpatient Sample (NIS) ICD-9-CM diagnostic codes, identified IE hospitalizations for patients <18 years old from 2001 to 2012. Changes in IE incidence before and after 2007 AHA guidelines were evaluated, with differences in IE clinical severity assessed using in-hospital mortality and length of stay. Analyses were stratified by pathogen type and age group (0-9 y/o and 10-17 y/o).

RESULTS

With 3,748 patients in the study, we observed rising trends in IE incidence, but no significant difference between pre- and post-guideline. There was a significant trend increase for IE due to viridans group streptococci (VGS) for ages >10 years old, comparing pre-guideline to post-guideline periods, but not in children 0-9 years of age. Neither in-hospital mortality nor length of stay changed significantly during study.

CONCLUSIONS

The data did not demonstrate an impact of the 2007 guideline changes on overall incidence of pediatric IE. However, a significant increase in disease incidence trend due to VGS was observed for the 10-17 year-old group, compared pre- and post-guideline.

Management of Tricuspid Regurgitation in Patients With Hypoplastic Left Heart Syndrome

Tricuspid valve (TV) performance is critical for palliation of hypoplastic left heart syndrome. We will review current TV repair techniques, outcomes, and novel approaches.