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.

INTRODUCTION: L'implantation de la prothèse valvulaire Edwards Sapien 3 (Edwards Lifesciences, Irvine, CA) par cathéter dans la bioprothèse valvulaire mitrale (VM) est une méthode de traitement établie chez les adultes. Toutefois, cette méthode n'a pas fait l'objet d'études approfondies auprès d'enfants. MÉTHODES: Une tentative d'implantation valvulaire mitrale de type valve-in-valve par cathéter a été réalisée chez quatre enfants symptomatiques qui avaient une bioprothèse VM dysfonctionnelle implantée antérieurement en raison d'une sténose VM ou d'une régurgitation grave. Nous avons passé en revue notre expérience d'implantation VM auprès de cette cohorte. RÉSULTATS: L'âge et le poids moyens des patients au moment de l'intervention étaient respectivement de 11,4 ans (étendue : 10-14 ans) et de 36 kg (étendue : 31-44 kg). La moyenne du gradient moyen transmitral a baissé. Elle est passée de 19,75 mmHg (étendue : 15-22 mmHg) à 1 mmHg (étendue : 0-3 mmHg) après l'intervention. La durée moyenne de la fluoroscopie était de 55,25 minutes (étendue : 40-72 minutes), et la durée moyenne du séjour à l'hôpital était de quatre jours (fourchette : 3-7 jours). La classification fonctionnelle des patients selon la New York Heart Association a montré une baisse. Les patients sont passés de la classe IV à la classe I durant la période de suivi. CONCLUSIONS: L'implantation valvulaire mitrale de type valve-in-valve par cathéter peut être pratiquée de façon sûre chez les enfants porteurs d'une bioprothèse VM dysfonctionnelle dont les issues à court ou à moyen terme sont favorables. Cette intervention est une alternative viable pour ces patients dont le risque lié à l'intervention chirurgicale est élevé ou considérés inaptes à subir une intervention chirurgicale traditionnelle. Toutefois, nous recommandons encore une étude à long terme sur cette approche, voire une vaste étude multicentrique de cohorte.

Transcatheter mitral valve-in-valve implantation in a pediatric patient.

An 11-year-old girl, with 25 mm mosaic tissue valve presented with clinical and echocardiographic appearance of stenotic mitral valve prosthesis. Her condition was treated via a transcatheter valve-in-valve implantation using a 23 mm Edwards Sapien 3, with satisfactory outcome.

Transcatheter valve-in-valve implantation in the tricuspid position.

AIMS: Transcatheter implantation of valved stents (Melody and Edwards valves) for replacement of the pulmonary valve is currently an established procedure. We reviewed our experience on implantation of such valves in the tricuspid valve position. METHODS AND RESULTS: Transcatheter valve implantation in the tricuspid position was attempted in five patients. Four patients had predominantly tricuspid valve regurgitation, two of whom also had tricuspid valve stenosis. All patients had severely symptomatic right heart failure. Patient median age and weight were 12 years and 50 kg (range six-43 years and 13-68 kg, respectively). All patients had a bioprosthetic valve already in place. The mean gradient across the tricuspid valve decreased from 12 to 3 mmHg after the procedure. Median procedure time and fluoroscopy time were 100 and 39 min (range 60-180 and 30-57 min, respectively). The patients' functional class improved from NYHA Class III to II in three and from Class III to I in two patients during a follow-up period of 15-22 months. CONCLUSIONS: Transcatheter replacement of malfunctioning bioprosthetic valves in the tricuspid position using valved stents is an attractive alternative to repeat surgery in high-risk or multi-operated patients. Longer follow-up and a larger number of patients are required to establish the long-term benefit of the procedure and freedom from reinterventions.

Clinical and genetic analysis of long QT syndrome in children from six families in Saudi Arabia: are they different?

Congenital long QT syndrome (LQTS) is an inherited cardiac arrhythmia disorder characterized by prolongation of the QT interval; patients are predisposed to ventricular tachyarrhythmias and fibrillation leading to recurrent syncope or sudden cardiac death. We performed clinical and genetic studies in six Saudi Arabian families with a history of sudden unexplained death of children. Clinical symptoms, ECG phenotypes, and genetic findings led to the diagnosis of LQT1 in two families (recessive) and LQT2 in four families (three recessive and one dominant). Onset of arrhythmia was more severe in the recessive carriers and occurred during early childhood in all recessive LQT1 patients. Arrhythmia originated at the intrauterine stages of life in the recessive LQT2 patients. LQT1, causing mutation c.387-5 T > A in the KCNQ1 gene, and LQT2, causing mutation c.3208 C > T in the KCNH2 gene, are presumably founder mutations in the Assir province of Saudi Arabia. Further, all LQTS causing mutations detected in this study are novel and have not been reported in other populations.