Mitral valve replacement in infants and children 5 years of age or younger: Evolution in practice and outcome over three decades with a focus on supra-annular prosthesis implantation

ObjectiveSuccessful mitral valve replacement in young children is limited by the lack of small prosthetic valves. Supra-annular prosthesis implantation can facilitate mitral valve replacement with a larger prosthesis in children with a small annulus, but little is known about its effect on the outcomes of mitral valve replacement in young children.MethodsOne hundred eighteen children underwent mitral valve replacement at 5 years of age or younger from 1976–2006. Mitral valve replacement was supra-annular in 37 (32%) patients.ResultsSurvival was 74% ± 4% at 1 year and 56% ± 5% at 10 years but improved over time (10-year survival of 83% ± 7% from 1994–2006). Factors associated with worse survival included earlier mitral valve replacement date, age less than 1 year, complete atrioventricular canal, and additional procedures at mitral valve replacement, but not supra-annular mitral valve replacement. As survival improved during our more recent experience, the risks of supra-annular mitral valve replacement became apparent; survival was worse among patients with a supra-annular prosthesis after 1991. A pacemaker was placed in 18 (15%) patients within 1 month of mitral valve replacement and was less likely in patients who had undergone supra-annular mitral valve replacement. Among early survivors, freedom from redo mitral valve replacement was 72% ± 5% at 5 years and 45% ± 7% at 10 years. Twenty-one patients with a supra-annular prosthesis underwent redo mitral valve replacement. The second prosthesis was annular in 15 of these patients and upsized in all but 1, but 5 required pacemaker placement for heart block.ConclusionsSupra-annular mitral valve replacement was associated with worse survival than annular mitral valve replacement in our recent experience. Patients with supra-annular mitral valve replacement were less likely to have operative complete heart block but remained at risk when the prosthesis was subsequently replaced

Predictors of rapid aortic root dilation and referral for aortic surgery in Marfan syndrome

Few data exist regarding predictors of rapid aortic root dilation and referral for aortic surgery in Marfan syndrome (MFS). To identify independent predictors of the rate of aortic root (AoR) dilation and referral for aortic surgery, we investigated the data from the Pediatric Heart Network randomized trial of atenolol versus losartan in young patients with MFS. Data were analyzed from the echocardiograms at 0, 12, 24, and 36months read in the core laboratory of 608 trial subjects, aged 6months to 25 years, who met original Ghent criteria and had an AoR z-score (AoRz)>3. Repeated measures linear and logistic regressions were used to determine multivariable predictors of AoR dilation. Receiver operator characteristic curves were used to determine cut-points in AoR dilation predicting referral for aortic surgery. Multivariable analysis showed rapid AoR dilation as defined by change in AoRz/year>90th percentile was associated with older age, higher sinotubular junction z-score, and atenolol use (R-2=0.01) or by change in AoR diameter (AoRd)/year>90th percentile with higher sinotubular junction z-score and non-white race (R-2=0.02). Referral for aortic root surgery was associated with higher AoRd, higher ascending aorta z-score, and higher sinotubular junction diameter:ascending aorta diameter ratio (R-2=0.17). Change in AoRz of 0.72 SD units/year had 42% sensitivity and 92% specificity and change in AoRd of 0.34cm/year had 38% sensitivity and 95% specificity for predicting referral for aortic surgery. In this cohort of young patients with MFS, no new robust predictors of rapid AoR dilation or referral for aortic root surgery were identified. Further investigation may determine whether generalized proximal aortic dilation and effacement of the sinotubular junction will allow for better risk stratification. Rate of AoR dilation cut-points had high specificity, but low sensitivity for predicting referral for aortic surgery, limiting their clinical use. Clinical Trial Number ClinicalTrials.gov number, NCT00429364

Exercise Capacity and Training Programs in Paediatric Fontan Patients: A Systematic Review

Background: Exercise training programs can effectively enhance exercise capacity in adults with congenital heart disease, including Fontan patients. However, few studies have explored the impact of exercise training exclusively on paediatric Fontan cohorts. This study systematically reviews exercise capacity in paediatric Fontan patients and the impact of training programs on their cardiovascular health. Methods: Medline and Embase were searched for articles published between January 1990 and November 2021. Studies were included in which data could be analyzed discretely for patients who had undergone the Fontan procedure and were ≤20 years old at the time of study. Cardiopulmonary exercise parameters were extracted from all studies, and training protocols were collected from training programs. Results: The studies demonstrated that Fontan patients exhibit significantly diminished peak exercise capacity relative to healthy peers. We identified 9 training programs that exclusively studied Fontan patients ≤20 years. The programs ranged from 6 weeks to 12 months in duration, with 8 programs incorporating aerobic activity and 1 focused only on inspiratory muscle training. At least 1 measure of maximal or submaximal exercise capacity improved significantly within each program in which statistical analysis was performed, with no reported adverse events. There were 2 additional training programs in which the patients were predominantly (>65%), but not exclusively, Fontan patients. Conclusions: Overall, the results indicate that exercise training programs can safely and effectively improve at least 1 measure of exercise capacity in paediatric Fontan patients. Résumé: Contexte: Les programmes d’entraînement peuvent améliorer efficacement la tolérance à l’effort des adultes atteints de cardiopathies congénitales, y compris les patients ayant subi l’intervention de Fontan. Toutefois, peu d’études portant sur l’effet de l’entraînement à l’effort ont été menées exclusivement au sein de cohortes d’enfants ayant subi l’intervention de Fontan. Notre revue systématique porte sur la tolérance à l’effort d’enfants ayant subi l’intervention de Fontan, de même que sur l’effet des programmes d’entraînement sur leur santé cardiovasculaire. Méthodologie: Nous avons effectué des recherches dans MEDLINE et Embase afin de recenser les articles publiés entre janvier 1990 et novembre 2021. Les études retenues comprenaient des données qui pouvaient être l’objet d’une analyse discrète et qui se rapportaient à des patients ayant subi l’intervention de Fontan et étant âgés de 20 ans ou moins lors de leur participation aux études. Nous avons consigné les paramètres d’entraînement cardiopulmonaire de toutes les études, de même que les protocoles des programmes d’entraînement. Résultats: Les études ont démontré que les patients qui ont subi l’intervention de Fontan présentent une tolérance à l’effort maximal significativement réduite par rapport aux pairs en bonne santé. Nous avons dénombré neuf programmes d’entraînement ayant servi exclusivement à des études portant sur des patients âgés de 20 ans ou moins qui avaient subi l’intervention de Fontan. La durée des programmes allait de six semaines à 12 mois. Huit programmes intégraient des activités aérobiques et un était axé uniquement sur l’entraînement musculaire inspiratoire. Les résultats pour au moins un indicateur de la tolérance à l’effort maximal ou sous-maximal se sont améliorés de façon significative dans chaque programme comportant une analyse statistique, sans qu’aucun événement indésirable soit signalé. Nous avons recensé deux autres programmes d’entraînement dont les participants étaient principalement (plus de 65 %), mais pas exclusivement, des patients ayant subi l’intervention de Fontan. Conclusions: Dans l’ensemble, les résultats indiquent que les programmes d’entraînement à l’effort peuvent améliorer efficacement et en toute sécurité au moins un indicateur de la tolérance à l’effort chez les enfants ayant subi l’intervention de Fontan