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Background: Right ventricular hypertrophy and failure are major causes of cardiac morbidity and mortality. A key event in the progression to right ventricular hypertrophy and failure is cardiomyocyte apoptosis due to mitochondrial dysfunction. We sought to determine whether localized intramyocardial injection of autologous mitochondria from healthy muscle treats heart failure., Methods: Mitochondria transplanted from different sources were initially tested in cultured hypertrophic cardiomyocytes. A right ventricular hypertrophy/right ventricular failure model created through banding of the pulmonary artery in immature piglets was used for treatment with autologous mitochondria (pulmonary artery banded mitochondria injected/treated n = 6) from calf muscle, versus vehicle (pulmonary artery banded vehicle injected/treated n = 6) injected into the right ventricular free-wall, and compared with sham-operated controls (sham, n = 6). Animals were followed for 8 weeks by echocardiography (free-wall thickness, contractility), and dp/dt max was measured concomitantly with cardiomyocyte hypertrophy, fibrosis, and apoptosis at study end point., Results: Internalization of mitochondria and adenosine triphosphate levels did not depend on the source of mitochondria. At 4 weeks, banded animals showed right ventricular hypertrophy (sham: 0.28 ± 0.01 cm vs pulmonary artery banding: 0.4 ± 0.02 cm wall thickness; P = .001), which further increased in pulmonary artery banded mitochondria injected/treated but declined in pulmonary artery banded vehicle injected/treated (0.47 ± 0.02 cm vs 0.348 ± 0.03 cm; P = .01). Baseline contractility was not different but was significantly reduced in pulmonary artery banded vehicle injected/treated compared with pulmonary artery banded mitochondria injected/treated and so was dp/dtmax. There was a significant difference in apoptotic cardiomyocyte loss and fibrosis in sham versus hypertrophied hearts with most apoptosis in pulmonary artery banded vehicle injected/treated hearts (sham: 1 ± 0.4 vs calf muscle vs vehicle: 13 ± 1.7; P = .001 and vs pulmonary artery banded mitochondria injected/treated: 8 ± 1.9, P = .01; pulmonary artery banded vehicle injected/treated vs pulmonary artery banded mitochondria injected/treated, P = .05)., Conclusions: Mitochondrial transplantation allows for prolonged physiologic adaptation of the pressure-loaded right ventricular and preservation of contractility by reducing apoptotic cardiomyocyte loss., (Copyright © 2020 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.)

Background: Application of extracorporeal membrane oxygenation in pediatric patients with severe heart failure steadily increases. Differentiation of outcomes and survival of diverse pediatric groups is of interest for adequate therapy., Methods: Between January 2008 and December 2016, a total of 39 pediatric patients needed veno-arterial extracorporeal membrane oxygenation support in our department. Patients were retrospectively divided into three groups: neonates (<30 days), infants (>30 days/<1 year), and toddlers/preadolescents (>1 year). Early outcomes as well as mid- and long-term survival up to 7-year follow-up were analyzed., Results: Basic demographics significantly differed in terms of age, height, and weight among the groups in accordance with the intended group categorization (p < 0.05). Survival after 30 days of extracorporeal membrane oxygenation application was equally distributed among the groups, and 44% of all patients survived. In terms of survival to discharge, no significant differences were found among groups. In total, 28% of patients survived up to 7 years. Infants were significantly more likely to undergo elective surgery (p < 0.001) and were predominantly weaned off extracorporeal membrane oxygenation, whereas need for urgent surgery (p < 0.001) was significantly higher in neonate group in comparison to other groups. Multinominal logistic regression analysis revealed significantly higher odds for need for re-exposure in infant group in comparison to toddler/preadolescent group as well as for incidence of neurological impairment of toddler/preadolescent group in comparison to neonate group (odds ratio = 14.67, p = 0.009 and odds ratio = 34.67, p = 0.004, respectively). Kaplan-Meier survival estimation analysis revealed no significant differences in terms of mid- and long-term survival among the groups (Breslow p = 0.198 and log-rank p = 0.213, respectively)., Conclusion: Veno-arterial extracorporeal membrane oxygenation is a lifesaving therapeutic chance for pediatric patients in the setting of either failure to wean from cardiopulmonary bypass or failed resuscitation from cardiac arrest. A fair part of patients could be saved by using this technology. Survival rate among the groups was similar.

Nowadays, an increasing number of neonatal and pediatric patients with severe heart failure benefits from extracorporeal membrane oxygenation (ECMO) support. A total of 39 pediatric patients needed venoarterial ECMO (vaECMO) support in our department between January 2008 and December 2016. Patients were retrospectively divided in two groups: 30-day survivor group (17 patients) and 30-day nonsurvivor group (22 patients). Outcome and factors predictive for 30-day mortality and mid- as well as long-term survival up to 7-year follow-up were analyzed by univariate analysis and Kaplan-Meier survival estimation. Basic demographics and preoperative characteristics did not differ between groups (P > 0.05). 67% of patients were successfully weaned off ECMO and 44% survived 30-day after ECMO application. After 7-year follow-up 28% of pediatric patients were alive. Thirty-day survivors were significantly more likely to undergo elective cardiac surgery (P = 0.001), whereas significantly more 30-day nonsurvivors underwent urgent surgery (P = 0.004). Odds of incidence of catecholamine refractory circulatory failure, failed myocardial recovery, and cerebral edema was significantly higher in 30-day nonsurvivor group (41.6-fold, 16-fold, and 2.5-fold, respectively). Kaplan-Meier survival estimation analysis revealed significant differences in terms of mid- and long-term survival among neonates, infants, toddlers, and preadolescents (Breslow P = 0.037 and Log-Rank P = 0.028, respectively). vaECMO provides an efficient therapy option for life-threatening heart disorders in neonates and pediatric patients being at high risk for myocardial failure leading to circulatory arrest. Urgency of surgery effected on higher mortality, but there was no difference in terms of mortality in 30-day survivor group in comparison to 30-day nonsurvivor group among neonates, infants, toddlers, and preadolescents., (© 2019 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.)