Heart transplantation in pediatric cardiomyopathies

Aetiology and 30-Year Long-Term Outcome of Children with Cardiomyopathy Necessitating Heart Transplantation

Studies assessing the long-term outcome after heart transplantation HTX in patients with cardiomyopathy (CM) in the paediatric age range are rare. The aim of this study was to determine the survival rate of children with CM undergoing HTX and to analyse how aetiology of cardiomyopathy influenced morbidity and mortality. We retrospectively analysed the medical records of children; who were transplanted in our centre between June 1988 and October 2019. 236 heart transplantations were performed since 1988 (9 re-transplants). 98 of 227 patients (43.2%) were transplanted because of CM. Survival rates were 93% after 1; 84% after 10 and 75% after 30 years. Overall; the aetiology of CM could be clearly identified in 37 subjects (37.7%). This rate increased up to 66.6% (12/19) by applying a comprehensive diagnostic workup since 2016. The survival rate was lower (p < 0.05) and neurocognitive deficits were more frequent (p = 0.001) in subjects with systemic diseases than in individuals with cardiac-specific conditions. These data indicate that the long-term survival rate of children with CM after HTX in experienced centers is high. A comprehensive diagnostic workup allows unraveling the basic defect in the majority of patients with CM undergoing HTX. Aetiology of CM affects morbidity and mortality in subjects necessitating HTX.

Reduction of Cold Ischemic Injury with the Addition of Compound Glycyrrhizin in HTK Solution in a Mouse Heart Transplantation Model

Cold ischemic injury in heart storage is an important issue pertaining to heart transplantation. This study aims to evaluate the addition of compound glycyrrhizin (CG) in histidine-tryptophan-ketoglutarate (HTK) solution on chronic isograft injury in comparison to traditional HTK solution.Hearts of mouse were stored for 8 h in 4°C cold preservation solution and then transplanted heterotopically into mouse. Five groups were evaluated: HTK, low dose of CG solution (LCG), medium dose of CG solution (MCG), high dose of CG solution (HCG), and hearts without cold ischemia (sham). Survival was assessed. Time to restoration of heartbeat and strength of the heartbeat was measured. Lactate dehydrogenase (LDH) and creatine kinase (CK) levels in the preservation solution were determined. The myocardial damage and interstitial fibrosis of transplanted hearts were evaluated. TGF-β1 expression in the transplanted hearts was assessed.Addition of CG to HTK solution significantly attenuated cold ischemic injury during cold storage, as evidenced by the lower time to restoration of heartbeat, higher strength of the heartbeat, lower LDH, and CK leakage. After transplantation, hearts stored in HTK solution containing CG had decreased the myocardial damage and interstitial fibrosis, compared with those stored without CG. The percentage of TGF-β1-positive cells and TGF-β1 level in the transplanted hearts were also decreased when stored in CG-containing HTK solution.The addition of CG to HTK solution attenuates cold ischemic injury during cold storage.

A Pilot Clinical Study of Liquid Ubiquinol Supplementation on Cardiac Function in Pediatric Dilated Cardiomyopathy

Background: Pediatric dilated cardiomyopathy (PDCM) is a life-threatening type of cardiac muscle dysfunction in children. Ubiquinone is a lipid-soluble nutrient that participates in energy synthesis. Recently, a novel hydrophilic ubiquinol supplement was developed. The purpose of this study was to assess the effect of liquid ubiquinol supplementation (10 mg/kg body weight/day) on cardiac function in children with PDCM. Methods: Ten children diagnosed with PDCM were recruited to this study and administered with liquid ubiquinol for 24 weeks. The cardiac function was measured by echocardiography. The New York Heart Association (NYHA) functional classification was used to assess symptoms of heart failure. Plasma coenzyme Q10 levels were measured during the study. Results: Ejection fraction (EF) and fractional shortening (FS) were significantly higher than the baseline values until week 16 of supplementation. Subjects who had higher plasma coenzyme Q10 concentration had significantly better EF and FS values. In addition, 30% of the subjects showed improvement in the NYHA classification after 24 weeks of supplementation. Conclusion: Liquid ubiquinol supplementation is associated with an increase the level of coenzyme Q10 to complementary improve cardiac function (particularly EF and FS) and ameliorate the symptoms of heart failure in children with PDCM.

Ratio of Creatine Kinase to Alanine Aminotransferase as a Biomarker of Acute Liver Injury in Dystrophinopathy

Objective

To investigate the ratios of creatine kinase (CK) to aminotransferases as biomarkers of acute liver injury in dystrophinopathy.

Methods

C57 and mdx (dystrophic) mice were treated with a hepatotoxic reagent D-galactosamine (D-GalN). The degrees of liver and muscle injury were assessed using histological examinations. To examine whether serum CK-adjusted aminotransferase levels could indicate liver status in dystrophic mice, the CK/alanine aminotransferase (ALT) and CK/aspartate aminotransferase (AST) ratios were analyzed. Furthermore, we enrolled 658 male patients with dystrophinopathy and 378 male patients without muscle and liver injury as control, whose serum ALT, AST, and CK levels were examined.

Results

Animal experiments indicated that D-GalN treatment could induce acute liver injury but not muscle injury. Additionally, D-GalN decreased the CK/ALT and CK/AST ratios in both C57 mice and mdx mice (P < 0.001). However, there was an overlap of the CK/AST ratio between dystrophic mice with and without acute liver injury. In patients with dystrophinopathy, CK-adjusted ALT diminished the variability associated with age, genotype, clinical phenotype, and motor function (P > 0.05).

Conclusions

CK/ALT is a potential biomarker for the differential evaluation of acute liver injury in dystrophic mice, which highlights the value to further evaluate the practice of CK/ALT in dystrophinopathy patients.