Parameters affecting outcome of paediatric cardiomyopathies in the intensive care unit: experience of an Egyptian tertiary centre over 7 years

Molecular analysis of dilated and left ventricular noncompaction cardiomyopathies in Egyptian children

BACKGROUND

Paediatric cardiomyopathy is a progressive, often lethal disorder and the most common cause of heart failure in children. Despite its severe outcomes, the genetic aetiology is still poorly characterised. High-throughput sequencing offers a great opportunity for a better understanding of the genetic causes of cardiomyopathy.

AIM

The current study aimed to elucidate the genetic background of cardiomyopathy in Egyptian children.

METHODS

This hospital-based study involved 68 patients; 58 idiopathic primary dilated cardiomyopathy and 10 left ventricular noncompaction cardiomyopathy. Cardiomyopathy-associated genes were investigated using targeted next-generation sequencing.

RESULTS

Consanguinity was positive in 53 and 70% of dilated cardiomyopathy and left ventricular noncompaction cardiomyopathy patients, respectively. Positive family history of cardiomyopathy was present in 28% of dilated cardiomyopathy and 10% of the left ventricular noncompaction cardiomyopathy patients. In 25 patients, 29 rare variants were detected; 2 likely pathogenic variants in TNNI3 and TTN and 27 variants of uncertain significance explaining 2.9% of patients.

CONCLUSIONS

The low genetic detection rate suggests that novel genes or variants might underlie paediatric cardiomyopathy in Egypt, especially with the high burden of consanguinity. Being the first national and regional report, our study could be a reference for future genetic testing in Egyptian cardiomyopathy children. Genome-wide tests (whole exome/genome sequencing) might be more suitable than the targeted sequencing to investigate the primary cardiomyopathy patients. Molecular characterisation of cardiomyopathies in different ethnicities will allow for global comparative studies that could result in understanding the pathophysiology and heterogeneity of cardiomyopathies.

Clinical Profile and Risk Factors for Cardiac Death in Pediatric Patients With Primary Dilated Cardiomyopathy at a Tertiary Medical Center in China

AIM

We sought to identify the clinical characteristics and risk factors for cardiac mortality in pediatric patients with primary dilated cardiomyopathy (DCM) in China.

METHODS

A total of 138 pediatric patients who were consecutively diagnosed with primary DCM from January 2011 to December 2020 were included. We assessed patients' clinical symptoms and performed laboratory examinations, electrocardiography, and echocardiography.

RESULTS

Of these patients, 79 (57%) had severe systolic dysfunction (left ventricular ejection fraction of < 30%), 79 (57.2%) developed DCM before 12 months of age, 62 (45%) were male, 121 (87.7%) presented with advanced heart failure (cardiac functional class III/IV), and 54 (39.1%) presented with arrhythmia. At a median follow-up of 12 months, the overall cardiac mortality rate was 33%, and 40 of 46 deaths occurred within 6 months following DCM diagnosis. A multivariate Cox regression analysis identified several independent cardiac death predictors, including an age of 12 months to 5 years [hazard ratio (HR) 2.799; 95% confidence interval (CI) 1.160-6.758; P = 0.022] or 10-15 years (HR 3.617; 95% CI 1.336-9.788; P = 0.011) at diagnosis, an elevated serum alanine aminotransferase (ALT) concentration (≥ 51.5 U/L) (HR 2.219; 95% CI 1.06-4.574; P = 0.031), and use of mechanical ventilation (HR 4.223; 95% CI 1.763-10.114; P = 0.001).

CONCLUSION

The mortality rate of primary DCM without transplantation is high. Age, an elevated serum ALT concentration, and the need for mechanical ventilation predict mortality in patients with primary DCM, providing new insights into DCM risk stratification.