Impact of genetic tests on survivors of paediatric sudden cardiac arrest

Arch Dis Child. 2022 Jan;107(1):41-46. doi: 10.1136/archdischild-2020-321532. Epub 2021 Jun 14.

Abstract

Objective: To retrospectively investigate the clinical spectrum, genetic profiles and outcomes of survivors of paediatric sudden cardiac arrest (SCA).

Design and patients: All 66 patients (aged 1-20 years), with unexpected SCA or syncope related to ventricular tachycardia (VT)/fibrillation and who survived to discharge from a tertiary centre, were enrolled from 1995 to 2018. Of these, 30 with underlying diseases prior to the events were excluded. Whole-exome sequencing targeting 384 channelopathy and cardiomyopathy-related genes (composite panel) was conducted to identify the possible genetic variants/mutations.

Results: A total of 36 patients were enrolled. Male adolescents predominated (66.7%), and the median age at onset was 13.3 years. Events occurred most often during exercise and daily activities. The yield rate of the genetic test was 84.6% (22/26); 14 had pathogenic variants; and 8 had likely pathogenic variants. The most common diagnoses were long QT in nine (25%), catecholaminergic polymorphic VT in six patients (16.7%), but other long QT and cardiomyopathy genes were also detected in eight patients (30.7%). The 10-year transplantation-free survival rate was 87.8% and was better for those who received genetic tests initially at the disease onset. An implantable cardioverter-defibrillator was implanted in 55.6% of the patients, with an appropriate shock rate of 61.1%. The defibrillator shock rate was lower for those who received composite panel initially.

Conclusion: Survivors of SCA in the paediatric population had favourable long-term outcomes aided by genetic test. A broad composite genetic panel brings extra diagnostic value in the investigation of ventricular fibrillation/sudden cardiac death.

Keywords: cardiology; genetics.

MeSH terms

  • Adolescent
  • Cardiomyopathies / genetics
  • Channelopathies / genetics
  • Child
  • Child, Preschool
  • Death, Sudden, Cardiac*
  • Defibrillators, Implantable
  • Female
  • Genetic Testing / methods*
  • Heart Arrest / genetics*
  • Heart Arrest / mortality
  • Heart Arrest / therapy
  • Humans
  • Infant
  • Long QT Syndrome / genetics
  • Male
  • Retrospective Studies
  • Survival Rate
  • Survivors*
  • Tachycardia, Ventricular / genetics
  • Young Adult

Supplementary concepts

  • Polymorphic catecholergic ventricular tachycardia