ACE and heart failure: However, causes of heart failure vary significantly from patient to patient and indeed, several different therapies, including digoxin, beta-blockers, diuretics or angiotensin-converting enzyme inhibitors, are used to improve heart failure.14 Moreover, in children, clinical decisions are often dependant on results recorded in adult heart failure trials.6 Therefore, treatment is negatively affected as there are substantial difficulties in adapting adult data to paediatric patients.