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This is a plain English summary of an original research article. The views expressed are those of the author(s) and reviewer(s) at the time of publication.

The vast majority of young children undergoing heart surgery survive the procedure; the survival rate is 98%. This means that the current practice of monitoring survival alone is a blunt measure that does not give a full picture of childrens’ recovery. New research suggests that complications may be a better indicator of the quality of surgery and related medical care. Complications that affect the whole child and their quality of life, may be particularly informative.

The researchers worked with families and medical staff to compile a list of the nine most important complications of children’s heart surgery (see the box below). They also looked at how common each complication was, and the impact it had, to assess how useful the agreed list was.

Parents and clinicians had overlapping but sometimes different views about which complications had the most impact. Clinicians prioritised problems related to the heart while parents were particularly concerned about complications that caused developmental problems. So the researchers developed a test to assess which children might go on to have developmental problems after surgery and need help catching up.

This work helps empower families as it focuses on the complications important to them. Data is now being routinely collected for seven of the nine complications identified in this study.

What’s the issue?

More than 5,000 heart operations are performed in children in the UK each year. Previously, when studying the quality of heart surgery in children, doctors and health researchers have relied on the 30-day survival rate, which is the proportion of children who are still alive 30 days after surgery.

This is clearly important, and 98 in 100 children now survive surgery. But survival alone does not provide sufficient information on the quality of surgery and related medical (peri-operative) care. There has not been as much focus on the complications or the quality of life that children experience after surgery because it is more challenging to assess this impact of care than to measure survival.

What’s new?

The researchers analysed previous studies and gathered information from an online discussion forum they created for families, as well as from interviews they conducted with three family focus groups. Together with other healthcare professionals, patients and carers, the researchers came up with a list of important complications of heart surgery in young children.

Professionals prioritised issues relating to the heart such as the need for life support with a mechanical pump, or further unplanned surgery. Parents and families put more emphasis on problems affecting the whole child: needing extra help reaching milestones in speech development, for example, or needing to be fed via a tube.

But there was overlap in the different views, and the researchers drew up a list of the nine most important complications of heart surgery in young children, on which all groups agreed.

To assess how relevant and useful the list was, the researchers calculated how often children experienced one of the nine complications. They studied young people aged under 17 who had heart operations for congenital heart disease – a range of birth defects that affect how the heart works – in five of the UK’s 10 specialist centres for children’s heart surgery. The researchers examined data on 3090 procedures. They found that 22 in every 100 children had at least one complication.

They then explored the effect of complications on quality of life in a group of 666 children, half of whom had one or more complications. Six weeks after surgery, these children had a lower quality of life than those without complications.

In the six months after surgery, complications increased costs for families and the NHS, and meant that children had fewer days at home. But quality of life improved with time. Six months after surgery, the majority of those who recovered from complications, had a similar quality of life to children who had no complications.

To find the children in need of extra support, the researchers created a test, called the brief developmental assessment (BDA), to look at children's development. Nurses tested it in 1200 children and found the tool worked best in children aged between 4 months and 5 years old.

Why is this important?

The research team says one of their aims in this project was to empower patients. Parents said it helped to know they were not alone in facing complications, that clinical teams had seen the complications before and knew how to deal with them.

Over the course of the project, the researchers kept in close contact with the organisation that monitors the outcomes of children’s heart surgery, called the National Congenital Heart Diseases Audit (NCHDA), and with those responsible for designing specialist health services. These groups now use the same definitions when talking about the complications of children’s heart surgery, and hospitals across the UK now use the list when recording what happens to children after their surgery.

What’s next?

Monitoring the frequency of the nine common complications on the agreed list helps give a full picture of children’s recovery from surgery. But monitoring problems in development is more difficult than recording survival rates. It requires resources and commitment from clinicians. The researchers say the BDA, which was tested in this study, could be an economical way of measuring aspects of child development.

The tool needs further evaluation. It is not known, for example, whether children identified by the tool as having developmental problems are more likely to receive early intervention that helps them catch up. The team has applied for research funding to continue testing the brief developmental assessment.

In this study, it was valid for children aged between 4 months and five years, but not in the youngest babies or in older children. Other tools are needed to assess children in these age groups. The researchers are also interested in identifying children at risk of more complex events after heart surgery, so that doctors can plan what extra help or treatment they may need.

You may be interested to read

The full study: Brown KL, and others. Early morbidities following paediatric cardiac surgery: a mixed-methods study. Health Serv Deliv Res. 2020. doi: 10.3310/hsdr08300

 A study of developmental problems in young children: Hoskote AU, and others. Neurodevelopmental status and follow-up in preschool children with heart disease in London, UK. Arch Dis Child. 2021;

Outcomes after children’s heart surgery in a quality improvement scheme: Gaies M, and others. Improvement in Pediatric Cardiac Surgical Outcomes Through Interhospital Collaboration. J Am Coll Cardiol. 2019;74:2786-2795

Research to identify the children most likely to have developmental problems after heart surgery: Bucholz EM, and others. Trajectories in Neurodevelopmental, Health-Related Quality of Life, and Functional Status Outcomes by Socioeconomic Status and Maternal Education in Children with Single Ventricle Heart Disease. J Pediatr. 2021;229:289-293

Patient information on congenital heart disease from the Royal Brompton and Harefield hospital: Congenital heart disease in children


Funding: This project was funded by the NIHR Health Services and Delivery Research programme.

Conflicts of Interest: The study authors declare no conflicts of interest.

Disclaimer: NIHR Alerts are not a substitute for professional medical advice. They provide information about research which is funded or supported by the NIHR. Please note that views expressed in NIHR Alerts are those of the author(s) and reviewer(s) and not necessarily those of the NHS, the NIHR or the Department of Health and Social Care.

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The nine complications are:

  • acute neurological event (such as a seizure)
  • unplanned reoperation
  • feeding problems
  • renal replacement therapy (the need for dialysis)
  • major adverse events (that lead to disability or prolonged hospital stay)
  • extracorporeal life support (with a mechanical pump)
  • necrotising enterocolitis (damaging inflammation of the gut)
  • surgical infection
  • prolonged pleural effusion (collection of fluid around the lung)
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