Explaining unexplained deaths in the young

In summary

Sudden unexplained deaths in young people were historically left without answers.

Research led by Professors Elijah Behr and Mary Sheppard at City St George’s has transformed the way such deaths are investigated.

Through specialist pathology, family screening, and national policy change, their work helps bring closure to families and prevents further deaths from inherited cardiac conditions.

What did we explore and how?

For over 20 years, City St George’s academic cardiology unit has been a centre of excellence in researching sudden cardiac death in the young.

In a major initiative, Professors Behr and Sheppard led the Sudden Death Syndrome (SDS) study, which analysed all sudden deaths over a 12-month period ending in 2000.

The team carried out specialist cardiac autopsies and toxicology tests, finding that 4% of cases remained unexplained even after thorough testing. These were classified as Sudden Arrhythmic Death Syndrome (SADS) - a now globally recognised term introduced by the study.

Their findings revealed that there are approximately 500–600 SADS cases each year in England, far more than previously understood.

The team also demonstrated the vital role of specialist cardiac pathology in enabling further investigation.

In families of those who died from SADS, inherited cardiac disease was found in around 50% of cases, showing how crucial it is for surviving relatives to receive clinical and genetic testing.

Our research has shown that further testing in SADS cases can provide some explanation for families, as well as the potential to identify the same condition in family members and offer them pre-emptive treatment.

It is crucial that coroners and pathologists are aware of this, and we are working hard to ensure that this is the case.

Benefits and influence of this research

The impact of this research has been significant and wide-reaching:

• Policy change: Findings helped shape the National Service Framework on Coronary Heart Disease and NHS England’s guidance for managing SADS families. International medical societies have also adopted the recommended protocols.
• Family prevention: The team created a standard protocol for investigating relatives in SADS cases. More than 40% of families referred can now receive a diagnosis and management plan to help prevent further deaths.
• Improved post-mortem practices: The proportion of SADS cases where tissue is retained for genetic testing has risen from under 10% in 2014 to over 60% today, enabling more comprehensive screening.
• Ongoing national support: Since 2014, over 1,500 SADS cases have been referred to City St George’s for expert pathology - about 40% of UK cases - demonstrating national reliance on their expertise.
• Current initiatives: Professors Behr and Sheppard are now leading a British Heart Foundation-funded pilot programme to improve integration between coroners, health services, and genomic testing providers.

We can now produce a diagnosis and management plan to prevent further deaths in more than 40% of families investigated.