Heart disease polygenic risk scores could be used by GPs

A world-first pilot study in England shows the potential for integrating genetic testing into primary care.

The NHS study, called HEART, assessed the impact of integrating polygenic risk tests into the typical NHS risk assessments for heart disease, which are based on factors including age, blood pressure, and smoking status, among others.

'The HEART study has shown us that this kind of genomic testing has the potential to transform the way we manage cardiovascular disease in primary care,' said Professor Ahmet Fuat, who led the study.

For the study, 836 people aged 45 to 64 who visited their GPs for NHS health checks were offered additional genetic testing (see BioNews 1129). Around a quarter of the participants showed significant changes in their heart disease risk when their polygenic risk score was analysed alongside their BMI and smoking status. In 13 percent of cases, GPs said they would change their management of the patient, for example by prescribing cholesterol-lowering statins.

Many factors contribute to the development of cardiovascular disease. For people aged 45 to 64, genetics accounts for as much as 40 percent of the disease risk. But individual differences in DNA are often insignificant on their own. A polygenic risk test looks at millions of genetic variations and calculates their cumulative impact.

More than 90 percent of the GPs involved said the test could be implemented into routine clinical testing in a straightforward manner, and 98.5 percent of patients said they found the test personally useful.

The company that developed the test, Genomics plc, claim that genetic testing could identify 700,000 people in England with an increased risk of heart disease. They suggest that giving statins to this group, currently 'invisible to the NHS', would prevent 11,000 cardiovascular events over ten years.

However, patients would need to be followed up over many years to see whether testing reduces cardiac events or saves lives, and that data is not yet available.

'We could not show it in a short study like this, but I believe this approach of integrating genetic information into routine best practice could save lives and be a game-changer for patients and GPs,' said Professor Fuat.

As with all polygenic scores, if the original data used to calculate genetic risk was gathered from people with predominantly European ancestry, there is a risk that the results may be less accurate for people from other ethnic groups, potentially widening inequalities in healthcare.