Improving diagnosis and care for inherited heart conditions
15 May 2014
The British Heart Foundation (BHF) has launched a new campaign calling for fresh research investment in inherited cardiac conditions or ICCs.
The BHF say that more research is urgently needed due to the large numbers of people in the UK living with genetic disorders that put them at high risk of heart disease and sudden cardiac death, sometimes at very young ages. In most cases the risk can be at least reduced with careful clinical management; in the case of the most common form of inherited cardiac condition, familial hypercholesterolaemia (FH), treatment with statins can reduce risk to normal levels.
The burden of inherited heart disease in the UK
The BHF has drawn on data from an earlier PHG Foundation report on current services for ICCs and emerging opportunities to improve care via genetic testing; Heart to Heart concluded that at least 340,000 people in the UK were affected by ICCs. The BHF suggests that high numbers of undiagnosed cases mean that the true figure is probably as high as half a million. In addition to those who could currently be diagnosed by genetic testing (and have not been), many more are likely to be affected by other rare ICCs for which the underlying mutations are not yet known.
The BHF campaign features a pregnant woman with an inherited form of cardiomyopathy and a 50% risk of passing the causative genetic mutation to her child, who observes: “If my baby has it, she could be affected from the day she’s born. And it could take her life away. But at least knowing she is at risk means we can protect her”.
The value of research and diagnosis
This highlights the value of a diagnosis for both an individual, and for their wider family, since if one person is diagnosed with an ICC then there is a relatively high probability that some other family members may also be affected, even though no symptoms may be apparent. This is why cascade testing (ie. genetic testing of at-risk family members) is an efficient way of detecting new cases and helping to protect them from serious health problems or premature death.
BHF Director Professor Peter Weissberg said that new funding to accelerate research into ICCs was vital, adding: “Pinpointing genes which cause inherited heart conditions will allow affected children to be protected and, in the long term, will lead to new treatments to overcome the effects of the faulty gene”.
This is very true, and the PHG Foundation strongly supports more research into ICCs. At the same time, it is important that the NHS should provide appropriate services to diagnose and manage those ICCs for which genetic testing and care is already possible. This means ensuring that all cardiologists are alert to the possibility of ICCs in patients, expanding the number of cardiologists with specialist skills to diagnose them, and putting in place more supporting systems.
In England, for example, there is as yet no national programme of cascade screening for cases of the single most common ICC, FH – despite the substantial cost-savings to the NHS that prompt diagnosis and preventative management of affected family members would produce; caring for patients with atherosclerosis and heart attacks is very expensive. Last year the BHF announced that it would provide funding for specialist nurses and genetic counsellors to support the introduction of cascade testing, in accordance with new NHS quality standards for diagnosis of FH, but a concerted national programme has not yet been put in place.
Lessons for genomic medicine
In many respects, services for ICCs provide a prime example of how genomics can help to improve diagnosis and clinical care in a mainstream medical specialty.
Experts have made great progress in their capacity to recognise and investigate potential cases, and to use genomics to allow precisely identification of the underlying cause of disease, which in turn informs the most appropriate clinical management. At the same time, whilst the UK prepares to embed genome sequencing and analysis more firmly within the NHS, addressing the potential gap between the capacity to identify diseases and the ability to reliably provide appropriate care for individuals in whom inherited conditions are identified and their families becomes more important than ever.