Scientists are developing a simple blood test to predict who is at greatest risk of the world's most common inherited heart disease.
Millions of people around the world suffer from hypertrophic cardiomyopathy (HCM), a heart muscle disease in which the heart wall thickens. It is caused by a change in one or more genes and is mainly inherited.
Some feel well most of the time and have few or no symptoms. But others may experience complications such as heart failure and abnormal heart rhythms, which can lead to cardiac arrest.
The problem is that there is no cure. Doctors also I don't know which patients those with a genetic disorder are at greatest risk of fatal complications.
But now a team of scientists from universities including Harvard and Oxford have found a way to predict the risk for people living with HCM.
A blood test can identify those patients who are most at risk for complications, allowing them to be monitored more closely or receive life-saving treatment.
In a landmark study, the team measured levels of a protein, N-terminal Pro-B natriuretic peptide (NT-Pro-BNP), in the blood of 700 patients with HCM.
NT-Pro-BNP is released by the heart during normal circulation. But high levels are a sign that the heart is working too hard. Those with the highest levels had worse blood flow, more scar tissue and changes in the heart that could lead to atrial fibrillation or heart failure.
A blood test that measures levels of NT-Pro-BNP could change care for millions of people with the world's most common inherited heart disease.
Study leader Professor Carolyn Ho, medical director of the Center for Cardiovascular Genetics at Harvard Medical School, said the test could help “target the right treatments to the right patients at the right time.”
She added: “Continued research into blood biomarkers will lead to a better understanding of HCM, and in the future we will be able to offer our patients blood tests to determine who is at high and low risk of experiencing serious consequences of the disease.
“People at highest risk may be targeted for potentially life-saving treatment as they stand to benefit the most, while people at the lowest risk may avoid unnecessary treatment.”
Lara Johnson, 34, from Southampton, UK, is one of many who could benefit.
Eight years ago, she began experiencing shortness of breath and fatigue. After her physician referred her to the hospital for evaluation, she was diagnosed with HCM. Subsequently, several relatives on her father's side were also diagnosed with the disease.
“One of the hardest parts of living with HCM is the constant uncertainty of not knowing what might change next,” Johnson said. “A simple blood test that could help identify future risks earlier would eliminate much of this concern.”
She added: “This could give people like me the opportunity to prepare and adjust our lifestyle as needed, and help us feel better. This clarity would not only help me, but would make a huge difference for my entire family.”
Professor Brian Williams, chief scientific and medical director of the British Heart Foundation, which funded the study, said the test “could benefit patients around the world”.
“Once diagnosed with HCM, patients and their families want to know what the future holds. This study shows that measuring different proteins circulating in the blood can help predict how the heart is functioning and the future risk of complications from heart disease.”
“This new technique may also provide insight into the evolution of cardiac structure and function in people with HCM, which may point to new ways to treat the disease to reduce risk in the future.”
