Healthcare (Commonwealth Union) – A recent study conducted by researchers at the University College London (UCL) and Queen Mary University of London suggests that more individuals in the UK may be at risk of hereditary cardiac amyloidosis, a potentially deadly heart condition, than was previously understood.
The research, published in JAMA Cardiology, examined genetic data from 469,789 participants in the UK Biobank. The study discovered that approximately one in 1,000 people carry genetic variants that are likely linked to cardiac transthyretin (ATTR) amyloidosis.
The risk was found to be significantly higher among participants of African descent, with one in 23 (4.3%) carrying genes associated with the condition.
Cardiac amyloidosis occurs when abnormal proteins, known as amyloid, accumulate in the heart tissue, causing the heart to become stiff and reducing its ability to pump blood. If not treated, the condition can be fatal within four to six years.
Symptoms of cardiac amyloidosis often develop gradually and can include shortness of breath, fatigue, swelling in the legs and ankles, a rapid or irregular heartbeat, chest pain, dizziness, and fainting. As the condition progresses, it can lead to heart failure and other life-threatening complications. Early diagnosis and treatment are crucial for managing this disease and improving quality of life for those affected.
Senior author Dr Luis Lopes, who is from the UCL Institute of Cardiovascular Science, says “We found a higher than expected number of people in the UK with potentially harmful genetic variants linked to cardiac ATTR amyloidosis, an often fatal condition.
“Many people with these variants will not go on to develop disease. However, it is important to try to identify those who do as early as we can, as there are promising new medicines that can effectively treat the condition, and acting earlier with these medicines is likely to help patients more.”
The lead author, Dr. Nay Aung of the William Harvey Research Institute at Queen Mary University of London, indicated that individuals with these potentially dangerous genetic variants face a two to three times greater risk of developing heart failure and cardiac arrhythmias. He pointed out that it underscores the importance of early identification and ongoing surveillance for disease progression.
Researchers indicated that in the past, ATTR amyloidosis was thought to be rare, affecting between one in 120,000 and one in 830,000 people worldwide. However, recent years have seen a rise in diagnoses in the UK, partly due to advancements in imaging technology developed at the UCL Centre for Amyloidosis.
ATTR amyloidosis can be inherited, resulting from a mutation in the transthyretin (TTR) gene, but it can also occur with age, even in the absence of a genetic mutation.
The hereditary form is notably more frequently seen in specific geographic regions, such as parts of Portugal, Japan, and Sweden, as well as among individuals of Black African descent as indicated by the researchers.
Unlike previous studies that focused on the prevalence of a single genetic variant associated with ATTR amyloidosis (Val142Ile), this new research estimated the prevalence of 62 variants that might be linked to the disease.
Analyzing an average of 12 years of data from UK Biobank participants, the researchers found that individuals with these variants had a greater risk of heart failure, thickening of the heart muscle, and heart rhythm disturbances, even after accounting for factors like age, sex, BMI, and cardiovascular risk factors.
Hospital data indicated that only a small percentage, 2.8%, of this group had been diagnosed with cardiac amyloidosis. The UK Biobank participants, with an average age of 57, may have been too young for the disease to have fully developed or it might have been in its early stages during the study.
The percentage doubled when researchers considered extra-cardiac symptoms related to the hereditary form of ATTR amyloidosis, suggesting that the disease may be underrecognized in its early stages.
The researchers emphasized the need for increased clinical awareness of potential hereditary ATTR amyloidosis in individuals with these symptoms or with unexplained thickening of the heart muscle.
