There is a new algorithm-based diagnostic test on the table for a dangerous heart condition, and doctors could apply it in the office, eliminating the need for anxious patients to make a hospital appearance. The goal? Lower the percentage of people walking around with cardiac amyloidosis but no diagnosis.
The condition is a type of amyloidosis that affects the heart; amyloidosis can actually occur virtually anywhere in the body. It is a disease characterized by misfolded proteins gathering in clumps in the body tissues. There are two kinds of cardiac amyloidosis, defined by what type of protein that is aggregating:
Light-chain amyloidosis, where the defective protein is part of an antibody, produced by plasma cells in the bone marrow
Transthyretin amyloidosis, where transthyretin protein, either due to mutation or gradual degradation, causes amyloidosis
Light-chain amyloidosis is the most commonly diagnosed form of systemic amyloidosis, but the present study, from Boston University, puts transthyretin amyloidosis on the stand, often caused by a mutation in the TTR gene. An accurate diagnosis of amyloidosis requires a biopsy, a sample of tissue, to look for any protein aggregation that may be present.
Addressing this condition is vital for the prevention of organ failure, congestive heart failure, and death. However, researchers have reason to believe that as much as ten percent, potentially even more, of elderly patients with congestive heart failure could unknowingly have cardiac amyloidosis.
The Boston University study of patients with congestive heart failure led to the identification of a blood protein that can be used to help doctors identify the patients most at risk of developing cardiac amyloidosis. The researchers developed an algorithm based on the blood protein, called retinol-binding protein 4 (RBP4) and other clinical tests used in the past to test for this type of cardiac amyloidosis.
"Given that new targeted pharmacologic therapies are being developed that specifically treat [cardiac amyloidosis], identifying patients with this disease and providing an early and accurate diagnosis is crucial to treatment,” explained corresponding author of the study and research leader Frederick L. Ruberg, MD.
The present study was recently published in the journal JAMA Cardiology.