A blood test that could potentially serve as a life-saving treatment against heart failure has been developed by researchers from the New York Institute of Technology (NYIT). In the study, which was published in Frontiers in Physiology, scientists assert that nearly half the number of patients ailing from heart failure are likely to have decreased levels of the hormone T3 in their cardiac tissue.
An increasing number of studies have provided evidence that suggests that low T3 levels contribute significantly to a patient's symptoms and their primary heart dysfunction. "Despite this treatability, clinicians are hesitant to prescribe T3 to heart patients, as too much of the hormone could accidentally trigger an irregular heartbeat," wrote the authors.
T3 Hormone Imbalance
The symptoms of low cardiac T3 are also virtually indistinguishable from other conditions that lead to heart failure, suggesting that a significant number of underlying heart dysfunction and heart failure symptoms may actually be caused by a treatable T3 hormone imbalance. In addition, no method has yet been identified to titrate, or continually measure and adjust, for the dosage of T3 needed to safely restore the heart's thyroid hormone function.
Now, an existing biomarker called brain natriuretic peptide (BNP) may provide the much-needed solution, the researchers said. In medicine, biomarkers are biological molecules found in a patient's blood, fluid, or tissue sample that can indicate whether a disease or condition is present.
They can also be used to see how well the body responds to treatments. During heart failure, the heart will secrete higher levels of the biomarker BNP into blood, a key indication that the heart disease is worsening.
Safe Restoration of Cardiac Hormone Balance
The researchers hypothesized that by analyzing a patient's BNP levels in response to added T3, clinicians could titrate for just the right dosage required. Using rat models of heart failure caused by low T3 and heart attack, the researchers tested their theory, examining changes in BNP, cardiac function, and heart failure genes after T3 treatment.
For the first time, they discovered through a simple blood test, not an extensive, invasive procedure, that T3 could be adjusted to safely restore cardiac hormone balance. In addition, because heart patients routinely undergo BNP and thyroid hormone testing, these widely used biomarkers could be easily monitored from blood tests.
"The results were remarkable, suggesting that serum BNP levels can be used to titrate the volume of T3 required," said study researchers Martin Gerdes from NYIT. "When T3 treatment led to a reduction in serum BNP levels, this was associated with improved cardiac function and reversal of these heart failure genes," Gerdes added.
(With inputs from agencies)