By AMERICAN HEART ASSOCIATION NEWS
Novel tests for heart failure can better guide the diagnosis and ongoing care of heart failure, which could reduce deaths and re-hospitalizations, according to a scientific statement published Wednesday by the American Heart Association.
The noninvasive blood or urine tests measure biomarkers, which are substances released by the body during heart failure, a complex condition involving several body processes. This includes the response to inflammation, the death of heart cells, and the restructuring of the heart, wrote the statement’s authors.
Measuring known biomarkers of heart failure is a way to gather information about the severity of the disease, while aiding in the diagnosis, prognosis and potential management, said Sheryl L. Chow, PharmD, who led the statement writing group and is associate professor at Western University of Health Sciences in Pomona, California.
Roughly half of all people diagnosed with heart failure will die within five years. The disease is chronic and progressive and there won’t be any cures until stem cell therapies are improved, Chow said.
With an aging U.S. population and more people surviving heart attack, the numbers of people with heart failure are on the rise. By 2030, an estimated 8 million patients will be diagnosed, compared to approximately 6 million in 2012.
The exploration continues for novel biomarkers that can help identify patients at an earlier phase of the heart failure syndrome or identify those who need specialized care, said Mariell Jessup, M.D. a heart failure expert and former president of the AHA.
“Clearly in a disease like heart failure, there are many different patterns of clinical symptoms. Sometimes patients respond very appropriately to traditional therapy,” she said. “But in other patients, biomarkers might help clinicians to recognize who needs specialized care before they’re sitting in the emergency department in significant distress.”
Researchers have studied newer biomarkers based on the increased understanding of what goes on during heart failure. An emerging school of thought is that heart failure is an inflammatory process, Chow said.
Ironically, the body’s protective response to inflammation resulting from injury or stress can further damage the heart muscle during heart failure.
If you cut your arm, Chow said, small signaling proteins called cytokines are sent to the cut to help repair it. Healing differs in the heart because the repair process can actually cause more harm, she said.
Cytokines and other mediators of inflammatory repair go to the heart when injury occur during a heart attack, but the process ends up causing more heart damage. Rises in these markers can indicate worsening of heart failure and prognosis.
Measuring the specific types of troponin, a protein the body releases when heart cells die, can also help better assess heart failure.
Troponin is a well-established biomarker of a heart attack, but newer, more sensitive troponin tests can detect damage from heart failure in people who may lack obvious symptoms or warning signs, or who have not had a heart attack.
Natriuretic peptides have been the gold standard of biomarkers that help doctors quickly diagnose heart failure patients since 2000. These are peptides that help regulate sodium in urine, and reflect stress on the heart. Physicians have found them particularly useful when measured during hospitalization after fluid buildup to help predict how well the patient responded to treatment.
However, there’s uncertainty about relying on this biomarker alone to manage heart failure medications. A large research study had to be stopped early last year when researchers found using natriuretic peptides to guide treatment gave similar results to guidelines-based treatment. The final results of the study have not yet been published.
Currently researchers are focusing on which combination of biomarkers is better, Chow said. Academic institutions are combining natriuretic peptides with one or more of the newer categories of biomarkers. Specific combinations are not currently recommended in the statement because more research is needed, Chow said.
“The goal of personalized medicine is to tailor therapy based on risk for future events – biomarkers can stratify that risk,” Chow said. This can better inform physicians as they make medical decisions, she said.
A heart failure patient may physically appear to be doing better, but biomarker testing might reveal the need for more intensive medical management or time in the hospital but more studies are needed.
Biomarkers provide a snapshot of how well the patient is doing at the moment and offer a noninvasive approach to help define patient risk of future events, Chow said.