Heart health: High levels of cardiac protein may raise death risk

  • Researchers investigated the link between blood levels of the protein cardiac troponin and mortality within two years.
  • They found that patients with higher levels of the protein had a 76% higher mortality rate than those with healthy levels.
  • Further study is needed to understand how this information could be used to improve patient heart health.

Cardiac troponins (cTn) are a kind of protein only found in the heart muscle. They are released into the bloodstream when the heart has been damaged.

Clinicians typically conduct troponin blood tests on patients suspected of having experienced a heart attack. Above normal levels indicate a heart attack.

Studies have shown, however, that many people have elevated levels of cTn’s even if they don’t experience heart attacks. Other research suggests that elevated levels of cTn’s are linked to a wide range of chronic conditions regardless of age.

One study found that in 20,000 patients, 94% without a perceived clinical need for testing had elevated cTn levels and that this was linked to an increased likelihood of dying within a year.

Understanding more about cTn’s potential as a mortality risk factor could aid the development of healthcare strategies.

Recently, researchers assessed the link between cTn levels in the blood and mortality within a couple of years. They found that patients with higher cTn levels were almost four times more likely to die within two years than patients with typical levels.

Dr. Robert Pilchik, board certified cardiologist with Manhattan Cardiology and contributor to LabFinder.com, who was not involved in the study, told Medical News Today:

“This study suggests that obtaining a cTn in all patients in all settings (inpatient, outpatient, critically ill, emergency visits, etc.) can provide important prognostic information in terms of identifying those patients at high risk for mortality from all causes in the subsequent two years.”

The study was published in the journal Heart.

Dying from cancer and cardiovascular disease

For the study, the researchers included 20,000 hospital patients who had a cTn blood test in 2017. They had an average age of 61 years, and 52.9% were women.

A quarter were inpatients, 28.5% were emergency care patients, and 47% were outpatients. Only 8.6% had a clinical need for cTn tests. The remaining patients had no clinical need for testing, and were considered to have a ‘lower risk of mortality’. Altogether, 5.4% of patients had ‘above normal’ cTn levels.

Ultimately, 8.9% of patients died after a year of testing, and 14.1% died after just over two years. Among those who died, 45.3% had elevated cTn levels, whereas the same was true for 12.3% of those in the typical range.

After accounting for factors including age, sex, and kidney function, the researchers found that those with high cTn levels had a 76% higher chance of dying from cardiovascular disease and other causes. Altogether, 46% died of cancer and 13% of cardiovascular disease.

The link between higher cTn levels and mortality remained after excluding deaths occurring within 30 days of testing, indicating that a short-term risk of death could not explain the results.

Why may cardiac troponin lead to more deaths?

MNT asked Dr. Razvan Dadu, an interventional cardiologist with Memorial Hermann, who was not involved in the study, about what may explain the link between higher cTn levels and all-cause mortality.

“Although an elevated cTn level by itself is unlikely to cause increased death, it could indicate undiagnosed heart conditions such as blockages in the coronary arteries, damaged valves, or a weak heart,” he said.

“These underlying heart problems, undetected at the time of hospitalization, could be responsible for the increased risk of death later on,” he explained.

“Another possible explanation, although less likely, is that the primary illness that led to hospitalization is causing injury to the heart muscle itself,” he added.

MNT also spoke withDr. Sameer Chaudhari, a cardiologist with Novant Health Heart & Vascular Institute in Monroe, North Carolina, who was also not involved in the study.

He noted that abnormal levels of cTn may indicate several other clinical conditions beyond heart attack. These include:

  • acute or chronic inflammation from sepsis of infection
  • blood clots in the lungs or other parts of the body
  • physical or mental stress
  • dehydration
  • burns or injury
  • kidney failure
  • inflammation of the heart muscle or pericardium—the protective layer around the heart
  • autoimmune diseases
  • chronic weakness

“All of these factors by themselves increase the risk of worsening of health status requiring hospitalization or death. This can be compared to a machine in the factory or a car on the road, being operational but not being kept in a good condition where failure and unfortunate outcomes are likely going to happen,” he explained.


Dr. Cheng-Han Chen, interventional cardiologist and medical director of the Structural Heart Program at MemorialCare Saddleback Medical Center in Laguna Hills, California, who was not involved in the study, told MNT:

“The main limitation of the study is related to our inability to determine cause-and-effect from a purely observational study; it is highly unlikely that the cTn molecule itself will “cause” harm to someone.”

Dr. Chen said that it remains to be seen whether the findings apply to other geographical populations and demographics. He added that it also remains unknown whether the increased mortality risk can be lessened, or if it is ‘purely a marker of prognosis’.

Nevertheless, he noted that the findings have potential implications for assessing an individual’s overall health prognosis.

“However, more research needs to be done before we understand how we can use this information to actually improve someone’s health status,” he concluded.

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