Coronary artery calcium may be a predictor for all-cause mortality, including non-cardiac conditions

In a new study of more than 40,000 patients, researchers at Intermountain Health in Salt Lake City have found that patients who have no evidence of calcium in their coronary arteries are not only significantly less likely to die from heart conditions—including heart attacks and heart failure—but also are at reduced risk of death from non-cardiac medical conditions.

Coronary artery calcium (CAC) is a strong predictor of how likely someone is to develop clinical coronary artery disease. It is an excellent measure of coronary plaque burden.

When cholesterol-laden plaque builds up in the coronary arteries, blood flow to heart muscle is limited, and plaque rupture with coronary thrombosis can block off blood flow completely, leading to unstable angina or a heart attack.

As plaques age, they attract calcium, which can be imaged with computed tomography. If someone has a coronary artery calcium (CAC) score of zero, the chance that their coronary arteries are clear of advanced plaques is very high. If CAC is present, then their risk of a future heart attack is much greater and in proportion to the CAC score.

In the Intermountain Health study, researchers found that patients with any level of coronary artery calcium have more than two times greater risk of dying of any medical condition than patients with no evidence of CAC—including medical conditions not related to heart health.

“We know that not having any coronary artery calcium is a predictor of being in good coronary health, but we were surprised to find that it may also be a sign you’re in good general health,” said Jeffrey L. Anderson, MD, distinguished clinical and research physician at Intermountain Health and principal investigator of the study.

“Someone’s coronary artery calcium score could be a more powerful predictor of a person’s overall health than we previously thought. We don’t know the mechanism for this extended benefit, but coronary plaque may be correlated with plaque in blood vessels in other parts of the body, and having atherosclerosis may also negatively impact immune surveillance, an important protective mechanism against cancer.”

Findings from the study were presented at the American Heart Association Scientific Sessions 2025 in New Orleans on Saturday, Nov. 8.

In the large, retrospective study, Intermountain researchers reviewed the medical records of 40,018 Intermountain Health patients, whose doctors determined they were at risk of having or developing heart disease, and as part of that care, underwent a PET/CT stress test.

Of the patients in the study, 7,967 had no evidence of coronary artery calcium, and 32,051 had some levels of CAC. Researchers then followed up with patients for five years and reviewed all-cause mortality of people with a CAC score of zero compared to those with a CAC score of greater than zero.

Researchers found that people who had any level of coronary artery calcium were 2 to 3 times more likely to have died than those without CAC in those five years.

Even more surprising, of those with CAC who died, only about one quarter did so from cardiovascular disease. That means most of these patients died of something else, i.e., non-cardiovascular diseases.

Researchers say they’re not sure why patients’ all-cause mortality rates were higher for those with evidence of coronary artery calcium. The next step in this research, they say, is to examine those non-cardiovascular deaths, and better stratify the causes behind them.

“This may help uncover the mechanism of why a coronary artery calcium score predicts death due to non-coronary artery problems,” said Dr. Anderson. “It’s not clear to us right now, and it requires more study, but it’s a very interesting observation and suggests that coronary artery calcium has prognostic value beyond just heart attacks and other heart -related causes.”