A simple CT scan to detect the possible presence of calcium deposits in arteries could identify people who might be at risk of premature death, a study has found.
The test for coronary artery calcification, or CAC, looks for specks of calcium present in the wall of the arteries carrying blood around the body.
The presence of the specks, known as calcification, in the three major arteries that carry blood away from the heart, could tell doctors how long you're likely to live, say researchers at the Emory University School of Medicine in Atlanta.
A 15-year study tracking almost 10,000 people showed those with the highest levels of calcium had an early death risk six times that of those who showed no calcium deposits, the researchers found.
The participants, who underwent scans as part of a community-outreach program at an outpatient clinic, displayed no symptoms of artery disease when they underwent the scans.
A score based on the level of calcification accurately predicted mortality up to 15 years in the study participants, says study leader Leslee Shaw, an Emory professor of cardiology.
Calcium deposits develop in response to plaque, caused by blood cholesterol, forming on artery walls, she explains.
These plaques, building up over time, narrow the arteries and can result in heart disease as the heart has to work harder to pump blood around the body, she says.
"Patients with high calcium scores might be advised by their physicians to adopt healthier lifestyles, which could lead to better outcomes and potentially help lengthen their lives," Shaw says.
Although doctors have known since the 1990s that the calcifications can show up on CT scans, previous studies intended to use scans to assess a person's long-term health risk have had a follow-up of five years or less, the Emory researchers note.
The new 15-year study has yielded strong evidence of just how much the risk of early death rises with large deposits of calcium in the arteries, they say.
"These findings give us a better understanding of the importance of coronary calcium scans to predict mortality," says Shaw.
Calcium scans could eventually become part of a person's annual physical exam, as common as blood cholesterol tests, she suggests, noting such scans normally cost less than $100.
"I think it's headed that way," she says. "We're kind of on the edge of this becoming more accepted."