Coronary Artery Calcium Testing Predicts Death in Patients Under 50

For adults in their 30s and 40s with risk factors for cardiovascular disease (CVD), high coronary artery calcium (CAC) scores were associated with increased risk for actual CVD and mortality, researchers found.

Data on 22,346 individuals with a mean age of 43.5 (SD 4.5; range 30-49) in the CAC Consortium registry — set up to capture data on patients undergoing CAC testing because of increased CVD risk — indicated that about one-third showed some degree of CAC and 7.2% had scores exceeding 100, reported Michael Miedema, MD, MPH, of the Minneapolis Heart Institute Foundation, and colleagues in JAMA Network Open.

The CHD death rate was 0.69 per 1,000 person-years among those with a CAC score over 100 (95% CI 0.41-1.16) — 10 times higher than those with a CAC score of 0 (0.07 per 1,000 person-years, 95% CI 0.04-0.12).

Previously, clinicians did not consider coronary artery calcium testing in younger individuals to be worth it because they often thought they were unlikely to find anything, would expose patients to radiation, and had concerns regarding cost, Miedema told MedPage Today.

“This paper gives credence to the idea that in certain individuals this might be something you want to think about. The radiation dose is pretty similar to a mammogram, so it’s a pretty low dose, and the cost now is around a $100, so it’s not a super expensive test, and it can provide some meaningful information clinically,” Miedema said.

Among younger populations, the utility of CAC testing is somewhat less clear, Miedema and colleagues noted in their paper. Prior research on younger adults have been limited by short follow-up periods, lack of cause-specific death, and small sample sizes, they said.

“Coronary artery calcium may potentially be used as a tool to aid decision-making among select young adults at elevated lifetime risk for cardiovascular disease; the relatively high prevalence of CAC in younger adults with cardiovascular risk factors reinforces the need for the adoption of healthy lifestyle behaviors early in life,” the researchers wrote.

But one prominent cardiovascular researcher cautioned that the study didn’t fully make the case for routine use of CAC testing in younger adults.

Although it could be useful in making decisions, the degree to which CAC scores add to traditional risk factors in gauging risk remains unclear, said JoAnn Manson, MD, DrPH, of Brigham and Women’s Hospital in Boston, who was not involved in the study. She told MedPage Today that the number of events was too small to completely resolve this uncertainty.

“Moreover, healthy lifestyle behaviors should be emphasized for the entire population, including young adults and even children. Most other treatments would depend on the assessment of actionable CVD risk factors, such as hypertension, dyslipidemia, or smoking,” Manson said.

Three-quarters of the CAC Consortium participants included in the study were men. Participants were free of clinical CVD at baseline.

Participants underwent CAC testing for indications such as hyperlipidemia or family history at baseline and were evaluated for cause-specific death at follow-up. The CAC Consortium includes patients at four medical centers in Ohio, California, and Minnesota.

There were 298 total deaths in the sample, 40 CHD-related deaths, and 84 CVD-related deaths over a mean follow-up of 12.7 years, the investigators found. Other data indicated that among patients with CAC at baseline, 27 CHD-related deaths occurred.

Limitations of the study included lack of vital status ascertainment in the U.S., self-reporting of risk factors, that generalizability must involve consideration of context, and potential referral bias.