Coronary calcium scores better than age for predicting CVD risk

Coronary artery calcium scores can be more valuable than age as a trait to be used in predicting the risk of cardiovascular (CVD) events in in people over the age of 60, according to new study.

Researchers, led by Yuichiro Yano, MD, PhD, with the department of preventive medicine at Northwestern University’s Feinberg School of Medicine, analyzed combined data from three large, population-based studies in the U.S. They found that, for an older person without known CVD, the coronary artery calcium score provided more valuable information than age alone in predicting that person’s risk of coronary heart disease during an 11-year follow-up.

The team’s findings were published online July 26 in JAMA Cardiology.

The work is important because if clinicians adhere to the 2013 CVD lipid treatment guidelines from the American College of Cardiology/American Heart Association, nearly every person older than 60 would be a potential candidate for statin treatment. However, events due to artherolsclerotic cardiovascular disease are unlikely to strike even elderly adults if they have few risk factors. Other measures, besides age, are needed to guide treatment decisions in older adults, and to spare many patients possible side effects of statins, including rhabdomyolysis.

The researchers analyzed combined data from the Framingham Heart Study, the Multi-Ethnic Study of Atherosclerosis and the Cardiovascular Health Study. The 4,778 participants were all adults older than age 60 who, at baseline, were free of any known atherosclerotic cardiovascular disease. These older adults underwent screening for coronary artery calcium (CAC), using CT scans, between 1998 and 2006. The investigators compared the U.S. data with data from two Europeans cohorts as well.

Follow up continued for 11 years. During that time, the coronary calcium score had a greater association with incident coronary heart disease than age. The authors acknowledged that aging is the most consistent, robust contributor to incident atherosclerotic cardiovascular disease.

However, they said, considering the complexity of the aging process, age does not act as an invariant risk factor for coronary atherosclerotic cardiovascular events. Data from the new study showed that older patients with a CAC score of zero may safely avoid the long-term use of statins.

"[CAC] score provided superior prediction for incident coronary heart disease compared to chronological age in both U.S. and European cohorts,” wrote Yano et al.

Accordingly, they concluded that CAC may serve as an alternative measure to help clinicians better distinguish those older adults who are low-risk of heart attacks and strokes from those who are at high risk for such events.