Coronary artery calcium scores and risk for cardiovascular events in women classified as “low risk” based on Framingham risk score: the multi-ethnic study of atherosclerosis (MESA).

Description

In this investigation performed among low-risk women of the Multi-Ethnic Study of Atherosclerosis (MESA), Lakoski et al. identified 34 women who had a cardiovascular disease (CVD) event over a mean follow-up period of 3.75 years. They sought to determine whether coronary artery calcification (CAC) as measured by coronary computed tomography increased CVD risk. Among these low-risk women, approximately 30% had prevalent CAC. The unadjusted CVD hazard ratio was 5.2 (95% CI=2.5-10.8) and 2.3 (1.0-5.3) after adjusting for traditional risk factors included in the Framingham risk score. Women with the highest CAC score also had lower event-free survival rates. Given the very low prevalence of intermediate or high-risk women under the age of 70 and the fact that CVD is still the most frequent cause of death in this population, these results suggest that current risk algorithms are not capturing a number of risk factors/markers. This article was accompanied by an editorial by Preis and O’Donnell who, citing the findings of Lakoski et al., questioned the “one-size-fits-all” approach used by risk factor algorithms. If more evidence comes to light in the coming years, they suggested that it might be reasonable to recommend CAC screening in these low-risk women. However, two important limitations of CAC screening were identified: the relatively high cost of screening for CAC and its potential side effects, such as increased lifetime cancer risk and exposure to allergic and/or nephrotoxic hazards.