UCLA

Background

Cardiovascular screening of women using traditional risk factors has been challenging, with results often classifying a majority of women as lower risk than men. The aim of this report was to determine the long-term prognosis of asymptomatic women and men classified at low-intermediate risk undergoing screening with coronary artery calcium (CAC) scoring.

Methods and results

A total of 2363 asymptomatic women and men with traditional risk factors aggregating into a low-intermediate Framingham risk score (6%-9.9%; 10-year predicted risk) underwent CAC scanning. Individuals were followed up for a median of 14.6 years. We estimated all-cause mortality using Cox proportional hazards models; hazard ratios with 95% confidence intervals were calculated. The area under the curve from a receiver operating characteristics curve analysis was calculated. There were 1072 women who were older (55.6 years) when compared with the 1291 men (46.7 years; P<0.0001), resulting in a greater prevalence and extent of CAC; 18.8% of women and 15.1% of men had a CAC score ≥100 (P=0.029). This older group of women had a 1.44-fold higher 15-year adjusted mortality hazard when compared with men (P=0.022). For women, the 15-year mortality ranged from 5.0% for those with a CAC score of 0 to 23.5% for those with a CAC score ≥400 (P<0.001). For men, the 15-year mortality ranged from 3.5% for those with a CAC score of 0 to 18.0% for those with a CAC score ≥400 (P<0.001). Women with CAC scores >10 had a higher mortality risk when compared with men.

Conclusions

Our findings extend previous work that CAC effectively identifies high-risk women with a low-intermediate risk factor burden. These data require validation in external cohorts but lend credence to the use of CAC in women to improve risk detection algorithms that are currently based on traditional risk factors.