Coronary calcium score may better discriminate against high-risk subjects with little conventional cardiovascular risk factors

Abstract Background Cardiovascular (CV) screening using traditional risk factors has been challenging, often classifying a population with a real considerable risk of CV events as lower risk. Objective This study aimed to know the long-term prognosis of an asymptomatic population with few traditional risk factors at low-intermediate CV risk by European SCORE2 and to evaluate whether adding coronary artery calcium score (CACS) improves risk stratification. Methods A total of 1276 asymptomatic participants without cardiovascular disease (CVD) and few traditional risk factors were selected from our data set. They were stratified according to SCORE2, and the low-intermediate group was considered (6%–9.9%; 10-year predicted risk). CACS was obtained using cardiac computed tomography, reported as Agatston units (AU), and categorized into five groups: 0, 1-10, 11-99, 100-399, and ≥400. Participants were followed for a mean of 7.3±6.0 years. We estimated risk factors associated with CV events using bivariate and multivariate logistic analysis. The Cox proportional hazard model adjusted for all risk factors and CACS categories described the relation between the event incidence, as expressed by the hazard function and a set of covariates. Kaplan-Meier's methods assessed survival. Results 595 individuals were at intermediate/low risk by SCORE2. Kaplan-Meier compared the survival time between the five CACS groups concerning CV events. The two lowest CACS categories (0 and 1-10) had better event-free survival, followed by the intermediate group (11-99) and finally the two highest CACS groups (100-399 and ≥400) displaying the lowest CV events free-time. Regarding the hazard function, the trend is the same. After Cox regression analysis, adjusted for all the confounding variables, only the CACS≥400 remained as independently and significantly associated with CV events, presenting a HR=4.4 (p=0.026). Conclusions The addition of CACS improved risk prediction in this middle-aged population based on SCORE2, allowing adequate therapies interventions precociously. These data require validation in other large cohorts of different ages, mainly in younger populations.