Coronary computed tomography angiography improves coronary risk prediction in general population

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Carlos III Health Institute and the European Regional Development FundAgency for Management of University and Research Grants

In the next decades, it is expected an increasing incidence of acute coronary syndrome in the Spanish population. Identify high-risk patients could be the most cost-effective way to reduce its incidence and morbi-mortality burden. We studied the effect of adding coronary artery calcification (CAC) and the extent of atherosclerotic disease (SIS score) to classical cardiovascular (CV) risk factors in coronary risk prediction.

This was a prospective cohort study of 325 asymptomatic patients recruited between 2013-2017. Demographic characteristics and CV risk factors were obtained and all participants underwent a coronary computed tomography angiography exam in which CAC and SIS were determined. The cohort was followed-up (median= 4 years) for a composite endpoint that included CV death, myocardial infarction, coronary angiography and/or revascularization. Improvement in discrimination and in reclassification by the inclusion of CAC/SIS in the Framingham-REGICOR function were examined with the Sommer's D index and with the Net reclassification index (NRI) (categorical and continuous), respectively.

Nine of the 251 individuals included in the study had an event in the follow-up. Of the included participants, 94 had a CAC = 0 and 85 a SIS = 0. These participants had no events. The addition of SIS or of SIS and CAC scores to the Framigham-REGICOR risk function increased significantly the discrimination capacity from 0.71 to 0.88 (Table 1). Reclassification measured by the continuous NRI also improved significantly from 69.5 to 112.4/115.5 when SIS or both scores were included (Table 2).

CAC and SIS scores were associated to 4-year CV event incidence, independently of coronary risk estimation. Discrimination and reclassification of the Framigham-REGICOR coronary function were significantly improved by both indexes, but SIS overrode the effect of CAC.