We read the article by Schneer et al studying the correlation of coronary computerized tomography angiography (CTA) with conventional risk scoring systems (Framingham risk score [FRS] and Systematic Coronary Risk Evaluation [SCORE] scores) for the estimation of cardiovascular risk in asymptomatic Israeli subjects. One hundred and ninety asymptomatic patients (84% men, mean age: 55 ± 9.7 years [range: 34–92 years]) with ≥1 atherogenic risk factors underwent coronary CTA and calcium scoring as a screening tool. When comparing the SCORE and FRS, the authors found that there were significant correlations between the calcium score and plaque severity on coronary CTA in their study population.

Although the FRS (<10% low risk; 10%–20% intermediate risk; >20% high risk) and SCORE (<1% low risk; 1%–5% intermediate; >5% high risk) are the most commonly used risk-estimation systems that enable clinicians to estimate cardiovascular risk in asymptomatic patients, they were based on a combination of risk factors and were calibrated with different geographic regions and populations, like this study. In Schneer et al’s sample, the median FRS was 10.25% (0.1%–54.9%), the median SCORE was 1.8% (0%–22%), and median calcium score was 11 (0–1,936). Thus, the study group comprised mainly low- to intermediate-risk patients for future cardiovascular events. However, the authors preferred to use low-high risk because of predefined cutoff points, which differed from the original scoring systems, rather than low-intermediate-high risk groups. Despite the use of this kind of classification, a significant percentage of the low-risk patients (per the FRS and SCORE systems) had severe coronary lesions (48.4% for SCORE <2% and 49% for FRS <10%). Similarly, in a study by Canpolat et al, 662 symptomatic consecutive outpatients (56.9 ± 10.7 years, 50.8% men) without known coronary artery disease underwent coronary CTA, which revealed that patients with low FRS and SCORE had a large number of coronary atherosclerotic plaques (CAP; 33.8% and 40.4%), although CAP was more prevalent in the high-risk groups (67% and 78%, respectively). Although FRS and SCORE predict long-term cardiovascular events, a significant number of cardiovascular events occur in low-risk and/or intermediate-risk patients. Thus, risk stratification of patients using only “population-based” scores is a weak discriminator of the overall CAP burden, and there was a paradigm shifting to “individualized” stratification.

Additionally, previous studies have suggested that coronary noncalcified CAPs are associated, more so than other CAPs, with future cardiovascular events such as acute coronary syndrome. Therefore, CAP subtype is another important issue to be considered for further risk stratification using coronary CTA.

In conclusion, traditional risk scoring systems are inadequate to predict future cardiovascular events in low-risk patients in whom a significant amount of CAP is present by coronary CTA. Further evaluation of the CAP burden and subtypes in addition to severity may increase the prognostic role of coronary CTA in this article by Schneer et al. It is important to keep in mind that radiation exposure is the main limitation for the application of coronary CTA as screening tool in young, asymptomatic adults.