CAC score provides modest gain in CVD risk assessment at expense of increasing cost: JAMA
Australia: A study determining the incremental gain from coronary artery calcium score (CACS) addition to a standard cardiovascular disease (CVD) risk calculator showed that CACS provides some further discrimination to standard CVD risk calculators. However, no evidence suggests that this provides clinical benefit. The study appears in JAMA Internal Medicine.
CACS is used for assessing patients' cardiovascular status and risk. However, there is no clarity on their best use in risk assessment beyond traditional cardiovascular factors in primary prevention.
Considering the above, Katy J. L. Bell, School of Public Health, University of Sydney, Sydney, Australia, and colleagues aimed to find, assess, and synthesize all cohort studies that assessed the incremental gain from the addition of a CACS to a standard CVD risk calculator, that is, comparing CVD risk score plus CACS with CVD risk score alone.
Cohort studies in primary prevention populations that used 1 of the CVD risk calculators recommended by national guidelines (Framingham Risk Score, QRISK, pooled cohort equation, NZ PREDICT, NORRISK, or SCORE) and assessed and reported incremental discrimination with CACS for estimating the risk of a future cardiovascular event were deemed eligible.
The researchers identified 6 eligible cohort studies (with 1043 CVD events in 17 961 unique participants) from the US (n = 3), the Netherlands (n = 1), Germany (n = 1), and South Korea (n = 1). from 2772 records screened.
From 2772 records screened, 6 eligible cohort studies were identified (with 1043 CVD events in 17 961 unique participants) from the US (n = 3), the Netherlands (n = 1), Germany (n = 1), and South Korea (n = 1). Study size varied from 470 to 5185 participants (range of mean ages, 50 to 75.1years; 38.4%-59.4% were women).
The study revealed the following findings:
- The C statistic for the CVD risk models without CACS ranged from 0.693 to 0.80. The pooled gain in C statistic from adding CACS was 0.036.
- Among participants classified as being at low risk by the risk score and reclassified as at intermediate or high risk by CACS, 85.5% (65 of 76) to 96.4% (349 of 362) did not have a CVD event during follow-up (range, 5.1-10.0 years).
- Among participants classified as being at high risk by the risk score and reclassified as being at low risk by CACS, 91.4% (202 of 221) to 99.2% (502 of 506) did not have a CVD event during follow-up.
"Systematic review and meta-analysis showed that CACS appears to add some further discrimination to the traditional CVD risk assessment equations used in these studies, which appears to be relatively consistent across studies," wrote the authors. "The modest gain however be outweighed by rates of incidental findings, costs, and radiation risks."
In selected patients, CACS may have a role in refining risk assessment but which patients would benefit is not clear, the authors note. At present, no evidence suggests that adding CACS to traditional risk scores provides clinical benefit, they concluded.
Reference:
Bell KJL, White S, Hassan O, et al. Evaluation of the Incremental Value of a Coronary Artery Calcium Score Beyond Traditional Cardiovascular Risk Assessment: A Systematic Review and Meta-analysis. JAMA Intern Med. Published online April 25, 2022. doi:10.1001/jamainternmed.2022.1262
