Evaluation of the Incremental Value of a Coronary Artery Calcium Score Beyond Traditional Cardiovascular Risk Assessment

Abstract

IMPORTANCECoronary artery calcium scores (CACS) are used to help assess patients' cardiovascular status and risk. However, their best use in risk assessment beyond traditional cardiovascular factors in primary prevention is uncertain.OBJECTIVE To find, assess, and synthesize all cohort studies that assessed the incremental gain from the addition of a CACS to a standard cardiovascular disease (CVD) risk calculator (or CVD risk factors for a standard calculator), that is, comparing CVD risk score plus CACS with CVD risk score alone.EVIDENCE REVIEW Eligible studies needed to be 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.FINDINGS 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). Studies varied in size from 470 to 5185 participants (range of mean [SD] ages, 50 [10] to 75.1 [7.3] years; 38.4%-59.4% were women). The C statistic for the CVD risk models without CACS ranged from 0.693 (95% CI, 0.661-0.726) to 0.80. The pooled gain in C statistic from adding CACS was 0.036 (95% CI, 0.020-0.052). 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 CONCLUSIONS AND RELEVANCE This systematic review and meta-analysis found that the 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. However, the modest gain may often be outweighed by costs, rates of incidental findings, and radiation risks. Although the CACS may have a role for refining risk assessment in selected patients, which patients would benefit remains unclear. At present, no evidence suggests that adding CACS to traditional risk scores provides clinical benefit.

Decision Support Tools for Coronary Artery Calcium Scoring in the Primary Prevention of Cardiovascular Disease Do Not Meet Health Literacy Needs: A Systematic Environmental Scan and Evaluation

“…It is noteworthy that none of the thirteen resources included estimates of effect for both benefits and harms. These might include the number of people correctly and incorrectly reclassified as high risk or low risk when CAC score is added to the traditional risk score [ 7 ].…”

“…The role of CAC in primary prevention remains controversial due to the lack of direct evidence on its effectiveness in reducing CVD outcomes and limited evidence of clinical utility beyond that provided by current risk assessment tools [ 4 , 5 , 6 ]. Despite its strong prognostic ability as a stand-alone test, studies have found only modest prognostic value beyond traditional risk factors [ 7 ]. Adding CAC into CVD risk assessment also raises issues about cost-effectiveness and equity of access [ 4 , 8 ].…”

A Unified Model of Age-Related Cardiovascular Disease

“…High cholesterol [ 150 , 173 ] or hypertension, for example, are clearly upstream risk factors but may operate through the acceleration of cell aging [ 90 , 174 , 175 , 176 ]. Coronary calcium scans [ 177 ], on the other hand, are a downstream biomarker, but cell aging may be the driving force behind plaque buildup [ 178 ].…”

Addition of Coronary Artery Calcium Scores to Primary Prevention Risk Estimation Models—Primum Non Nocere

“…In this issue of JAMA Internal Medicine , Dr Bell and colleagues report the findings of a meta-analysis demonstrating that addition of CACS to traditional CVD risk models was associated with improvement in model discrimination, with a pooled gain in C statistic of 0.036 (95% CI, 0.020-0.052)—a small but statistically significant finding of unknown clinical significance. The authors based their literature search on a prior systematic review that was used by the US Preventive Services Task Force for its 2018 guidelines, which concluded that there was insufficient evidence to recommend adding CACS to traditional risk models . Six studies were found to meet the study criteria for inclusion in the meta-analysis by Dr Bell and colleagues .…”