Abstract
OBJECTIVES: To review the available evidence of screening for atherosclerosis in adults in a primary prevention setting with coronary artery calcium scoring (CACS) on the impact on cardiovascular (CV) risk factor control, health behaviour and clinical events. DESIGN: Systematic review, reported in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. DATA SOURCES: We searched MEDLINE, Embase and Cochrane Central Register of Controlled Trials through 22 January 2025. ELIGIBILITY CRITERIA: We included randomised controlled trials (RCTs) and prospective cohorts, without language restrictions, comparing adults without cardiovascular diseases undergoing CACS to a control group that either did not undergo CACS or where the participants and physicians were blinded to its result. Outcomes included changes in CV risk factor control, CV therapy, changes in health behaviour at follow-up and clinical events (all-cause and CV mortality and non-fatal CV events). DATA EXTRACTION AND SYNTHESIS: Two independent reviewers extracted data and assessed the risk of bias. Due to substantial heterogeneity among the included studies, a quantitative analysis was not possible. RESULTS: We identified seven RCTs and one observational study, with participants ranging from 56 to 43 447 with a total of 51 554. Populations were heterogeneous with a mean age range of 42-64 years, % women ranging from 21% to 100% and mean baseline CACS from 1.37 to >100 Agatston units. Interventions following CACS were also heterogeneous, ranging from simply communicating results to participants to initiating statin therapy for detectable CACS. One RCT demonstrated improvement regarding blood pressure (BP) (n=2137; change in systolic BP: CACS: -5 mm Hg; control: -7 mm Hg; p=0.02), several an improvement in blood lipids between groups (five studies, n=3693; eg, low-density lipoprotein (LDL) cholesterol: range -6.0 to -4.9 mg/dL). Results regarding CV medication (seven studies, n=51 104) were more discrepant, with some studies showing a decrease and others an increase in indication for or usage of CV medication. Three trials (n=3338) investigated adherence to CV medication, with only one showing increased adherence to statins (CACS: 63.3%; control: 45.6%; p=0.03). Five trials (n=3692) investigated behavioural changes, with one showing an increased motivation to change lifestyle (CACS: 94%; control: 62.8%; p=0.002) and another a higher adherence in self-reported physical activity (CACS: 96%; control: 59%; p<0.01). Due to low event rates, short follow-up and/or limited sample size, none (three studies, n=6552) demonstrated an effect on clinical CV events or all-cause mortality. Heterogeneity in interventions following CACS, population and studied outcomes did not permit pooling of results. Key limitations of this review reflect the limited availability of evidence and include the omission of potential harms of CACS screening, study heterogeneity, insufficient data on clinical events, a lack of economic assessments and the moderate to high risk of bias in most studies. CONCLUSIONS: CACS screening with a CACS-guided intervention might have a favourable effect on CV risk factor control and potentially on adherence to CV medication and increased motivation to change lifestyle in populations at intermediate to high risk. The available evidence is insufficient to determine whether screening asymptomatic patients with CACS has an impact on all-cause mortality or CV events. Despite its known strengths in predicting outcomes in individual patients, more evidence regarding the impact on clinical outcomes is needed to determine the clinical use of CACS for screening purposes in asymptomatic patients. PROSPERO REGISTRATION NUMBER: CRD42022377727.