Lung cancer screening CT-based coronary artery calcification in predicting cardiovascular events: A systematic review and meta-analysis

BACKGROUND: Coronary artery calcificition (CAC) is a well-established predictor of cardiovascular events (CVEs). We aimed to evaluate whether lung cancer screening computed tomography (CT)-based CAC score has a good cost-effectiveness for predicting CVEs in heavy smokers. METHODS: A literature search was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Pubmed, EMBASE, and Cochrane library databases were systematically searched for relevant studies that investigated the association between lung cancer screening CT-based CAC and CVEs up to December 31, 2017. We selected fixed-effect model for analysis of data heterogeneity. Statistical analyses were performed by using Review Manager Version 5.3 for Windows. RESULTS: Four randomized controlled trials with 5504 participants were included. Our results demonstrated that CVEs were significantly associated with the presence of CAC (relative risk [RR] 2.85, 95% confidence interval [CI] 2.02–4.02, P < .00001). Moreover, higher CAC score (defined as CAC score >400 or >1000) was associated with a significant increased CVE count (RR 3.47, 95% CI 2.65–4.53, P < .00001). However, the prevalence of CVEs was not different between male and female groups (RR 2.46, 95% CI 0.44–13.66, P = .30). CONCLUSION: CAC Agatston score evaluated by lung cancer screening CT had potential in predicting the likelihood of CVEs in the early stage without sexual difference. Thus, it may guide clinicians to intervene those heavy smokers with increased risk of CVEs earlier by CAC score through lung cancer screening CT.