Association Between Breast Arterial Calcification on Mammography and Coronary Artery Disease: A Systematic Review and Meta-Analysis

Background: Breast arterial calcification (BAC), which may be detected during screening mammography, is hypothesized to be a noninvasive imaging marker that may enhance cardiovascular risk assessment. Materials and Methods: In this systematic review and meta-analysis, we sought to assess the association between BAC and coronary artery disease (CAD) by conducting a meta-analysis. We conducted a literature search of PubMed, Scopus, Cochrane library, ClinicalTrials.gov, and conference proceedings, from inception through December 24, 2019. The outcome of interest was the presence of CAD in patients with BAC. This was reported as crude and adjusted odds ratio (OR). Results: A total of 18 studies comprising 33,494 women (mean age of 60.8 +/- 3.7 years, 25% with diabetes, 57% with hypertension, and 21% with history of tobacco smoking) were included in the current meta-analysis. The prevalence of BAC among study participants was 10%. There was a statistically significant association between BAC and CAD (unadjusted OR 2.14; 95% confidence interval [CI] 1.63-2.81, p < 0.001, I-2 = 76.5%). Moreover, adjusted estimates were available from 10 studies and BAC was an independent predictor of CAD (OR 2.39; 95% CI 1.68-3.41, p < 0.001, I-2 = 61.7%). In the meta-regression analysis, covariates included year of publication, age, hypertension, diabetes mellitus, and history of tobacco smoking. None of these study covariates explained the heterogeneity across studies. Conclusions: BAC detected as part of screening mammography is a promising noninvasive imaging marker that may enhance CAD risk prediction in women. The clinical value of BAC for cardiovascular risk stratification merits further evaluation in large prospective studies.