Joint BrEast CAncer & CardiOvascular ScreeniNg: BEACON Study to Assess Opportunistic Cardiovascular Screening Using Breast Arterial Calcification on Mammography

<b>Purpose:</b> Breast arterial calcifications (BAC) are not routinely reported on mammography but are linked to coronary artery calcification (CAC) and cardiovascular disease (CVD) events. We sought to assess primary care provider (PCP) follow-up after BAC and CAC notification and the association between BAC on mammography and CAC on CT. <b>Methods:</b> Participants without known CVD undergoing mammography at a single centre were prospectively recruited over 18 months. BAC were qualitatively scored (none/mild/moderate/severe) by 2 breast radiologists. All participants had research cardiac CT for CAC within 6 months, scored using the Agatston method. Questionnaires collected baseline demographics, risk factors, and follow-up data. <b>Results:</b> 286 participants were included (median age 62 ± 10). Prevalence of BAC was 13% (38/286), 248 had none, 18 mild, 16 moderate, and 4 severe. For CAC: 180 had none, 70 had mild (CAC 1-99), 28 had moderate (CAC 100-399), and 8 had severe (CAC >400). For detecting CAC, BAC presence had 92% specificity (166/180), 23% sensitivity (24/106), and 67% negative predictive value (166/248). Most participants with BAC and CAC (71%, 17/24) were not on lipid-lowering therapy and 63% (15/24) did not believe they had elevated CVD risk. At follow-up (median 202 days), 46% (11/24) with BAC and CAC implemented lifestyle modifications, 92% (22/24) scheduled PCP follow-up, and 56% (10/18) underwent further CV risk assessment following their appointment. One participant with BAC and CAC had a stroke during follow-up. <b>Conclusion:</b> In a prospective cohort without known CVD undergoing mammography, notification of BAC and CAC status prompted high follow-up rates with PCPs and lifestyle modifications.