Maryland mammography centers are now legally required to tell patients when a scan turns up breast arterial calcification, or BAC — tiny calcium deposits in breast artery walls that have been linked to heart disease risk. The requirement, which took effect October 1, makes Maryland the first state in the country to mandate this kind of disclosure, turning a routine breast cancer screening into a potential early warning system for cardiovascular trouble.
The law stems from legislation the Maryland General Assembly passed earlier this year, with both the House of Delegates and the state Senate approving it unanimously before Maryland's governor signed it into law on May 26, according to the Maryland Daily Record. The measure, formally House Bill 1364, amends the same section of the state's Health-General Article that already governs breast density notifications, and it explicitly states the disclosure requirement does not create a civil cause of action or a new legal standard of care for providers, according to Inflo Health.
BAC is distinct from the calcifications radiologists look for when screening for breast cancer, and it is not itself a diagnosis of heart disease or breast cancer, per the Daily Record's reporting. Instead, it reflects calcium buildup in the middle, or medial, layer of the arterial wall — a sign of vascular stiffening that differs from the inner-layer plaque buildup seen in coronary artery disease, though a 2022 American Heart Association study found postmenopausal women with BAC face a 51% increased risk of cardiovascular disease and stroke, according to Radiology Business.
Why Radiologists See an Opening for Early Detection
Tahira Ahmed, medical director of breast imaging at Maryland Imaging Network—RadNet, told the Daily Record that research has found an association between BAC and coronary artery calcification. She pointed to a 2016 study that evaluated 292 women who underwent digital mammography and nongated CT scans within a year of each other and found BAC had a 69% positive predictive value for coronary artery calcification in that population. Ahmed said identifying BAC gives physicians additional information when assessing a patient's overall cardiovascular risk, a factor that can be weighed alongside tools like the American Heart Association's PREVENT risk calculator, developed in 2023 to estimate cardiovascular disease risk using factors such as age, body mass index, cholesterol, kidney function, diabetes status, tobacco use, and blood pressure or statin medications.
Ahmed supports the new law and told the Daily Record that younger women who might not otherwise be flagged as high risk stand to gain the most from learning about a BAC finding, since it can open the door to addressing modifiable cardiovascular risk factors through lifestyle changes and preventive care. She advised that patients who receive a BAC notification should first contact their primary care provider. House Speaker Joseline Peña-Melnyk, who represents Anne Arundel and Prince George's counties, told the Daily Record that person-centered knowledge of increased cardiovascular risk could save lives, calling it simply, “Knowledge is power.”
Nationally, the push to repurpose mammograms for heart screening has institutional momentum. The American College of Radiology and the American College of Cardiology are advocating for opportunistic screening frameworks that use existing diagnostic imaging like mammograms to catch cardiovascular risk early, without added radiation or out-of-pocket cost, per Radiology Business. The stakes are significant: heart disease remains the leading cause of death for American women, claiming 310,661 lives in 2021 — roughly one in five female deaths — according to the CDC.
Johns Hopkins Doctors Call the Mandate Premature
Not everyone in Maryland's medical community is on board. Emily Ambinder, division chief of breast imaging at Johns Hopkins Medicine, and Pouneh Razavi, the health system's director of breast imaging for the national capital region, opposed the measure in written testimony to the Maryland Senate Finance Committee, according to the Daily Record. They argued the legislation was premature, insufficiently supported by evidence, and risked undermining mammography's primary purpose of catching breast cancer early.
Ambinder and Razavi questioned what clinical pathway actually awaits a patient notified of BAC, warning that such notices lack a clear, evidence-based next step for most people and could cause anxiety without a corresponding benefit. They specifically opposed a standardized notice issued for every instance of BAC regardless of its extent, clinical context, or a patient's individual risk profile. Their concerns echo written testimony the Maryland Radiological Society submitted in February, which noted that no standardized national clinical practice guidelines currently exist for measuring, reporting, or managing BAC found on mammograms — leaving primary care physicians without a clear playbook when patients start calling with questions, per the Maryland Radiological Society's testimony.
The law anticipates some of that friction may need addressing over time. It grants the Maryland Department of Health regulatory authority to revise the statutory wording of patient BAC notices if state health officials determine the current language has drifted significantly from evolving medical evidence, according to the Maryland Department of Legislative Services.
How Many Patients Will This Actually Affect
BAC is not a rare finding. Clinical studies published between 2022 and 2025 show it shows up on roughly 15% to 26% of routine screening mammograms, with prevalence climbing sharply with age to as high as 50% among women in their 80s, according to Applied Radiology. Separate epidemiological research published in Annals of Epidemiology has found higher rates of BAC among Black and Hispanic women, suggesting opportunistic BAC reporting could serve as an accessible screening tool for historically underserved populations.
The law covers hospitals, radiology centers, outpatient clinics, and private medical practices that operate mammography equipment across Maryland, though it explicitly exempts federal Veterans Affairs health facilities from compliance, per Inflo Health. Maryland's move also follows the pattern set by its own earlier dense-breast notification requirements, which helped pave the way for the FDA's nationwide Mammography Quality Standards Act update that took effect in September 2024, requiring standardized breast density disclosures in screening summary letters at mammography facilities across the country.
Despite their objections to a blanket notification requirement, Ambinder and Razavi agreed that patients who do receive a BAC notice should discuss the finding with a healthcare provider who can weigh other risk factors and determine whether further evaluation or prevention measures make sense. Maryland officials have framed the law's goal in similar terms: enabling more informed conversations between patients and physicians, without stoking unnecessary fear or confusion. Whether other states follow Maryland's lead, and how quickly cardiology and radiology societies move to publish standardized BAC protocols, remains to be seen.
