Blood tests measure what’s circulating in your bloodstream — lipids, inflammation markers, glucose — but they cannot see what’s actually deposited inside your arterial walls. The Complete Metabolic Heart Scan (Coronary Artery Calcium score, or CAC scan) uses a low-radiation CT scan to directly image calcium deposits in your coronary arteries. Calcium in arteries is a definitive marker of atherosclerotic plaque — the condition that causes heart attacks. Studies from Johns Hopkins show that blood test-based risk models misclassify 15–35% of patients’ cardiac risk; some people with “perfect” cholesterol numbers have significant arterial calcium, while others with elevated LDL have zero. The calcium score gives you a ground-truth picture of what’s actually happened inside your arteries — information no blood test can provide.

The ACC/AHA (American College of Cardiology / American Heart Association) guidelines recommend CAC scoring for adults aged 40–75 who have intermediate cardiovascular risk or when a treatment decision (such as starting a statin) is uncertain. In practice, the scan is most valuable for: anyone aged 40+ with at least one risk factor (family history, smoking history, hypertension, elevated cholesterol, or diabetes), men over 45 and women over 55 regardless of risk factors, anyone with a strong family history of early heart disease (father before age 55, mother before age 65), and anyone on the borderline of starting lipid-lowering medication who wants objective data before deciding. A calcium score of zero in a 50-year-old is powerful — it confers a very low 10-year risk of cardiac events and may justify deferring medication.

A CAC scan delivers approximately 1–3 millisieverts (mSv) of radiation — comparable to a bilateral mammogram (0.4–0.6 mSv) or roughly 3–12 months of natural background radiation from the environment. For context, a standard chest CT scan delivers 5–7 mSv. The scan takes approximately 10–15 minutes, requires no contrast dye, and involves no needles, claustrophobic tunnels, or physical stress. The ACC/AHA guidelines consider the radiation dose appropriate for the clinical benefit in eligible adults. The scan is not recommended for anyone under 40, pregnant individuals, or people with already-confirmed coronary artery disease (since the result won’t change management).

Most private insurance plans and Medicare do not cover CAC scanning as a routine preventive screening — it is classified as a “screening” rather than a diagnostic test, making reimbursement uncommon. However, CAC scans are HSA and FSA eligible, making Vitals Vault’s heart scan a straightforward use of pre-tax health savings dollars. Out-of-pocket costs for a CAC scan vary by facility, typically ranging from $75 to $250. Some state Medicaid programs and select commercial insurers cover it for high-risk individuals; check your specific plan. Vitals Vault’s scan offering provides transparent, no-surprise pricing.

A calcium score of zero (CAC = 0) is a strong favorable finding. In studies including the MESA (Multi-Ethnic Study of Atherosclerosis) cohort, individuals with a CAC score of zero had a 10-year cardiovascular event rate of less than 1% — one of the lowest risk categories measurable. A zero score does not guarantee zero risk, because soft (non-calcified) plaque can exist without generating a calcium signal on a CT scan. Soft plaque is detected by CT angiography, a different and more expensive procedure. However, for most adults under age 60, a zero calcium score is highly reassuring and provides strong evidence to defer statin therapy if that decision was uncertain.

These three tests serve fundamentally different purposes. A CAC scan is a screening tool for asymptomatic adults — it detects calcified plaque before symptoms develop, takes 10 minutes, and costs under $200. A stress test (exercise or pharmacologic) evaluates how the heart responds to exertion in people with symptoms (chest pain, shortness of breath) — it detects functional ischemia but cannot directly visualize plaque. A CT angiogram uses contrast dye to image the coronary arteries in detail, detecting both calcified and soft plaque — it’s more comprehensive but delivers higher radiation, costs significantly more, and is typically ordered for people with symptoms or very high-risk profiles. Vitals Vault’s Complete Metabolic Heart Scan is a CAC scan — the right first step for asymptomatic adults seeking preventive cardiovascular risk assessment.

No referral is needed. The Complete Metabolic Heart Scan is available as a direct add-on to any Vitals Vault plan at vitalsvault.com/scans. After purchase, Vitals Vault coordinates scheduling at imaging facilities in your area. For adults aged 40+, self-referral for a CAC scan is widely accepted at imaging centers across the United States. The scan result report will be shared with you directly through your Vitals Vault dashboard and can be shared with your cardiologist or primary care physician at your discretion.

If your first calcium score is zero, the ACC/AHA guidelines suggest re-screening in 5 years for adults over 55, and potentially longer intervals for younger adults. A zero score in a 45-year-old is reassuring for at least 5–7 years; a zero score in a 60-year-old warrants a follow-up closer to the 3–5 year mark, as plaque can accumulate more rapidly with age. If your score is greater than zero, your cardiologist will typically recommend annual follow-up blood work and a repeat scan in 3–5 years to monitor progression. Doubling of a calcium score over time is a significant finding that typically warrants intensified risk factor management.

Alexis Ohanian (Reddit co-founder) publicly credited his CAC scan with detecting early arterial disease that his bloodwork had missed, calling it one of the most important tests he’d ever taken. Brad Gerstner and other high-profile investors in the longevity space have made CAC scanning a centerpiece of their annual health protocols. The argument for ROI is straightforward: a CAC scan costs $75–$200, takes 15 minutes, delivers minimal radiation, requires no preparation, and can fundamentally change your risk trajectory if it reveals significant calcium. Knowing you have a score above zero — and by how much — creates the urgency needed to aggressively address cholesterol, blood pressure, and inflammation before a cardiac event occurs. No other $100–$200 medical test changes clinical decision-making as dramatically for asymptomatic adults.

A CAC scan detects only calcified atherosclerotic plaque — it cannot image the soft (non-calcified, lipid-rich) plaque that can also rupture and cause heart attacks. This is an important limitation to understand. Soft plaque detection requires a CT angiogram with contrast (coronary CTA), which images the arterial wall directly. In younger adults (under 45), most plaque is soft and not yet calcified — meaning a zero CAC score in a 35-year-old with many risk factors should not be interpreted as “clean arteries.” For this reason, Vitals Vault recommends pairing the heart scan with the comprehensive blood panel: biomarkers like ApoB, Lp(a), hs-CRP, and homocysteine reveal the risk environment that drives plaque formation, while the CAC scan reveals what has already accumulated.