The Coronary Artery Calcium (CAC) scan is a non-invasive imaging procedure that uses computed tomography (CT) to assess an individual’s risk of future heart events. This scan detects and measures the amount of calcified atherosclerotic plaque in the walls of the heart’s arteries. The resulting CAC score provides an objective measure of the total plaque burden, which directly relates to the presence and extent of underlying coronary artery disease. Physicians use this quantifiable data to better understand a person’s cardiovascular risk, particularly for those without symptoms.
Understanding the Coronary Artery Calcium Score
The CAC score is calculated using the Agatston scoring system. This system assigns a numerical value by combining two factors for each calcified lesion: the size of the area covered by the calcium and the density of the calcium deposit. The score is reported in Agatston units, representing the total burden of calcification across all four major coronary arteries. Since the calcium detected is a component of hardened atherosclerotic plaque, the score acts as a marker for the overall amount of atherosclerosis present.
The Agatston score translates into general risk categories that guide medical decisions. A score of zero indicates no detectable calcified plaque and is associated with a very low risk of a heart event over the next decade. Scores between 1 and 100 represent minimal to mild plaque burden and a moderate risk. Individuals with scores ranging from 101 to 400 are categorized as having a moderate plaque burden, which significantly increases cardiovascular risk.
Interpreting a Score of 600
A Coronary Artery Calcium score of 600 is considered a severely elevated plaque burden, placing the individual in the highest risk category. Scores greater than 400 Agatston units are classified as severe calcification and indicate extensive, long-standing atherosclerosis. A 600 score suggests a substantial amount of calcified plaque has accumulated in the coronary arteries. This level of calcification often places an individual in a very high percentile compared to others of the same age and sex.
This level of calcification is well beyond the threshold where medical intervention is strongly recommended. For comparison, a score of 300 or more is already considered indicative of a high-risk status. A score of 600 is double this high-risk threshold, reflecting the extensive nature of the disease. The score points toward a widespread presence of atherosclerotic disease throughout the coronary vasculature.
Immediate Health Implications and Risk Stratification
A CAC score of 600 implies a significantly elevated 10-year risk of a major adverse cardiovascular event (MACE). This includes heart attack, stroke, and cardiac death. Compared to a person with a score of zero, a score exceeding 400 has been associated with a risk of cardiac events that can be seven times higher. This high level of risk mandates an aggressive approach to prevention and management.
In clinical practice, a CAC score greater than 300 is often treated as the risk equivalent of having established atherosclerotic cardiovascular disease. A score of 600 means the individual is at a similar, if not higher, risk level as someone who has already experienced a heart attack or stroke. This finding translates the physical measure of calcium into a clear prediction of future health outcomes. The presence of such a high score means the patient is considered to have subclinical coronary artery disease.
Recommended Medical Management and Lifestyle Changes
The immediate next step after receiving a CAC score of 600 is a consultation with a cardiologist to develop a comprehensive, aggressive treatment plan. A score of this magnitude makes the initiation of high-intensity statin therapy highly likely, regardless of current cholesterol levels. The goal of this medication is to significantly lower LDL-C, often targeting a level below 70 mg/dL, to stabilize existing plaque and prevent further buildup. Depending on the overall risk profile, a daily low-dose aspirin regimen may also be recommended, as evidence supports its use for scores over 100.
Lifestyle modification must be implemented alongside medical therapy to manage this high-risk condition. Smoking cessation is paramount, as is the management of other risk factors like high blood pressure and diabetes. Dietary changes should focus on heart-healthy patterns, such as the Mediterranean or DASH diets, which emphasize fruits, vegetables, whole grains, and lean protein. Regular aerobic exercise, aiming for at least 150 minutes per week, and maintaining a healthy body weight are essential components of risk reduction.