A coronary artery calcium (CAC) score is a valuable tool for assessing heart disease risk. It identifies calcified plaque in the heart’s arteries, offering insights into atherosclerosis progression and helping healthcare providers understand cardiovascular health. This article explores the commonness and significance of a zero calcium score.
Understanding Calcium Scores
A calcium score test involves a non-invasive computed tomography (CT) scan of the heart. This scan measures calcified plaque in the coronary artery walls. Calcified plaque indicates atherosclerosis, a condition where plaque builds up and can narrow arteries.
The test does not measure “soft” or non-calcified plaque, which can also contribute to heart disease. Results are provided as an Agatston score, ranging from zero to over 1,000. A score of zero indicates no detectable calcified plaque, suggesting a low risk of coronary artery disease. Higher scores (e.g., 1 to 99, 100 to 399, or 400 and above) indicate increasing calcified plaque and a progressively higher risk of heart disease.
Prevalence of a Zero Score
The occurrence of a zero calcium score varies across demographics. Younger individuals and women are more likely to have a zero score. For instance, approximately 91.9% of individuals aged 32 to 46 years, and 83% to 95% of younger women under 50, have a zero CAC score.
As people age, the prevalence of a zero score decreases. In a study of individuals aged 30 to 45, around 79% had a zero score, with males showing a higher prevalence of non-zero scores (25%) compared to females (9%). Even in middle-aged women, about 67% may still have a zero score. Overall, roughly 54% of symptomatic patients (median age 58) have a calcium score of zero.
Meaning of a Zero Score for Heart Health
A zero calcium score is associated with a very low risk of major cardiovascular events, such as a heart attack or stroke, over the next five to ten years. Studies indicate individuals with a zero score have less than a 1% chance of a heart attack each year for five years, with one study showing only 0.5% experienced a major adverse cardiovascular event.
A zero score does not signify zero risk. It indicates the absence of calcified plaque but does not rule out soft, non-calcified plaque, which can still contribute to heart disease. Approximately one-fourth to one-third of all cardiovascular events can still occur in individuals with a zero CAC score.
Beyond a Zero Score
Even with a zero calcium score, maintaining a heart-healthy lifestyle remains important for overall health. This includes a balanced diet, regular physical activity, and avoiding smoking. A zero score is a snapshot in time and does not guarantee immunity from future heart disease.
Managing other cardiovascular risk factors, such as blood pressure, cholesterol levels, and blood sugar, remains necessary, regardless of the CAC score. Discussing these with a healthcare provider helps develop a personalized plan to maintain long-term cardiovascular health.