Calcium in your heart arteries: Does it mean you have a blockage?

A recent report explores the relationship between calcium deposits in the heart's arteries and the presence of blockages. Two patients served as examples of the complexity involved. The first was a man in his 30s with a high calcium score of around 900. This led to an invasive coronary angiography, which revealed blockages that were not severe enough to necessitate stenting; instead, management involved medication and controlling risk factors.

On the other hand, a 38-year-old diabetic man with chest pain on exertion had a calcium score of zero. Contrary to expectations, he had a 90 percent blockage requiring stenting. This discrepancy arises from understanding the calcium score's limitations and its actual purpose. The calcium score measures calcified plaque, not the degree of blockage, within coronary arteries.

While a calcium score of 900 indicates a significant burden of coronary calcium and increased cardiovascular risk, it does not directly correlate with a percentage of artery blockage. This becomes apparent when considering that some plaques are soft or non-calcified, which the calcium score does not detect. Thus, a score of zero does not guarantee the absence of significant coronary disease, particularly in patients with risk factors like diabetes.

The report emphasizes the distinction between a calcium score and CT coronary angiography (CTCA). While the calcium score assesses the presence and amount of calcified plaque, CTCA provides detailed visualization of the coronary arteries, including non-calcified plaque, to determine if artery narrowing is present. Consequently, CTCA serves as an essential tool when anatomical assessment is required.

The calcium score should not replace CTCA, nor should it be solely interpreted without considering a patient's symptoms and risk profile. It is crucial to avoid misconceptions regarding the calcium score's direct correlation with blockage percentages. The calcium observed in a calcium score scan is not solely due to calcium supplements or vitamin D intake.

Instead, it reflects the progression of atherosclerotic disease within the coronary arteries. Similarly, the presence of calcium is not attributable to vitamin D supplementation. Aspirin or blood clot-busting medications should not be automatically prescribed based on the presence of calcium. Instead, these decisions should be made after carefully considering an individual's overall risk, age, diabetes status, cholesterol levels, other medical conditions, and the cardiologist's assessment. The calcium score should be viewed as a warning signal rather than a precise measurement tool.