Zero calcium score does not equal zero coronary risk

High calcium scores are commonly considered a risk factor for coronary stenosis, but even a zero calcium score doesn’t assure coronary health in a high-risk population, concluded a pair of studies presented at ECR 2009.

Researchers from the Netherlands and China compared calcium scores against coronary stenosis in a high-risk population. In both studies, high calcium scores generally correlated with coronary stenosis.

In a small subset, however, zero calcium scores did not assure the absence of coronary stenosis.

A study from the University Medical Center Groningen in the Netherlands found that patients with a zero coronary score had a 93% chance of not having coronary stenosis but could not rule out stenosis when the pretest probability was high.

The study included 160 patients. Most (96) were admitted for chest pain. The remaining 64 were considered to have a high cardiovascular risk profile.

Among the study set, 43 had zero calcium scores. CT angiography scans found that three of the 43 (7%) had significant stenosis.

The study also showed that patients without stenosis on CTA had a mean calcium score of 109 (Agatston scale). Those with one or more signs of stenosis on CTA had a mean calcium score of 1030.

The distribution of calcium scores was the following:

• zero, 37%
• 10 to 100, 13%
• 101 to 400, 18%
• more than 400, 36%

A study from Tuen Mun Hospital in Hong Kong examined 147 patients admitted for chest pain. Sixty-eight had zero calcium scores. Among those, four (5.9%) had significant stenosis on CTA angiography. Another four had mild stenosis on CTA.