Background: Coronary artery calcium is almost pathognomonic of atherosclerosis. In 1990, Agatston designed a method to measure the coronary calcium score by computed tomography. Our aim was to establish the association between coronary calcified plaque volumes calculated by 64 slice computed tomography and the presence of significant coronary stenosis diagnosed by invasive coronary angiography.
Method: 150 consecutive patients, 66.6% male, scheduled for invasive coronary angiography were studied. Coronary calcium score was measured per patient and per artery by computed tomography previous to invasive coronary angiography. 128 calcified plaques were enrolled and volume was determined by Callister method introduced in 1998. According to the volume, the plaques were classified in two groups: small if volume ≤ 10 mm3 and big if > 10 mm3.
Results: In 79% of plaques with a volume > 10 mm3, significant coronary stenosis was detected by invasive coronary angiography versus 17% with small volume (p < 0.0001). More than 75% of plaques with volume > 10 mm3 in circumflex artery, anterior descending artery and right coronary artery were associated with significant coronary stenosis (p < 0.0001). Spearman correlation was 0.8. The sensitivity and specificity of significant coronary stenosis were 98.7% and 71.7% respectively for a cut off value of 6,5 mm3, area under the curve of 0,88 ± 0,32 (CI 95%, 0.815 to 0.940).
Conclusions: Association between coronary calcified plaque volume diagnosed by computed tomography and the presence of significant coronary stenosis diagnosed by invasive coronary angiography was observed.