Coronary calcification and coronary atherosclerosis: site by site comparative morphologic study of electron beam computed tomography and coronary angiography.

OBJECTIVES: We compared, on a site by site basis, the morphologic features of coronary calcifications determined by electron beam computed tomography (EBCT) and angiographically defined coronary atherosclerosis.
BACKGROUND: Quantification of coronary calcification using EBCT is clinically useful for the prediction of coronary stenosis. However, the relation between calcification and angiographic findings has not been evaluated by site.
METHODS: We studied 251 consecutive patients who underwent elective coronary angiography for suspected coronary artery disease by EBCT and analyzed findings by site. Coronary calcifications were classified according to their length and width versus the diameter of the coronary artery in which the calcification was observed as: none, spotty, long, wide and diffuse.
RESULTS: Coronary calcifications were found in 666 (27%) of 2,470 segments. The positive predictive value (PPV) of coronary calcification for significant stenosis (> or = 75% densitometric narrowing) and for all angiographically detectable atherosclerotic lesions in a segment was 0.36 and 0.80, respectively. The PPV for significant stenosis and all atherosclerotic lesions was 0.04 and 0.17 in none, 0.18 and 0.59 in spotty, 0.32 and 0.87 in long, 0.40 and 0.84 in wide and 0.56 and 0.96 in diffuse calcifications, respectively. The PPV for both significant stenosis and all lesions differed significantly (p = 0.001) among the morphologic groups. Of the 105 eccentric significant stenoses, 54 (53%) were classified as long or diffuse calcifications. Of the 95 significant stenoses with multiple irregularities, 61 (64%) showed diffuse calcification.
CONCLUSIONS: Morphologic evaluation of coronary calcifications using EBCT improved the prediction of coronary stenosis on a site by site basis and provided information related to angiographic morphology.