Differential coronary artery calcification detected by electron beam computed tomography as an indicator of coronary stenosis among patients with stable angina pectoris

BACKGROUND: The detection of coronary artery calcification by electron beam computed tomography (EBCT) has been suggested as an indicator of atheroscl erosis and coronary artery disease (CAD). There is no consensus on the corr elation between coronary calcification and angiographically significant ste nosis on an artery-by-artery basis. OBJECTIVE: To examine the relationship between coronary calcification score (CCS) and the presence of significant CAD on an artery-by-artery basis in patients with stable angina pectoris. METHODS AND RESULTS: EBCT and coronary angiogram (CAG) were evaluated in 71 patients with stable angina and in nine control subjects. The CCSs of each of the four major coronary arteries were highest in patients with signific ant CAD (n=43), followed by patients with insignificant CAD (n=5), patients with syndrome X (n=23) and control subject, respectively. Calcification sc ores of the four major coronary arteries appeared to have different predict ive power for significant stenosis on the same vessel. For left main (LM) a nal left anterior descending (LAD) coronary arteries, CCSs of vessels with significant stenoses were not different from those without significant sten oses (values expressed as medians: LM 0 versus1; LAD 98.5 versus 70; not si gnificant). Calcification scores of left circumflex (LCX) and right coronar y arteries (RCA) were significantly higher in vessels with significant sten osis (LCX 49.5 versus 0; RCA 53 versus 1; P <0.05). CCSs appeared to be mod erately useful to predict significant stenoses in these two vessels (areas under receiver operating characteristic curves: LCX 0.68 +/-0.08, 95%, CI 0 .52 to 0.81; RCA 0.71 +/-0.08, 95% CI 0.55 to 0.84). CONCLUSIONS: The CCSs or RCA and LCX arteries, but not those of LM and LAD arteries, may predict significant angiographic stenosis on an artery-by-art ery basis among patients with stable angina pectoris.