Exclusion of coronary calcium with electron beam computed tomography: an effective filter before diagnostic heart catheterization in symptomatic patients?

Electron beam computed tomography (EBCT) is the most sensitive and accurate method of measuring coronary calcium which indicates coronary atherosclero sis. We performed a prospective study in 1764 symptomatic patients who were referred to our hospital for coronary angiography because of suspected cor onary artery disease. In all of these patients cardiac catheterization and coronary calcium scanning was performed within 3.2+/-4 days. 454/1225 men (37.0%) and 165/539 women (30.6%) had significant coronary ste noses greater than or equal to 75%. Only two men (0.4%) and no single woman (0.0%) with stenoses greater than or equal to 75% and only 3/323 patients (0.9%) with moderate stenoses (50-75%) did not exhibit coronary calcium. Coronary angiography excluded stenoses in 822 patients. Of these patients 2 61 (29.4%) did not reveal coronary calcium. In younger patients (<60 years) without stenosis exclusion of coronary calcium was a frequent finding: 31% of men and 55.8% of women were free of coronary calcium. Thus, exclusion of coronary calcium with electron beam tomography defines a substantial subgroup of patients who have an extremely low risk of signifi cant coronary stenosis despite suspected coronary artery disease in history and non-invasive testing. Determination of coronary calcium might, therefo re, be an effective filter before invasive angiography in selected groups o f symptomatic patients.