Abstract 1899: Zero Calcium Score does Not Exclude Significant Coronary Stenosis : Incremental Value of 64-slice Cardiac Computed Tomography over Calcium Scan
Background: Although coronary calcium assessment has been demonstrated to be strongly associated with significant coronary artery disease (CAD) and future cardiac events, it is still not clear whether zero calcium on CT scan can exclude significant coronary artery stenosis and eliminate the need for further multi-detector computed tomography (MDCT) coronary angiography.
Purpose: To test the hypothesis that zero coronary calcium on MDCT does not exclude significant coronary artery disease and 64-slice MDCT coronary angiography is required to exclude CAD in diverse populations who have a zero calcium score.
Methods: We studied 737 consecutive patients, 383 females and 354 males (average age 57.4 +/− 12.9 years), referred to MDCT coronary angiography from June 1, 2005 to January 31, 2007 for clinically suspicious coronary artery disease (CAD). All patients underwent 16-slice MDCT (n=287) or 64-slice MDCT (n=450) calcium score scan prior to MDCT coronary angiography at one center. We analyzed atherosclerotic plaques and degree of coronary artery stenosis on MDCT coronary angiography, and coronary calcification score calculated on MDCT calcium scan. Significant CAD was defined >50% coronary artery diameter stenosis.
Results: Significant CAD was found in 211 of 737(29.6%) patients. Of these patients, 186(89.6%) patients had a positive calcium score and 25 (11.8%) patients had a zero calcium score (Table⇓).
Conclusion: We conclude that absence of coronary calcium deposit does not exclude the presence significant coronary artery stenosis with non-calcified plaque. Therefore, a calcium score of zero on MDCT calcium scan does not preclude the need for MDCT coronary angiography in patients with clinically suspicious CAD.