Author + information
- Received August 20, 1998
- Revision received April 9, 1999
- Accepted May 16, 1999
- Published online September 1, 1999.
- Axel Schmermund, MD∗,* (, )
- Ali E. Denktas, MD§,
- John A. Rumberger, PhD, MD, FACC∗,
- Timothy F. Christian, MD, FACC∗,
- Patrick F. Sheedy II, MD†,
- Kent R. Bailey, PhD‡ and
- Robert S. Schwartz, MD, FACC∗
- ↵*Reprint requests and correspondence: Dr. Axel Schmermund, Department of Cardiology, University Clinic Essen, Hufelandstrasse 55, D-45122 Essen, Germany
The study was done to test the ability to predict the extent of angiographically determined coronary artery disease (CAD) by quantification of coronary calcium using electron-beam computed tomography (EBCT) and to compare it with more conventional parameters for delineating the angiographic extent of CAD, that is, cardiovascular risk factors and radionuclide single-photon emission computed tomography (SPECT).
The angiographic extent of CAD is a powerful predictor of subsequent events. Use of EBCT may be able to define it by virtue of its ability to determine plaque burden.
We examined 308 patients presenting with suspected but not previously known CAD who underwent selective coronary angiography. As measures of the angiographic extent of CAD, coronary artery greater even 20 (CAGE ≥20) and CAGE ≥50 scores represented the total number of coronary segments with ≥20% or ≥50% stenoses, respectively. The EBCT-derived total calcium scores were obtained in 291 patients, risk factors as defined by the National Cholesterol Education Program in 239 patients, and SPECT scans in 136 patients.
Using multiple linear regression analysis, total calcium scores were better independent predictors of both CAGE ≥20 and CAGE ≥50 scores than either a SPECT-derived radionuclide perfusion score or the risk factors age, male gender and ratio of total/high-density lipoprotein (HDL) cholesterol. The association between EBCT and angiographic scores remained highly significant after excluding the influence of all interrelated risk factors and SPECT variables (r = 0.65; p < 0.001 for CAGE ≥20 scores, r = 0.50; p < 0.001 for CAGE ≥50 scores).
Coronary calcium predicts the angiographic extent of CAD in symptomatic patients and provides independent and incremental information to the more conventional clinical parameters derived from SPECT or risk assessment.
☆ This study was funded by the Mayo Foundation, Rochester, Minnesota. Dr. Schmermund was supported by a Heart Center Cardiovascular Research Grant (Schm 97-1) from the University Clinic Essen, Germany.
- Received August 20, 1998.
- Revision received April 9, 1999.
- Accepted May 16, 1999.
- American College of Cardiology