Cardiac dual-source computed tomography in patients with severe coronary calcifications and a high prevalence of coronary artery disease

Background

Cardiac multidetector computed tomography (MSCT) permits the visualization of coronary artery stenosis. However, in patients with severe coronary calcifications, higher heart rates, and arrhythmia, MSCT was found to have limitations because of insufficient temporal and spatial resolution.

Objective

The aim was to evaluate the diagnostic accuracy of a new dual-source computed tomography (DSCT) scanner generation with 83-ms temporal resolution in cardiac imaging, especially in patients with high calcium scores and a high prevalence of coronary artery disease (CAD).

Methods

Of 82 unselected consecutive patients scheduled for invasive coronary angiography, 41 persons were identified to have severe coronary calcifications (Agatston score > 350; 35 men; 66.2 ± 8.4 years). All coronary segments were analyzed after intravenous injection of contrast media for the presence of coronary artery lesions.

Results

Mean heart rate was 64 ± 14 beats/min. Sixteen (39%) of 41 patients had nonsinus rhythm. Mean Agatston score equivalent (ASE) was 1391 (median 1146; range 358–3898). Prevalence of CAD was 98% (40 of 41). From a coronary segment model, sensitivity was 91%, specificity was 84%, positive predictive value was 70%, and negative predictive value was 96% for the detection of significant lesions (>50% diameter stenosis). Vessels with false-positive results had significantly higher ASE values than coronaries without false-positive results (median, 319.1 vs 143.3; P < 0.001).

Conclusion

In unselected patients with severe coronary calcifications, a high prevalence of CAD and a large percentage with heart rhythm irregularities, our data indicate that the accuracy of DSCT is limited in clinical routine.

Keywords: Calcium score, Coronary arteries, Coronary artery disease, CT, Computed tomography, Dual-source CT, Noninvasive procedure