Noninvasive evaluation of the prevalence of noncalcified atherosclerotic plaques by multi-slice detector computed tomography: results of a pilot study.

BACKGROUND

Multi-slice detector computed tomography (MDCT) not only allows for the determination of coronary calcifications, but also for the noninvasive visualization of noncalcified plaques. Thus, coronary artery disease (CAD) can be detected at a fairly early stage. Since data on the prevalence of potentially rupture prone noncalcified coronary lesions are still missing, it was aim of the present investigation to study this in patients with a distinct cardiovascular risk profile, but without known CAD.

METHODS

68 patients with clinical suspicion of CAD and multiple cardiovascular risk factors were included in this prospective study. Calcium scoring, as well as the detection of noncalcified plaques were performed using a Somatom VZ scanner (Siemens, Forchheim, Germany).

RESULTS

Calcium scoring could be performed in all patients on native scans; 63/68 (96%) of contrast enhanced scans showed sufficient image quality to perform a screening for noncalcified plaques. The three scans without diagnostic image quality had been performed at heart rates of 95 +/- 18/min. Coronary calcifications were found in 36/65 (55%) patients (Agatston score: 247 +/- 358). Additional noncalcified plaques were detected in 16/36 (45%) of these patients; 29/65 (45%) patients had no coronary calcifications (Agatston score: 0), but noncalcified plaques could be detected in 3/29 (10%) of these patients.

CONCLUSIONS

The prevalence of noncalcified plaques was 29% in the whole study group, and even in 10% of patients without coronary calcifications. Further prospective large scale studies are required to confirm these data, and to evaluate the clinical implication of this finding.